Survival of familial adenomatous polyposis coexistence colorectal cancer in Iran

Abstract

Context: Familial adenomatous polyposis (FAP) is an autosomal dominant disorder. Colorectal cancer (CRC) has been implicated as the most common cause of death in FAP patients, especially in those with coexisting CRC at initial diagnosis (FAP-CRC). Aim: We aimed to determine the survival rate of FAP-CRC and the factors affecting FAP-CRC survival. Setting and Design: This was a retrospective cohort FAP study conducted in northwest Iran. Subjects and Methods: From 2006 to 2016, 51 FAP-CRC individuals were selected from among 4588 CRC patients. Statistical Analysis: A Student's t-test, life table method, log-rank tests, a Kaplan-Maier survival curve, and Cox regression analysis were performed and a value of P < 0.05 was set as statistically significant. Results: A total of 51 FAP-CRC patients were selected, (30 males and 21 females), with a mean age of 42.2 years at diagnosis. The most common presenting symptom was abdominal pain and the most common primary tumor site was the rectum. The 1-, 5- and 10-year overall survival rates were 76%, 59%, and 52%, respectively. Factors affecting the FAP-CRC survival rate, namely, sex, age at CRC diagnosis, and extracolonic manifestations showed no significant differences. The difference in 5-year survival rates between patients with colon and rectal cancers was significant (75% vs. 33%, P = 0.02). The survival rate was significantly higher among patients with disease Stages I and II than those in disease Stages III and IV (P = 0.001). 5-year survival rates in patients with ileal pouch-anal anastomosis and ileorectal anastomosis were 71% and 78%, respectively (P = 0.001). There was an interesting difference in survival between FAP and attenuated FAP (P = 0.01). In cox regression analysis, distant metastasis was a significant predictor of survival (P = 0.001). Conclusions: Long-term survival from FAP-CRC remains poor; therefore, early-stage detection and the choice of an appropriate surgical method can improve survival in such patients.