Mercy Utilizes Single-Dose Breast Cancer Radiotherapy For Older Americans

(Baltimore, MD)  – For decades, the National Comprehensive Cancer Network (NCCN) recommended forgoing post-lumpectomy radiation therapy for women over the age of 70, believing that the patient’s natural life expectancy was shorter than the chance the cancer would recur in 5 or 10 years. While the governing body has recently revised these guidelines, many in the oncology community still hesitate to endorse External Beam Radiation Therapy (EBRT) for elderly patients because of potential side effects such as skin rashes and blistering or fear the treatment will exacerbate existing comorbidities such as heart disease and emphysema.

This National Senior Citizens Day, Sat., August 21st, Mercy Medical Center is emphasizing that there is another option besides the difficult decision between the secondary risks that come with weeks of daily external radiation or no radiation at all. Intraoperative Radiation Therapy (IORT) is a single dose of targeted radiation delivered from inside the breast while the patient remains asleep immediately following the removal of the tumor. The 20-year TARGIT-A international clinical trial compared IORT to EBRT, and long-term data consistently demonstrated no difference in local and distant breast cancer control, breast preservation, and breast cancer mortality.

“Treating breast cancer in senior citizens can present a special challenge for physicians, having to weigh the positive outcomes of post-operative radiation treatment verses the side effects specifically detrimental to older patients,” said Maria C.E. Jacobs, M.D., Director of Radiation Oncology at Mercy. “IORT addresses this issue. Unlike traditional whole breast radiation which may impact surrounding tissues, IORT only impacts the tumor bed. This makes IORT an especially appropriate treatment for older patients who may need to consider certain comorbidities that increase with age.”

The current average life expectancy for women in the United States is over 81 years. The NCCN now advises those treating older adults to define them “based on functional status rather than chronologic age… Advanced age alone should not be the only criterion to preclude effective treatment that could improve quality of life (QOL) or lead to survival benefit in older patients.

EBRT involves treating the entire breast from the outside and although the radiation therapy is directed to the breast rather than the surrounding tissues, the proximity of the heart, lungs and skin limit the dose of radiation that can be given at any one time. This leads to a prolonged treatment course of 3-6 weeks following surgery. The IORT treatment administers the radiation dose from inside the breast precisely where it is needed, allowing the radiation oncologist to deliver a much higher dose at one time.

The effectiveness of IORT was investigated in an international study called the TARGIT-A Trial, in which the Intrabeam^® System from ZEISS was used. Following lumpectomy, the randomized clinical trial compared risk-adapted partial breast single dose targeted intraoperative radiotherapy to 3-6 weeks of post-operative whole breast radiotherapy. Long term follow-up of 2,298 patients in the US, UK, Europe, Canada, and Australia demonstrated no difference in the long-term survival without local recurrence; survival without a mastectomy; and survival without distant metastatic disease. In addition, there were 41% fewer deaths from other causes (such as cardiovascular causes and other cancers).

References

1. National Comprehensive Cancer Network. Breast Cancer (Version 5.2020), July 15, 2020

https://www.nccn.org/professionals/physician_gls/pdf/breast.pdf

2. “Radiation for Breast Cancer,” American Cancer Society, September 18, 2019

https://www.cancer.org/cancer/breast-cancer/treatment/radiation-for-breast-cancer.html

3. “Long term survival and local control outcomes from single dose targeted intraoperative radiotherapy during lumpectomy (TARGIT-IORT) for early breast cancer: TARGIT-A randomized clinical trial,” BMJ, August 19, 2020

https://www.bmj.com/content/370/bmj.m2836.full.pdf

4. National Comprehensive Cancer Network. Older Adult Oncology (Version 1.2021), January 2021

https://www.nccn.org/professionals/physician_gls/pdf/senior.pdf