A refined prediction of early recurrence combining tumor deposits in patients with resected rectal mucinous adenocarcinoma

Purpose Early recurrence (ER) of rectal mucinous adenocarcinoma (MAC) has yet to be defined. We therefore explored risk factors for ER and constructed a predictive nomogram. Method A total of 145 rectal MAC patients undergoing radical surgery were included. The minimum P value method was used to determine the optimal cut-off point to discriminate between ER and late recurrence (LR). Risk factors for ER were determined by a logistic regression analysis, and a predictive nomogram was constructed. Results A total of 62 (42.8%) patients developed tumor recurrence. The optimal time to define ER was 12 months. A pre-treatment tumor distance from the anal verge ≤ 7 cm, pathological N stage, lymphovascular invasion, tumor deposits, and time to recurrence ≤ 12 months were significantly associated with a poor post-recurrence survival in patients with recurrence. A pre-treatment serum carcinoembryonic antigen (CEA) level > 10 ng/ml, pre-treatment tumor distance from the anal verge ≤ 7 cm, pathological N + stage, perineural invasion, and tumor deposits were identified as independent risk factors associated with ER. A nomogram predicting ER was constructed (C-index 0.870). Conclusion The pre-treatment serum CEA level, pre-treatment tumor distance from the anal verge, pathological N + stage, perineural invasion, and tumor deposits were significantly predictive of ER for rectal MAC patients.