Cancer and oral hygiene — a hidden connection no one talks about?

Aim of the study: Oral hygiene has been suspected to contribute to the aetiology of head and neck cancer (HNC). Based on the meta-analysis, we evaluated the impact of oral hygiene on head and neck cancer (HNC) and its survival.

Results: Oral hygiene was associated with HNC. Tooth brushing ≥2 a day, dental floss use, denture wearing, caries ≥3, and dental visit ≥1 reduced the risk of oral cavity cancer while mouth wash use, missing teeth >5, gum bleeding, and periodontal disease increased the risk of oral cavity cancer. For oropharynx cancer, tooth brushing ≥2 and caries ≥3 were associated with reduced risk of it. Tooth brushing ≥2 and dental visits ≥1 decreased the risk of pharynx cancer risk and larynx cancer risk, however, missing teeth >5 increased both of them. Oral hygiene was associated with HNC and its sub sites. Oral hygiene should be strengthened, a dental floss use and dentist's visits can be recommended.

Aim of the study: Epidemiological studies have reported the association of poor oral hygiene, especially periodontal disease, and tooth loss with the risk of pancreatic cancer (PC). However, these studies have yielded inconsistent results. Therefore, this systematic review and meta-analysis aimed to investigate the relationship between oral disease and PC.

Results: We identified 17 relevant observational studies involving 1,352,256 participants. Notably, oral disease correlated significantly with PC (hazard ratio [HR], 1.32; 95% confidence interval [CI], 1.13-1.54). In subgroup analyses, subjects with periodontal disease (HR, 1.38; 95% CI, 1.12-1.71) had a higher risk of developing PC than those with tooth loss (HR, 1.19; 95% CI, 0.97-1.46). The results suggest that subjects with oral disease may face a significant and independent risk of PC. However, the mechanisms linking oral disease and PC are uncertain, and additional investigations of this correlation are warranted.

Aim of the study: Poor oral hygiene is closely associated with bacteraemia and systemic inflammation, which are known mediators of cancer development. We investigated the relationship between oral hygiene indicators and the risk of gastrointestinal cancer in a nationwide population-based cohort.

Results: During a median 11.6 years of follow-up, the estimated 10-year event rate for gastrointestinal cancer was 6.76%. In a multivariable analysis, after adjusting for age, sex, income level, regular exercise, alcohol consumption, smoking status, body mass index, history of comorbidities, systolic blood pressure and laboratory findings, frequent toothbrushing (≥3/day) was significantly associated with a reduced risk for gastrointestinal cancer (hazard ratio: 0.91, 95% confidence interval (0.86-0.96), p < .001, p for trend < .001). Good oral hygiene behaviour, especially frequent toothbrushing, could be associated with a lower risk of gastrointestinal cancer.

Results: A total of forty-four studies were included, of which forty were case-control and four were cohort in nature. These comprised of a total of 52,863 patients of which 33,000 were devoid of head and neck cancer (HNC) while, 19,863 had a confirmed diagnosis of HNC. Oral hygiene and HNC were found to be associated. Poor oral hygiene was concluded to be associated with HNC and the subsites thereof.

Aim of the study: Oral dysbiosis and periodontal inflammation might play a role in oesophageal carcinogenesis via the translocation of periodontal pathogens. We aimed to assess whether poor oral health is associated with oesophageal cancer.

Results: After matching, 4238 cases and 16,904 controls were included in the oral health analysis, and 18,905 cases and 75,604 controls were included in the claims-based analysis. In the multivariable analysis, missing teeth (adjusted OR [aOR], 1.16; 95% confidence interval [CI]: 1.08-1.25) and periodontal disease (aOR, 1.05; 95% CI: 1.01-1.09) were both significantly associated with increased odds of oesophageal cancer. Poor oral hygiene practices including infrequent brushing, irregular bedtime brushing, lack of interdental cleaning and dental visits also showed positive associations. Subgroup analyses showed consistent associations across obesity and smoking status, whereas the associations were less consistent in women, the elderly and non-drinkers. Poor oral health indicators including inadequate oral hygiene behaviours were associated with elevated odds of oesophageal cancer, suggesting the potential utility of oral health status in risk stratification.

Aim of the study: Poor oral hygiene, regular use of mouthwash and absence of visits to the dentist could correspond to potential risk factors for the development of head and neck cancer. The objective of this study was to determine whether oral hygiene is associated with the occurrence of oral cavity and head and neck cancer in a Brazilian sample.

Results: The most frequent malignancies in the 899 patients included were those of the tongue border (11.41%) and tongue base (10.92%). The multivariable statistical analysis found odds ratio values: Brushing once 0.33 (95%CI 0.25 - 0.44); Brushing twice 0.42 (95%CI 0.35 - 0.52); Flossing always 0.19 (95%CI 0.13 - 0.27); Flossing sometimes 0.19 (95%CI 0.15 - 0.24); Bleeding 2.40 (95%CI 1.40 - 4.09); Prosthesis 1.99 (95%CI 1.54 - 2.56); Visiting the dentist 0.29 (95%CI 0.22 - 0.37); Good hygiene 0.21 (95%CI 0.17 - 0.27); Regular hygiene 0.20 (95%CI 0.15 - 0.25); number of missing teeth (6 or more) 3.30 (95%CI 2.67 - 4.08). These data showed that, in the population studied, indicators of good hygiene such as brushing teeth and flossing were protective factors for mouth and head and neck cancer, while bleeding and many missing teeth were risk factors.

Aim of the study: Poor oral hygiene is an established risk factor of head and neck cancer (HNC); however, its role in the survival of HNC patients is unclear. This study evaluated the association between oral hygiene habits, including regular dental visits, frequency of tooth brushing, and use of dental floss, and the overall survival (OS) of HNC patients using interview data collected from 740 HNC patients.

Results: The analysis indicated that poor oral hygiene was significantly associated with poorer OS of HNC patients (hazard ratio (HR) = 1.38, 95% confidence interval (CI): 1.03-1.86). This association was modified by a single nucleotide polymorphism, rs11536889, of TLR4. A significant association between poor oral hygiene and worse survival of HNC was observed among those with the CG or CC genotype (HR = 2.32, 95% CI: 1.41-3.82) but not among those with the GG genotype (HR = 0.95, 95% CI: 0.65-1.40). Our results suggested that poor oral hygiene is not only a risk factor but may also be a prognostic factor of HNC.

Aim of the study: Oral cavity cancer (OCC) is a significant clinical challenge within head and neck oncology. It is characterized by significant morbidity, high recurrence rates, and only modest improvements in long-term survival over recent decades.

Results: The microbiome plays a crucial role in regulating the host's physiological, immunological, and metabolic functions. Changes in the composition of the microbiome can influence our health status of local diseases of the oral cavity and oropharynx, as well as systemic diseases. In recent years, the role of the oral microbiome in oral potentially malignant disorders progression and OCC development has been emphasized. Changes in the oral and gut microbiome can lead to the induction of chronic inflammation, modulation of the immune system, and the production of carcinogenic metabolites. Dysbiosis can lead to critical inflammatory responses and consequently contribute to neoplastic events. Microbiome-modulating therapies tailored to the patient's individual profile and aimed at improving cancer treatment outcomes are being introduced, including the introduction of antibiotics to reduce harmful bacteria.

Aim of the study: Lung cancer patients often have poor oral health due to treatment toxicities, increasing risks of oral mucositis, and pulmonary infection. Oral health literacy (OHL) is a key determinant, and psychosocial factors such as anxiety and family support also play roles. However, prior studies examined only single dimensions, not underlying mechanisms.

Results: The oral health status score for lung cancer patients was (9.14 ± 1.94) points, the oral health literacy score was (28.07 ± 5.39) points. Notably, oral health status among lung cancer patients was significantly positively correlated with both oral health literacy (r = 0.389, p < 0.001) and psychosocial factors (r = 0.402, p < 0.001). Furthermore, psychosocial factors were significantly positively correlated with oral health literacy (r = 0.333, p < 0.001). Importantly, psychosocial factors partially mediated the relationship between oral health literacy and oral health status in lung cancer patients, with an indirect effect size of 0.264 (95% CI: 0.106-0.351), accounting for 49.70% of the total effect. Psychosocial factors partially mediate the relationship between oral health literacy and oral health status. These findings suggest a potential pathway linking OHL to oral health status through psychosocial factors.