Evaluating the risk factors associated with radiation skin irritation after radiotherapy in patients with breast cancer

This study evaluated the risk factors associated with acute radiation dermatitis (ARD; skin irritation) after radiotherapy (RT) in patients with breast cancer (BC). The data showed that patients with diabetes, smokers, and those with a body mass index (BMI; a measure of body weight in relation to height) of more than 25 kg/m² had a significantly higher risk of developing ARD while hypofractionated RT reduced the risks of ARD in these patients.

Breast cancer (BC) is one of the most common forms of cancer in women. Treatments for BC usually involve a combination of surgery, chemotherapy, and radiotherapy (RT). Chemotherapy is commonly given before the surgical treatment to reduce tumor size. This allows surgeons to use breast-conserving surgery (BCS) instead of breast-removal surgery (mastectomy). BCS involves the removal of the tumor only, with the preservation of the breast. RT is commonly used following BCS to destroy any remaining cancer cells.

RT targets tumor cells resulting in cell damage and death. RT also affects healthy tissues surrounding the tumor. Acute radiation dermatitis (ARD) is one of the most common side effects after RT in BC patients. It negatively affects patients’ quality of life. The patient may have skin changes ranging from reddening, peeling skin, death of skin cells, and ulceration. Some studies have reported several risk factors that can predict BC patients who are at a high risk of ARD. However, there are few studies evaluating both patient-related and treatment-related risk factors associated with ARD in women with BC after RT.

This study analyzed 38 studies and involved 15,623 patients with BC. These patients previously underwent BCS for early-stage BC and mastectomy for late-stage BC and were recommended RT.

Patients with a BMI of more than 25kg/m², those with a large breast volume, a habit of smoking, and diabetes had a significantly higher risk of developing ARD.

Hypofractionated RT involves a shorter course of treatment (4-6 weeks) with larger doses of radiation delivered in each treatment. Hypofractionated RT reduced the risk of ARD in patients by 72% compared to conventional fractionated RT (using small doses of radiation 5 times a week for 6-8 weeks).

Other factors such as chemotherapy regimens, hormone therapy, biological therapy like trastuzumab (Herceptin), and RT to the nodes were not associated with ARD.

This study showed that patients with a BMI of more than 25 kg/m², those with diabetes, smokers and those with large breast volumes had a significantly higher risk of developing ARD while hypofractionated RT reduced the risks of ARD in patients with BC.

The number of studies analyzed was very small. This study only evaluated the risk factors associated with ARD. Other side effects of RT such as inflammation of the lung tissue, inflammation of the esophagus need to be explored.