Basaloid squamous cell carcinoma of the hypopharynx: an analysis of 213 cases

Purpose: Basaloid squamous cell carcinoma (BSCC) is a rare aggressive variant of squamous cell carcinoma (SCC) with a poor prognosis. No large series of exclusively hypopharyngeal BSCC patients have been previously reported. Therefore, this retrospective population-based study aims to explain the patient demographics, clinicopathologic characteristics, incidence, and survival outcomes of hypopharyngeal BSCC and how it relates to conventional-type SCC.

Methods: The National Cancer Institute's Surveillance, Epidemiology, and End Results database registry was queried for patients diagnosed with hypopharyngeal BSCC and conventional-type SCC between 2001 and 2016.

Results: The incidence of hypopharyngeal BSCC from 2001 to 2016 was 0.0161 per 100,000 individuals. The BSCC group comprised 213 patients, and the SCC group 7958 patients. The majority of BSCCs were considered high grade (Grade III/IV, 89.58%). Most BSCC patients were diagnosed at an advanced stage (American Joint Committee on Cancer [AJCC] stage IV, 65.38%). The 1-, 5-, and 10-year disease-specific survival (DSS) rates for hypopharyngeal BSCC were 84.10%, 57.40%, and 46.20%, respectively. Multivariate analysis, after adjustment for sex, age, race, tumor location, grade, and AJCC stage, showed that patients with BSCC had significantly better DSS than those with conventional-type SCC. Surgery with radiation contributed to a favorable DSS for BSCC patients in comparison with other treatments.

Conclusion: This analysis of the largest hypopharyngeal BSCC series indicates a better prognosis for this pathologic type compared with conventional-type hypopharyngeal SCC. Multimodality treatment with surgery and radiation may result in a favorable prognosis for hypopharyngeal BSCC patients.