Adenosquamous carcinoma of the gallbladder: a Bi-institutional experience in managing this rare entity

Adenosquamous Gallbladder Cancers (ASGBC) are rare variety of GBCs. Relative paucity of data with regards to the management of ASGBC exists.

Patients with diagnosis of ASGBC from January 2012 to March 2022 were categorised into 'Early', 'Locally advanced (LA)' and 'Metastatic (M)' ASGBC as per the predefined 'TMH Criteria'.

A total of 196 patients included were categorised into early ASGBC (n = 19,9.7%), LA - ASGBC (n = 53,27%) and M - ASGBC (n = 124,63.3%) with median overall survival (OS) being worst for M - ASGBC (3.9 months) and best for early ASGBC (not reached). The 1-year and 3-year OS of LA-ASGBC patients who underwent surgery was significantly higher than those with non-surgical treatment (72.6%, 35.6% vs 25.1%, 0%, p <0.001). Although, the median OS of resected ASGBC was less as compared to resected gallbladder adenocarcinomas (GBACs) (40.8 vs. 56.1 months), it did not reach statistical significance (p=0.06). However, at higher stages of resected LA - ASGBC (Stage III), the median OS was significantly lower as compared to stage-matched resected GBACs (14.5 vs. 30.1 months, p= 0.006).

Multimodality treatment consisting of margin negative surgical resection with perioperative chemotherapy offers the best chance of long-term survival in ASGBC.