Cáncer y Microbiota

Assessment of various etiological factors for oral squamous cell carcinoma in non-habit patients- a cross sectional case control study

BACKGROUND

Oral squamous cell carcinoma (OSCC) is one of the most prevalent oral cancers in the world. The major etiological factors are considered to be tobacco and alcohol. However, the etiological factors for non-habit associated oral squamous cell carcinoma (NHOSCC) remains an enigma. So we focused in assessing various etiological factors like genetic factor, microbial factor, dental factor and the biochemical factor of non-habit associated oral squamous cell carcinoma. The aim was to assess Harvey Rat Sarcoma Virus gene (HRAS) mutation, total bacterial count, Herpes Simplex Virus-1 (HSV-1), regressive changes of teeth, total antioxidant capacity and its association with NHOSCC.

MATERIALS AND METHODS

A total of 564 (n = 564) patients with OSCC were included in the study. Out of 564 patients, 282 patients had NHOSCC and 282 patients had habit associated oral squamous cell carcinoma (HOSCC). The isolated DNA from the tissue was subjected to Sanger's sequencing analysis for mutation analysis of the HRAS gene. The isolated serum was subjected to HSV-1 ELISA analysis and TAC ELISA analysis. The dental cast used to analyze the presence of sharp teeth/ any other form of regressive changes of teeth.

RESULTS

Firstly, we found 3 novel pathogenic mutations c.16C > A/p.L6M (missense mutation), c.359 T > C/p.L120P (point mutation), c.382C > T/p.R128W (missense mutation) of HRAS gene in NHOSCC samples by genetic analysis. No significant difference was noted in the total bacterial count between the non-habit associated and habit associated oral squamous cell carcinoma (HOSCC). The binary logistic regression showed patients with HSV1 infection have 2.667 odds (2.667 OR, CI, 1.589- 4.484) of getting NHOSCC and it was found to be statistically significant (p < 0.001).The dental analysis revealed that patients with regressive changes have 4.432 odds (4.432 OR, CI, 2.807- 6.998) of getting NHOSCC and it was found to be statistically significant (p < 0.001). The biochemical analysis revealed patients with lower total antioxidant capacity have 0.671 odds (0.671 OR, CI, 0.621-0.725) of getting NHOSCC and was found to be statistically significant (p < 0.001). Our results suggest that the frequency of HRAS mutation in NHOSCC is high. HSV1, oxidative stress and regressive changes of teeth are associated with NHOSCC.

CONCLUSION

Our results suggest that the frequency of HRAS mutation in NHOSCC is high. HSV1, oxidative stress and regressive changes of teeth are associated with NHOSCC.

Microbial dysbiosis in oral squamous cell carcinoma: A systematic review and meta-analysis

OBJECTIVE

The aim of this study was to summarize previously published data and assess the alterations in the composition of the oral microbiome in OSCC using a systematic review and meta-analysis.

DESIGN

Electronic databases were systematically searched for studies on the oral microbiome in OSCC published before December 2021. Qualitative assessments of compositional variations at the phylum level were performed. The meta-analysis on abundance changes of bacteria genera was performed via a random-effects model.

RESULTS

A total of 18 studies involving 1056 participants were included. They consisted of two categories of studies: 1) case-control studies (n = 9); 2) nine studies that compared the oral microbiome between cancerous tissues and paired paracancerous tissues. At the phylum level, enrichment of Fusobacteria but depletion in Actinobacteria and Firmicutes in the oral microbiome was demonstrated in both categories of studies. At the genus level, Fusobacterium showed an increased abundance in OSCC patients (SMD = 0.65, 95% CI: 0.43-0.87, Z = 5.809, P = 0.000) and in cancerous tissues (SMD = 0.54, 95% CI: 0.36-0.72, Z = 5.785, P = 0.000). The abundance of Streptococcus was decreased in OSCC (SMD = -0.46, 95% CI: -0.88-0.04, Z = -2.146, P = 0.032) and in cancerous tissues (SMD = -0.45, 95% CI: -0.78-0.13, Z = -2.726, P = 0.006).

CONCLUSIONS

Disturbances in the interactions between enriched Fusobacterium and depleted Streptococcus may participate in or prompt the occurrence and development of OSCC and could be potential biomarkers for detection of OSCC.