Pertuzumab and Trastuzumab Combination with Concomitant Locoregional Radiotherapy for the Treatment of Breast Cancers with HER2 Receptor Overexpression.

BACKGROUND: The combination of pertuzumab and trastuzumab dual HER2 blockade with concomitant curative dose locoregional breast radiotherapy in patients with metastatic breast cancer is an important part of treatment strategy. METHODS: This was a retrospective study conducted at the Institut Curie on all patients treated concomitantly with pertuzumab/trastuzumab and locoregional breast radiotherapy. Toxicity was evaluated according to the NCICTCAEv4.0. Overall survival, progression-free survival and locoregional recurrence-free survival were evaluated in metastatic patients who were initially well controlled by chemotherapy, for whom local treatment was decided by the multidisciplinary team. RESULTS: Fifty-five patients treated between October 2013 and December 2019 were included, with a median follow-up of 4.1 years. The median age was 53 years (range: 28-81). All patients received curative dose radiotherapy (RT) concomitantly with pertuzumab and trastuzumab (Pertu/Trastu). The median radiation dose was 50 Gy. Safety evaluation did not reveal any significant adverse effects, with 3 cases of grade 3 radiodermatitis (5.4%), but no significant gastrointestinal or cardiac toxicity. The mean difference in LVEF before any chemotherapy and after radiotherapy was -2.43% (p < 0.01). CONCLUSIONS: This study demonstrates that the combination of locoregional breast RT with dual HER2 blockade by Pertu/Trastu was very well tolerated, suggesting that RT can be safely administered to patients with HER2-positive breast cancer.

Bilateral parotid gland metastasis from a breast invasive ductal carcinoma.

Metastases to the parotid gland are very rare. We report the second case of bilateral metastases to the parotid gland from a breast invasive ductal carcinoma. A 50-year-old female was treated for an early left breast cancer in 2007. A pulmonary metastatic relapse was diagnosed in 2013. A metastatic skin extension required several lines of treatment from June 2014 to July 2016. Bilateral parotid gland metastases from a breast invasive ductal carcinoma were confirmed in December 2016. The patient died on May 2017 from cerebral metastases. Only 16 cases of metastasis to the parotid gland from breast cancer have been reported in the literature. Only one case had a bilateral involvement. Prognosis is poor, and there are no specific guidelines for the treatment.