Characteristics and survival prognosis of patients with pure squamous cell carcinoma of the gallbladder.

BACKGROUND

Pure squamous cell carcinoma (SCC) of the gallbladder is rare and often confused with the adenosquamous carcinoma (ASC) subtype in previous studies. The present study was attempted to differentiate SCC from ASC by resolving their characteristics and prognosis.

METHODS

The Surveillance, Epidemiology, and End Results database was queried for SCC and ASC of gallbladder cases from 1988 to 2015. Patients' clinicopathological characteristics and survival were analysed between the groups.

RESULTS

Of the 709 patients with primary gallbladder cancer included in this study, 249 (35.1%) had pure SCC and the remaining 460 (64.9%) had ASC. It was found that pure SCC was associated with a larger median tumour size (58.0 versus 41.0 mm, P < 0.001), while ASC presented with a worse histological grade (47.4% versus 37.8% for grades III-IV, P = 0.019) and more lymph node invasion (27.4% versus 18.9%, P = 0.041). The 3-year overall survival and disease-specific survival rates in pure SCC were lower than those in ASC (7.5% versus 11.5% for overall survival, P < 0.001; 6.2% versus 10.9% for disease-specific survival, P < 0.001). Multivariate analysis showed that early Surveillance, Epidemiology, and End Results historic stage, treatment with surgery and chemotherapy were significant favourable prognostic factors for pure SCC, while tumour size, late study period, treatment with surgery and radiotherapy were significant predictors for ASC.

CONCLUSION

There were significant differences in the clinicopathological characteristics and survival prognosis between pure SCC and ASC. Surgery combined with chemotherapy is the preferred treatment option for pure SCC.