A paper from an Australian pathology group has suggested that, “Any proportion of ductal adenocarcinoma in radical prostatectomy specimens predicts extraprostatic extension.”
This paper by Samaratunga et al. addresses the risk posed by ductal carcinoma based on data from 268 consecutive patients who had radical prostatectomies as a curative procedure for treatment of clinically localized prostate cancer. Ductal carcinoma in a patient with prostate cancer is variation of the common and garden “acinar” adenocarcinoma exhibited by the vast majority of prostate cancer patients. There has long been controversy over its precise pathobiology. It has also been referred to as “endometrial carcinoma of the prostate,” “adenocarcinoma with endometrioid features,” and “papillary carcinoma of the prostate.” A case study by Shazer et al. and the associated commentary by Montgomery and Virgin gives additional information.
In their series of 268 patients, Samaratunga et al. identified 34 cases in whom ductal adenocarcinoma of the prostate comprised between 5 and 100 percent of the total tumor volume. For these ductal adenocarcinoma patients, they state that:
- The mean age at diagnosis was 60 years (range, 49-69 years).
- The mean serum PSA level at diagnosis was 8.4 ng/ml (range, 0.8-21 ng/ml).
- The rate of positive surgical margins was 17.6 percent, which did not differ significantly from that of the pure adenocarcinoma group.
- 34/34 patients (100 percent) had peripheral zone involvement while 16/34 (46 percent) also had transition zone involvement.
- 25/34 patients (73 percent) had extraprostatic extension (pT3), which compared to 32.9 percent of the patients with acinar adenocarcinoma.
- The presence of ductal adenocarcinoma of the prostate, high tumor volume, and Gleason score > 7 significantly predicted pT3 staging category.
- The presence of ductal adenocarcinoma of the prostate remained a significant predictor for pT3 after adjusting for tumor volume and Gleason score > 7.
- The proportion of ductal adenocarcinoma of the prostate did not significantly modify the strength of the observed association with pathological stage.
The authors conclude that any proportion of ductal adenocarcinoma of the prostate should be clearly reported by the pathologist in reports based on core biopsy and radical prostatectomy specimens.