Radiation therapy in breast cancer linked to increased risk of melanoma and hemangiosarcoma: JAMA

This study was published in the journal JAMA Network Open by Shawheen J. and colleagues. Radiation therapy is a common treatment modality for breast cancer, but its potential long-term effects on skin health have been a subject of concern.

This study utilized longitudinal data from the Surveillance, Epidemiology, and End Results (SEER) Program, covering the period from January 1, 2000, to December 31, 2019. Patients with newly diagnosed breast cancer were identified, and subsequent development of nonkeratinocyte skin cancers was evaluated. Standardized incidence ratios (SIRs) were calculated to assess the risk of nonkeratinocyte skin cancer development based on treatment type (radiation therapy, chemotherapy, or surgery), skin cancer site, and subtype.

Key Findings:

• The study included 875,880 patients with newly diagnosed breast cancer, of whom 50.3% received radiation therapy.

• From 2000 to 2019, 3,839 patients developed nonkeratinocyte skin cancers after breast cancer treatment, including melanoma (89.1%), Merkel cell carcinoma (3.2%), hemangiosarcoma (2.7%), and other subtypes.

• The risk of nonkeratinocyte skin cancer diagnosis after breast cancer treatment with radiation was 57% higher (SIR, 1.57 [95% CI, 1.45-1.7]) compared to the general population, particularly on the skin of the breast or trunk.

• Stratified by skin cancer subtype, the SIRs for melanoma and hemangiosarcoma were both statistically significant, indicating an elevated risk associated with radiation therapy.

• Radiation therapy was associated with a greater risk of nonkeratinocyte skin cancer compared to chemotherapy and surgical interventions.

This study provides evidence of an increased risk of melanoma and hemangiosarcoma following breast cancer treatment with radiation therapy. Although occurrences of nonkeratinocyte skin cancers are rare, physicians should be aware of this elevated risk to facilitate appropriate follow-up care and surveillance strategies for patients who have undergone radiation therapy for breast cancer.

Reference:

Rezaei, S. J., Eid, E., Tang, J. Y., Kurian, A. W., Kwong, B. Y., & Linos, E. Incidence of nonkeratinocyte skin cancer after breast cancer radiation therapy. JAMA Network Open,2024;7(3):e241632. https://doi.org/10.1001/jamanetworkopen.2024.1632