Radiation to the lymph nodes in stage II and II breast cancer; is it necessary?

The authors aimed to assess the effectiveness of radiotherapy treatment (uses high-energy radiation to kill cancer cells by damaging their DNA) on women with breast cancer who have previously had surgery.

Breast- conserving surgery (removes the breast cancer but not the breast itself) is just one method of breast cancer treatment. Radiotherapy is often administered to the breast following these treatments to ensure complete removal of the cancer cells. Elective nodal irradiation (ENI) is radiotherapy where radiation is further delivered to lymph nodes (tiny bean shaped organs, often the first site to which cancer will spread) even if cancer is not found to be present, in order to prevent cancer spreading to these lymph nodes. 

It is as yet unclear whether the addition of radiation to these lymph nodes is required, regardless of whether cancer is present in the lymph nodes.

The aim of this study was to determine if the use of ENI following breast-conserving surgery could improve a patients prognosis (treatment outlook).

A total of 260 women with stage II or III breast cancer were evaluated, all of whom had received breast-conserving surgery and various forms of radiotherapy. 77% of the women had also received chemotherapy before surgery. 136 of the women were allocated to a course of ENI while 124 of the women were not. 96% of these women had some lymph node involvement.

Overall, the study showed that the ENI treatment had no significant effect on the survival of these women. The survival rates after 5 years were 96%. There was no significant difference in the rates of cancer recurrence (return of the cancer) between the two treatment groups.

The authors concluded that additional ENI treatment had no significant effect on the survival of the women with stage II or III breast cancer with lymph node involvement.

The patients included in this study were from multiple medical institutions.

If considering elective nodal irradiation, talk to your doctor about the risk-benefit balance of increased toxicity associated with radiation compared to survival outcomes.