A questionnaire for men with prostate cancer that evaluates comorbidities may help in clinical decision-making about treatment by estimating their likelihood of dying from other conditions, researchers found.
A study of almost 3,000 responses to the Total Illness Burden Index for Prostate Cancer (TIBI-CaP) questionnaire found that those men who scored highest were 10 times more likely to die of causes other than prostate cancer compared with men with the lowest scores (HR 10.3, 95% CI 5.4 to 19.5), according to Timothy Daskivich, MD, of the University of California, Los Angeles, and colleagues.
These results suggest that the presence and severity of comorbidities should be a key consideration in clinical decision-making for prostate cancer because of the indolence of many early stage cases, Daskivich and co-authors wrote in a research letter published in the August 9/23 Archives of Internal Medicine.
A survival advantage for definitive local therapy only becomes significant eight years after treatment, and men with severe comorbidities may not live long enough to see that benefit, the authors noted.
But previously there has not been a practical, standardized comorbidity assessment tool, so Daskivich and colleagues evaluated the use of the TIBI-CaP, an 84-item questionnaire a patient can complete in 15 minutes during an office visit.
For the study, the TIBI-CaP was sent to 4,635 active participants in the Cancer of the Prostate Strategic Urologic Research Endeavor (CaPSURE), a national, observational prostate cancer registry. A total of 2,900 men filled out the questionnaire and were followed for a median of 6.2 years.
Overall mortality in the study cohort was 14.5% — while prostate cancer-specific mortality was only 3%, the investigators found.
Among men whose TIBI-CaP scores were 12 or higher, 41% died of causes other than prostate cancer, as did 6% of those with scores of two or lower (P<0.001). "Our data show that men with significant comorbidity (i.e., TIBI-CaP ≥12) have a 41% risk of death from other causes six years after treatment, several years before significant survival benefits of aggressive local treatment can be realized," Daskivich and colleagues wrote. Such patients may wish to strongly consider conservative treatment, the researchers advised. In an invited commentary, Richard J. Ablin, PhD, of the University of Arizona in Tucson, and colleagues agreed and also argued that prostate-specific antigen (PSA) testing does not distinguish between potentially dangerous and less consequential prostate cancer, which should be the hallmark of screening. During recent decades, it has become generally-accepted that PSA testing is inherently beneficial and, like screening for other malignancies such as breast and colon cancer, will result in a greater chance of cure. Unfortunately, the promise of early detection has led to overdiagnosis and overtreatment -- often resulting in life-altering adverse outcomes such as bowel, bladder, and sexual dysfunction -- in millions of men whose prostate cancers would never have metastasized, Ablin and colleagues asserted. "We believe that accurate assessment of the characteristics of the prostate cancer (Gleason scores, clinical stage, number of positive biopsy results, and the percentages of cancer in the positive cores), as well as the life expectancy, comorbid conditions, and quality of life concerns of the patients, become ever more paramount to any clinical decision making for prostate cancer and most notably in the selection of aggressive and potentially morbid treatment in young men with early-stage disease," Ablin and colleagues wrote. They strongly encourage the practice of active surveillance for men with early-stage disease, recommending that physicians who do not advise this approach reconsider their position. They also suggested that a rise in PSA after local treatment does not necessarily warrant further treatment, but added that PSA kinetics can be very helpful. For example, a PSA doubling time of less than three months is associated with a very high risk of prostate cancer death, they noted, while a doubling time of 15 months carries a very low risk. "Doing less may be more for the majority of patients we diagnose," Ablin and colleagues concluded. source: Archives of Internal Medicine