by ecancer reporter Janet Fricker

Poor oral health and poor dental care both increase the risk of oral cancer, the ARCAGE study shows.

The study, published in Oral Oncology, also showed using mouthwash more than three times a day increased risk.

Cancers of the oral cavity, larynx, oropharynx, hypopharynx and oesophagus, i.e. upper aerodigestive tract tumours (UADT), account for approximately 129,000 new cancer cases annually in the European Union.

While the most important risk factors are considered to be consumption of alcohol and tobacco (with a greater than multiplicative joint effects); it has also been suggested that a lack of oral hygiene and poor oral health are risk factors for cancers of the UADT, independent from smoking and alcohol consumption.

In the ARCAGE study, funded by the International Agency for Research on Cancer (IARC), investigators led by Wolfgang Ahrens and Paul Brennan interviewed 1963 patients with UADT cancers (recruited from 13 centres in nine European countries) and 1993 controls about oral health and dental care behaviours.

The investigators constructed a composite weighted score of oral health (OH) based on three variables: wearing of dentures, age at starting to wear dentures, and frequency of gum bleeding from brushing teeth; and dental care (DC) behaviour based on the variables frequency of tooth cleaning, use of tooth brush, toothpaste or dental floss and frequency of visiting a dentist.

Subjects were also asked about smoking, alcohol drinking, diet, occupations, medical conditions and socio-economic status.

Results showed that patients with low DC scores had an OR of 2.36 [CI= 1.51-3.67]for developing UADT cancers in comparison to those with high scores; and that patients with low OH scores had a OR of 2.22 [CI=1.45-3.41] for developing UADT cancers in comparison to those with high scores.

Furthermore, the OR for frequent use of mouthwash (three or more times/day) was 3.23 [CI=1.68-6.19].

“In conclusion our study provides further evidence for an elevated risk of UADT cancer associated with poor oral health and poor dental care that is not explained by smoking, alcohol or other confounding factors,” write the authors, adding that excessive use of mouthwash also increased risk for UADT cancer.

“But the question whether this effect is mediated by alcohol content or just due to bias or reverse causation cannot be decided with our data.”

The mouth wash data did not allow the investigators to distinguish between alcohol-containing relative to alcohol-free mouth wash.

Furthermore, the investigators add, using mouthwash three plus times/day might indicate some underlying oral disease since people with oral problems are more likely to use mouth wash.

Reference

W Ahrens, H Pohlabeln, R Foraita, et al. Oral health, dental care and mouthwash associated with upper aerodigestive cancer risk in Europe: The ARCAGE study. Oral Oncology.