Highlights on the morphology, prognostic factors, diagnostics, and treatment (chemotherapy, chemotherapy + radiation, targeted therapy, immunotherapy, and surgery) in small cell lung cancer

The article present a review and experience from a a single institution on the morphology, diagnostics, and treatment (chemotherapy, radiation, targeted therapy, and immunotherapy)) of small cell lung cancer (SCLC). The characteristic molecular, genetic, histological, and immunohistochemical features of NSCLC and SCLC are compared. An important issue of SCLC histogenesis is highlighted, taking into account its neuroendocrine characteristics. Paraneoplastic syndromes associated with SCLC and other clinical features of SCLC are discussed. The algorithm of examination of a patient with histologically or cytologically confirmed SCLC, staging schemes, and main prognostic factors are presented. The following aspects of chemoradiotherapy of localized SCLC are considered: features of “early,” ”late,” simultaneous, and sequential therapy, and the need for whole brain radiotherapy in patients with localized and extensive SCLC. The article discusses the treatment algorithm for extensive disease SCLC, taking into account the recent success of chemoimmunotherapy in the first-line treatment of SCLC. As is known, the combinations of atezolizumab, etoposide, carboplatin and durvalumab, etoposide, cisplatin, or carboplatin showed a real benefit compared to chemotherapy alone. Although the second line treatment has not changed, it is now possible to prescribe a third line therapy because of the proven effectiveness of immunotherapy. Targeted therapy, although not shown to be effective in SCLC, is discussed in terms of the key features of genetic alterations as a possible target for therapy. An important issue in the treatment of patients with superior vena cava syndrome is considered separately. The tasks of future prospective research in SCLC are described.