|D.G. Haller, MD, Univ of Pennsylvania Cancer Center, Philadelphia, reviewed recently published data, outlined a proposed evidence-based surveillance program to follow colon cancer surgery, and identified two promising therapies. Interim results from Study INT 0089 and other trials support a 6-month regimen of 5-fluorouracil (5-FU) and leucovorin (LV) for stage III colon cancer, compared to 12 months' of 5-FU with levamisole (LEV). Pelvic radiation therapy, given either before or after surgery in high-risk rectal cancer patients, awaits results from ongoing studies.|
Study INT 0089 compared four FU-based regimens in nearly 3800
high-risk stage II and stage III colon cancer patients. One
group received postoperatively 12 months' treatment with 5-FU
and levamisole (LEV). The 6 months' group had one of three
regimens, 5-FU with low dose leucovorin (5-FU/LDLV), 5-FU with
high dose leucovorin (5-FU/HDLV), or 5-FU/LDLV/LEV.
Based on a recent interim analysis (Proc ASCO 1997; 16:211, Abst No. 940), 6 months of 5-FU/LV seems as effective as 12 months of 5-FU/LEV. A final analysis is planned for mid-1997.
As seen below, grade 3/4 granulocytopenia and stomatitis occurred less frequently in patients treated with 5-FU/HDLV:
|Age-related infection and toxicity||
Haller reported unpublished safety data on patients treated with the adjuvant regimens given in INT-0089:
The >70 year-old group showed significantly higher percentages of infection, stomatitis and leukopenia, but were able to complete therapy in the same proportion as younger individuals.
|Innovations in chemotherapy||
The treatment of colon cancer has made a significant advance with the evaluation of 5-FU. Buyse et al conducted a meta-analysis on the results from controlled trials on 5-FU alone or combined with other drugs (JAMA 1988; 259:3571-3578). The analysis covered English language reports published up to 1987. Using 5-FU alone or in combination led to a survival advantage of 2.3% compared with surgery alone. This advantage later rose to 12% to 15% from the combination of 5-FU with LEV, according to Haller, owing to improved administration techniques and quality of clinical studies.
Therapies in research range from monoclonal antibody 17-1a which mimics IgG antibodies to tegafur (prodrug or precursor of 5-FU) with uracil.
Presented at the Annual Meeting of the American Society of Clinical Oncology (ASCO) on May 17-20, 1997
CONRAD NOTES, © 1997 All Rights Reserved
Eugene A. Conrad, PhD, MPH / ISSN 1078 / June 1997