Oral cancer together with pharyngeal cancer is the sixth most common malignancy reported worldwide and one with high mortality ratios among all malignancies . Worldwide 450,000 new cases are estimated in 2014. About 90% are a type of cancer called squamous cell carcinoma (SCC). SCC of the tongue is the most common oral malignancy accounting for approximately 40% of all oral carcinomas.
Spectroscopy techniques are extremely sensitive for the analysis of biochemical changes in the cellular systems. These techniques can provide a clear picture of alterations that occur during the development of cancer that lie beyond visual range. This is especially important in oral cancer, where "tumor detection is complicated by a tendency towards field cancerization, leading to multi-centric lesions" and "current techniques detect malignant change too late" , and "biopsies are not representative of the whole pre-malignant lesion" 
Aim: To determine the efficacy of Laser induced fluorescene spectroscopy in the early detection of tongue malignancy
Current work deal with in vivo fluorescence studies of tongue malignancy using home assembled Laser Induced Fluorescence (LIF) system . About 892 fluorescence spectra from tongue (top, tip, bottom and lateral) have been recorded from 330 subjects under normal (133), premalignant (154) and malignant (63) condition, by excitation with 325 nm CW He-Cd laser.
Results: Tongue top, tongue tip, tongue lateral, and bottom give spectra differing from each other. Under clinically normal, potentially-malignant and malignant conditions the fluorescence spectra are found to be noticeably different. The analyzed results have shown very good sensitivity and specificity to diagnose tongue malignancy.
Conclusion: From the analysis results it can be attributed that, LIF technique is a promising tool for the early detection of precancerous and cancerous conditions of tongue.