Can lower aldehyde dehydrogenase activity in saliva be a risk factor for oral cavity cancer?

OBJECTIVES: Salivary ALDH3A1 protects the oral cavity from aromatic and medium-chain aliphatic aldehydes originating from food and air pollution and generated during oxidative stress. Due to their reactivity, aldehydes may exhibit an irritating effect as well as cytotoxic, genotoxic, mutagenic and even carcinogenic effects. The aim of this study was to verify whether lower ALDH3A1 activity is a risk factor for oral cavity cancer. SUBJECTS AND METHODS: Fasting saliva samples were collected one day before and about one week after surgery from patients with oral cancer (OCC) (n = 59), other tumours (cysts, neoplasms) (n = 108), gnathic defects and fractures (controls after the surgery) (n = 63), and from healthy volunteers (n = 116). Enzyme activity was measured using a fluorometric method. RESULTS: Total ALDH3A1 activity [U g(-1) ] in patients with OCC was statistically lower than in patients with keratocystic odontogenic tumour (KCOT) (P = 0.00697), odontogenic cysts (OC) (P < 0.00001), neoplasms (P = 0.03343) and the healthy volunteers up to and over 40 years old (P < 0.00001; P = 0.00019). The activity in the saliva of OCC after surgery was lower than in the healthy volunteers (P < 0.00001) and in the groups with fractures (P = 0.00303) and gnathic defects (P = 0.00538). CONCLUSION: Low salivary ALDH activity may be a risk factor for oral cancer development.

Smoking, alcohol, diet, dentition and sexual practices in the epidemiology of oral cancer in Poland.

The effect of smoking, drinking, diet, dental care and sexual habits on the risk of oral and pharyngeal cancer was investigated in a case-control study conducted in Warsaw, Poland. The study comprised 122 patients (including 44 females) aged 23-80 years with histologically confirmed cancer of oral cavity and pharynx. Controls were 124 subjects (including 52 females) admitted to the hospital for different non-neoplastic conditions unrelated to tobacco and alcohol consumption, with frequency matched to cases by age and sex. Smoking and drinking were strongly associated with an increased risk of oral cancer. Among consumers of both products, risks of oral cancer tended to combine in a multiplicative fashion and were increased more than 14-fold among those who consumed more than 15 cigarettes and seven or more drinks per day. Cessation of smoking was associated with reduced risk of this cancer. The risks varied by type of cigarettes smoked, being lower among those consuming filtered cigarettes only (OR = 1.6) than nonfilter (OR = 6.5) or mixed (OR = 4.2) cigarettes. High fruit intake was associated with significantly decreased risk (OR = 0.4) with the strongest significant inverse association found for fruit juices and citrus fruits ( < 0.01). After adjustment for tobacco smoking and alcohol drinking, poor dentition as evidenced by missing teeth, frequency of dental check-ups and frequency of teeth brushing emerged as a strong risk factor. Number of missing teeth and frequency of dental check-ups and frequency of tooth brushing showed increased ORs of 9.8, 11.9 and 3.2, respectively. Denture wearing did not affect oral cancer risk. No differences were detected in sexual practices (including oral sex and intercourse with prostitutes). In terms of attributable risk, smoking accounted for 57% of oral cancer cases in Poland, alcohol for 31% and low fruit intake for 12%. Attributable risks for low frequency of tooth brushing and dental check-ups were 56% and 47%, respectively. In conclusion, smoking and drinking cessation and increase of fresh fruit intake are likely to be effective preventive measures against oral cancer. These findings indicate also that poor oral hygiene may be an independent risk factor.