Options for Breast Cancer Survivors With Genetic Mutations
Feb. 1, 2000 (Baltimore) -- In a study of women with a genetic
predisposition to breast cancer who have already been diagnosed with the
malignancy once, researchers have found that these women may benefit from
surgical removal of the unaffected breast, removal of the ovaries, and/or
treatment with tamoxifen. These therapies may result in increased life
expectancy in women with breast cancer and genetic mutations.
"The utility of this study is that it takes a lot of data ? and provides
a springboard for discussion between physicians and their patients," says
Deborah Schrag, MD, lead author of the study, in an interview with WebMD. The
study is based on mathematics, and as such is not able to provide data on
observed clinical benefit, according to Schrag. The results are published in
the Feb. 2 issue of the Journal of the American Medical Association.
Two genes, BRCA1 and BRCA2, are associated with an increased risk of breast
cancer when they undergo mutations, thus often leading to several women in one
family with the disease.
Schrag and colleagues at the Dana-Farber Cancer Institute in Boston wanted
to assess how well various interventions would affect the chance of being
diagnosed with breast cancer again in women with BRCA mutations. The
researchers compared removal of the unaffected breast, removal of the ovaries,
tamoxifen therapy, a combination of tamoxifen therapy with either of the two
surgical therapies or with both, or simply careful watching.
The study shows that compared with careful watching alone, a 30 year-old
early-stage breast cancer patient with a BRCA mutation could expect to gain 0.4
to 1.3 years of life from tamoxifen therapy, 0.2 to 1.8 years from removal of
the ovaries, and 0.6 to 2.1 years from removal of the unaffected breast.
Gains in life expectancy were consistently lower for women whose cancer had
spread to their lymph nodes and for older women, who would have fewer years of
natural remaining life expectancy.
Schrag, who is now with Memorial Sloan-Kettering Cancer Center in New York
City, says, "No estimate tells any patient what to do. I would say every
woman I've ever seen makes these decisions based on personal preferences, but
this study provides a context for discussion between a woman and her
Roy Smith, MD, director of medical oversight for the National Surgical
Adjuvant Breast and Bowel Project in Pittsburgh, gave objective comment on the
study to WebMD. In an interview, Smith says, "This study is entirely
hypothetical and retrospective, but it is interesting. The assumptions about
tamoxifen benefit are consistent with what I would predict based on our
experience, but there's no substitute for clinical trials. Before I put a young
woman with a BRCA mutation on five years of tamoxifen therapy, I'd want to be
satisfied that it was going to be beneficial."
Even though the analysis showed the greatest benefit was for women who
underwent removal of their unaffected breast, Smith says, "I'm not sure
that's a very useful observation because there are so few people doing it. The
Holy Grail of breast cancer research remains finding a type of intervention
that is not mutilating or high risk and that can be used early on. I don't
think tamoxifen is that agent, but I think there are agents in studies and
under development that seem quite promising."