Complete response to chemoimmunotherapy in a patient with metastatic squamous cell non-small cell lung cancer: A case report

Non-small cell lung cancer (NSCLC) is a common type of malignant neoplasm that is the leading cause of cancer death worldwide. In the Russian Federation, according to statistical reports, there is also an increase in morbidity. Squamous cell histological variant of NSCLC is detected in 25–30% of lung cancer cases and belongs to unfavorable subtype. More than 10 years ago, chemotherapy was approved the treatment for metastatic squamous cell NSCLC only. In the era of checkpoint inhibitors, the number of treatment options for NSCLC has increased. The results of a double-blind, randomized, placebo-controlled phase III trial of KEYNOTE-407 showed undoubtedly better efficacy of the combination of pembrolizumab + chemotherapy compared with chemotherapy and placebo in patients with metastatic squamous cell carcinoma in terms of median progression-free survival –8.0 versus 5.1 months and median overall survival – 17.1 versus 11.6 months. This article presents a clinical observation efficacy combination of pembrolizumab and standard chemotherapy for the treatment of metastatic squamous cell NSCLC with high tumor burden. A significant reduction in disease symptoms and partial response were recorded after two courses of chemoimmunotherapy. Complete response achieved after four courses. Maintenance therapy with pembrolizumab was prescribed. According to the results of chest CT scans in March 2025, a complete response was maintained. Combination of pembrolizumab and chemotherapy in real clinical practice of therapy of a patient with a big tumor burden of squamous cell NSCLC demonstrates high efficacy in the treatment.