Systemic therapy for lung cancer

Abstract

The standard of care for early stage non-small cell lung cancer is surgery. However, even though it is at an early stage, more than half of the patients present with local recurrences or systemic metastases within the first 2 years. In order to prevent such possibilities, adjuvant treatment is suggested. Doublet regimens that include platinum are the most commonly used ones. Even though the benefit of such treatment for stage IA is not proven, it is highly recommended for stages IB, II, and resected III. If the treatment is performed prior to surgery, it is called neoadjuvant chemotherapy. Such treatment is mostly prescribed to patients who have local progressive disease. For stages IIIA and IIIB, neoadjuvant treatment with or without radiotherapy or induction chemotherapy is performed. NSCLC patients are mostly diagnosed at later stages (stage IV), and in such cases, platinum-based systemic chemotherapy is recommended. However, in the light of the latest researches, targeted therapies depending on the molecular specialties are introduced as the first line of treatment. For patients with EGFR-mutated nonsquamous adenocarcinoma subtype, erlotinib, gefitinib, and afatinib and for ALK-mutated patients, crizotinib can be prescribed. The standard of care as the second-line treatment is docetaxel, pemetrexed, and erlotinib. For the nonsquamous subtypes, it is shown that anti-VEGFR treatments increase the response rates, prolonging the overall survival. Recently, checkpoint inhibitors (PD-1 and PDL-1 inhibitors) have been introduced, showing an increase in the overall survival.