Therapy improves rectal cancer outlook.

Therapy improves rectal cancer outlook

In a clinical trial of patients recovering from surgery for rectal cancer, people who received a combination of radiation and drugs after surgery had a significantly lower rate of disease recurrence than those treated with radiation alone, researchers report in the March 14 NEW ENGLAND JOURNAL OF MEDICINE. The new approach might save more than 4,000 lives in the United States each year, they estimate.

"We've opened up the door to much more accelerated progress [in the treatment of rectal cancer]," says study coauthor Charles G. Moertel of the Mayo Clinic in Rochester, Minn. This particularly deadly and difficult-to-treat cancer strikes about 45,500 people in the United States annually.

At present, high-risk rectal cancer patients who undergo surgery to remove the diseased tissue run a 60 percent risk of dying from a malignant recurrence. Moertel and James E. Krook of the Duluth (Minn.) Community Clinical Oncology Program set out to determine whether additional treatment after surgery would improve the outlook for these patients.

Their study involved 204 people who had undergone surgery for invasive rectal cancer. The researchers randomly assigned 100 people to radiation therapy, while the rest received radiation plus the drugs 5-fluorouracil and methyl-CCNU.

After a mean of seven years, the team observed a 34 percent reduction in cancer recurrence among the patients who received the combined treatment, compared with the radiation-only group. More important, the dual treatment shaved cancer-related deaths by 36 percent, they report.

Preliminary results of a separate study by the same group may prompt researchers to exclude methyl-CCNU from that treatment. The new findings, to be presented in May at the meeting of the American Society of Clinical Oncology, suggest that methyl-CCNU adds nothing to 5-fluorouracil's cancer-killing prowess and may itself trigger serious health problems.

Moertel adds that further fine-tuning of the postsurgical chemotherapy regimen may yield even stronger weapons in the battle against rectal cancer. In 1989, he led a study showing that a combination of 5-fluorouracil and another drug, called levamisole, decreased by one-third the risk of dying from colon cancer recurrence (SN: 10/7/89, p.228). Moertel and his colleagues now want to see whether that combo can do the same for people with rectal cancer.