Is Radiation a Good Decision?
The ability of radiation therapy (RT) to lower risk for local breast cancer recurrence (LR) after breast-conserving surgery is disputable. Even though it is highly recommended and most commonly performed, a recent study titled, “Is Radiotherapy Unnecessary for Some Breast Cancer Patients?” revealed some startling information. Some breast cancer types actually have a near four fold increase in cancer reoccurrence should radiation be performed. For example, prior reports have suggested that patients with luminal A molecular subtype tumors — defined as estrogen receptor (ER)-positive, progesterone receptor (PR)-positive, human epidermal growth factor receptor 2 (HER2)-negative, low proliferative rate, and low-to-intermediate nuclear grade — may have such a low baseline risk for LR that RT is unnecessary. So, is radiation a good idea?To examine this issue further, investigators conducted a reanalysis of the Toronto–British Columbia (TBC) trial (N Engl J Med 2004; 351:963) involving 769 women aged ≥50 with an invasive axillary node–negative adenocarcinoma (≤5 cm) who were randomized to tamoxifen with or without RT after lumpectomy. The researchers performed immunohistochemical analysis of six biomarkers (ER, PR, HER2, cytokeratin 5/6, epidermal growth factor receptor, and Ki-67) on 501 tumor samples, of which 265 were molecular subtype luminal A, 165 were luminal B, and 71 were high-risk (luminal-HER2, HER2-enriched, basal-like, or triple-negative nonbasal).
Rates of 10-year LR were 5.2% for luminal A, 10.5% for luminal B, and 21.3% for high-risk tumors. The interaction between tumor subtype and treatment was not significant. Luminal A patients with low-risk clinical features (age >60, T1 stage, grade 1 or 2 histology) had a 10-year LR rate of 1.3% with tamoxifen alone versus 5.0% with tamoxifen plus RT.
What does this mean?
- Breast cancer patients that are estrogen receptor (ER)-positive, progesterone receptor (PR)-positive, human epidermal growth factor receptor 2 (HER2)-negative, low proliferative rate, and low-to-intermediate nuclear grade should reconsider RT use.
- Radiation therapy for breast cancer may actually INCREASE reoccurrence rates.
Dr. Conners graduated with his doctorate from Northwestern Health Sciences University in 1986 and has been studying alternative cancer care for over 20 years. He holds AMA Fellowships in Regenerative & Functional Medicine and Integrative Cancer Therapy.
He is the author of numerous books including, Stop Fighting Cancer and Start Treating the Cause, Cancer Can’t Kill You if You’re Already Dead, Help, My Body is Killing Me, Chronic Lyme, 3 Phases of Lyme, 23 Steps to Freedom, and many more you can download for FREE on our books page.