Oral microbial carriage in oral squamous cell carcinoma patients at the time of diagnosis and during radiotherapy - a comparative study

Objectives: Tobacco chewing habit, presence of squamous cell carcinoma in oral cavity and radiotherapy causes alterations in healthy oral microflora. Abnormal flora developed due to radiotherapy in oral squamous cell carcinoma (OSCC) patients can exacerbate mucositis and can cause systemic infections. The role of oral microorganisms in carcinogenesis is gaining interest recently. Abnormal flora in development of second tumor in the field of first tumor is to be established. The study fundamentally tries to evaluate the shift that occurs during the radiotherapy in OSCC patients.

Methods: Microbial analysis of saliva samples from OSCC patients undergoing radiotherapy, tobacco chewers and controls was undertaken. The microorganisms were grouped into categories as total aerobes, total anaerobes, candida, coliforms and gram negative anaerobic bacteria.

Results: The frequency of isolation of total aerobes, total anaerobes, coliforms and gram negative anaerobic bacteria was significantly high in OSCC patients compared to healthy controls whereas candida was isolated most frequently during radiation period. The tobacco chewers showed significant increase in colony forming units of total aerobes and coliforms. All the microbial groups were high in OSCC and radiotherapy patients. While OSCC patients showed significant increase in total anaerobes and gram negative anaerobes, candida was increased in radiotherapy patients only.

Conclusion: Habits promote coliforms. Tumor supports efficiently anaerobes and candida. The latter is supported more by radiation. The study stresses the importance on administration of appropriate antimicrobial therapy right at the time of diagnosis of the lesion.