[Long-term outcomes and risk factors of lymph node metastases in invasive submucosal colorectal cancer].

To evaluate the risk factors associated with lymph node(LN)metastases described in the Japanese Society for Cancer of Colon and Rectum (JSCCR) guidelines, we retrospectively analyzed 40 patients with submucosal invasive colorectal cancer who underwent surgical resection after endoscopic resection at Osaka Medical Center for Cancer and Cardiovascular Diseases between 2006 and 2008. We examined clinicopathological factors such as sex, age, tumor diameter, morphology, histological grade, submucosal invasion, lymphatic invasion, venous invasion, and LN metastasis and 5-year disease-free survival(DFS) and overall survival (OS). All patients had tubular adenocarcinoma. Ten patients had LN metastasis. Histological grade, tub2, and a positive vertical margin were significant risk factors. Submucosal invasion was greater than 1,000 µm in patients with LN metastasis. There was no difference in clinicopathological factors between patients with colon cancer and those with rectal cancer, but LN metastasis occurred in 18.7% and 50.0% of colon cancer and rectal cancer patients, respectively. There were no recurrences or cancer-related deaths, although one patient died of other causes. In conclusion, patients who were treated according to the JSCCR guidelines had a favorable prognosis.