Purpose: Five-year results from the 1989 patterns of care study (PCS) for prostate cancer are now ready for analysis. The PCS was initiated to determine national averages for treatments and examine outcomes prospectively; the 1989 prostate study is the first to have collected pre- and post-treatment serum PSA data.
Methods and materials: Six hundred patients treated with radiotherapy with curative intent for prostate cancer at 71 separate institutions in the year 1989 made up the study population. Three hundred ninety-one cases were fully analyzable. Pretreatment patient and tumor characteristics were as follows: of the 391 analyzable, 255 had pretreatment PSA values obtained, and 245 had a Gleason's sum (GS) reported. Three hundred fifty-eight were Caucasian, 24 African-American, and 3 Hispanic (also 6 unknown). One hundred three patients had PSA < 10, 60 had PSA 10-19, and 92 presented with PSA >20. Ninety-seven patients were from Radiation Therapy Oncology Group (RTOG), Community Cancer Centers (CCC), or teaching institutions; 141 patients were from other hospital-based, nonteaching institutions; and 153 were from freestanding radiation oncology facilities. Seventy-one patients were T1, 203 T2, and 100 T3/4. Twenty-four out of 391 patients also received neoadjuvant hormone therapy. Survival curves were constructed using Kaplan-Meier methods, and differences between groups were tested for significance using the log-rank test. For cumulative incidence curves, Gray's test was used to investigate failure distributions between groups. The variables entering Cox model for multivariate analysis included age, race, T stage, pretreatment PSA, and GS. A patient was considered a PSA failure if the treating radiation oncologist reported it as such.
Results: With a median follow-up of 5.7 years, the 5-year biochemical no evidence of disease (bNED) and overall survival were 56% and 79% respectively for Stage T1, 52% and 81% for T2, and 36% and 63% for Stages T3 and T4 combined. As expected, higher pretreatment PSA, GS, and T stage were all prognostic of poorer outcome. On univariate analysis, bNED survival was adversely impacted by T stage (p = 0.009), pretreatment PSA (p = 0.0035), and by the GS (p = 0.0038). Cause-specific failure was significantly lower for higher T stage (p = 0.014), GS (p = 0.001), and also pretreatment PSA (p = 0.0004). Overall survival was significantly lower in patients with higher T stage (p = 0.047) or GS (p = 0.0191), but not pretreatment PSA (p = 0.284). On multivariate analysis, pretreatment PSA was found to be statistically significant in association with bNED survival, and GS was associated with overall survival, cause-specific survival, and distant metastasis. Few late complications were reported: 13/391 and 13/391 Grade 2-3 gastrointestinal (GI) and genitourinary (GU) complications respectively, with two patients having required surgery with or without a permanent colostomy.
Conclusion: For a representative cross-section of institutions in the United States, radiotherapy achieved high rates of bNED and CSS in selected groups of prostate cancer patients. When studied retrospectively, increased pretreatment PSA was a strong predictor of both biochemical failure and death due to prostate cancer. New strategies for patients with high-stage, high-grade tumors and/or pretreatment PSA >20 deserve testing.