Colorectal cancer is the most common visceral malignant neoplasm in the United States and will affect an estimated 123,000 persons in 1982. While surgical resection remains the only generally accepted curative therapy, the impetus for development of effective treatment for systemic disease continues because more than half the patients eventually have widely disseminated cancer. In this issue of The Journal Levine and colleagues (p 2809) describe a patient with well-documented hepatic metastases who survived for 15 years. The rub, as the authors point out, is that we understand very little about why occasional patients with metastatic colon cancer have extended survival, with or without therapy, when median survival is only seven to nine months. Similarly, we have little understanding of the determinants of tumor growth rates or patterns of metastases.
The chemotherapy of colorectal cancer has for two decades involved fluorouracil alone and in multidrug combinations. Clinical researchers have exhaustively