Association between coca (Erythroxylum coca) chewing habit and oral squamous cell carcinoma: a case-control study from Argentina

Abstract

Objective: Previous isolated reports have hypothesized that chewing coca leaves, a pre-Columbian tradition found in certain regions of South America, may be associated with the development of oral squamous cell carcinoma (OSCC). Coca chewing (CC) is a habit that shares many characteristics with the well-known practice of betel chewing observed in Asia. The aim of this study is to analyze the association between CC and OSCC among patients who attended the Señor del Milagro Hospital in Salta, Argentina. Study Design: A case-control study was conducted from 2013 to 2018. For each case of OSCC, three healthy control patients were included. Odds ratios were calculated to compare demographics, concurrent oral conditions, and other classical risk factors for OSCC. Results: A total of 62 cases and 180 controls were included, adjusted for sex and age. OSCC was significantly associated with tobacco use (27.4% vs 9.4%, P = .001), CC (62.9% vs 32.2%, P < .001), and poor oral condition (81.1% vs 67.7%, P = .02). In the multivariate analysis, smoking (OR = 2.77, 95% CI 1.23-6.25, P = .0139), CC (OR = 2.98, 95% CI 1.58-5.63, P = .0007), and poor oral condition (OR = 3.1, 95% CI 1.62-5.85, P = .0006) remained independently associated with OSCC development. Conclusions: Chewing coca leaves could be considered a risk factor for oral cancer in a subset of Argentinean patients. Further studies are necessary to validate our findings and to elucidate the underlying pathways linking this habit to oral carcinogenesis.