The American Cancer Society estimates that this year about 233,000 new cases of invasive breast cancer will occur among women in the United States. In addition, approximately 63,000 new cases of noninvasive breast cancer—the earliest form—will occur among women in 2014. It’s also projected that 40,000 women will die from breast cancer this year.
Excluding cancers of the skin, breast cancer is the most common cancer among women, accounting for nearly 1 in 4 cancers diagnosed in American women. However, breast cancer death rates have declined by almost 20 percent over the past decade, partly because of treatments that remove the cancer before it has a chance to spread to other parts of the body. Finding and treating breast cancer in the early stages can oftentimes lead to cure.
For most women diagnosed with early-stage breast cancer, a lumpectomy, or partial mastectomy, may be an appropriate treatment option. Unlike a mastectomy, a lumpectomy only removes a portion of the affected breast. After the procedure, follow-up external beam radiation therapy is traditionally given to the entire breast approximately five times a week, over the course of three to six weeks, to reduce the likelihood of the cancer from returning to that area.
However, this time requirement and added cost proves challenging to many women, especially those who must travel a distance to their radiation facilities, causing some to shorten or even stop their radiation therapy despite the possibility of recurrence. Moreover, whole breast radiation can have serious short- and long-term side effects in some patients.
A new advancement in breast cancer radiation therapy called intraoperative radiation therapy, or IORT, is a promising treatment that may help alleviate some of this burden for women with early-stage disease.
Used successfully for decades with a different type of radiation therapy as part of treatment for intra-abdominal cancers, a new type of IORT is now being used to deliver high doses of radiation during lumpectomies, concentrated only in the cavity where tumors were removed.
After excising the tumor and surrounding tissue from the breast, radiation is delivered through an applicator directly to the former tumor’s site, where the risk of cancer recurrence is highest.
Shielding of the rest of the body is not required as the radiation is focused only in the lumpectomy cavity and the focused radiation does not damage the heart or lungs—as can happen with whole breast radiation. After about 30 minutes of treatment, the applicator is removed.
The single dose of intraoperative radiation delivers a single very high dose of radiation to the area around the lumpectomy cavity—different from traditional whole breast radiation, which delivers multiple small doses over many days.
Based on the results of a large clinical trial, focusing the radiation on the tumor bed, IORT has been shown to be as effective as whole breast radiation for selected patients with early stage breast cancer: the rate of cancer recurrence is comparable after both forms. The study also showed the risk of skin toxicity is decreased after IORT compared to conventional radiation therapy.
Intraoperative radiation therapy is significantly less costly than standard whole breast radiation treatment. And with fewer trips made to the hospital for radiation therapy planning and radiation therapy and less time spent in treatment, intraoperative radiation therapy provides a significant boost to the quality of life for patients with early stage breast cancer.
Where Are They Now
IORT for a subset of breast cancer patients is a great alternative to save time and stress caused by traditional whole breast external beam radiation therapy, which usually consists of multiple sessions over a course of 3 weeks. However, recurrence rates for IORT patients were found to be at least double those of EBRT patients, and doctors are exercising caution while awaiting long-term study results before adopting this new method as a standard of care.