Published June 10, 2013 By Dr. Susan Love
If you thought the media has been covering a lot of cancer-related stories this past week, and wondered why, the answer is this: The annual American Society of Clinical Oncology meeting was held in Chicago the first week of June. Because its focus is on the latest developments in cancer care, this conference always generates a media buzz, and this year was no different.
While the big news on immunological drugs did not include any breast cancer treatments— several intriguing breast cancer stories did emerge from this annual meeting.
The study I found most interesting showed that more than one in five African-American women with breast cancer had one of the 18 inherited genetic mutations known to increase breast cancer risk. Conducted by researchers at the Cancer Risk Clinic at the University of Chicago, the study found that 56 (22%) of the 249 African-American women they studied had at least one inherited mutation. Most—46 of the 56—had a BRCA 1 or a BRCA2 genetic mutation; the others had less common mutations. As expected, the mutations were more likely to be found in women with triple-negative breast cancer, women under 45, women with bilateral breast cancer, and women with a strong family history.
This study not only suggests that women with these characteristics should consider being tested for a BRCA genetic mutation, but also may explain why African-American women tend to be diagnosed at a younger age and have a more aggressive type of breast cancer.
Another interesting study with implications for women with breast cancer was the aTTom trial, which looked at whether 10 years of tamoxifen is better than five. This study of almost 7,000 women in the UK showed that more is better, reducing both breast cancer recurrence and mortality by 25 percent. As with past studies, this one also found that tamoxifen increases the risk of uterine cancer. The researchers estimated that 10 years of tamoxifen would prevent 30 breast cancer deaths for every uterine cancer death it caused, suggesting the benefits outweighed the risks.
This finding confirms the findings from the Atlas trial of 12,000 women, which was reported six months ago. Since we are now starting to see late recurrences in women with hormone positive cancers, this approach may well make sense. Neither of these studies looked at aromatase inhibitors, which were not as commonly used 10 years ago when these studies started, and it has not yet been shown that 10 years of an aromatase inhibitor would be better than five—even though women have already begun to stay on these drugs longer as well.
Another confirmatory study looked at whether it is necessary to do a full axillary dissection in addition to radiation therapy if a non-palpable node found during a sentinel node biopsy turns out to be positive. This study confirmed a previous one showing that radiation was just as good as the axillary dissection, and resulted in fewer side effects such as lymphedema and problems with arm mobility.