Guidelines from the National Comprehensive Cancer Network (NCCN) and the American Society of Clinical Oncology (ASCO) recommend post-mastectomy radiation therapy (PMRT) for women with N2/N3 breast cancer. However, according to a recent study published in the Journal of the American College of Surgeons, not all women are getting access to PMRT.
Evidence from previous research studies have shown that PRMT diminishes breast cancer recurrence risk, and also improves survival in women in advanced cancer stages (N2/N3, meaning four or more organs spread).
To further examine the compliance rate of PMRT, in their study titled “Post-mastectomy Radiation for N2/N3 Breast Cancer: Factors Associated with Low Compliance Rate,” the research team led by Quyen D. Chu, MD, MBA, FACS, professor of surgery at Louisiana State University (LSU) Health Sciences Center, Shreveport, evaluated 56,990 women with N2/N3 breast cancer. The population was retrieved from a large database comprising 2,720,368 breast cancer cases diagnosed between 1998 and 2011.
Results revealed that women (mean age of 58 years) were followed for a median period of 61 months. Nearly 82% of these women were treated with chemotherapy, however, only 65% had access to PMRT.
Neither socioeconomic factors, geographic characteristics such as treatment facility, nor the type of cancer program accounted for the non-compliance with PMRT. Results also revealed that factors associated with PMRT use were tumor grade, regional lymph node surgery, readmission within 30 days of surgical discharge, receipt of chemotherapy and hormonal therapy, and 30-day mortality. Using Multivariate analyses, the researchers found that receipt of chemotherapy, readmission within 30 days after surgery, and being alive within 30 days after surgery were all predictors of compliance with PMRT. Based on these results, a third of patients with N2/N3 disease did not receive PMRT, and non-compliance to PMRT is related to lack of receipt of chemotherapy, non-readmission ,or death within 30 days after surgery.
“My colleagues and I were quite startled by the finding that a third of patients with N2/N3 disease did not receive PMRT, which is the standard of care,” said lead author Quyen D. Chu, MD, MBA, FACS, professor of surgery at Louisiana State University (LSU) Health Sciences Center, Shreveport.
“From this study, we could not tease out whether patients refuse treatment or there is a lack of awareness among women and physicians about the need for radiation therapy after mastectomy for locally advanced breast cancer,” Dr. Chu said in the news release. “If women with N2/N3 breast cancer who plan a mastectomy are not offered PMRT, they should ask their physician why.”
Last November, the CoC began to use a measure that assesses the percentage of women who are eligible in each CoC-accredited program receiving PMRT, said CoC Chair Daniel P. McKellar, MD, FACS, a general surgeon in Greenville, Ohio.
Dr. McKellar said in the news release that some recently diagnosed breast cancer patients are surprised to learn that if they have a mastectomy, they sometimes will need radiation therapy afterward.
Women who had prior radiation therapy or have connective tissue disorders are exceptions for PMRT in women with advanced cancer stages.
“This study by Dr. Chu’s group illustrates an important issue regarding dissemination of new research findings and implementation into clinical practice,” Dr. McKellar said. “On average, it takes nine years from the time a new intervention is recommended as an evidence-based practice to when it is fully adopted.5 The Commission on Cancer is working to shorten this gap for all types of cancer.”