Treatment of human
colonic cancer in early stages when the process is still limited to the colonic wall is primarily surgery. We wished to see if
maltose tetrapalmitate (MTP)
immunotherapy alone or in combination with
radiotherapy (R) and
cyclophosphamide (C)
chemotherapy would be effective against primary
colon cancer in a fashion similar to that reported by us for primary
liver cancer (Anticancer Research 6: 245-250, 1986). One hundred female CD1 mice were subjected to
dimethylhydrazine (
DMH) treatment once a week for 26 weeks, a period one week before which,
colon cancer was histologically documented in each animal of a group that was sacrificed. Surprisingly, many of the animals harboured early
anal cancer as well. At 28 weeks, 85 of the available animals were divided into 6 groups that received: Gr. 1, no treatment; Gr. 2, MTP alone (M); Gr. 3,
radiotherapy alone (R); Gr. 4, cyclosphophamide alone (C); Gr. 5, R + C; Gr. 6, M + R + C. Criteria of treatment efficacy were: number, size and staging of
colorectal tumors and the incidence and the size of anal
tumors at death. Mean survival time was also determined although it remained a questionable criterium since most animals died due to complication (hepatic toxicity,
pyelonephritis, thrombose) elicited by
DMH, R and C toxicities and not as a result of colonic
tumor size or
metastases. As a single
therapy, M appeared to be superior to either R or C alone. However, R + C combination was effective and was further improved upon by its association with M. With the triple combination, (M + R + C), lesions of both
cancers decreased in size and/or number and the
colon cancer histologically eclipsed from 46% of the treated animals.