Radiation-Induced Lung and Breast Cancers Remain Rare Despite Screening

Research into radiation-induced secondary malignancies indicates that the risk of developing primary lung cancer following radiation therapy for breast cancer is significantly lower than previous studies had suggested.

According to a study published October 31, 2023, in JTCVS Open, the increased risk of developing a primary lung cancer secondary to radiation therapy (RT) exposure for breast cancer has decreased. The researchers noted that this updated risk profile is an important factor for the surveillance and counseling of breast cancer patients.

The improvement in the risk profile is attributed in part to the implementation of modern radiation therapy techniques.

Mechanisms of Secondary Malignancies

Secondary malignancies are categorized as late complications of radiation treatment for primary cancers. These malignancies occur through DNA damage caused by the radiation process.

A review published via ScienceDirect highlights that several tissues are particularly vulnerable to this radiation damage. Following breast cancer radiation, there is an increased risk for developing secondary malignancies in the following areas:

• Lung cancer
• Esophageal cancer
• Contralateral breast cancer

Radiation-Induced Lung Injury

Beyond the risk of secondary cancer, radiation treatment can lead to other pulmonary complications. A study published June 29, 2023, in Front Oncol, examined radiation-induced lung injury (RILI) within the CANTO-RT cohort.

The findings indicate that RILI is strongly associated with specific dosimetric parameters and various clinical conditions.

These findings, combined with the updated data on secondary lung cancer risks, assist medical professionals in managing the long-term health of patients who have undergone thoracic radiation.