Adjuvant therapy in early-stage small-cell lung cancer: what’s new?

Small-cell lung cancer (SCLC) represents approximately 15% of primary lung carcinomas. About 70% of patients are diagnosed as having extensive disease (ED) while in the other one third of patients, SCLC is diagnosed as limited disease (LD) (1). The prognosis of SCLC strongly depends on tumor stage. Staging of SCLC is traditionally based on the Veterans Administration Lung Study Group system, which classifies patients as having either LD [disease which is limited to one hemi-thorax, with hilar and mediastinal nodes that can be encompassed within one tolerable radiotherapy (RT) portal] or ED (when disease has progressed beyond any-type LD) (2). The new tumor-node-metastasis (TNM) version 7 staging system as adopted for non-small-cell lung cancer should also be used for SCLC. The current TNM staging system is based on 8,088 SCLC patients and provides better prognostic information and more precise nodal staging. In fact, LD stage includes T1–4, N0–3 M0 tumors, and in particular T1–2, N0–1 M0 tumors (previously described as ‘very limited stage’) were identified as a group with a more favorable outcome and represents about 5% of all new SCLC diagnosis (3).