FRIDAY, Dec. 16, 2011 (HealthDay News) -- The number of women with breast cancer who receive targeted radiation to the breast after a lumpectomy has jumped dramatically over the last decade.
However, only about a third of these women were considered "suitable" for the treatment, according to criteria used in a new study published in the Dec. 16 online issue of the Journal of the National Cancer Institute.
But guidelines on which women should or should not receive this type of radiation treatment, known as brachytherapy, are only newly published and it's unclear what the findings might mean to current breast cancer patients.
Use of "accelerated partial breast irradiation using brachytherapy" has risen steadily since about 2002, said study author Dr. Jona Hattangadi, a radiation oncologist with Brigham and Women's Hospital and the Harvard Radiation Oncology Program in Boston.
Although brachytherapy is vastly more convenient (taking place over the course of a week rather than six weeks), the worry is that directed radiation isn't comprehensive enough to find and kill all cancer cells lingering in the breast as compared with the current standard, whole breast radiation (WBI).
So, in 2009, the American Society for Radiation Oncology (ASTRO) issued the first guidelines for the use of brachytherapy, which identified patients as either "suitable," "cautionary" (suitability unclear) or "unsuitable" for the treatment, depending on a number of factors including age as well as various tumor characteristics.
These authors rounded up data on 138,815 U.S. women who had been diagnosed with breast cancer from 2000 to 2007 and who had either undergone brachytherapy or whole breast irradiation after a lumpectomy.
Some 2.6 percent of women underwent brachytherapy, two thirds of whom were either deemed "cautionary" (29.6 percent) or "unsuitable" (36.2 percent) according to ASTRO criteria.
Only about a third (32 percent) of patients would have been considered suitable under ASTRO's recommendations, the study authors said.
Use of brachytherapy rose from less than 1 percent in 2000 to almost 7 percent in 2007, but this varied greatly between geographical regions, the researchers noted.
For instance, women in urban areas were more likely to get brachytherapy than women in rural areas, which is surprising given that rural women would have the most to benefit from the convenience.
And white women were more likely to get brachytherapy than black women if they were considered "cautionary" or "unsuitable."
It's unclear what accounts for the variation or for the rise in numbers, although the authors did postulate that reimbursement patterns may play a role. Medicare started reimbursing for brachytherapy in 2004.
The main drawback of this study, the authors acknowledged, is that the data was gathered before the ASTRO guidelines were published.
Dr. Eric Horwitz, M.D., chair of radiation oncology at Fox Chase Cancer Center in Philadelphia, agreed that brachytherapy is "not for everybody" but that "it's an excellent technique if used on the right patients."
But who is the right patient? Generally people with smaller, localized tumors, he said.
Still, in the absence of long-term data, Hattangadi recommends that women getting treatment for early-stage breast cancer have a "thorough discussion with their physicians on the pros and cons of the approach."
The findings come just a week after presenters at a national conference found that women who had brachytherapy had double the rate of mastectomy later on compared with women who got whole breast irradiation. That study was led by Dr. Benjamin Smith of M.D. Anderson Cancer Center in Houston and presented at the San Antonio Breast Cancer Symposium
The U.S. National Cancer Institute has more on radiation therapy for cancer.