CYP1A2*1F Gene Variant, Alkaline Salt Tea Intake and Risk of Esophageal Squamous Cell Carcinoma.

Unlike many other cancers, the relationship of CYP1A2*1F (rs762551) polymorphism with esophageal squamous cell carcinoma (ESCC) risk has not been assessed so far. To evaluate its association with ESCC, we conducted a case control study in Kashmir, India, a high risk region. We recruited 404 histopathologically confirmed ESCC cases and 404 controls, individually matched for sex, age and residence to the respective cases. Information was obtained on dietary, lifestyle and environmental factors in face to face interviews using a structured questionnaire from each subject. Genotypes were analyzed by polymerase chain reaction, restriction fragment length polymorphism and sequencing randomly selected samples. Conditional logistic regression models were used to calculate odds ratios (ORs) and 95% confidence intervals (95% CIs). We found that mutant genotype (AA) of CYP1A2*1F polymorphism was associated with ESCC risk (OR = 3.11; 95% CI: 1.72-5.36). A very strong ESCC risk was observed in subjects who drank >1250 ml of salt tea daily and harbored mutant genotype of CYP1A2*1F (OR = 14.51; 95% CI: 5.33-39.47). The study indicates that CYP1A2*1F polymorphism is associated with ESCC risk and the risk is modified in salt drinkers. However, more replicative and mechanistic studies are needed to substantiate the findings.

Incidence of primary hypothyroidism in patients exposed to therapeutic external beam radiation, where radiation portals include a part or whole of the thyroid gland.

INTRODUCTION: Hypothyroidism is a known consequence of external-beam radiotherapy to the neck encompassing a part or whole of the thyroid gland. In this non-randomized prospective study, we have tried to evaluate the response of the thyroid gland to radiation by assessing thyroid function before irradiation and at regular intervals after irradiation. AIMS AND OBJECTIVES: THE AIM OF THIS STUDY WERE TO ASSESS IN THE CANCER PATIENTS, WHO WERE EXPOSED TO THE THERAPEUTIC EXTERNAL BEAM RADIATION, WHERE RADIATION PORTALS INCLUDE A PART OR WHOLE OF THE THYROID GLAND: the incidence of primary hypothyroidism, the time required to become hypothyroid, any relation between the total dose for the development of hypothyroidism, and whether there are any patient or treatment-related factors that are predictive for the development of hypothyroidism, including the use of concurrent chemotherapy. MATERIALS AND METHODS: This non-randomized, prospective study was conducted for a period of 2 years in which thyroid function was assessed in 59 patients (cases) of head and neck cancer, breast cancer, lymphoma patients and other malignancies, who had received radiotherapy to the neck region. 59 euthyroid healthy patients (controls) were also taken, who had not received the neck irradiation. These patients/controls were assessed periodically for 2 years. RESULTS: The incidence of hypothyroidism after external beam radiation therapy (EBRT) to neck where radiation portals include part or whole of the thyroid gland was 16.94%, seven cases had subclinical hypothyroidism (11.86%) and three cases had clinical hypothyroidism (5.08%). Mean time for development of hypothyroidism was 4.5 months. There was no effect of age, gender, primary tumor site, radiation dose and chemotherapy, whether neoadjuvant or concurrent with the development of hypothyroidism. CONCLUSION: In summary, we found that thyroid dysfunction is a prevalent, yet easily treatable source of morbidity in patients undergoing radiation therapy to neck where radiation portals include a part or whole of the thyroid gland.

Combined impact of polymorphism of folate metabolism genes; glutamate carboxypeptidase, methylene tetrahydrofolate reductase and methionine synthase reductase on breast cancer susceptibility in kashmiri women.

BACKGROUND: Folate and methionine play a crucial role in DNA synthesis, repair and the epigenetic profile of cell. Hence, the alterations in the folate metabolism can lead to aberrant proliferation leading to neoplasia. Most of the studies have associated polymorphisms in methylene tetrahydrofolate reductase (MTHFR) and methionine synthase reductase (MTRR) genes with reduced risk of cervical and colorectal cancer. However, the association with breast cancer is still controversial. Further, the involvement of Glutamate carboxypeptidase II (GCPII) polymorphism in cancer is not known. In the present study, we analyzed if the individual and combined effects of polymorphisms in folate pathway genes viz., MTHFR 677C > T, MTHFR 1298A > C, MTRR 66A > G and GCP II 1561 C>T, have any role in altering the susceptibility to breast cancer. METHODS: The DNA of 35 female breast cancer patients and 33 healthy individuals, in the Kashmiri population from India, were analyzed using a PCR-RFLP approach for the above mentioned polymorphisms. RESULTS: Individuals carrying the MTHFR 677CT/TT and GCPII 1561 CT genotype showed a 3.5 (95% CI: 3.1-3.7, P<0.02) and 7.7 (95% CI: 6.7-9.1, P<0.001) fold decreased risk for breast cancer than the wild types (MTHFR 677CC and GCPII 1561 CC). Subjects with MTRR 66 G-allele showed a 4.5 fold decreased risk (OR: 0.22, 95% CI: 0.20, 0.24, P<0.0005) compared to the wild type (MTRR 66A). Further, subjects with combined polymorphisms in MTHFR, GCPII and MTRR loci revealed a significant reduction of breast cancer risk. CONCLUSION: This study indicates (i) a protective role of polymorphisms in MTHFR, GCPII, MTRR against breast cancer in the study subjects, and (ii) combined effect of polymorphisms is more pronounced than single genetic polymorphism, thereby emphasizing the role of gene-gene interaction in the susceptibility to breast cancer.