European Journal of Cardiovascular Medicine

Head and neck squamous cell carcinoma (HNSCC) represents a significant global health burden. According to GLOBOCAN 2020 estimates, approximately 890,000 new cases of cancer and 450,000 cancer-related deaths occur annually worldwide, with head and neck cancers accounting for nearly 4.5% of all cancer diagnoses and deaths [1]. The most well-established risk factors for cancers of the oral cavity, oropharynx, hypopharynx, and larynx include tobacco use and alcohol consumption [2]. In addition to these, several other factors such as infection with oncogenic viruses—particularly human papillomavirus (HPV)—exposure to ultraviolet radiation, and poor oral hygiene have been implicated in the etiopathogenesis of head and neck cancers [3]. Certain risk factors, including mouthwash use, irritation from ill-fitting dentures, and suboptimal oral health, remain unproven or controversial, particularly in relation to oropharyngeal cancers [4]. Although poor oral hygiene has been suggested as a potential independent risk factor for head and neck cancers, definitive evidence remains limited due to small sample sizes, heterogeneity of oral hygiene indicators, and confounding effects of tobacco and alcohol use in many studies [5,6]. As most oral cavity and oropharyngeal cancers are diagnosed at advanced stages, self-examination and timely consultation with healthcare professionals play a crucial role in early detection and improved prognosis [7,8]. Globally, India bears a disproportionately high burden of oral cavity and oropharyngeal cancers, making these malignancies a major public health concern in the country [9]. While tobacco and alcohol remain the predominant etiological factors in the Indian population, the role of poor oral hygiene as an independent risk factor has not been clearly established. Furthermore, emerging evidence suggests that alterations in oral microbial flora may contribute to chronic inflammation and carcinogenesis, highlighting the need to explore the association between oral hygiene, oral bacterial flora, and head and neck cancers [10].

Head and neck squamous cell carcinoma (HNSCC) is a significant global health concern, with tobacco and alcohol as established risk factors. Poor oral hygiene has been suggested as an independent risk factor, though evidence remains limited. This study analyzes the association between oral hygiene, oral bacterial flora, and HNSCC among 180 patients. Findings indicate that very poor oral hygiene is highly prevalent and independently associated with an increased risk of head and neck cancers, highlighting the importance of preventive oral health measures.

Study design: This is a cross-sectional study Place of study: This study will be conducted in the department of Otorhinolaryngology and Head & Neck surgery at IPGME&R and SSKM hospital, Kolkata Period of study: The study was conducted over a period of 12 months, from 1st March 2024 to 28th February 2025, after obtaining approval from the Institutional Ethics Committee of IPGME&R and SSKM Hospital, Kolkata. Study Population: The study population will comprise patients attending the Outpatient Department of Otorhinolaryngology (ENT) at IPGME&R and SSKM Hospital, Kolkata, diagnosed with head and neck squamous cell carcinoma during the 10-month study period. Sample size: 175-200 cases. Inclusion Criteria: • pathologically confirmed case of squamous cell carcinoma of head and neck • no previous diagnosis of any cancer • age > 20 years • giving valid consent for the studyExclusion criteria: • cases diagnosed as carcinoma in situ • precancerous oral cavity lesion like lukoplakia, erythroplakia, lichen plannus, smoker’s ulcer. • Karnofsky’s performance score < 50%. Study Variable: • Head and Neck Cancer occurrence/type • Sites: Oral cavity, Oropharynx, Hypopharynx, Larynx • Oral hygiene status (primary variable of interest) • Oral hygiene components (used to calculate score) • Gum disease (yes/no) • Denture use (yes/no) • Number of missing teeth (<5, ≥5) • Dental visit frequency (>1/year, <1/year) • Smoking status (yes/no, frequency) • Alcohol consumption (yes/no, frequency) • Demographic variables • Age • Gender Statistical Analysis: Data were analyzed using standard statistical software. Descriptive statistics were used to summarize demographic variables, oral hygiene status, and oral bacterial flora, expressed as mean ± standard deviation for continuous variables and frequency with percentages for categorical variables. Normality of continuous data was assessed using the Shapiro–Wilk test. Comparisons between head and neck cancer patients and controls were performed using the independent t-test or Mann–Whitney U test for continuous variables and the Chi-square or Fisher’s exact test for categorical variables. The association between oral hygiene parameters, specific oral bacterial species, and head and neck cancer was evaluated using logistic regression analysis after adjusting for potential confounders such as age, gender, tobacco use, and alcohol consumption. Results were considered statistically significant at p < 0.05.

Table 1: Distribution of Head & Neck Cancer Cases by Site (n = 180)

Table 2: Oral Hygiene Score Distribution Among Head & Neck Cancer Patients

Among the 180 patients with head and neck cancer, the most common site involved was the oral cavity, accounting for 78 cases (43.3%), followed by the oropharynx with 46 cases (25.6%), hypopharynx with 34 cases (18.9%), and larynx with 22 cases (12.2%).

Table 3: Association Between Oral Hygiene Status and Site of Head & Neck Cancer

Table 4: Multivariate Logistic Regression Analysis of Risk Factors for Head & Neck Cancer

Figure 1: Distribution of Head & Neck Cancer Cases by Site (n = 180)

Based on the oral hygiene scoring system, the majority of patients exhibited very poor oral hygiene, with 96 cases (53.3%), followed by average oral hygiene in 58 patients (32.2%), while only 26 patients (14.5%) demonstrated good oral hygiene.

A higher proportion of patients with oral cavity and oropharyngeal cancers had very poor oral hygiene, observed in 61.5% and 56.5% of cases respectively. In contrast, patients with laryngeal cancer predominantly exhibited average to good oral hygiene, with 45.4% having average and 27.3% having good oral hygiene. Overall, very poor oral hygiene was more frequently associated with cancers of the oral cavity and oropharynx compared to hypopharyngeal and laryngeal cancers.

Multivariate logistic regression analysis showed that very poor oral hygiene was significantly associated with an increased risk of head and neck cancer (OR = 3.6; 95% CI: 1.9–6.8; p < 0.001), whereas average oral hygiene did not show a statistically significant association. Smoking and alcohol consumption were strong independent risk factors, with odds ratios of 5.4 and 3.2 respectively. After adjustment for smoking and alcohol, poor oral hygiene remained a significant independent risk factor for head and neck cancer (adjusted OR = 2.9; 95% CI: 1.4–5.6; p = 0.003).

In our study of 180 head and neck cancer patients, the oral cavity was the most commonly affected site, and a majority of patients exhibited very poor oral hygiene, particularly those with oral cavity and oropharyngeal cancers, suggesting a strong association between poor oral hygiene and these cancer sites. This finding aligns with previous studies; for instance, Guha et al. [11] reported that poor oral hygiene, including infrequent tooth brushing and periodontal disease, increased the risk of head and neck cancers independent of tobacco and alcohol use. Similarly, other studies [12–15] have shown that chronic periodontitis and tooth loss are associated with oral cavity and oropharyngeal cancers, while routine dental care was protective [16]. Our logistic regression analysis confirmed that very poor oral hygiene significantly increased the risk of head and neck cancer (adjusted OR = 2.9), consistent with the observations of Hashibe et al. [17] and Divaris et al. [18], who also reported oral health as an independent risk factor after adjusting for smoking and alcohol. Moreover, the strong associations of smoking and alcohol with head and neck cancers in our cohort corroborate global evidence [19, 20]. Overall, our findings support the hypothesis that poor oral hygiene is not only prevalent among head and neck cancer patients but may act as an independent risk factor, highlighting the importance of preventive oral health measures in reducing cancer risk.

The present study demonstrates that poor oral hygiene is highly prevalent among patients with head and neck cancers, particularly those affecting the oral cavity and oropharynx, and is independently associated with an increased risk of these cancers even after adjusting for smoking and alcohol. Our findings underscore the role of oral health as a modifiable risk factor and highlight the importance of promoting good oral hygiene and regular dental care as potential preventive strategies to reduce the burden of head and neck cancers.

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