Comparing whole-breast radiotherapy and partial-breast radiotherapy for breast cancer patients who have undergone breast conservation surgery

This study aimed to compare the outcomes for patients who received whole and partial breast radiotherapy after undergoing breast conservation surgery.

This study concluded that partial breast radiotherapy and lower dose radiotherapy had similar outcomes for patients when compared to whole breast radiotherapy.

Surgery and radiation are common treatment options for breast cancer. Breast conservation surgery (BCS) is a less radical option compared to a mastectomy where the whole breast is removed. In BCS only part of the breast tissue is removed instead of the entire breast. Radiotherapy uses high-energy rays to kill cancer cells. It kills only cells in the area that is targeted by the radiation. It is often used for breast cancer patients after surgery has taken place. Whole breast radiotherapy is targeted at the whole breast. Partial breast radiotherapy targets a certain portion of the breast.

It was unknown what different outcomes would occur for patients who receive full breast radiotherapy and for patients who receive partial breast radiotherapy. 

This study involved 2016 women aged 50 and older with breast cancer who had undergone BCS. Patients were split into three groups and received different radiotherapy treatments. The control group received 40 Gy whole breast radiotherapy. Gy is a measure of radiation strength. The Gy value of radiotherapy used normally depends on the type and stage of cancer. The reduced dose breast group were treated with 36 Gy whole breast radiotherapy and 40 Gy to the partial breast. The partial breast group received 40 Gy to the partial breast only. Patients were followed for an average of 72.2 months.

The 5-year estimate of the incidence of relapse (cancer returns) for the control group was 1.1%. The estimate for the reduced dose group was 0.2% and the estimate for the partial breast group was 0.5%.

Similar adverse effects (side effects) were seen in the reduced-dose and partial-breast radiotherapy groups.  There was a lower incidence of adverse effects in these groups when compared to the whole-breast radiotherapy group. 

This study concluded that partial-breast and reduced-dose radiotherapy outcomes were comparable to whole-breast radiotherapy. 

Consult your physician about the differences between whole and partial breast radiotherapy.