On Mar. 4, 1991, researchers reported that post-operative (adjuvant) radiation therapy and chemotherapy were found to improve survival in rectal cancer. After a median follow-up of more than seven years, the combined therapy had reduced the recurrence of rectal cancer by 34 percent (P = 0.0016; 95 percent confidence interval, 12 to 50 percent).

The research team concluded that the combination of postoperative local therapy with radiation plus fluorouracil and systemic therapy with a fluorouracil-based regimen significantly and substantively improved the results of therapy for rectal carcinoma with a poor prognosis, as compared with postoperative radiation alone.