Improving the Care of Patients With Stage IB Non–Small-Cell Lung Cancer: Role of Prognostic Signatures and Use of Cell Cycle Progression Biomarkers

Patients with non–small-cell lung cancer have relatively poor survival outcomes after surgery (overall 5-year survival rate < 50%). Adjuvant chemotherapy adds only a small incremental survival benefit (hazard ratio, 0.89) with a 5% improvement in 5-year survival. There is no proven benefit to adjuvant chemotherapy in stage 1A or 1B disease. However, for patients with stage IB disease, outcomes after chemotherapy have been mixed; therefore, additional risk stratification measures are needed to guide decision-making in this patient population. Several significant prognostic indicators have been identified, including the presence of poorly differentiated tumors, tumors > 4 cm, blood vessel invasion, visceral pleural invasion, and incomplete lymph node dissection. A new risk stratification tool based on the expression of cell cycle genes recently has become available. Assessment of cell cycle gene expression may provide useful prognostic and predictive data when considered along with existing prognostic indicators to help identify patients with a poor prognosis and highly proliferative disease who would benefit the most from adjuvant chemotherapy.