Impact of immunotherapy on survival and treatment patterns of patients with extensive-stage small cell lung cancer: a study using a Japanese nationwide database

Although immune checkpoint inhibitor (ICI) therapy for patients with extensive-stage small cell lung cancer (ES-SCLC) has shown promising results in clinical trials, it is not as widely used as for other cancers. Thus, investigating the association between ICI therapy and overall survival and treatment patterns of patients with ES-SCLC provides a new perspective regarding the introduction of ICI.
This retrospective cohort study identified patients newly diagnosed with SCLC between January 2015 and January 2023 who received first-line treatment with etoposide from a nationwide database in Japan. Patients were divided into those who received ICI and conventional chemotherapy. Overall survival was assessed with a Cox proportional hazards model weighted by the inverse propensity score. The treatment patterns were visualized using a Sankey diagram.
Of the 4537 patients, 2433 received conventional chemotherapy and 2104 received ICI therapy. The hazard ratio for mortality with ICI therapy was 0.892 (95% CI, 0.797–0.998). Less than half of the patients received ICI therapy as first-line treatment. Older patients tended to receive conventional chemotherapy.
Compared with conventional chemotherapy, ICI therapy was associated with increased overall survival in patients with ES-SCLC. However, clinical implementation of ICI therapy was delayed, particularly in older patients.
Lung cancer is a serious disease, and many people die from it every year. One type of lung cancer, called extensive-stage small-cell lung cancer (ES-SCLC), grows very fast and is difficult to treat. In recent years, new medicines called immune checkpoint inhibitors (ICIs) have become available. These medicines help the body’s immune system fight cancer and have helped patients live longer than with older treatments.In this study, we looked at how ICIs are used in everyday medical care in Japan. We also examined if patients lived longer after ICIs became available. We found that patients who received ICI treatment lived longer on average than patients who received treatments without ICIs. However, many patients did not receive ICIs. Older patients were less likely to be treated with ICIs. Doctors chose treatments based on how well patients could manage daily activities and if they had other lung problems.These results show that ICIs can help patients with ES-SCLC live longer, but they are not suitable for everyone. More research is needed to help doctors choose the best treatment for different patients, especially older people and those with other health conditions.