DaskivichAnnalsManuscript-1

Embed Size (px)

Citation preview

  • 7/30/2019 DaskivichAnnalsManuscript-1

    1/27

    1

    Impact of Age, Tumor Risk, and Comorbidity on Competing Risks for Survival in a U.S.1Population-Based Cohort of Men with Prostate Cancer2

    Running Title: Age, Comorbidity, and Tumor Risk in CaP3

    4

    Timothy J. Daskivich, MD15

    Kang-Hsien Fan, MS26

    Tatsuki Koyama, PhD 27

    Peter C. Albertsen, MD3

    8

    Michael Goodman, MD, MPH4

    9

    Ann S. Hamilton, PhD5

    10

    Richard M. Hoffman, MD, MPH611

    Janet L. Stanford, PhD, MPH7

    12

    Antoinette M. Stroup, PhD8

    13

    Mark S. Litwin, MD, MPH114

    David F. Penson, MD, MPH9,1015

    161Department of Urology, David Geffen School of Medicine, University of California, Los Angeles,17Los Angeles, CA182Department of Biostatistics, Vanderbilt University, Nashville, TN193Department of Urology, University of Connecticut, Farmington, CT204Department of Epidemiology, Emory University, Atlanta, GA215Department of Preventative Medicine, Keck School of Medicine, University of Southern22California, Los Angeles, CA23

    6Department of Internal Medicine, University of New Mexico, Albuquerque, NM247Department of Urology, Fred Hutchinson Cancer Center, Seattle, WA258Department of Internal Medicine, University of Utah, Salt Lake City, UT26

    9Department of Urology, Vanderbilt University, Nashville, TN27

    10VA Tennessee Valley Geriatric Research, Education, and Clinical Center (GRECC), Nashville,28

    TN29

    30

    31

    Corresponding author:32

    David F. Penson, MD, MPH33

    Professor of Urologic Surgery34

    Director, Center for Surgical Quality and Outcomes Research35

    Vanderbilt University Medical Center36

    2525 West End Avenue, Suite 60037

    Nashville, TN 37203-173838

    (615) 343-152939

  • 7/30/2019 DaskivichAnnalsManuscript-1

    2/27

    2

    fax (615) 936-82911

    2

    david.penson @vanderbilt.edu3

    4

    Word Count: 3604 Abstract: 299 Number of Tables: 2 Number of Figures: 35

    6

  • 7/30/2019 DaskivichAnnalsManuscript-1

    3/27

    3

    ABSTRACT

    Background: Accurate estimation of life expectancy is essential to offering appropriate

    care to men with early-stage prostate cancer, but mortality risks associated with

    comorbidity remain poorly defined.

    Objective: To determine the impact of age, comorbidity, and tumor risk on other-cause

    and prostate cancer-specific mortality in men with early-stage disease

    Design: Prospective cohort study

    Patients: 3,183 men with non-metastatic prostate cancer at diagnosis

    Setting: A nationally representative, population-based cohort

    Measurements and analyses: Baseline self-reported comorbidity scored as a count of

    twelve major comorbid conditions, tumor characteristics, initial treatment, and overall

    and disease-specific mortality through 14-year follow up. Survival analyses accounting

    for competing risks.

    Results: Fourteen-year cumulative other-cause mortality was 24%, 33%, 46%, and 57%,

    for men with comorbidity counts of 0, 1, 2, and 3+, respectively. For men diagnosed at

    age 65, subhazard ratios (95%CI) for other-cause mortality among men with 1, 2, or 3+

    comorbidities (vs. none) were 1.2 (1.01.5), 2.0 (1.62.4), and 2.6 (2.13.2), respectively.

    With each decade increase in age, the subhazard of other-cause mortality associated

    with each comorbidity count doubled; in men with 3+ comorbidities, subhazard ratios

    (95%CI) for ages 65 and 75 (vs. 55) were 2.0 (1.62.5) and 4.0 (2.76.1). In men with

    3+ comorbidities, ten-year other-cause mortality rates were 26%, 40%, and 71% for

    those aged 60, 6174, and 75 at diagnosis, respectively. Prostate cancer mortality

    was minimal in low-(3%) and intermediate-risk(7%) disease but appreciable in high-risk

  • 7/30/2019 DaskivichAnnalsManuscript-1

    4/27

    4

    disease(18%) and did not vary by co-morbidity count will all groups having 10-11%

    prostate cancer specific mortality.

    Limitations: Self-report of comorbid conditions

    Conclusions: Older men with multiple major comorbidities are at high risk of other-cause

    mortality within ten years of diagnosis. Such men should consider this information when

    deciding between conservative management and aggressive treatment for low- or

    intermediate-risk prostate cancer.

  • 7/30/2019 DaskivichAnnalsManuscript-1

    5/27

    5

    INTRODUCTION

    Men with a new diagnosis of clinically localized prostate cancer are faced with numerous

    treatment options, ranging from no initial therapy (watchful waiting or active surveillance)

    to aggressive therapy with surgery and radiation. The first question a newly diagnosed

    man should consider is whether immediate aggressive treatment is necessary. Because

    the survival benefits of aggressive treatment for low- and intermediate-risk disease are

    delayed for eight to ten years (1), clinical guidelines recommend that men with a life

    expectancy of shorter than ten years be spared the morbidity and expense of aggressive

    treatment (2,3).

    Despite the recognized importance of estimating life expectancy in medical decision

    making for men with prostate cancer, physicians remain poor judges of prognosis (4);

    this often leads to inappropriate treatment decisions. Recent retrospective data have

    shown that men with Charlson scores of 3 or greater are treated aggressively with

    surgery or radiation more often than not, despite a 70% other-cause mortality rate at

    eight years after diagnosis (5). This practice may be due to several reasons. First, the

    long-term risk of other-cause mortality associated with different ages and comorbidity

    states remains unclear. The current data on risk of other-cause mortality associated with

    comorbidity are either from institutional case series (6-9) or from populations treated

    with only one treatment modality(10); to our knowledge, to date there has been no true

    population-based assessment of risk of other-cause mortality associated with

    comorbidity in U.S. prostate cancer patients. Second, the current instruments used to

    determine risk of other-cause mortality are prohibitively cumbersome to use in the

    clinical setting. Lastly, little data simultaneously integrate risk assessment for both

  • 7/30/2019 DaskivichAnnalsManuscript-1

    6/27

    6

    cancer-specific and other-cause mortality and include relevant variables to predict both,

    including age, comorbidity, and tumor risk.

    In this study, we sought to characterize the association of comorbidity, age, and tumor

    features with long-term other-cause and prostate cancer-specific mortality in a large,

    population-based sample of men with clinically localized prostate cancer. We simplified

    our comorbidity assessment to a count of twelve major conditions to allow for easy

    translation to the clinical setting. We hoped to identify groups of men that have a high

    risk of other-cause mortality and low risk of prostate cancer-specific mortality, so that

    these men might better understand the risks and benefits of various therapeutic

    strategies and make a truly informed decision regarding treatment.

  • 7/30/2019 DaskivichAnnalsManuscript-1

    7/27

    7

    METHODS

    Study Participants

    The Prostate Cancer Outcomes Study (PCOS) is based on a population-based cohort of

    men diagnosed with prostate cancer ascertained from the National Cancer Institute

    Surveillance, Epidemiology, and End Results (SEER) program. Details of the PCOS

    have been published previously (11). In brief, the study includes men diagnosed with

    prostate cancer between October 1, 1994 and October 31, 1995 who resided in an area

    covered by one of six SEER tumor registries: the states of Connecticut; Utah; and New

    Mexico; and the metropolitan areas of Atlanta, Georgia; Los Angeles County, California;

    and King County, Washington (Seattle). All men aged 39 to 89 years were eligible

    except in King County, where inclusion was limited to men aged 60 to 89 years. Subjects

    were identified within 6 months of diagnosis using a Rapid Case Ascertainment System.

    Population attrition is reported in Appendix Figure 1. A total of 3,533 (62%) of the eligible

    men completed the 6 or 12 month survey. The institutional review board of each

    participating institution approved the study.

    For the current analysis, we included all men in PCOS with non-metastatic prostate

    cancer at diagnosis. We excluded men with nodal or distant metastases, those without

    information on comorbidities at diagnosis, and those diagnosed incidentally at the time of

    cystoprostatectomy. Our final analytic sample comprised 3,183 men.

    Data Collection

  • 7/30/2019 DaskivichAnnalsManuscript-1

    8/27

    8

    All patients included in this analysis completed a baseline survey within 6 months of

    diagnosis that included sociodemographic and clinical information (including presence or

    absence of comorbid conditions) as well as self-reported function and quality of life.

    Medical record data. All participants underwent a review of their medical records at one

    and five years after diagnosis. Abstractors obtained demographic information, clinical

    symptoms, diagnostic examinations, tumor-related information (diagnostic Prostate

    Specific Antigen (PSA), Gleason score, and clinical stage), and primary treatment type.

    Treatment types were defined as aggressive therapy (surgery, external beam radiation

    therapy, or brachytherapy) or non-aggressive therapy (androgen deprivation therapy

    (ADT) or watchful waiting). In addition, information on tumor characteristics, primary

    treatment, and vital status were collected from the SEER registries.

    Comorbidity. We assessed comorbidity using a modified version of the Charlson

    Comorbidity Index (12). In the current analysis, comorbidity was expressed as a count of

    the following twelve major conditions at the time of diagnosis: Diabetes, bleeding

    gastrointestinal ulcer, chronic lung disease, congestive heart failure (CHF), stroke,

    myocardial infarction, angina/chest pain, cirrhosis/liver disease, arthritis, inflammatory

    bowel disease, hypertension, and depression. Subjects answered yes/no for each of

    these comorbidities on the baseline survey. Responses were not validated by chart

    review.

    Tumor characteristics. Tumors were stratified by clinical and pathological features using

    the widely accepted DAmico criteria, which utilize diagnostic PSA level, Gleason score,

    and clinical stage at diagnosis to predict risk of progression, overall mortality, and

  • 7/30/2019 DaskivichAnnalsManuscript-1

    9/27

    9

    cancer-specific mortality. Tumors are classified as low- (PSA < 10, clinical stage T2a,

    and Gleason score 6), intermediate- (PSA 10-20, clinical stage T2b, or Gleason score

    7), or high-risk (PSA > 20, clinical stage T2c, or Gleason score 8) (13, 14). Tumors

    are categorized into higher risk strata by having at least one of the characteristics of that

    stratum.

    Vital status. Vital status and underlying cause of death were determined through 14

    years following diagnosis using SEER data.

    Statistical Analysis

    We first grouped patients by comorbidity count (0, 1, 2, and 3+) and compared baseline

    characteristics using the analysis of variance for continuous variables and chi-square

    test for categorical variables. Cumulative incidence rates were computed for overall,

    prostate cancer specific, and other-cause mortality.

    Other-cause mortality was modeled with the proportional subdistribution hazards

    regression as described by Fine and Gray treating prostate cancer death as a

    competing risk (15). A competing event eliminates a possibility of the primary event of

    interest, and treating it as a mere censored observation would violate the non-

    informative censoring assumption of the Cox proportional-hazard model. When modeling

    competing risks, the conclusion may be based on cause-specific hazard or sub-

    distributional hazard. As summarized by Dignam et. al, both approaches are valid and

    informative, and the choice often depends on questions of interest (16). We choose to

    use Fine and Gray model, which applies a regression modeling directly on a cumulative

  • 7/30/2019 DaskivichAnnalsManuscript-1

    10/27

    10

    incidence function (CIF) and allows for estimation of the effect of covariates on the

    CIF.We included comorbidity count, age, race, SEER site, DAmico tumor risk, and

    treatment type as covariates. An interaction term between age and comorbidity count

    was included to allow age-specific effects of comorbidity counts on survival. Prostate

    Cancer-specific mortality was modelled using a similar approach. We checked the

    proportional hazard assumption using scaled Schoenfeld residuals(17) as suggested by

    Fine and Gray (15). A weak evidence of violation of the assumption on the categorized

    comorbidity counts was found for other-cause mortality (p=0.04); however, closer

    graphical examination of the Schoenfeld residuals revealed that the proportionality

    seems to hold except for the very end of the study period (13+ years) where the data are

    scarce. Similar trend was found for DAmico tumor risk (p=0.02); only 94 patients were

    categorized into the unknown group that causes assumption violation. For prostate

    cancer mortality, proportional hazard assumption was likely to be violated for comorbidity

    counts (p < 0.01), as well as age, SEER site, tumor risk and treatment type; however, for

    this secondary endpoint we still present average subhazard ratios (18) to denote its

    relationship with comorbidity count.

    To determine if aggressive treatment was associated with better prostate cancer-specific

    survival among men with higher comorbidity counts, we further analyzed the potential

    interaction between treatment (aggressive/non-aggressive) and comorbidity. An alpha

    level of 0.05 was used to denote statistical significance, and all tests were two-sided.

    Statistical analyses were performed using R 2.14 (19), with cmprsk package (20) for

    Fine and Gray modeling.

    Funding Source

  • 7/30/2019 DaskivichAnnalsManuscript-1

    11/27

    11

    This study was funded by grant R01CA114524 from the National Cancer Institute of the

    National Institutes of Health. Dr. Daskivich is supported by grants from the Robert Wood

    Johnson Clinical Scholars Foundation and American Urological Association. The various

    funding sources had no role in the design, conduct, analysis, or decision to publish the

    study.

  • 7/30/2019 DaskivichAnnalsManuscript-1

    12/27

    12

    RESULTS

    Baseline characteristics of the sample after stratification by comorbidity count are shown

    in Table 1. Older men, and African American race/ethnicity, and those with higher tumor

    risks tended to have higher comorbidity counts. Men with higher comorbidity counts

    tended to be treated aggressively less often than those with lower comorbidity counts.

    However, 256 of 419 men (61%) with comorbidity counts of 3 or greater were treated

    aggressively for clinically localized disease. Counts of specific co-morbid conditions

    across comorbidity groups are reported in Table 1 of the appendix.

    Cumulative other-cause mortality rates by comorbidity count are shown in Appendix

    Table 2. At fourteen years of follow-up, other-cause mortality estimates were 24%, 33%,

    46%, and 57% for men with comorbidity counts of 0, 1, 2, and 3+, respectively.

    Cumulative incidence curves depicting cumulative other-cause and prostate cancer-

    specific mortality by comorbidity count are shown in Figure 1.

    Proportional subdistributional hazards models investigating the association between

    other-cause mortality and comorbidity count also showed an increasing subhazard of

    other-cause mortality with higher comorbidity count. Accounting for age, race, SEER site,

    tumor risk stratum, and type of treatment, the subhazards of other-cause mortality for

    men with 1, 2, or 3+ comorbidities were 1.2 (95% CI 1.01.4), 1.7 (95% CI 1.42.0), and

    2.4 (95% CI 2.02.8) respectively, compared with men with no comorbidities.

  • 7/30/2019 DaskivichAnnalsManuscript-1

    13/27

    13

    In order to illustrate the impact of increasing age on risk of other-cause mortality in men

    with the most severe comorbidity, we calculated ten-year cumulative other-cause

    mortality rates for men with three or more comorbidities across different age strata.

    Among those with three or more comorbidities, men aged 75 years at diagnosis had ten-year other-cause mortality rates of 26% (17 of 65 men),

    40% (108 of 272 men), and 71% (58 of 82 men), respectively.

    Cumulative incidence of prostate cancer and other-cause mortality by DAmico tumor

    risk categories and comorbidity countafter stratification into younger (age 70) groupsare illustrated in Figures 2 and 3.

    In all age groups, the risk of other-cause mortality increased with greater comorbidity

    count, and the risk of prostate cancer mortality increased with higher tumor risk-stratum.

    In concordance with our multivariable models, the absolute impact of comorbidity on risk

    of other-cause mortality was markedly less pronounced in men younger than 60,

    compared with older men. Across the entire cohort, prostate cancer mortality was low in

    men with low- (3%) and intermediate-risk (7%) disease but appreciable in men with high-

    risk disease (18%). Proportions of men treated aggressively vs. non-aggressively within

    each age/tumor risk subgroup are reported in Appendix Table 3. The risk of prostate

    cancer mortality associated with tumor risk was similar across age groups.

    A competing risks model analyzing the subhazard of prostate cancer mortality

    associated with non-aggressive treatment among comorbidity groups suggested that

    there may be a benefit to aggressive therapy in men with little or no co-morbid

    disease. These treatments may, however, not be of as much value in men with more

    comorbid conditions. Men with zero or one comorbidity who were managed

  • 7/30/2019 DaskivichAnnalsManuscript-1

    14/27

    14

    conservatively had 2.4 (95% CI 1.63.5) and 2.2-fold (95% CI 1.53.3) increase

    respectively in the subhazard of prostate cancer mortality compared with men treated

    aggressively. Men with two or three or more comorbidities who were managed

    conservatively did not have a statistically significant increase in prostate cancer mortality

    (HR:1.6, 95%CI=1.0-, 2.7 and 1.5, 95%CI=0.9-2.5 respectively).

    In an effort to further inform clinical decision-making in non-metastatic prostate cancer,

    we recapitulated our analysis including men who elected ADT as primary therapy in the

    aggressive management group, effectively exploring the decision of any therapy vs none

    whatsoever. The results were virtually the same, with the exception the competing risks

    model analyzing the subhazard of prostate cancer mortality associated with no treatment

    whatsoever. While men with no comorbid conditions still had a increased risk (hazard

    ratio: 2.0, 95% CI 1.3-3.0), men with 1, 2 or 3+ co-morbid conditions were not at

    increased risk of prostate cancer mortality (HR:1.1, 95%CI=0.7-1.9; 1.2, 95%CI=0.7-2.2

    and; 1.1, 95%CI=0.6-2.0 respectively)

  • 7/30/2019 DaskivichAnnalsManuscript-1

    15/27

    15

    DISCUSSION

    These results illustrate the contemporary long-term risks of other-cause and prostate

    cancer mortality associated with age at diagnosis, comorbidity, and tumor risk in a

    population-based cohort of men diagnosed with clinically localized prostate cancer.

    These population-based data provide more accurate estimates of long-term prognosis

    for men with newly diagnosed prostate cancer, since they are not limited by the selection

    bias incurred by using single institutional (6-9) or modality-specific data (10). In fact,

    several studies have shown that the risk of other-cause mortality associated with a given

    comorbidity score increases in a stepwise manner when comparing men treated with

    radical prostatectomy, radiation therapy, and watchful waiting (6, 21). Since men who

    undergo surgery are generally younger, have better functional status, and have less

    severe manifestations of disease than men who choose radiation therapy (and even

    more so compared with those who choose watchful waiting), other-cause mortality rates

    among men receiving surgery may be lower for a given comorbidity score than those

    who choose radiation or watchful waiting. Using a population-based sample of men who

    are balanced in age, tumor characteristics, and primary treatment will provide a more

    accurate estimate of mortality risk associated with comorbidity. We feel that a

    population-based cohort best mimics the relevant clinical scenario: counseling a man

    with newly diagnosed with clinically localized prostate cancer who has not yet made a

    treatment decision.

    Our data also verify the strong prognostic utility of comorbidity in predicting risk of other-

    cause mortality and show that its prognostic strength persists even when comorbidity

    assessment is reduced to a simple count of twelve major comorbid conditions. It is

    unknown whether more complicated, weighted systems of comorbidity assessment,

  • 7/30/2019 DaskivichAnnalsManuscript-1

    16/27

    16

    such as the Charlson comorbidity index (12), provide better risk stratification than a mere

    count of comorbidities, but our data suggest that a count may be sufficient for assessing

    prognosis in men at the highest risk. Such a simplification of comorbidity assessment

    may be essential for widespread application of these findings to the clinical setting.

    We also found that the subhazard of other-cause mortality associated with a given

    comorbidity count doubles with each decade of age at diagnosis above 55 years.

    Therefore, a comorbidity count of 3+ for a man aged 65 years at diagnosis is associated

    with double the risk compared with a man having an equal number of comorbidities but

    aged 55 years at diagnosis. A man aged 75 years at diagnosis with 3+ comorbidities has

    quadruple the risk of a similar 55-year-old. A simple frequency analysis mirrors this

    relationship, showing 10-year other-cause mortality rates of 26%, 40%, and 71% for men

    with 3 or greater comorbidities aged 75 years at diagnosis,

    respectively.

    These data provide benchmarks for evaluating risk of prostate and other-cause mortality

    among men with different baseline comorbidity, age, and tumor features. The decision of

    whether to pursue aggressive treatment is preference sensitive, affected by an

    individual's knowledge of and personal attitudes about potential benefits and harms;

    therefore, the optimal risk ratio of prostate cancer vs. other-cause mortality may differ

    from individual to individual. Regardless, our data provide a framework upon which all

    patients can apply their own attitudes and assess their likelihood of treatment-related

    benefit based on their age, comorbidity, and disease characteristics. However, from a

    public health perspective, the precedent of the widely-recognized 2008 US Preventative

    Services Task Force recommendations on cessation of screening and treatment for men

    greater than 75 years (22) has established that men with less than a 10-year life

  • 7/30/2019 DaskivichAnnalsManuscript-1

    17/27

    17

    expectancy (i.e. populations with greater than 50% other-cause mortality at ten years)

    garner little or no benefit from aggressive treatment. Applying a similar cutoff for

    comorbidity and age, our data show that men with 3+ comorbidities aged 60 and older

    approach 50% mortality at 10 years after diagnosis. Therefore, given the low likelihood

    of short-term prostate cancer mortality and high likelihood of other-cause mortality, older

    men with more than 3 major comorbidities should strongly weigh the risk of dying from

    other causes prior to realizing any potential survival benefit from aggressive therapy

    when choosing primary treatment.

    A corollary analysis investigating whether non-aggressive treatment is associated with

    an increased risk of prostate cancer mortality among comorbidity groups suggested that

    men with two or more comorbidities may derive little survival benefit from aggressive

    treatment. Men with two or more comorbidities did not have a statistically significant

    increase in risk of prostate cancer mortality with non-aggressive treatment compared

    with men treated aggressively, although we had limited power to discern differences.

    Men with fewer than two comorbidities, however, did have a significant increase in risk.

    This stands in contrast to a previous claims-based study comparing overallsurvival in

    men older than 65 who were treated aggressively vs. conservatively, which suggested a

    survival benefit with aggressive treatment that persisted after correction for comorbidity

    (23). This study also showed a benefit in prostate cancer-specific survival with

    aggressive treatment after correction for propensity scoring alone, but propensity scores

    were not balanced by number of comorbidities. Although thought-provoking, our results

    should be treated as exploratory given that the analysis has limited power, that there is

    likely a selection bias between groups treated aggressively and non-aggressively and

    that there does appear to be some benefit in other studies.

  • 7/30/2019 DaskivichAnnalsManuscript-1

    18/27

    18

    Our study is limited by several methodological issues. First, the comorbidity assessment

    relied on self-report by participants and was not confirmed by medical records or

    physicians. However, numerous studies have shown that patient report of co-morbid

    conditions, particularly common ones like those assessed here, is fairly reliable (24).

    Second, because self-reporting of conditions does not allow for a detailed assessment of

    comorbidity severity, a broad spectrum of disease is subsumed under each of the twelve

    major comorbidity categories. Men with mild (or severe) disease manifestations may

    have lower (or higher) rates of other-cause mortality than those estimated by our raw

    comorbidity counts. Furthermore, information regarding the presence or absence of

    other cancers at the time of diagnosis was not collected at the time of enrollment in

    PCOS, so It is not included in our comorbidity count. Third, since the intake

    questionnaire was completed within six months of diagnosis, it is possible that some

    comorbid conditions may not have been present before treatment. However, the majority

    of our twelve designated conditions are chronic in nature and should have been

    apparent at the time of diagnosis. Fourth, a small proportion of men (32 men) were too

    sick or lacked the capacity to fill out the intake questionnaire and were excluded from

    PCOS; this may result in underestimation of other-cause mortality in the sickest men.

    Fifth, since the majority of the cohort was treated aggressively for prostate cancer, rates

    of prostate cancer mortality may be lower than if these men had been managed

    conservatively, especially at more distant time points and for men with high-risk tumors.

    However, for men with low- and intermediate-risk tumors, our estimates will

    underestimate prostate cancer-specific mortality by less than 10% at ten years, based

    on survival differences observed between aggressively and non-aggressively treated

    men in a randomized controlled trial (1). Sixth, we did not collect information on length of

    time from diagnosis to baseline survey and could not, therefore, conduct sensitivity

    analyses on the assumption that no temporal bias related to comorbidity reporting was

  • 7/30/2019 DaskivichAnnalsManuscript-1

    19/27

    19

    introduced into the study. Lastly, although current randomized controlled trial data

    suggests that there is no significant survival benefit with aggressive treatment of early-

    stage prostate cancer until 8 to 10 years after local therapy (1), further data on efficacy

    of aggressive treatmentespecially for men with intermediate-risk diseasewill help to

    define appropriate cut points for triage of care.

    When considering these data, the reader may be inclined to inappropriately apply the

    results of these findings to the decision as to whether or not to screen for prostate

    cancer, particularly given the recent USPSTF assignment of a grade D to prostate

    cancer screening (25). Unfortunately, these data do not inform this decision and should

    not be used to decide whether or not to screen. While the risk of overtreatment (which is

    driven primarily by the morbidity associated with aggressive therapy) is cited as one of

    the risks of screening that led the panel to their conclusion, they do not state in their

    recommendation that men who have been diagnosed with prostate cancer should or

    should not undergo treatment. We strongly believe that the decisions to screen or to

    treat prostate cancer are two separate entities and should always be considered

    individually.

    In summary, because the potential for morbidity is high, men with a new diagnosis of

    prostate cancer should first understand the likely benefit vs. potential harm associated

    with aggressive treatment. These data provide a basis upon which to counsel men

    regarding their risk of prostate cancer-specific and other-cause mortality. Our data are

    based on simple variables that are commonly available to the clinician at the time of

    treatment decision: age, number of major comorbidities at diagnosis, and tumor risk.

    Older men with multiple major comorbid conditions should be informed of their higher

    probability of death from other causes before deriving a survival benefit from surgery or

  • 7/30/2019 DaskivichAnnalsManuscript-1

    20/27

    20

    radiation therapy for low- and intermediate-risk disease. The information provided herein

    aims to make the competing risks of mortality clearer to both patients and their

    physicians.

  • 7/30/2019 DaskivichAnnalsManuscript-1

    21/27

    21

    ACKNOWLEDGEMENTS

    We wish to thank the men who participated in PCOS who, by their participation, have

    contributed to a better understanding of the effects of prostate cancer on mens lives.

    We also thank the physicians in the six Surveillance, Epidemiology and End Results

    areas who assisted us in the collection of data from their patients and from medical

    records. We thank all the study managers and chart abstractors for their outstanding

    efforts in data collection. Finally, we thank all the staff in the six cancer registries for their

    help with the study.

  • 7/30/2019 DaskivichAnnalsManuscript-1

    22/27

    22

    Address for Reprint Requests:

    David F. Penson, MD, MPH

    Professor of Urologic Surgery

    Director, Center for Surgical Quality and Outcomes Research

    Vanderbilt University Medical Center

    2525 West End Avenue, Suite 600

    Nashville, TN 37203-1738

    Current Mailing Address for All Authors:

    Timothy J. Daskivich, MDRobert Wood Johnson Clinical ScholarsUniversity of California, Los Angeles7th Floor, Suite 71010940 Wilshire Blvd

    Los Angeles, CA 90024

    Kang-Hsien Fan, MS

    Vanderbilt University

    571 Preston Research Building

    Nashville, Tennessee 37232-6848

    Tatsuki Koyama, PhD

    Assistant Professor of Biostatistics

    571 Preston Research BuildingNashville, TN 37232-6848

    Peter C. Albertsen, MD

    Chief and Program Director, Division ofUrology

    University of Connecticut Health Center

    263 Farmington Avenue

    Farmington, CT 06030 3955

    Michael Goodman, MD, MPHAssociate Professor, Department of Epidemiology

    Emory University Rollins School of Public Health

    1518 Clifton Rd. NE

    Atlanta, GA 30322

    Ann S. Hamilton, PhD

  • 7/30/2019 DaskivichAnnalsManuscript-1

    23/27

    23

    Associate Professor of Research, University of Southern California

    Health Services Campus

    SSB 318E

    M/C 9239

    Los Angeles, CA 90089-9239

    Richard M. Hoffman, MD, MPH

    Professor, Department of Internal Medicine

    Department of Veterans Affairs Medical Center

    General Internal Medicine 111GIM

    1501 San Pedro Dr., S.E.

    Albuquerque, NM 87108

    Janet L. Stanford, PhD, MPH

    Research Professor, Department of Epidemiology

    Fred Hutchinson Cancer Research Center

    Box 358080 M4-B874

    1100 Fairview Ave N., Building M

    P.O. Box 19024

    Mailstop: M4-B874

    Seattle, WA 98195-1024

    Antoinette M. Stroup, PhD

    Associate Professor of Research, Department of Clinical Epidemiology

    University of Utah

    Utah Cancer Registry

    650 Komas Drive, Suite 106B

    Salt Lake City, UT 84108

    Mark S. Litwin, MD, MPHProfessor and Chair, Department of Urology

    University of California, Los Angeles

    BOX 957383

    924 Westwood Blvd, Ste 1000

    Los Angeles, CA 90095-7383

    David F. Penson, MD, MPH

    Professor of Urologic Surgery

    Vanderbilt University Medical Center

    2525 West End Avenue, Suite 600

  • 7/30/2019 DaskivichAnnalsManuscript-1

    24/27

    24

    Nashville, TN 37203-1738

    Reproducible Research Statement: The authors of this study are commited to theconcept of reproducibility of medical research. Our methods section details our researchprotcol and our statistical code was provided to the statisticians atAnnals in order to

    validate our results. Our detailed research protocol and statistical code may be madeavailable at the discretion of the corresponding author. Use of our dataset is restricted tomembers of the PCOS study team and their designates.

  • 7/30/2019 DaskivichAnnalsManuscript-1

    25/27

    25

    TABLE AND FIGURE LEGENDS

    Table 1. Sample characteristics by comorbidity count, % (No of patients)

    Footnote: Percentages are reported across rows and may not sum to 100% due torounding.

    PSA is summarized with median and quartiles.

    * Chi-squared tests except ANOVA for age and PSA.

    ** Aggressive = surgery or radiation therapy

    *** ADT = Androgen deprivation therapy

    Figure 1. Cumulative Incidence Curves for Other-cause Specific Mortality and

    Prostate Cancer Specific Mortality by Comorbidity Count

    Figure 2. Competing Risks Model Depicting Cumulative Incidence of Other-Causeand Prostate Cancer-Specific Mortality by Comorbidity Count for Men Ages (a) 70 Years

    Figure 3. Competing Risks Model Depicting Cumulative Incidence of Other-Causeand Prostate Cancer-Specific Mortality by DAmico risk criteria for Men Ages (a) 70 Years

    APPENDIX TABLES AND FIGURE LEGENDS

    Appendix Table 1: Frequency of Comorbid Conditions Across Comorbidity Count

    GroupsAppendix Table 2. Fourteen-year cumulative other-cause mortality by comorbiditycount

    Footnote: OCM = Other-cause Mortality.

    Appendix Table 3: Type of Treatment by Age/Tumor Risk Subgroups

    Appendix Figure 1: CONSORT Diagram for PCOS

  • 7/30/2019 DaskivichAnnalsManuscript-1

    26/27

    26

    REFERENCES

    1. Bill-Axelson A, Holmberg L, Ruutu M, Garmo H, Stark JR, Busch C, Nordling S,Hggman M, Andersson SO, Bratell S, Spngberg A, Palmgren J, Steineck G, AdamiHO, Johansson JE; SPCG-4 Investigators. Radical prostatectomy versus watchful

    waiting in early prostate cancer. N Engl J Med. 2011 May 5;364(18):1708-17.2. Mohler J, Bahnson RR, Boston B, Busby JE, D'Amico A, Eastham JA, Enke CA,George D, Horwitz EM, Huben RP, Kantoff P, Kawachi M, Kuettel M, Lange PH,Macvicar G, Plimack ER, Pow-Sang JM, Roach M 3rd, Rohren E, Roth BJ, Shrieve DC,Smith MR, Srinivas S, Twardowski P, Walsh PC. NCCN clinical practice guidelines inoncology: prostate cancer. J Natl Compr Canc Network 2010 Feb;8(2):162-200.

    3. Thompson I, Thrasher JB, Aus G, Burnett AL, Canby-Hagino ED, Cookson MS,D'Amico AV, Dmochowski RR, Eton DT, Forman JD, Goldenberg SL, Hernandez J,Higano CS, Kraus SR, Moul JW, Tangen CM; AUA Prostate Cancer Clinical GuidelineUpdate Panel. Guideline for the management of clinically localized prostate cancer:2007 update. J Urol. 2007 Jun;177(6):2106-31.

    4. Walz J, Suardi N, Shariat SF, et al. Accuracy of life tables in predicting overall survivalin patients after radical prostatectomy. BJU Int. 2008;102:33-8.

    5. Daskivich TJ, Chamie K, Kwan L, Labo J, Palvolgyi R, Dash A, Greenfield S, LitwinMS. Overtreatment of men with low-risk prostate cancer and significant comorbidity.Cancer. 2011 May 15;117(10):2058-66.

    6. Tewari A, Johnson CC, Divine G, et al. Long-term survival probability in men withclinically localized prostate cancer: a case-control, propensity modeling study stratifiedby race, age, treatment and comorbidities. J Urol. 2004;171:1513-9

    7. Walz J, Gallina A, Saad F, et al. A nomogram predicting 10-year life expectancy incandidates for radical prostatectomy or radiotherapy for prostate cancer. J Clin Oncol.2007;25:3576-81.

    8. Cowen ME, Halasyamani LK, Kattan MW. Predicting life expectancy in men withclinically localized prostate cancer. J Urol. 2006;175:99-103.

    9. Daskivich TJ, Chamie K, Kwan L, Labo J, Dash A, Greenfield S, Litwin MS.Comorbidity and competing risks for mortality in men with prostate cancer. Cancer. 2011Apr 8.

    10. Albertsen PC, Moore DF, Shih W, Lin Y, Li H, Lu-Yao GL. Impact of comorbidity onsurvival among men with localized prostate cancer. J Clin Oncol. 2011 Apr1;29(10):1335-41.

    11. Potosky AL, Harlan LC, Stanford JL, Gilliland FD, Hamilton AS, Albertsen PC, et al.Prostate cancer practice patterns and quality of life: the Prostate Cancer OutcomesStudy. J Natl Cancer Inst 1999;91:171924.

    12. Charlson ME, Pompei P, Ales KL, MacKenzie CR. A new method of classifyingprognostic comorbidity in longitudinal studies: development and validation. J Chronic Dis.1987;40:373-83.

    13. D'Amico AV, Whittington R, Malkowicz SB, et al. Biochemical outcome after radicalprostatectomy, external beam radiation therapy, or interstitial radiation therapy forclinically localized prostate cancer. JAMA. 1998;280:969-74.

  • 7/30/2019 DaskivichAnnalsManuscript-1

    27/27

    27

    14. Boorjian SA, Karnes RJ, Rangel LJ, Bergstralh EJ, Blute ML. Mayo Clinic validationof the D'amico risk group classification for predicting survival following radicalprostatectomy. J Urol. 2008;179:1354-60.

    15. Fine, J. P., and R. J. Gray. A proportional hazards model for the subdistribution of acompeting risk. Journal of the American Statistical Association 1999;94:496-509.

    16. Dignam JJ, Zhang Q, and Kocherginsky MN. The use and interpretation ofcompeting risks regression models. Clinical Cancer Research 2012; 18: 2301-2308.

    17. Grambsh P, Therneau T. Proportional hazards tests and diagnostics based onweighted residuals. Biometrika 1994; 81: 515-526.

    18. Grambauer N, Schumacher M, Bayersmann J. Proportional subdistribution hazardsmodeling offers a summary analysis, even if misspecified. Statistics in Medicine 2010;29: 875-84.

    19. R Development Core Team (2011). R: A language and environment for statisticalcomputing. R Foundation for Statistical Computing, Vienna, Austria. ISBN 3-900051-07-0, URL http://www.R-project.org/.

    20. Bob Gray. cmprsk: Subdistribution Analysis of Competing Risks. 2011; R package

    version 2.2-2.21. Fowler JE Jr, Terrell FL, Renfroe DL. Co-morbidities and survival of men withlocalized prostate cancer treated with surgery or radiation therapy. J Urol.1996;156:1714-8.

    22. U.S. Preventive Services Task Force. Screening for prostate cancer: U.S. PreventiveServices Task Force recommendation statement. Ann Intern Med. 2008;149(3):185-91.

    23. Wong YN, Mitra N, Hudes G, Localio R, Schwartz JS, Wan F, Montagnet C,Armstrong K. Survival associated with treatment vs. observation of localized prostatecancer in elderly men. JAMA. 2006; 296(22): 2683-93.

    24. Klabunde CN, Reeve BB, Harlan LC, Davis WW, Potosky AL. Do patientsconsistently report comorbid conditions over time?: results from the prostate cancer

    outcomes study. Med Care 2005; 43(4): 391-400.

    25. Moyer, VA and the U.S. Preventive Services Task Force: Screening for ProstateCancer: US Preventive Services Task Force recommendation statement. Ann InternMed 2012; 157(2): 120-34