Multistate oral carcinogenesis-A prospective cohort study and a parallel case-control study in Taiwan

Area of Science:

• Oral carcinogenesis research
• Cancer epidemiology
• Translational research in oncology

Background:

• Multistate oral carcinogenesis was characterized using a cohort study of oral precancer patients and a parallel case-control study of oral cancers and controls in Taiwan.
• Betel-quid chewing, smoking, and alcohol were identified as major risk factors, contributing to 71% of oral precancers and 62% of oral cancers cross-sectionally.

Purpose of the Study:

• To characterize the natural history of oral precancer, including regression, persistence, incidence, and progression to invasive cancer.
• To assess the risk of oral cancer development in patients with oral precancer.
• To establish a comprehensive biospecimen resource for ongoing investigations into oral carcinogenesis.

Main Methods:

• A cohort of 1998 oral precancer patients was followed biannually for up to five years, with data and biospecimens collected at multiple timepoints.
• A parallel case-control study included 768 oral cancer patients and 717 hospital-based controls.
• Natural history was evaluated through follow-up visits and linkage with Taiwan's Cancer Registry; risk was assessed using standardized incidence ratios and cumulative incidence.

Main Results:

• Oral precancer patients exhibited a substantially elevated risk of oral cancer (SIR=14.1).
• Among precancer patients, 156 incident oral cancers occurred over a median follow-up of 6.4 years, with a 5-year cumulative incidence of 6.9%.
• Baseline histopathology strongly predicted cancer progression, with severe dysplasia showing a 45.9% 5-year cumulative incidence; 88.5% of cancers were preceded by identified precancers.

Conclusions:

• A majority of oral precancers and cancers in Taiwan are attributable to betel-quid chewing, smoking, and alcohol.
• Patients with oral precancer have a significantly elevated risk of developing site-concordant oral cancer.
• The study provides a valuable resource for collaborative research on oral precancer/cancer natural history and clinical management.