Elderly women with early-stage breast cancer who received adjuvant radiation therapy after lumpectomy surgery have improved cause-specific survival (CSS) compared to those patients who underwent surgery alone, according to research presented today at the American Society for Radiation Oncology’s (ASTRO’s) 54th Annual Meeting.

Additionally, the data suggests that patients who have a life expectancy of at least 10 years after diagnosis and treatment benefit in local tumor control and in overall survival if they receive adjuvant radiation therapy.

This study evaluated the records of 29,949 women from the Surveillance, Epidemiology and End Results (SEER) database between 1990 and 2008, ages 70 to 84, diagnosed with clinical stage I, estrogen receptor positive (ER+) breast cancer who underwent lumpectomy with or without adjuvant radiotherapy and who survived at least one year after initial diagnosis.

Seventy six percent of the patients (22,781) received adjuvant radiation treatment. The median survival was 13.1 years for patients treated with surgery and radiation and 11.1 years for patients receiving surgery alone. CSS after five years was statistically significant at 98.3 percent for patients who received adjuvant radiation treatment compared to 97.6 percent of patients who received surgery alone.

After 10 years, CSS was 95.4 percent for patients who received adjuvant radiation compared to 94.3 percent of patients who received surgery alone. At five, 10 and 15 years, the overall survival (OS) of patients was 89.5 percent, 66.8 percent and 40.8 percent, respectively, for those treated with surgery and radiation, compared to 83.0 percent, 56.1 percent and 30.2 percent for those treated with surgery alone.

The Kaplan-Meier method was used to calculate CSS and OS. As women aged, the use of radiation therapy decreased?accounting for 80 percent of women aged 70-74, 74 percent of women aged 75-79 and 61 percent of women aged 80-84.

This study furthered results of a previous Cancer and Leukemia Group B (CALGB) study that examined the addition of radiation to lumpectomy and tamoxifen in women age 70 and older with clinical stage I, ER+ breast cancer.

The CALGB study included 636 patients; 317 patients, or almost 50 percent, were treated with adjuvant radiation therapy. The study concluded an absolute reduction of six percent in ipsilateral breast tumor recurrence with the use of radiation at a median follow-up of 10.5 years, but there was no improvement in CSS or OS.

“Our study reviewed a large population and found that elderly women with early-stage breast cancer who were treated with adjuvant radiation after surgery had an improvement of their breast cancer survival rate, which suggests that radiation, for appropriate elderly women, should be strongly considered as part of their treatment plan,” said Randi J. Cohen, MD, lead author of the study and a radiation oncologist at the University of Maryland in Baltimore. “A woman’s age alone should not impact whether or not radiation treatment is presented as a viable treatment option.”

The abstract, “Improved Survival with Adjuvant Radiation in Elderly Women with Early-Stage Breast Cancer,” was presented in detail during a scientific session at ASTRO’s 2012 Annual Meeting.

Source: ASTRO