Clinical outcome of surgical treatment for invasive early colorectal cancer in Japan.

BACKGROUND/AIMS: Despite the high frequency of early colorectal cancer, little is known about the clinicopathologic features of invasive early colorectal cancer for which endoscopic polypectomy is not indicated. We wanted to determine the clinicopathologic features of these early colorectal cancers.
MATERIALS AND METHODS: From 1973 to 1994, a total of 728 patients with colorectal cancer were reviewed retrospectively from hospital records. The clinicopathologic features of the 90 invasive early colorectal cancer patients who underwent major surgeries were compared with those of 626 patients with advanced colorectal cancer.
RESULTS: The frequency of early colorectal cancer increased significantly from the periods 1973-1979 to 1990-1994: 0% in the former period and 18.3% in the later period. Minimally invasive surgery was chosen more frequently for the treatment of early colorectal cancers than for the treatment of advanced cancers (p < 0.005). Lymph node metastasis, lymph vessel invasion, and vascular invasion were more prevalent in advanced cancer cases than in early cancer cases (p < 0.005). Lymph node metastasis was found in 7 patients with early colorectal cancer (7.8%). There was no difference in histologic type between the early and advanced colorectal cancers. The 5-year survival rates of early colorectal cancer patients were higher than those of advanced cancer patients: 97.5% in early colon cancer patients; 93.5% in early rectal cancer patients; 59.8% in advanced colon cancer patients; 55.4% in advanced rectal cancer patients. Three early colorectal cancer patients died of recurrence.
CONCLUSION: Minimally invasive surgery such as laparoscopic colectomy should be performed on patients with invasive early colorectal cancer when it is impossible for the cancer to be removed by endoscopic polypectomy.