ABSTRACT
Head and neck Squamous cell carcinoma (HNSCC) is highly prevalent in Northeast India. The widespread use of tobacco exposure is a known risk factor, makingmitochondrial DNA (mtDNA) more susceptible to damage by oxidative stress incomparison to nuclear DNA. Mitochondrial dysfunction being a hallmark of cancer, thestudy aims to evaluate liquid biopsy involving circulating cell-free mitochondrial DNA(cfmtDNA) as an early diagnostic marker by reducing the dependability over tumor tissuebiopsy specimen. A total of 50 HNSCC cases reported at Cancer Hospital, Guwahati MedicalCollege from January 2018 to August 2018 were included in this study. Cell-free DNA wasisolated using QIAamp Circulating Nucleic Acid Kit. PCR based amplification ofmitochondrial D-loop, followed by direct sequencing. Our result indicated the presence ofsomatic mutations (73(A/G), 93(G/A), 146(T/C) and 207 (G/A)). Polymorphism was alsoobserved in the sequences (263A>G, 275G>A, 318T>C, 16034T>C, 16257C>A and16519T>C) upon comparison with reference sequence. Analysis of c-tract region showedthe presence of an additional cytosine nucleotide at position 309.Identifying somaticmutations in cfmtDNA using liquid biopsy approach will certainly minimize thedependency of clinicians and molecular biologist over the availability of tumor tissuespecimens. The identified somatic variations from our study will help in theimplementation of preventive measure. Therefore, our study provides an early mtDNAdiagnostic marker using liquid biopsy approach.
ABSTRACT
Background: Vocal cord paresis or paralysis due to iatrogenic injury of the recurrent laryngeal nerve (RLNI) is one of the main problems in thyroid surgery. Although many procedures have been introduced to prevent the nerve injury, still the incidence of recurrent laryngeal nerve palsy varies between 1.5-14%. The aim of the present study is to assess the risk factors of recurrent laryngeal nerve injury during thyroid surgery. Methods: This was a prospective, observational study conducted in the Department of ENT and Head & Neck Surgery, Gauhati Medical College & Hospital, Guwahati for a period of 3 years from 1st October, 2010 to 30th September, 2013. Factors predisposing to recurrent laryngeal nerve injury were evaluated such as pathology of the lesions and the type of operations and identification of recurrent laryngeal nerve intra-operatively. Preoperative and postoperative indirect laryngoscopic examinations were performed for all patients. Results: A total of 171 cases of thyroid surgery were performed during the study period. Majority of patients were females. The most common pathology observed in the thyroid gland for which surgery was indicated, according to preoperative FNAC report, was colloid goitre. RLN injury was observed in 3 cases (1.75%) in our study which occurred post hemi thyroidectomy. All these cases had unilateral vocal cord palsy. Conclusion: RLN palsy is one of the common complications after thyroid surgery. Most of the palsy is transient. Meticulous thyroid dissection and identification of RLN during surgery can reduce the rate of RLN palsy.
ABSTRACT
Background: Head and Neck cancers are basically squamous cell carcinomas. It is the fifth most common cancer and the sixth most common cause of cancer mortality in the world. Incidence of cancer as a whole for all sites is fourth highest in Kamrup Urban District (KUD) in males (AAR 185.2) and second highest (AAR 156.3) in females out of all Population Based Cancer Registries (PBCR) in India. Incidence of head and neck cancers in KUD is quite high both nationally and internationally. This retrospective study was carried out to assess the incidence pattern of head and neck cancers in Kamrup Urban District of Assam, India for the period of 2009-2011. Methods: Cancer is not notifiable in India, so method of collecting information on cancer was active in PBCR Guwahati. A total of 4416 cases were registered during the three years (1st January 2009- 31st December 2011) of which 2508 were male and 1908 female. Statistical analysis used: Age Adjusted Rate (AAR), Crude Rate (CR) and Population pyramids are provided by NCRP-ICMR. Results: The relative proportion of head and neck cancers of total cancer cases registered in KUD constitutes 26% (654/2508) and 12% (225/1908) in male and female respectively. In males cancer of hypopharynx (AAR 14.7) was most common followed by tongue (AAR 9.4) and mouth (AAR 7.7). In females cancer of mouth (AAR 7.6) is most common followed by cancer of tongue (AAR 3.2). Conclusion: The pattern and incidence of various head and neck cancers is of utmost importance for primary prevention and early detection to adequately manage these cancers comprehensively in the community.