Baseline Patient Characteristics
Clinical and pathological demographics of the cohort are reported in Table 1. The average PSA value was 20.5 ng ml−1 (median: 9.6 ng ml−1; IQR: 6.3–18.6 ng ml−1). Considering pathological GS, 595 (37%) patients had 8–10 GS. Average number of RLNs and positive LNs was 19.0 (median: 17; IQR: 11–23) and 1.7 (median: 0; IQR: 0–1), respectively. Overall, 547 (34.5%) and 865 (54.5%) patients were treated with adjuvant hormonotherapy and RT, respectively.
Cox Regression Analyses and Survival Estimates
At univariable analyses, GS 8–10 (hazard ratio (HR): 4.3), positive surgical margin (HR: 1.8), number of positive nodes (HR: 1.03) and number of RLNs (HR: 1.02) were the only predictors of CSM rate (all P≤0.01). At multivariable analyses, GS 8–10 (HR: 2.5), aRT (HR: 0.5) and a higher number of positive LNs (HR: 1.06) were independently associated with higher CSM rate (all P≤0.05). Conversely, higher number of RLNs (HR: 0.94) was an independent predictor of a lower CSM rate (P≤0.03) (Table 2). Survival estimates were calculated based on the multivariable model. Mean and median follow-up were 80 and 72 months, respectively. Patients were stratified according to the number of RLNs using the points of maximum separation (Figure 1a). The predicted CSM-free rate increased consistently with rising number of RLNs, from 93% for patients with 10 RLNs to 98% for patients with 60 RLNs (Figure 2a). Similar trends were observed when patients were stratified according to GS and aRT status (Figure 2b and c).
Kaplan–Meier survival estimates based on multivariable analysis, assessing cancer-specific survival rate in 1586 pT3-T4 prostate cancer patients treated with surgery and pelvic lymph node dissection. Patients were stratified according to the total number of lymph nodes removed.
Prostate Cancer Prostatic Dis. 2016;19(1):63-67. © 2016 Nature Publishing Group