Clinical implications of squamous cell carcinoma in the colon and rectum: A comprehensive analysis from the National...

Squamous cell carcinoma (SCC) of the colon and rectum represents an exceptionally rare manifestation of gastrointestinal malignancy. The primary aim of this study was to elucidate baseline characteristics of colon SCC and its impact on overall survival (OS) in comparison with rectal SCC.

We conducted a retrospective analysis utilizing the National Cancer Database encompassing patients diagnosed with SCC of the colon and rectum from 2004 to 2019. Propensity score matching was employed to facilitate the comparison of OS between patients diagnosed with rectal and colon SCC who underwent surgery across four different tumour stages, with each stage evaluated individually.

A cohort comprising 249 colon SCC cases and 5398 rectal SCC cases was analysed. Colon SCC patients, compared with rectal SCC patients, were older (mean age 66 ± 13 vs. 62 ± 12 years, p < 0.05), predominantly male (44% vs. 30%, p < 0.05), more frequently diagnosed at an advanced stage (Stage IV: 51% vs. 16%, p < 0.05) and demonstrated a higher proportion of poorly differentiated to undifferentiated tumours (51% vs. 30%, p < 0.05). Treatment methods were also different, with 58% of colon SCC cases receiving surgical intervention compared with only 25% of rectal SCCs. In matched data, rectal SCC had a higher 5-year OS rate across all stages except Stage 4: Stage I (colon 70%, rectum 79%), Stage II (colon 46%, rectum 49%) and Stage III (colon 44%, rectum 45%), Stage IV (colon 15%, rectum 12%).

This study provides the largest cohort of patients with colon and rectal SCC to date and their distinct clinical and survival data acquired from a national database. The colon SCC group exhibited worse prognosis than rectal SCC patients.