Prostate-specific antigen response after definitive radiotherapy for Skene's gland adenocarcinoma resembling prostate adenocarcinoma

Objectives: To assess prostate-specific antigen response after definitive radiotherapy in a patient with localized Skene's gland adenocarcinoma resembling prostate adenocarcinoma. Materials and methods: A 71-year-old patient was evaluated for a 2 year history of painless hematuria and found to have a localized Skene's gland adenocarcinoma resembling prostate adenocarcinoma with a pre-therapy PSA of 54.52 ng/ul. She elected to undergo definitive radiotherapy holding radical surgery for salvage. She received 73.8 Gy of intensity modulated radiotherapy in 41 fractions. Serum PSA, imaging, and cystoscopy were followed at 6 month intervals for 2.5 years. Results: The PSA decreased to 0.65 ng/ul 32 months after treatment, her clinical symptoms resolved, and on imaging and exam she has no evidence of residual disease. The PSA half life was 6.16 months (r² = 0.97). Conclusions: For this rare tumor we show that PSA is a reliable marker for disease response and also show that definitive radiotherapy can be an option for organ and functional preservation in patients with localized disease. Cases of periurethral adenocarcinomas should be pathologically screened to assess if they are of Skene's gland origin, as our results suggest a radiotherapy treatment paradigm may be appropriate management in a select subgroup of women with periurethral adenocarcinoma.