The clinical pathological features correlated with lymph node metastasis in T1 stage rectal carcinoma

Objective To investigate the association between clinical pathological factors and lymph node metastases in T1 stage rectal carcinoma. Methods We retrospectively reviewed the 251 consecutive T1 rectal carcinoma patients who had undergone radical colectomy with lymph node dissection in a single institution. The histopathological factors were reviewed. The correlation between these factors and lymph node metastasis, tumor recurrence and survival were analyzed. Results A total of 251 consecutive patients with T1 rectal carcinoma were included in this study. Lymph node metastasis occurred in 11.2% (28/251) of patients. The 3, 5 and 10 years overall survival was 98.6%, 96.8% and 94.9%, respectively, for all patients. The 3, 5 and 10 years overall survival of patients with or without lymph node metastasis were 100%, 95.6% and 90.9% or 99%, 96.9% and 95.4%, respectively. There was no statistical difference between the two group in overall survival. Univariate analysis showed that each of the following histopathological factors had a significant influence on lymph node metastasis, which are patients′ age (P=0.05); adenomatous background (P<0.01), tumor differentiation (P<0.01), cribriform structure (P=0.03), PDC (P=0.02), tumor budding (P=0.01), lymphvascular invasion (P<0.01), submucosa venous invasion (P<0.01) and glandular pattern at the submucosal invasive front (P=0.04). Multivariate analysis showed that age (P=0.02), no adenomatous background (P<0.01), tumor differentiation (P=0.04) and submucosa venous invasion (P=0.02) were significantly associated with lymph node metastasis. We also found that open-type glandular pattern is also correlated with gross plat-type (P=0.03); no adenoma background (P=0.03), complete disruption of the muscularis mucosa (P=0.05), high grade tumor budding (P<0.001) and tumor necrosis (P<0.001). Conclusion In the present study, we not only verified the effectiveness of those classical pathological factors, but proposed the cribriform structure, open-type glandular pattern at the submucosal invasive front in predicting lymph node metastasis in T1 stage rectal carcinoma. Key words: Rectal neoplasms; Neoplasm metastasis; Prognosis; T1 stage; Recurrence; Risk factor