Concurrent administration of anti-HER2 therapy and radiotherapy: Systematic review

Over the past few years, anti-HER2 targeted therapies have proven to be a key treatment in the management of human epidermal growth receptor 2 (HER2)-positive breast cancers, as well as gastrointestinal tract tumors and head and neck tumors. Anti-HER2 therapies administered alone or in combination with chemotherapy have been extensively studied, but only limited robust data are available concerning the safety and efficacy of anti-HER2 molecules in combination with radiotherapy.

We searched on Medline, Embase and Cochrane databases the articles providing data on the concomitant association between the antiHER2 therapies used in clinical practice (trastuzumab, pertuzumab, lapatinib and T-DM1) with radiotherapy. The articles were selected according to their pre-clinical and clinical relevance.

The trastuzumab-irradiation combination is the most studied, with a focus on the cardiac toxicity. The combination of lapatinib-irradiation was particularly studied in the context of cerebral metastases of HER2-positive breast cancer. The data on pertuzumab and T-DM1 were poor and are mainly case reports.

To date, reliable conclusions about the toxicity and/or efficacy of concomitant irradiation with anti-HER2 therapies are difficult to make due to the heterogeneity of the data in the literature and need to be confirmed on a larger scale and long term follow-up. Nevertheless, no serious adverse events are reported and the toxicity profile seems to be manageable.