Significance of IASLC/ATS/ERS classification for early-stage lung adenocarcinoma patients in predicting benefit from adjuvant chemotherapy

Non-small cell lung cancer (NSCLC) is currently the leading cause of cancer-related deaths worldwide and represents an incredibly challenging problem for clinicians. Despite advances in methods of detection and treatment, there is an expected increase in mortality in both developed and developing countries (1,2). The most common histologic subtype is adenocarcinoma (ADC), which accounts for approximately 50% of NSCLCs (3,4). In developed countries it is detected at an early-stage only in 25% of cases. The current gold standard for treatment of early-stage lung ADC when there are no significant risk factors is lobectomy. Despite recent progress and development of surgical techniques and minimally invasive approaches, approximately 40% of lung ADC patients experience tumor recurrence and death following complete resection (3,4). While meta-analysis has confirmed survival benefits for patients with pathologic stage II or IIIA lung ADC who have undergone adjuvant chemotherapy following surgical resection (5), there is still controversy over the role of chemotherapy in pathologic stage I patients. Additionally, its role in combination with surgery versus radiotherapy has yet to be elucidated.