Patients Who Have Left Breast Tumors Have Comparable OS to Those with Right Breast Tumors

“Tumor laterality (left-side vs. right-side) does not impact overall survival in breast cancer patients treated with breast-conserving surgery and adjuvant external beam radiation therapy, according to a study published in the October 1, 2014 issue of the International Journal of Radiation Oncology • Biology • Physics (Red Journal), the official scientific journal of the American Society for Radiation Oncology (ASTRO).

“Studies have shown that breast cancer patients treated with radiation therapy have improved local-regional recurrence, and breast cancer-specific survival after breast-conserving surgery and overall survival (OS) after mastectomy. Long-term follow-up of historic radiation therapy trials for breast cancer has demonstrated a potential increase in cardiac mortality. However, these studies used earlier modes of radiation therapy including Cobalt and orthovoltage radiotherapy, and did not employ CT-based planning, which allows for greater cardiac avoidance. Three recent studies suggest that cardiac mortality has not been greater for patients treated for left-sided breast cancer since the 1980s, when techniques allowing for greater cardiac avoidance became more commonplace[1-3].

“This study, ‘Breast Cancer Laterality Does Not Influence Survival in a Large Modern Cohort: Implications for Radiation-Related Cardiac Mortality,’ examines the impact of tumor laterality on overall survival in a modern cohort of patients from the National Cancer Database (NCDB). The NCDB, a joint project of the Commission on Cancer of the American College of Surgeons and the American Cancer Society, contains deidentified data from approximately 70 percent of newly diagnosed cancers in the United States. The NCBD is more than two times larger than the Surveillance, Epidemiology and End Results (SEER) database, and the NCBD contains data not found in SEER, including histopathologic data and specific treatment information such as sequencing of therapies, dose, technique (e.g., intensity modulated radiation therapy vs. brachytherapy) and target (e.g., breast only vs. breast and regional nodes).”