Paclitaxel, ifosfamide, cisplatin (TIP) in patients with advanced urethral adenocarcinoma: A single center, retrospective analysis.

Abstract

656 Background: Urethral adenocarcinoma (UA) is a very rare subtype of cancers arising in urethra, which is known for female predominance and poor prognosis. Rarity of UA impedes the conduction of prospective clinical trial, thus the treatment option for advanced UA is very limited. Usually platinum-based chemotherapy is given based on case reports. We conducted retrospective single center cohort review of TIP regimen in patients (pts) with locally advanced, recurrent or metastatic UA to evaluate its efficacy and safety. Methods: Clinical data of 18 pts with locally advanced, metastatic, or recurrent UA who received TIP regimen at the Department on Oncology, Asan Medical Center from Jul 2016 to Jan 2024 were collected. To be eligible, pts should have histologic confirmation of adenocarcinoma, adequate clinical information, and baseline and follow-up imaging test results. TIP regimen consists of paclitaxel 200 mg/m 2 over 3 hours intravenously (iv) on day 1 (D1), ifosfamide 1,500 mg/m 2 over 1 hour iv on D1-3 with mesna 300 mg/m 2 3 times a day iv on D1-3, and cisplatin 70 mg/m2 over 1 hour iv on D1. We recommended pegylated G-CSF for prevention of severe neutropenia and febrile neutropenia. The primary endpoint was objective response rate (ORR) according to RECIST v1.1, and secondary end points were progression-free survival (PFS), overall survival (OS), and toxicity. Results: A total of 18 pts were enrolled. All pts were female, and median age was 62 (range 43-74). Disease status was locally advanced (32%), recurrent (47%), and initially metastatic (16%), and ECOG PS were 0 (22%), 1 (72%), and 2 (6%). Most common site of metastasis were lymph nodes (50%), surgical bed (22%), lung (22%), and peritoneum (17%). Patients received TIP as 1 st line (67%) and 2 nd line (33%). Thirteen pts received prophylactic pegylated G-CSF. Median 4 cycles (range 1-6) of TIP were administered, and ORR was 44% (partial response 44%, stable disease 50%, and progressive disease 6%). With a median follow-up duration of 38.7 months, median PFS and OS were 7.0 months [95% confidence interval (CI) 3.8-10.2] and 40.0 months (15.6-63.7), respectively. Most common adverse events included anemia, peripheral neuropathy, anorexia, nausea, fatigue, neutropenia, thrombocytopenia. Most adverse events were manageable, and no unexpected toxicities were found. Conclusions: TIP showed promising efficacy in pts with advanced UA. TIP might be considered as one of treatment options for pts with advanced UA, although efficacy and safety should be validated in larger cohort.