Epidemiology and risk factors in pancreatic cancer.

Pancreatic cancer is one of the most lethal neoplasms. Incidence in the United States has remained fairly stable over the past 25 years, with about 25,000 cases annually. Almost 100% of cases are fatal. Incidence in the developed world parallels that in the United States. Incidence in undeveloped nations is lower but may be underreported. Worldwide incidence is about 185,000 cases per year. There are no striking environmental risk factors, and geographic variation is less than with other gastrointestinal cancers. The most significant risk appears to be cigarette smoking, with a risk ratio of about 2. Alcohol and coffee consumption have been reported as possible risks in some (but not in most) studies. Diet is probably a significant factor, but is difficult to evaluate quantitatively. Other putative associations, including diabetes, probably are unimportant.

A prospective randomized comparison of continuous infusion fluorouracil with a conventional bolus schedule in metastatic colorectal carcinoma: a Mid-Atlantic Oncology Program Study.

One hundred seventy-nine patients with advanced measurable colorectal cancer not previously treated with chemotherapy were entered into a prospective randomized clinical trial by the Mid-Atlantic Oncology Program (MAOP) to compare two schedules of delivery for single-agent fluorouracil (5-FU). The "standard" treatment was a schedule commonly employed in clinical practice, namely, a daily bolus dose administered intravenously (IV) for five consecutive days and repeated at 5-week intervals. The investigational treatment was a continuous infusion of 5-FU administered 24 hours a day for a protracted time (10 weeks or more). Both treatments were continued until the development of disease progression or unless interrupted for toxicity. Using stringent objective criteria requiring independent confirmation of x-ray or scan-documented response, the tumor response rate reached 7% (six of 87) for the bolus arm and 30% (26 of 87) for the infusion arms (P less than .001). Toxicity was substantially different for the two arms with major leukopenia observed only on the bolus arm, 22% developing grade 3 (severe) or grade 4 (life-threatening) leukopenia with four sepsis-related deaths. Hand-foot syndrome was observed only in the infusional arm, requiring treatment interruptions and dose reductions in 24% of patients, but with little impact on quality of life. In spite of the major difference in objective response rate, overall survival for the two groups was comparable. Administration of 5-FU as a continuous infusion for protracted periods clearly improves the therapeutic index for this agent in patients with advanced colon cancer with respect to response rate and reduced toxicity. This schedule appears workable in the community setting and yields response rates similar to those reported for 5-FU with high-dose leucovorin, but without the gastroin testinal toxicity profile of the latter combination.

Current management of advanced and locally unresectable gastric carcinoma.

Gastric cancer is the most chemotherapy-responsive adenocarcinoma of the major gastrointestinal sites. For patients with advanced disease, the response rates and survival achieved with recently designed Adriamycin-based regimens represent an improvement over the past use of 5-fluourouracil alone or combined with a chloroethylnitrosourea. Effective palliative treatment can be administered in an out-patient setting without the necessity of producing severe or life-threatening toxicity. Nevertheless, response durations are finite, as is patient survival. It is essential that Phase II trials of new drugs be continued in an attempt to identify agents with greater therapeutic activity for this disease. For the locally unresectable stage, combined modality therapy incorporating palliative resection of the primary tumor, regional radiation therapy and chemotherapy, has provided long-term disease-free survival for 15--25% of all patients. The most promising aspect of current clinical investigation is the application of the Adriamycin-based drug combinations in controlled trials of surgical adjuvant therapy.