K. E. Koch1, P. Goffredo1, A. Beck1, P. Kalakoti1, I. Hassan1 1University Of Iowa,Surgery,Iowa City, IA, USA
Introduction: Rectal squamous cell carcinoma (RSCC) is a rare malignancy, accounting for approximately 0.01–0.025% of all colorectal cancers. As a result, literature regarding its treatment and prognosis is mainly based on small single institutional series. Our aim was to describe patient characteristics, stage specific management, and outcomes utilizing a national database.
Methods: We identified 2915 patients with stage I, II, and III RSCCs from the National Cancer Database treated between 2004 and 2014. Management strategies were categorized as local excision or chemoradiation alone, chemoradiation with local excision, and chemoradiation with radical resection. These modalities accounted for approximately 80% of patients in the cohort. Stratified survival analyses were adjusted by gender, age, and race. Data were examined using simple summary statistics, chi-square, student’s-T tests, Kaplan-Meier analysis, and Cox proportional hazards regression.
Results: The majority of patients were females (69%) and Caucasian (86%) with a mean age at diagnosis of 61 years (SD=13). The Charlson/Deyo score was 0 in 81% of patients. Mean tumor size was 41 mm (SD=25). The 5-year overall survival (OS) was 70% for stage I (1021 pts), 55.8% for stage II (711 pts), and 54.7% for stage III (809 pts, p<0.001). In univariate analysis for patients with stage II and III disease, no difference was observed in the 5-year OS among management strategies (p=0.90 and 0.07, respectively). However, for stage I disease, the combination of chemoradiation and local excision was associated with improved outcomes compared to chemoradiation or local excision alone (p <0.001) (Table 1). The results of the univariate analysis were confirmed in the multivariate model after adjustment for available demographic confounders.
Conclusion: Our data suggest that for stage I disease the combination of chemoradiation with local excision may be the optimal oncologic treatment. Conversely, the addition of local excision or radical surgery to a treatment strategy based on chemoradiation for stage II and III disease was not associated with a survival benefit. Therefore, a treatment approach based primarily on chemoradiation should be considered the optimal management strategy for squamous cell carcinomas of the rectum.
