Genetically altered fields in head and neck cancer and second field tumor.

The concept of field cancerization has been ever changing since its first description by Slaughter et al in 1953. Field cancerization explains the mechanisms by which second primary tumors (SPTs) develop. SPTs are the tumors, which develop in the oral cavity in succession to the primary malignant tumors, which might vary in duration ranging from few months to years. Conceivably, a population of daughter cells with early genetic changes (without histopathology) remains in the organ, demonstrating the concept of field cancerization. This review explains the concept of field cancerization and various field theories along with molecular basis of field formation.