Men who are diagnosed with high risk prostate cancer, meaning they are more likely to develop advanced prostate cancer are usually treated with Radiotherapy (RT) and long term androgen blockade (AB). Currently, we do not know what is the optimal duration of AB.

Looking at this problem, the researchers conducted a randomized study to compare outcomes between 36 vs. 18 months of AB in men with high risk prostate cancer who are also treated with RT (PCS IV trial, Clinical, #NCT00223171).

In the trial they randomized menwith node negative high risk prostate cancer (T3-4, PSA >20 ng/ml or Gleason score >7), to pelvic RT (whole pelvis 44 Gy/4 ½ weeks, prostate 70 Gy/7 weeks) and 36 (arm 1) vs. 18 months (arm 2) of AB (neo adjuvant, concomitant, adjuvant).

The hormone therapy (AB) was 50mg of bicalutamide for one month plus goserelin 10.8 mg every three months for 36 vs. 18 months. Their primary endpoint was Overall survival. Overall and cancer specific survival rates were compared between arms with Kaplan-Meier log rank test and Cox regression.

Three hundred and ten (310) men were randomized to arm 1 and three hundred and twenty (320) to arm 2 from October 2000 to January 2008. The men’s characteristics were well balanced between the two arms

At a median follow-up of 77 months, 71/310 pmen (22.9%) in arm 1 and 76/320 (23.8%) in arm 2 had died (p=0.802). Overall, one hundred and sixteen (116) men died of causes other than prostate cancer. Overall and cancer specific survival hazard ratios were 1.15 (0.83-1.59), p=0.398 and 1.13 (0.61-2.08), p=0.153, respectively. 5 year overall and disease specific survival rates were 92.1% (89.1-95.1) vs. 86.8% (83.0-90.6), p=0.052 and 97.6% (95.9-99.4) vs. 96.4% (94.2-98.6), p=0.473 and 10 year overall and disease specific survival rates were 63.6% (55.7-71.5) vs. 63.2% (54.7-71.7), p=0.429 and 87.2% (81.0-93.3) vs. 87.2% (80.9-93.6), p=0.838 for arm 1 and arm 2, respectively.

The finds were that there were no significant differences in the rates of biochemical, regional or distant failure between the arms of the study.

Based on this study long term hormone ntherapy (AB) can be safely reduced from 36 to 18 months without compromising outcomes when linked with radiation therapy.

J Clin Oncol 31, 2013 (suppl 6; abstr 3); Abdenour Nabid, Nathalie Carrier, André-Guy Martin, Jean-Paul Bahary, Luis Souhami, Marie Duclos, François Vincent, Sylvie Vass, Boris Bahoric, Robert Archambault, Céline Lemaire; Centre Hospitalier Universitaire de Sherbrooke, Sherbrooke, QC, Canada; Centre Hospitalier Universitaire de Québec, Québec, QC, Canada; Department of Radiation Oncology, Centre Hospitalier de l’Université de Montréal, Montreal University, Montreal, QC, Canada; McGill University, Montreal, QC, Canada; McGill University Health Centre, Montreal, QC, Canada; Centre Hospitalier Régional de Trois-Rivières, Trois-Rivières, QC, Canada; Centre de Santé et Services Sociaux de Chicoutimi, Chicoutimi, QC, Canada; Jewish General Hospital, Montréal, QC, Canada; Hôpital de Ganineau, Gatineau, QC, Canada; Hôpital Maisonneuve-Rosemont de Montréal, Montréal, QC, Canada.

General Poster Session A: Prostate Cancer Abstract Number: 3
Source of Funding: AstraZeneca Pharmaceuticals Grant. Clinical trial information: Clinical, #NCT00223171.

Joel T. Nowak, M.A., M.S.W.