RT-ADT combo may boost pN1 prostate cancer survival

Treatment with radiotherapy plus androgen deprivation therapy may improve survival for select patients who are found to have pathologic node-positive prostate cancer at radical prostatectomy

Boston-Treatment with radiotherapy (RT) plus androgen deprivation therapy (ADT) may improve survival for select patients who are found to have pathologic node-positive (pN1) prostate cancer at radical prostatectomy.

It appears, however, that only a minority of men are receiving this multimodal therapy, researchers reported at the AUA annual meeting in Boston.

“Current guidelines offer little guidance for treatment of men with pN1 prostate cancer after RP. The findings of our study suggest that many of these men are being undertreated and that consideration should be given to offering RT alone or with ADT as it may prolong their survival. However, determining whether or not there is a real benefit for these interventions will depend on conducting a prospective, randomized clinical trial,” said Alaa Hamada, MD, a urologist at Case Western Reserve University and Louis Stokes VA Medical Center, Cleveland.

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In order to determine treatment patterns of pN1 disease among men with prostate cancer and the effects of different regimens on patient outcomes, Dr. Hamada and colleagues analyzed data from the National Cancer Database for the years 2004 to 2013. Excluding patients who underwent lymph node biopsy or aspiration and those who underwent salvage prostatectomy, they identified 11,742 patients with pN1 disease after prostatectomy and pelvic lymph node dissection. Of those patients, 51% were subsequently managed with observation, 25% received ADT alone, 17% received ADT plus RT, and 7% received only RT.

Next: 5-year overall survival rates compared

5-year overall survival rates compared

Median follow-up for the group was 48 months. Findings of an unadjusted Kaplan-Meier analysis showed 5-year overall survival rates in the observation, RT plus ADT, RT, and ADT groups were 85.7%, 88%, 89.5%, and 83%, respectively. The differences comparing the RT plus ADT and RT groups with both the observation- and ADT-only cohorts were statistically significant.

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Comparisons between groups showed statistically significant differences in Charlson Comorbidity Index scores, extent of the pelvic lymph node dissection, Gleason grade distribution, T stage, number of lymph nodes examined, number of positive lymph nodes, and presence of positive margins. In a Cox regression analysis adjusting for these differences, RT plus ADT was associated with significantly longer overall survival compared with all other groups.

The authors also performed a logistic regression analysis to determine patient and disease characteristics associated with treatment selection. They found that younger patients and those who were healthier (Charlson Comorbidity Index=0) or who had positive margins, higher Gleason score, locally advanced tumors (pT3b or pT4 disease), or had underwent limited lymph node dissection (five or fewer nodes examined) were most likely to undergo subsequent RT plus ADT rather than be followed with observation or ADT alone.