Abstract PR-04: Curcumin is an effective chemopreventive substance for betel quid chewer's oral precancer in Sri Lanka.

Abstract Background: Oral squamous cell carcinoma has one of the highest recorded incidences in developing countries, comprising 20-30% of all neoplasms, and it is a major cause of cancer mortality in Sri Lanka and other South and Southeast Asian countries. Epidemiological studies have demonstrated that this high incidence is related to betel quid chewing. Curcumin is derived from the spice turmeric. It has been used in these countries for a long time and has antiinflammatory, antioxidative and antineoplastic effects. Objectives: In this study, we aimed to investigate the inhibitory potential of curcumin against betel quid-induced oral precancerous lesions in Sri Lanka. Study Design and Methods: To clarify the effects of curcumin against oral precancerous lesions, we made curcumin-coated chewing gum and placebo chewing gum and used them for a chemopreventive intervention study. One hundred eighteen Sri Lankan betel quid chewers were recruited. Forty-six chewers with oral submucous fibrosis were excluded because it is not measurable lesion. After pathological diagnosis of white lesions of the oral mucosa, seventy-two participants with oral precancer (mean age 53.9; 90.2% male; ethnic 98.6% Sinhala) were recruited from 15 national hospitals in Sri Lanka and randomly divided in two groups; a curcumin group and placebo group. Using person-to-person interviews, we collected data on habits including betel quid chewing, smoking and drinking. The sizes of lesions were measured every 6 months. They were followed every month by oral and maxillofacial surgeons in each hospital. The ethical committee of Hokkaido University, Health Sciences University of Hokkaido, Japan and Peradeniya University ethical committee of Sri Lanka Dental Hospital approved this study. Results: The results of analysis of covariance and the chi-square test showed that the oral precancerous lesions of the curcumin group were significantly smaller within 6 months (p<0.05). Moreover, quitting betel quid chewing and the use of curcumin had synergistic effects on the reduction of the lesion size (p<0.05). Conclusions: While the small size of the study limits its interpretation, these findings suggest that curcumin could have chemopreventive effects on the betel quid chewer's oral cancer prevalent in South and Southeast Asian countries. This abstract is also presented as Poster B18. Citation Format: Itsuo Chiba, Maiko Takeshima, Yoshihiro Abiko, Hiroshi Kobayashi, Malsantha Muthumala, Chihiro Sugiura, Makiko Onodera, Shibata Toshiyuki, Hirofumi Matsuoka, Naoki Kakudate, Shunichi Fukuhara, Toshio Takiguchi. Curcumin is an effective chemopreventive substance for betel quid chewer's oral precancer in Sri Lanka. [abstract]. In: Proceedings of the Eleventh Annual AACR International Conference on Frontiers in Cancer Prevention Research; 2012 Oct 16-19; Anaheim, CA. Philadelphia (PA): AACR; Cancer Prev Res 2012;5(11 Suppl):Abstract nr PR-04.