Purpose: Factors affecting treatment prognosis and therapeutic results for hepatic metastasis of colorectal cancer were investigated.
Methods: Therapeutic results, especially of hepatectomy, were investigated for hepatic metastasis of colorectal cancer in 763 patients (585 underwent hepatectomy) treated between 1992 and 1996 at 18 institutions that participated in the "Study for establishing treatments for hepatic and pulmonary metastasis of colorectal cancer" sponsored by a Grant-in-Aid (10-11) for Cancer Research from the Ministry of Health, Welfare and Labor of Japan.
Results: The five-year survival rate for those treated by hepatectomy was significantly higher (32.9 percent) than for those not undergoing hepatectomy (3.4 percent). After hepatectomy for hepatic metastasis, the most prevalent form of recurrence was in the remnant liver (41.4 percent), followed by recurrence of pulmonary metastasis (19.2 percent), and other (7.2 percent). Factors of the primary tumor adversely affecting prognosis after hepatectomy for hepatic metastasis included poorly differentiated adenocarcinoma or mucinous carcinoma, depth of invasion of si/ai, lymph-node metastasis of Stage n3 and n4 by the Japanese classification of colorectal carcinoma, number of metastatic lymph nodes of more than four, and Dukes Stage D. Factors at the time of hepatectomy adversely affecting prognosis after surgery for hepatic metastasis included residual tumor, extrahepatic metastasis, hepatic metastasis of degree H3 stipulated by the Japanese classification of colorectal carcinoma, number of metastases of four or more, pathology of hepatic metastasis of poorly differentiated adenocarcinoma, resection margin of <10 mm, and carcinoembryonic antigen value higher than normal preoperative and one month postoperative.
Conclusions: Among therapies for hepatic metastasis of colorectal cancer, the present study clearly revealed that hepatectomy is the treatment of choice whenever feasible. Postoperative recurrence often is localized in the remnant liver, or there may be a systemic recurrence of pulmonary metastasis. Thus, methods of prevention will be a future theme.