SIU 2017: Presence of Only Clinical Stage T2c Is Not Sufficient to be Classified as High Risk Prostate Cancer

Lisbon, Portugal ( According to the EAU guidelines cT2c stage is classified as high risk prostate cancer.  However, most patients presenting only with cT2c disease and no other negative prognostic factors, have better outcomes after local therapy. The aim of the study was to assess prognostic factors of biochemical recurrence (BR) in a subgroup of prostate cancer (PC) patients only with cT2c stage.

The study entailed retrospective analysis of 1864 PC patients who underwent radical prostatectomy (RPE). The included patients had a clinical stage of T1b-T2c in 1457 (78.2%) and T3a-T3b - in 407 (21.8%) pts. Stage cT2c was verified in 747 (40.1%) and prognostic factors of disease progression were assessed in this subgroup of patients. Mean PSA level (SD) in the cT2c group was 17.8+16.9 ng/ml, mean percentage of positive biopsy cores (SD) was 55.8+28.4%. Biopsy Gleason score 6 was verified in 398 (53.3%) pts; Gleason score of 7 (3+4) - in 172 (23.0%); 7(4+3) – in 83 (11.1%) and Gleason score of 8-10 - in 68 (9.1%). The Gleason score was not available in 26 (3.5%) patients. To stratify patients according to their corresponding risk group in the cT2c subgroup, standard risk classification was used without cT stage consideration. Intermediate risk PC (PSA 10-20 ng/ml, biopsy Gleason score 7) was verified in 541 (72.4%) pts; high risk PC (PSA >20 ng/ ml, biopsy Gleason score 8-10) – in 206 (27.6%) pts. Low risk PC was not observed among cT2c pts. Biochemical recurrence (BR) was assessed as elevation of PSA>0.2 ng/ml on three consecutive measurements.

Morphological stage downgrading to pT2a and pT2b was found in 26 (3.5%) patients, and stage upgrading to >pT3a was observed in 329 (44%) pts. Lymph node (LN) metastases were found in 124 (16.6%) patients. In the intermediate risk subgroup LN metastases were observed in 69 of 541 (12.8%) patients and in high risk - in 55 of 206 (26.7%) patients (p<0.001). Mean follow up was 35.5 months (3-174). BR was observed in 119 (16%) patients. Mean 5-year and 10-year biochemical progression-free survival (BPFS) were 60+3.5% and 42.4+5.9%, respectively. Mean 10-year overall and cancer-specific survival were 84.3+6.3% and 93.5+8.9%, respectively. 

In patients with cT2c and absence of any other negative predictor, BPFS was almost 2-fold higher. Thus, the mean 5-year BPFS in subgroup of intermediate and high risk PC in patients with cT2c only was 68.9+3.1% and 39.1+4.3%, respectively (p=0.002). PSA, biopsy Gleason score, and percentage of positive biopsy cores were predictors of outcome in the specific cT2c cohort. In a subgroup of patients with PSAs of 10 and above>10 ng/ml, the 5-year BPFS was 73.3+4.5% and 50.7+5.9%, respectively, p=0.001. In patients with biopsy Gleason 6, 7 and 8-10, difference in BPFS was also significant (p=0.001). Independent preoperative predictors of BR in multivariate Cox regression analysis in the specific cT2c subgroup of patients were: percentage of positive biopsy cores (OR=1.9; 95%CI=1.3–2.8; p=0.002), and biopsy Gleason score (OR=1.29; 95%CI= 1.1-1.6; p=0.09).

The authors concluded that clinical assessment of high risk PC is important for patient's stratification and should be done using multiple clinical parameters. Usage of only cT2c stage without other negative predictors of high risk PC could lead to incorrect stratification. Most importantly, the clinical important prognostic factors in cT2c cohort of patients were percentage of positive biopsy cores and biopsy Gleason score. Adding these parameters in consideration could help to better stratify patients with high risk PC.

Presented by: Nyushko K, Moscow Hertzen
Affiliation: Oncology Institute, Moscow, Russia

Written by: Hanan Goldberg, MD, Urologic Oncology Fellow (SUO), University of Toronto, Princess Margaret Cancer Centre.Twitter: @GoldbergHanan at the 37th Congress of Société Internationale d’Urologie - October 19-22, 2017- Lisbon, Portugal