Daskivich T, Sadetsky N, Kaplan SH, Greenfield S, Litwin MS. Severity of Comorbidity and Non–Prostate Cancer Mortality in Men With Early-Stage Prostate Cancer. Arch Intern Med. 2010;170(15):1396-1397. doi:10.1001/archinternmed.2010.251
Comorbidity is a key consideration in clinical decision making for prostate cancer. Early-stage prostate cancer often follows an indolent course, with the significant survival advantage of definitive local therapy developing at 8 years after treatment.1 Men with severe comorbidity may not live long enough to benefit from aggressive therapy and therefore may prefer to treat their disease conservatively. Unfortunately, the lack of a standardized and practical comorbidity assessment tool has limited the application of comorbidity to clinical decision making in this setting.
We have previously reported on the short-term prognostic utility of the Total Illness Burden Index for Prostate Cancer (TIBI-CaP), a patient-reported, questionnaire-based comorbidity assessment tool specifically designed for clinical use in prostate cancer.2,3 The TIBI-CaP is an 84-item questionnaire in 11 disease subdimensions that measures both presence and severity of comorbid illness and can be completed by a patient in 15 minutes. Men with the highest TIBI-CaP scores (≥12) were 13 times more likely to die of causes other than prostate cancer within 3.5 years of questionnaire administration, compared with men with the lowest scores.3 We recently followed this cohort for a median of 6.2 years after treatment to determine the utility of the TIBI-CaP in predicting long-term survival outcomes.
In 2002, the TIBI-CaP questionnaire was sent to 4635 active participants of the Cancer of the Prostate Strategic Urologic Research Endeavor (CaPSURE), a national, observational prostate cancer registry.4 Of the 3389 men who returned the questionnaire, 2900 completed it and were included in the study. The mean time from treatment to TIBI-CaP questionnaire completion was 41.4 months. Our primary outcome was death from causes other than prostate cancer, measured from the time of treatment. We used multivariate Cox proportional hazards regression to assess the association of TIBI-CaP score and nonprostate cancer mortality, while controlling for clinical and demographic factors.
After a median follow-up of 6.2 years, overall mortality was 14.5% (420 men), while prostate cancer-specific mortality was only 3% (86 men). Nonprostate cancer-specific mortality was significantly different among comorbidity groups; 41% of patients with the highest TIBI-CaP scores (≥12) died of causes other than prostate cancer, compared with 6% of those with the lowest scores (0-2) (P < .001) (Table). In multivariate analysis, higher TIBI-CaP comorbidity scores were significantly associated with elevated risk of non–prostate cancer mortality. Men with the highest TIBI-CaP scores were 10 times more likely to die of causes other than prostate cancer, compared with men with the lowest scores (hazard ratio, 10.3; 95% confidence interval, 5.4-19.5) (Table).
For men considering aggressive vs conservative treatment for clinically localized prostate cancer, comorbidity must be a primary consideration. Our data show that men with significant comorbidity (ie, TIBI-CaP ≥12) have a 41% risk of death from other causes 6 years after treatment, several years before significant survival benefits of aggressive local treatment can be realized.1 Because men with significant comorbidity have a high likelihood of short- to intermediate-term mortality, they may wish to strongly consider conservative over aggressive treatment for their clinically localized prostate cancer.
Although other comorbidity assessment tools such as the Index of Coexistent Disease, Charlson Comorbidity Index, and the Kaplan-Feinstein Index have been validated for use in prostate cancer,5 their clinical utility is limited by the infeasibility of thorough medical record review during an office visit. The TIBI-CaP, which can be completed by a patient in 15 minutes in the waiting room, offers a practical solution to this problem. Although formal comorbidity assessment may be unwarranted for men with minimal comorbidity, we believe that men with moderate or severe comorbidity ought to be offered this simple questionnaire to inform their decision making.
Correspondence: Dr Daskivich, Department of Urology, University of California, Los Angeles, PO Box 951738, Los Angeles, CA 90095-1738 (firstname.lastname@example.org).
Author Contributions:Study concept and design: Daskivich, Kaplan, Greenfield, and Litwin. Acquisition of data: Sadetsky. Analysis and interpretation of data: Daskivich, Sadetsky, Kaplan, Greenfield, and Litwin. Drafting of the manuscript: Daskivich. Critical revision of the manuscript for important intellectual content: Sadetsky, Kaplan, Greenfield, and Litwin. Statistical analysis: Daskivich and Sadetsky. Obtained funding: Litwin. Study supervision: Kaplan, Greenfield, and Litwin.
Financial Disclosure: None reported.