Top Line: What is the risk of second malignancy after breast radiation in patients with TP53 mutation?
The Study: Patients with pathogenic TP53 variants are felt to be at higher risk of second malignancy and radiation-induced malignancy. However, the data describing the risk of second malignancy after RT are limited. This study identified 61 breast cancer patients with pathogenic TP53 variants. Among these, 45.9% received adjuvant radiation. Patients who received radiation were more likely to have high grade disease, higher T stage, and lymph node involvement. The median age of patients receiving RT was 35. Pathogenic TP53 variant carriers who received RT had an 8.8% risk of developing an in-field sarcoma over 15 years. In a propensity matched cohort without TP53 variants, there were no in-field sarcomas. However, the risk of an in-field cancer was outweighed by the overall risk of any second cancer. At 10 years, the cumulative incidence of any second cancer among those with a pathogenic TP53 variant was 22.5% in those who received breast RT and 38% in those who didn’t. This data can be used to guide discussions of risk and benefit in breast cancer patients who need adjuvant RT.
TBL: In this series, breast cancer patients with pathogenic TP53 variants had an 8.8% risk of radiation induced breast sarcoma. However, this risk was considerably lower than the overall risk of second cancer unrelated to radiation therapy. | Cederquist, JAMA Oncol 2024
The Study: Patients with pathogenic TP53 variants are felt to be at higher risk of second malignancy and radiation-induced malignancy. However, the data describing the risk of second malignancy after RT are limited. This study identified 61 breast cancer patients with pathogenic TP53 variants. Among these, 45.9% received adjuvant radiation. Patients who received radiation were more likely to have high grade disease, higher T stage, and lymph node involvement. The median age of patients receiving RT was 35. Pathogenic TP53 variant carriers who received RT had an 8.8% risk of developing an in-field sarcoma over 15 years. In a propensity matched cohort without TP53 variants, there were no in-field sarcomas. However, the risk of an in-field cancer was outweighed by the overall risk of any second cancer. At 10 years, the cumulative incidence of any second cancer among those with a pathogenic TP53 variant was 22.5% in those who received breast RT and 38% in those who didn’t. This data can be used to guide discussions of risk and benefit in breast cancer patients who need adjuvant RT.
TBL: In this series, breast cancer patients with pathogenic TP53 variants had an 8.8% risk of radiation induced breast sarcoma. However, this risk was considerably lower than the overall risk of second cancer unrelated to radiation therapy. | Cederquist, JAMA Oncol 2024