Characteristics and outcomes of adenosquamous carcinoma of the pancreas.

Background: Adenosquamous carcinoma of the pancreas (ASCAP) is a rare histologic type of pancreatic carcinoma that constitutes 1% to 4% of all pancreatic exocrine malignancies. It has a clinical presentation similar to that of adenocarcinoma of the pancreas (ACP), but may have a worse overall prognosis, with most patients surviving for less than 2 years.

Methods: This was an institutional, retrospective, cohort analysis of 237 patients who underwent resection of pancreatic cancer with curative intent.

Results: Of the 237 cases examined, we identified 7 (2.9%) with histologically confirmed ASCAP. Demographics, comorbidities, risk factors, presenting symptoms, survival data, tumor characteristics, and types of treatment for each patient were included in the analysis. Risk factors for development of ASCAP were not conclusive. Although human papilloma virus (HPV) has been implicated in other squamous cell cancers, in our cohort, its involvement in ASCAP was 0%. Presurgical fine-needle aspiration failed to identify the invasive squamous cell component in all cases. In this cohort analysis, overall survival ranged from 3 to 25 months, with 2 patients surviving more than 20 months after surgical resection. With a median follow-up of 2.9 years, our data demonstrate a trend to worse median overall survival for ASCAP than for ACP (8.2 vs. 20.4 months; P = .23), with a limited number of long-term survivors.

Conclusions: Although recommended, adjuvant treatment was inconsistently provided for patients in this ASCAP cohort. Published data show variability in overall survival, but our findings support that surgical resection is one of the few options for control of this rare, poorly understood pancreatic malignancy. Further research is necessary to define risk factors and adjuvant and neoadjuvant treatments, to help improve patient outcomes.