BACKGROUND: Watchful waiting (WW) or deferred treatment (DT) is an accepted management strategy for selected men with prostate cancer. Although this approach is commonly utilized, the initial outcome studies were performed prior to the PSA era. The majority of recent series are single-institution or from referral centers. As a result, in the medical literature there is a paucity of national, community-acquired data concerning the use of WW or DT during the PSA era. We gathered data from a large, prospective, nationwide cohort study to examine clinical and demographic profiles of men who elected to pursue WW or DT.
METHODS: The nationwide, prospective, Physicians’ Health Study (PHS) cohort accumulated 1285 diagnosed cases of pathologically confirmed incident prostate cancer among 29,072 physicians between 1984 and 2004, for whom treatment status since diagnosis was retrospectively collected in 2005 via self-report. Those who opted for watchful waiting or deferred treatment for at least one year were compared across categories of demographic indicators, tumor characteristics, and PSA level to those who received immediate treatment. Among DT cases, Cox proportional hazards models adjusted for calendar time were used to calculate hazard ratios and 95% confidence intervals for time to eventual treatment.
RESULTS: Of the 1285 prostate cancer cases, 144 (12.6%) had DT as their principal management. Compared to cases treated <1 year post-diagnosis, DT cases were significantly older at diagnosis (mean 70.6 vs. 68.0, p<0.05), and had a significantly lower stage, Gleason grade, PSA at diagnosis (mean 7.3 vs.13.1), cancer severity/risk score, and number and percent of biopsy cores with cancer (p<0.05 for each). Of the 144 cases that selected DT for the first year after diagnosis, 65% subsequently received treatment, whereas 35% remained untreated for the duration of follow-up (mean 7.2 years after diagnosis). Factors predicting progression to treatment included younger age at diagnosis (<60 vs. ≥70 years; HR=3.2, 95% CI = 1.5-6.4), higher Gleason score (≥7 vs. ≤5; HR=2.4, 95% CI=1.2-4.4) and serum PSA (≥4 vs. <4 ng/mL; HR=1.9, 95% CI=1.1-3.4).
CONCLUSIONS: Watchful waiting or deferred treatment was selected as the management option of choice by a sizeable number of prostate cancer patient participants in the Physicians’ Health Study. Thirty-five per cent of patients who began on watchful waiting remained untreated at a mean of seven years after diagnosis, indicating a longer durability of watchful waiting in this nationwide cohort of physician patients than reported in contemporary referred-sample, single-institution series of watchful waiting. Older patients with favorable cancer severity profile, who opt for watchful waiting as primary management, can commonly remain on watchful waiting for many years.