NEW YORK, Jun 15 (Reuters Health) - Women with breast cancer who choose to
have breast-conserving surgery followed by radiation rather than having their
breast removed do not have a higher risk of developing cancer again years later,
according to the results of a new study.
Unlike a mastectomy, which involves the complete removal of the breast,
during a lumpectomy, a surgeon removes a breast tumor and some surrounding
tissue but spares most of the breast. After a lumpectomy, however, most women
undergo radiation treatments to zap any cancer cells lingering in the breast.
The survival odds of both techniques are roughly equal, but there has been some
concern that the radiation used after lumpectomy may increase the risk of having
another tumor, either in the breast or elsewhere in the body.
But in a 15-year study of women with early-stage breast cancer, the risk of
developing another breast tumor was 10% in all women, regardless of whether they
had mastectomy or lumpectomy plus radiation. The risk for tumors in other parts
of the body was 11% in the lumpectomy-radiation group and 10% in the mastectomy
group, a difference that was statistically insignificant.
"These data should be reassuring to women considering lumpectomy followed by
irradiation as a treatment option," Dr. Bruce G. Haffty and colleagues from Yale
University School of Medicine, in New Haven, Connecticut, report in the June
issue of the Journal of Clinical Oncology.
"There seems to be no increased risk of second malignancies in patients
undergoing lumpectomy followed by therapeutic doses of irradiation using modern
techniques, compared with surgically treated patients," they state.
Even among women younger than 45 years, for whom radiation has been thought
to be riskier, treatment with radiation did not increase their risk of a second
tumor, according to the report. The researchers did detect a slight trend
toward more second tumors in younger women, but the difference was not
statistically significant and may have been caused by older types of radiation
no longer in use, they say.
Despite the overall good news about radiation, however, the researchers
point out that a 15-year study may not be long enough to gauge the effects of
radiation, since radiation-induced cancer may take longer to develop. They plan
to keep following the women in the study to see whether any increased risk shows
up several years later.
In the study, the researchers followed 1,029 women with early-stage breast
cancer who were treated with lumpectomy and radiation and 1,387 who were treated
with mastectomy from 1970 to 1990.
Besides the good news about radiation, Haffty and his colleagues also report
that chemotherapy did not increase the risk of a second tumor. And women who
received hormone-based drug therapy had a somewhat lower risk of getting cancer
again. This difference was not statistically significant, but the researchers
note that there may not have been enough women taking these drugs to detect the
full effect.
Not surprisingly, smoking increased the risk of having cancer years after
treatment, especially lung cancer.
