The Role of Performance Status in Small-Cell Lung Cancer in the Era of Immune Checkpoint Inhibitors

After decades of platinum-based chemotherapy for advanced small-cell lung cancer, there has finally been a therapeutic advance. The combination of a platinum chemotherapy, etoposide, and an immune checkpoint inhibitor has yielded overall survival benefits in two successive phase 3 trials. Unfortunately, these trials only included fit patients, namely those with an Eastern Cooperative Oncology Group performance status of 0-1. In the real-world setting, roughly a third of patients with advanced small-cell lung cancer has a performance status of 2, and an additional 15% have a performance status of 3 or 4, meaning that approximately half of all patients are excluded from chemoimmunotherapy trials. Poor performance status is a known negative prognostic factor, with a dismal prognosis among patients with disease that does not respond to the first cycle of chemotherapy.We review current data on immunotherapy in advanced small-cell lung cancer and discuss how we integrate the new therapeutic options into daily practice.