The clinical outcome of prostate ductal adenocarcinoma: a multicentre matched cohort comparative study

Abstract

Introduction and Objective: Prostate Ductal Adenocarcinoma (PDA) is a rare variant of prostate cancer (PCa). There are conflicting reports regarding the oncological outcome and prognosis of PDA. To date there is no consensus on what the best treatment option is. Materials and Methods: All patients who were diagnosed with PDA in three institutions from London (UK), Hong Kong and Kingston (Jamaica) during 2005-2015 period were included. Treatment included radical surgery, radical radiotherapy or hormone manipulation. Patients who were diagnosed with at least Gleason 8 prostate acinar adenocarcinoma (PAA) served as control groups. Results: Of 9812 patients who were diagnosed with PCa, 157 (1.8%) had PDA and 958 had (PAA). PSA at presentation was lower for PDA. 346 (247-PAA, 99-PDA) patients were treated with radical prostatectomy. 314 (295-PAA, 19-PDA), had radical radiotherapy. 449 (416-PAA, 33-PDA) had hormone treatment. In the surgery group positive margin were 51% (PDA) vs 54% (PAA), p=0.13. At follow up 57% (PDA) vs 46% (PAA) had biochemical recurrence, and 14% (PDA) vs 5.3% (PAA), p=0.08 developed distant metastasis and 4.5% (PDA) vs 5.3% (PAA) have died. In the radiotherapy group 16% (PDA) vs 22% (PAA) had biochemical recurrence, 16% (PDA) vs 9% (PAA), p=0.01 developed distant metastasis and 17% (PDA) vs 18% (PAA), p=0.76 have died. In the hormone group 71% (PDA) vs 47% (PAA) developed metastasis at 32 months and 71% (PDA) vs 45% (PAA) have died. The mean follow-up for all groups is 71 months. Conclusion: PDA patients had higher risk of metastasis compared to the acinar group regardless of the treatment offered. An early adjuvant treatment may be required in prostate ductal cancer.