Rectal Versus Non-rectal Primary Signet Ring Cell Carcinoma of the Colorectum: a Retrospective Survival Analysis Controlled for Confounders

Purpose: Our objective was to compare the outcomes of rectal and non-rectal primary signet ring cell adenocarcinoma of the colorectum. Methods: A retrospective survival analysis was performed using the Surveillance, Epidemiology, and End Results Program database between 2004 and 2009 on subjects who were diagnosed as having a primary signet ring cell carcinoma of the colorectum. Cox proportional hazard regression analysis controlled for confounders was used to assess overall survival comparing rectal and non-rectal cancers. Results: Our population was composed of 1,484 patients: 200 affected by rectal cancer and 1,284 by non-rectal cancer. Unadjusted survival curves resulted to be almost superimposable (P = 0.916). After controlling for age, gender, race, tumor stage, grade, and size, tumor location demonstrated a statistically significant impact on overall survival (P = 0.032; 95 % confidence interval 0.640–0.980; hazard ratio 0.792). Conclusion: On the basis of analysis of information from the SEER database, the signet ring cell carcinoma of the rectum was associated to a worse prognosis as compared to non-rectal cancer. © 2014, Springer Science+Business Media New York.