Writing in the Journal of the National Cancer Institute, Dr. Norman Wolmark of Allegheny University Hospital in Pittsburgh, Pennsylvania, and colleagues report that "postoperative radiotherapy resulted in no beneficial effect on disease-free survival... or overall survival, regardless of which chemotherapy was utilized."
According to the team, these results -- taken together with previous National Surgical Adjuvant Breast and Bowel Project findings -- "indicate that postoperative radiotherapy, administered alone or in concert with chemotherapy, is unsuccessful in altering the subsequent incidence of distant disease."
The combined use of radiotherapy and chemotherapy was, however, associated with "a reduction in (local) relapse when compared with chemotherapy alone."
Dr. Daniel Haller, of the University of Pennsylvania Cancer Center in Philadelphia, writes in an accompanying editorial that the established guidelines for treatment of rectal cancer will now be reexamined in light of these results.
As he told Reuters Health, "this trial asked whether all patients with high-risk rectal cancer require postoperative radiation. The answer seems to be no."
But Haller, whose specific focus of clinical research is the use of chemotherapy in patients with advanced colon and rectal cancers, added that "patients and physicians should not consider that this settles the role of postoperative treatment for patients with high-risk (for recurrence) rectal cancer."
In Haller`s view, additional clinical trials will be required to answer what he regards as an obvious question: do patients at relatively low risk for recurrence indeed benefit from radiotherapy, or will "newer, more intensive chemotherapy agents... further improve the overall survival of patients while keeping the risk of local recurrence to a minimum?"
He believes that these upcoming studies will help to individualize therapies "taking into account newer prognostic and predictive tests... based not only on the anatomy and pathology of the tumor (itself) but also on molecular markers of tumor biology."
SOURCE: Journal of the National Cancer Institute 2000;92:361-362, 388-396.