Key Point

• Small cell lung cancer (SCLC) represents approximately 15% of lung cancer cases.
• SCLC is generally divided into two functional stages, limited (LS-SCLC) and extensive (ES-SCLC). Limited-stage is disease confined to a single radiation port – within one hemithorax with or without involvement of lymph nodes in the mediastinum. Extensive stage is disease beyond those confines, generally outside the chest or with contralateral chest involvement. LS-SCLC median overall survival is 20 months, 1-year survival 60%, 5-year survival 20%. ES-SCLC median overall survival is 13 months, 1-year survival 54%, 5-year survival 1%. In the 8th edition of the AJCC staging manual, TNM staging is now applied to small cell lung cancer but most clinicians continue to use the old system.
• The standard treatment for LS-SCLC is chemotherapy (e.g. etoposide/platinum) and concurrent chest radiotherapy, followed by PCI in responding patients; this is associated with a long-term survival rate of 15% to 20%. Stage I(small tumor, node-negative) cases can be approached with surgical resection followed by adjuvant systemic chemotherapy with four cycles of cisplatin and etoposide.
• Standard therapy for ES-SCLC is systemic chemotherapy (e.g., four cycles of etoposide/platinum) with immunotherapy (anti-PD-L1 antibodies atezolizumab or durvalumab) followed by maintenance immunotherapy.
• Despite high response rates to initial chemotherapy and radiation, more than 80% of patients relapse and die within 1 to 2 years.
• Patients with resected SCLC, any stage, should be offered adjuvant chemotherapy (e.g., four cycles of etoposide/platinum).
• Median survival time at relapse after first-line therapy is approximately 6 months.
• Second-line chemotherapy (e.g., topotecan, lurbinectedin, CAV, temozolomide) can prolong survival and improve symptoms.
• Surgical intervention is rarely considered in the management of SCLC, but there are several instances where surgery may be indicated, including in stage I disease, for mixed-histology tumors (10%-15%), for second primary tumors (often non-SCLC), and large, isolated and symptomatic brain metastases.
• Age alone should not be a primary determinant in the decision to treat. Fit, older patients should be considered candidates for combination chemotherapy and thoracic radiation.