Evidence-based clinical guidelines recommending postmastectomy radiation therapy (RT) for women with advanced breast cancer were not followed for almost half of a group of 5,000 seniors, according to an article published online June 27 in Cancer.
Researchers from MD Anderson Cancer Center at the University of Texas conducted a study using the U.S. National Cancer Institute's (NCI) Surveillance, Epidemiology, and End Results (SEER) Medicare database to determine if postmastectomy RT use had increased in response to evidence-based guidelines recommending the treatment.
In a patient cohort of 4,978 women (66 years and older) who had undergone a mastectomy for high-risk invasive breast cancer between 1999 and 2005, the researchers found that guidelines were ignored for 45% of the group.
From 1996 through 1998, the percentage of these patients who received postmastectomy RT increased from 36.5% to 57.7%, an increase the researchers attributed to the publication of landmark clinical trials. Organizations including the NCI, the American Society of Clinical Oncology (ASCO), and the National Comprehensive Cancer Network (NCCN) published a series of evidence-based guidelines on postmastectomy RT use between 1997 and 2002, based on randomized, controlled trials that showed it decreased locoregional recurrence and improved survival rates among high-risk breast cancer patients.
However, from 1999 through 2005, only 55% of patients in the study group received radiation therapy. Within this high-risk group, patients with smaller tumors or less advanced lymph node involvement were at risk for postmastectomy RT omission, according to lead author Dr. Benjamin D. Smith, associate professor of radiation oncology, and colleagues.
Further research is needed to determine why postmastectomy RT was excluded for these patients, according to the researchers. They suggested that barriers to care may include transportation limitations, access to care, and access to radiation oncologists.
