Studies Examine Developments In Breast Cancer Treatment, Prevention

Several recent studies on breast cancer examined the benefits of interoperative radiotherapy, new drugs that prolong survival and the benefits of a diet containing the estrogen-like plant chemical lignan. Summaries appear below.

Radiation: One dose of radiation to the spot where a breast cancer tumor was removed is as effective at preventing recurrence as treating the whole breast with the standard, extended daily radiation regimen, according to findings from an ongoing international study reported in the Lancet on Saturday, the San Francisco Chronicle reports (Allday, San Francisco Chronicle, 6/5). The study tracked more than 2,000 women ages 45 or older with invasive ductal breast carcinomas who were undergoing breast-conserving surgery at 28 medical centers in nine countries in Asia, Europe and North America. Half of the women were randomly assigned to undergo the standard radiation treatments and half got targeted intraoperative radiotherapy during surgery, which involves a single, 30-minute dose of radiation delivered from a probe placed inside the surgery cavity. Both groups had the same recurrence rate, complication rate and side effects. However, the major benefit for the targeted therapy group was convenience. They experienced a shorter treatment time, in addition to no irradiation of the heart, lung and esophagus. About 14% of the patients in the targeted group later needed conventional radiation to kill remaining cancer cells. According to a commentary by French radiation oncologist David Azria, researchers are awaiting long-term follow-up and the results of similar studies, but "we are already convinced that accelerated part-breast irradiation is the new standard and intraoperative radiotherapy an excellent option" (Shelton, Chicago Tribune, 6/6).

 Survival rates: An experimental drug by Eisai Oncology of Japan called eribulin can prolong breast cancer survival rates by an average of about 2.5 months in women whose cancer has been resistant to other forms of chemotherapy, according to the results of the Phase III trial presented on Sunday at the annual meeting of the American Society of Clinical Oncology¸ Reuters reports. The trial involved 762 breast cancer patients with different types of tumors who had all been through at least two rounds of chemotherapy. Two-thirds of the patients received the experimental drug, while one-third received another round of chemotherapy or supportive care(Fox, Reuters, 6/6). Patients who received eribulin lived an average of 13.12 months, compared with 10.65 months for those who did not receive the new drug. Last week, FDA granted the drug an expedited review. Eisai originally applied for FDA approval three years ago, but the agency told the company to produce more clinical data. The drug is a derivative of a toxin made by the black Pacific sea sponge and blocks the replication of cancer cells, causing them to self-destruct (Maugh, "Booster Shots," Los Angeles Times, 6/6).

Diet: Postmenopausal women with diets containing foods with lots of the estrogen-like plant chemical lignans -- such as flaxseed, sesame and whole grains -- have a modestly lower risk of developing breast cancer, according to an analysis published in the American Journal of Clinical Nutrition, Reuters reports. The analysis of 21 studies published over the last 13 years found that overall there was no correlation between lignan intake and breast cancer risk but in postmenopausal women, those who had the highest intake of lignans were 14% less likely to develop breast cancer than those with low intake. The new study adds to the conflicting body of research on the link between breast cancer risk and dietary phytoestrogens -- plant-based substances that are structurally similar to estrogen and can function somewhat like estrogen in the body. Some research suggests that high phytoestrogren is linked to lower breast cancer rates, while other research has found that it actually spurs breast cancer growth or has no effect (Norton, Reuters, 6/4).

Broadcast coverage

NPR's "Talk of the Nation" on Friday examined two recent studies looking at breast cancer prevention. One in the journal Nature Medicine examines a possible new cancer vaccine; the other in the Lancet examined the influence of lifestyle on genes. The program includes discussion with immunologist Vincent Tuohy and oncologist Cliff Hudis ("Talk of the Nation," NPR, 6/4).