Breast metastasis from primary lung cancer and its association with ablative radiotherapy: A case report

This is a case report of a patient with PD-L1 positive metastatic lung adenocarcinoma who underwent palliative and ablative dose radiotherapy directed to metastatic axillary nodal disease and went on to develop localized followed by diffuse breast and cutaneous metastases. This case serves as an example of the potential utility of ablative dose radiotherapy for controlling sites of progression and highlights the risk of ablative radiotherapy for altering lymphatic drainage and promoting retrograde spread of disease. Given the increased incidence of oligometastatic NSCLC, and the increased utilization of ablative dose radiotherapy to treat metastatic sites in this clinical setting, we believe that this article may inform clinical practice. Our results provide additional support for the utility of ablative dose radiotherapy for this patient population and highlight the need for clinicians to employ a patient-specific approach when deciding on treatment, understanding that the use ablative doses of radiotherapy may provide a better chance for radiologic control, but may come at the cost of an increased risk of altered lymphatic drainage and retrograde spread of disease. The case was overseen by a multidisciplinary team consisting of primary care, medical and radiation oncologists as well as palliative care physicians.