Interrupted Systemic Therapy (Drug Holiday) for Metastatic Sarcoma: Is It Safe?

Sarcomas are a diverse group of rare, mesenchymal tumors that vary in terms of clinical behavior, aggressiveness, and responsiveness to treatment. The management of metastatic sarcoma is challenging and requires a multidisciplinary approach. Apart from a few subtypes of sarcomas that respond to targeted therapies, the vast majority of metastatic sarcomas are treated with chemotherapy regimens that have been unchanged for decades. These regimens are aggressive and cause clinically relevant toxicity. Despite this, treatment outcomes remain unsatisfactory and prognosis dismal. Metastatic disease is largely incurable, and new strategies are needed to simultaneously control metastatic disease while preserving patients' quality of life. For example, the optimal duration of palliative treatment for patients with metastatic sarcoma is unknown, as is the role and feasibility of planned treatment holidays. Whereas the benefit to patient quality of life from a treatment break can be easily predicted, it is not well understood the influence these treatment "holidays" have on overall survival (OS). Herein, we summarize the available literature on drug holidays in sarcoma and offer clinicians updated guidance for managing patients with metastatic disease.