Marked local and distant response of heavily treated breast cancer with cardiac metastases treated by combined low dose radiotherapy, low dose immunotherapy and hyperthermia: a case report

Breast cancer (BC) with cardiac metastases (CMs) is often associated with poor prognosis due to late stage of diagnosis. Palliative radiotherapy (RT) for CMs is generally used for symptomatic treatment and to maintain normal cardiac function. Palliative RT with hyperthermia (HT) or immunotherapy have been reported to be effective in prolonging the overall survival and progression-free survival in metastatic patients. In this case report, we present a heavily pretreated 51-year-old lady of metastatic BC presented with recurrent right breast mass with progressive exertional dyspnea caused by symptomatic CM. She received combined palliative low-dose palliative RT [20 Gray (Gy) in 12 fractions], combined with lowdose chemotherapy, biweekly HT treatment course, and low-dose "double blockade" immunotherapy by ipilimumab (0.3 mg/kg) and nivolumab (0.5 mg/kg). The irradiated right chest tumors responded rapidly to treatment. Interestingly, unirradiated metastatic lesions outside the RT and HT treatment field also demonstrated a sustained abscopal response. She continued monthly low-dose immunotherapy in conjunction with HT after RT. The posttreatment cardiac echography disclosed considerably reduced pericardial effusions without cardiac wall motion abnormalities. She remained stable for more than 6 months with no notable treatment-related toxicities. The combination of low-dose RT, low-dose immunotherapy, and HT protocol appears to be a safe method with promising efficacy in metastatic BC patients.