Materials and methods: We conducted a retrospective pathology review of IDC-P in primary prostate biopsy or surgery specimens from 38 men who subsequently developed advanced prostate cancer. Overall survival was calculated using the Kaplan-Meier method. To demonstrate the response of IDC-P to ADT, we established PDXs from seven men with familial and/or high-risk sporadic prostate cancer. After castration and testosterone restoration of host mice, we measured the volume and proliferation of IDC-P within PDX grafts.
Results: IDC-P was a prominent feature in the primary prostate specimens, present in 63% of specimens and often co-existing with poorly-differentiated adenocarcinoma. Overall survival was similar in patients with or without IDC-P. In the PDXs from all seven patients, IDC-P was identified and present at a similar volume to adenocarcinoma. Residual IDC-P lesions persisted after host castration and, similar to castrate-tolerant adenocarcinoma, testosterone restoration led to tumour regeneration.
Conclusion: IDC-P is prevalent in aggressive prostate cancer and contains cells that can withstand androgen deprivation. Thus, IDC-P appears functionally relevant in advanced prostate cancer. The presence of IDC-P may be a trigger to develop innovative clinical management plans.
- prostate cancer
- intraductal carcinoma of the prostate
- androgen deprivation therapy
- patient-derived xenografts