Surgical removal of the breast tumor without mastectomy, plus treatment with tamoxifen, may be sufficient for elderly women with early-stage breast cancer, according to new research.

The results of one study indicate that omitting radiotherapy has no effect on survival and only a slight effect on disease recurrence. The results of another study, however, suggest that, at least for now, radiotherapy is indicated for all younger women.

Both reports appear in the current issue of The New England Journal of Medicine.

In one, Dr. Kevin S. Hughes from Massachusetts General Hospital in Boston, and colleagues assessed the outcomes of 636 women, 70 years of age or older, who were randomly assigned to undergo surgical removal of the breast tumor without mastectomy, or “lumpectomy,” plus tamoxifen with or without radiotherapy. All of the subjects had early-stage cancer (stage I) and estrogen-receptor-positive breast tumors.

The groups did not differ significantly in rates of overall survival at five years. There were also no differences seen in the frequency of tumor spread to other sites in the body or the need for mastectomy after recurrence, the authors report.

The recurrence rate at or around the site of the original breast cancer was statistically significantly higher when radiotherapy was omitted, but the absolute difference between the groups was small - four percent vs. one percent.

“The difference in recurrence rates between the groups was just three percent, which in my opinion is not clinically relevant,” Dr. Ian E. Smith, co-author of a related editorial, told Reuters Health. “The findings suggest that radiotherapy is not needed for older women with small breast cancers.”

Also, in terms of cosmetic results and adverse events, the non-radiotherapy approach was consistently favored by clinicians and patients over the more traditional approach.

“I think this paper will be considered controversial, but I imagine that many of my colleagues will support the conclusion” that radiotherapy can be omitted in older women with early stage disease, Smith, from Royal Marsden Hospital in London, added.

In a similar study, Dr. Anthony W. Fyles, from Princess Margaret Hospital in Toronto, and colleagues looked at the added benefit of radiotherapy in patients who were 50 years of age or older with early-stage cancer.

Once again, no significant differences were seen between the groups in rates of distant relapse or overall survival, the authors found.

As in the first study, the local recurrence rate increased when radiotherapy was not given, but the difference between the groups was more pronounced - 7.7 percent vs. 0.6 percent. Also, omitting radiotherapy was associated with a drop in five-year disease-free survival - from 91 percent to 84 percent.

“An important message from these studies is that most women who don’t receive radiotherapy will not experience a disease recurrence,” Smith noted.

The findings suggest that radiotherapy can be omitted in women over 70, but “further studies are needed to identify factors, perhaps molecular markers, that predict when such therapy can be omitted in younger women.”

SOURCE: The New England Journal of Medicine, September 2, 2004.