Radiation therapy after lumpectomy for breast cancer improves survival chances for patients receiving this treatment, according to researchers from the Breast Conserving Surgery Project. Vincent Vinh-Hung, MD, and Claire Verschraegen, MD, found that women who don’t receive radiotherapy after their breast-conserving surgery increase their risk of dying from the cancer by 8.6%.

The finding, published in the Journal of the National Cancer Institute (Vol. 96, No. 2: 115-121), was based on a review of previous clinical trials.

The research "reinforces the view that the large majority of patients undergoing breast-conserving surgery should also receive radiotherapy," said Katherine Vallis, MD, and Ian Tannock, MD, of Toronto's Princess Margaret Hospital, in an editorial accompanying the study.

Many studies have shown that radiation therapy to the breast after lumpectomy will lower the chance that the cancer will come back in the same breast. This led to a National Institutes of Health consensus that radiotherapy was the proper treatment after lumpectomy. Vinh-Hung and Verschraegen confirmed this in their study: women who avoided radiotherapy were 3 times more likely to have the cancer recur in the same breast.

None of the earlier studies found that the radiation might be life saving, probably because the difference was too small to show up convincingly in any single study. When Vinh-Hung and Verschraegen combined 13 studies involving 8,206 women, however, the benefit became apparent.

Although almost all doctors believe that lumpectomy is as effective as mastectomy for small breast cancers, the radiation afterwards can be problematic for some women. The usual course of radiation lasts about 6-7 weeks. This can place a big burden on women who may have to take time off work or make alternate arrangements for childcare and other household responsibilities. Also, many communities, particularly rural ones, don't have a nearby radiation center; women may have to travel long distances to be treated.

Because of these inconveniences, some patients skip radiation and take their chances that the cancer won't come back. But Vallis and Tannock suspect that the increased death rate in women who did not have radiation therapy was due to the cancer coming back in the breast and spreading elsewhere before it could be found. Studies in the past have shown that if the cancer comes back, even if only in the breast, the woman is more likely to die of her cancer.

Vallis and Tannock also point out that past problems with radiotherapy, such as heart damage, have been largely overcome with modern techniques so that it carries little risk today.

Still, radiation isn't for everyone.

Vinh-Hung and Verschraegen note that women with certain other medical conditions may experience too many side effects. And for older women with very small tumors, the increase in life expectancy with radiation may be miniscule. Except for these instances, though, they conclude that "radiotherapy should not be omitted after breast-conserving surgery."