Polymorphisms in ADH1B and ALDH2 genes associated with the increased risk of gastric cancer in West Bengal, India.

BACKGROUND: Gastric cancer (GC) is one of the most frequently diagnosed digestive tract cancers and carries a high risk of mortality. Acetaldehyde (AA), a carcinogenic intermediate of ethanol metabolism contributes to the risk of GC. The accumulation of AA largely depends on the activity of the major metabolic enzymes, alcohol dehydrogenase and aldehyde dehydrogenase encoded by the ADH (ADH1 gene cluster: ADH1A, ADH1B and ADH1C) and ALDH2 genes, respectively. This study aimed to evaluate the association between genetic variants in these genes and GC risk in West Bengal, India. METHODS: We enrolled 105 GC patients (cases), and their corresponding sex, age and ethnicity was matched to 108 normal individuals (controls). Genotyping for ADH1A (rs1230025), ADH1B (rs3811802, rs1229982, rs1229984, rs6413413, rs4147536, rs2066702 and rs17033), ADH1C (rs698) and ALDH2 (rs886205, rs968529, rs16941667 and rs671) was performed using DNA sequencing and RFLP. RESULTS: Genotype and allele frequency analysis of these SNPs revealed that G allele of rs17033 is a risk allele (A vs G: OR = 3.67, 95% CI = 1.54-8.75, p = 0.002) for GC. Significant association was also observed between rs671 and incidence of GC (p = 0.003). Moreover, smokers having the Lys allele of rs671 had a 7-fold increased risk of acquiring the disease (OR = 7.58, 95% CI = 1.34-42.78, p = 0.009). CONCLUSION: In conclusion, rs17033 of ADH1B and rs671 of ALDH2 SNPs were associated with GC risk and smoking habit may further modify the effect of rs671. Conversely, rs4147536 of ADH1B might have a protective role in our study population. Additional studies with a larger patient population are needed to confirm our results.

Association of DNA repair and xenobiotic pathway gene polymorphisms with genetic susceptibility to gastric cancer patients in West Bengal, India.

Gastric cancer is one of the most common malignancies in India. DNA repair gene or xenobiotic pathway gene polymorphisms have recently been shown to affect individual susceptibility to gastric cancer. Here, the possible interaction between common polymorphisms in X-ray repair cross complementing group I (XRCC1) gene and glutathione S-transferase (GST) genes (GSTM1, GSTT1 and GSTP1), smoking and alcohol consumption and overall survival in gastric cancer patients were evaluated. In this population-based case control study, 70 gastric cancer patients and 82 healthy controls were enrolled. The epidemiological data were collected by a standard questionnaire, and blood samples were collected from each individual. XRCC1 Arg194Trp, Arg280His and Arg399Gln polymorphisms were determined by polymerase chain reaction and direct DNA sequencing. GSTM1 and GSTT1 null polymorphisms and GSTP1 Ile105Val polymorphism were identified by multiplex polymerase chain reaction and restriction fragment length polymorphism (RFLP), respectively. The risk of gastric cancer was significantly elevated in individuals with XRCC1 Arg/Gln +Gln/Gln (p = 0.031; odds ratio = 2.32; 95 % confidence interval (CI) 1.07-5.06) and GSTP1 Val/Val genotype (p = 0.009; odds ratio = 8.64; 95 % CI 1.84-40.55). An elevated risk for GC was observed in smokers and alcohol consumers carrying GSTP1 Ile/Val +Val/Val genotype (p = 0.041; odds ratio = 3.71; 95 % CI 0.98-14.12; p = 0.002; odds ratio = 12.31; 95 % CI 1.71-88.59). These findings suggest that XRCC1 rs25487 and GSTP1 rs1695 can be considered as a risk factor associated with gastric cancer and might be used as a molecular marker for evaluating the susceptibility of the disease.

A prospective observational study to assess the epidemiological profile of multiple primary cancers in Eastern India.

BACKGROUND: Multiple primary cancers once thought to be rare have become increasingly common as the lifespan of cancer survivors has increased with availability of better and more effective cancer treatment. However, their exact incidence is not known and data on their epidemiological characteristics are not available. AIM: The aim of this study is to study the epidemiologic characteristics of multiple primary cancers in the eastern region of India. MATERIALS AND METHOD: The study was conducted in the Department of Surgical Oncology, Medical College, Kolkata, from 2017 to 2020 over a period of 3 years. All patients with a diagnosis of second primary as per International Agency for Research on Cancer (IARC) definition or those developing a second primary within the study period were included for analysis. Data were recorded in form of preformed questionnaires. All the cases were followed up for at least 12 months. RESULT: Fifty cases of multiple primary tumors were identified, out of which 21 were synchronous while rest 29 were metachronous type. The male-female ratio was 1:1.2. The median age at presentation for index malignancy was 50 years. The most common malignancy in the synchronous group was a combination of variety of GI cancers (six cases). In the metachronous category, a combination of reproductive cancers (breast, ovary, cervix, and endometrium) along with Gastrointestinal cancer (GI) cancers (colon, rectum) was most frequently found (eight cases). Definite risk factors for multiple primary tumors were identifiable in 10 cases: arsenic exposure in 5 cases, hereditary in 4 cases, and immunosuppression in 1, while in 8 cases, risk factors were only speculative (radiation 5 cases, chemotherapy 3). At the time of the last follow-up, 36 subjects were alive and 3 dead while the status of 11 subjects was unknown. CONCLUSION: This is the first comprehensive study on multiple primary cancers and the largest so far in India. Our study overcomes the shortcoming of previous case series from our subcontinent. The merits of our study include the use of the most accepted IARC definition, updated staging guidelines with long follow-up, and reliable survival data. Additionally, we could identify risk factors in 50% of our subjects. And our study shows various new combinations of cancers not reported before. Clustering of cases in the young adolescent group (25-49) years is also a new finding. We also highlight the existing ambiguity in the way this entity is defined. Demerits include the loss of follow-up data in a significant number of patients.

A microsatellite study to disentangle the ambiguity of linguistic, geographic, ethnic and genetic influences on tribes of India to get a better clarity of the antiquity and peopling of South Asia.

An understanding of the genetic affinity and the past history of the tribal populations of India requires the untangling of the confounding influences of language, ethnicity, and geography on the extant diverse tribes. The present study examines the genetic relationship of linguistically (Dravidian, Austro-Asiatic, and Tibeto-Burman) and ethnically (Australian and East Asian) diverse tribal populations (46) inhabiting different regions of the Indian subcontinent. For the purpose, we have utilized the published data on allele frequency of 15 autosomal STR loci of our study on six Adi sub-tribes of Arunachal Pradesh and compared the same with the reported allele frequency data, for nine common autosomal STR loci, of 40 other tribes. Phylogenetic and principal component analyses exhibit geography based clustering of Tibeto-Burman speakers and separation of the Mundari and Mon-Khmer speaking Austro-Asiatic populations. The combined analyses of all 46 populations show clustering of the groups belonging to same ethnicity and inhabiting contiguous geographic regions, irrespective of their different languages. These results help us to reconstruct and understand three plausible scenarios of the antiquity of Indian tribal populations: the Dravidian and Austro-Asiatic (Mundari) tribes were possibly derived from common early settlers; the Tibeto-Burman tribes possibly belonged to a different ancestry and the Mon-Khmer speaking Austro-Asiatic populations share a common ancestry with some of the Tibeto-Burman speakers.

Ameloblastic Fibrosarcoma in Pregnancy: an Unreported Entity!

AFS is a rare tumor of odontogenic origin. Less than 100 cases have been reported so far in the literature. Due to its extreme rarity, we do not have clear management guidelines at present. The entire clinical spectrum and natural history of this uncommon malignancy is unknown. Most of the cases present with facial swelling along with varying degrees of oral signs and symptoms. AFS has higher incidence in male and common in third decade of life. However, presentation in female can be unique and may have a different course and outcome then what is known to us. The association of pregnancy and AFS is interesting and has hardly been emphasized before. Pregnancy can dramatically boost the growth of this tumor leading to impending airway obstruction or fatal hemorrhage. We report a case of an 18-year-old pregnant female who presented with rapidly enlarging bleeding mandibular mass and respiratory distress and present the challenges in its surgical management along with it long-term outcome on follow-up. We also discuss and explore the probable role of AFS in context of pregnancy and its oncological outcome.

Dermatofibrosarcoma Protuberans of the Breast-a Rare Entity.

Dermatofibrosarcoma protuberans (DFSP) represents about 1% of soft-tissue sarcomas with an estimated incidence of 0.8 to 5.0 cases per million per year. This lesion may occur anywhere in the body but more than 50% occur on the trunk, 20% on the head and neck and 30% on the extremities. DFSP of the breast is an extremely uncommon site of presentation. Data regarding DFSP of the breast is limited and mostly in the form of case reports. Clinical presentation is not uniform and may mimic benign skin lesions [1]. However, it typically presents as a nodular cutaneous mass in early or mid-adult life. We herein report a case of DFSP of the breast in a 33-year-old lady who was managed successfully in our institute and review the literature associated with it.

Phylogeographic distribution of mitochondrial DNA macrohaplogroup M in India.

Indian subcontinent harbours both the human mtDNA macrohaplogroups M and N, of which M is the most prevalent. In this study, we discuss the overall distribution of the various haplogroups and sub-haplogroups of M among the different castes and tribes to understand their diverse pattern with respect to geographical location and linguistic affiliation of the populations. An overview of about 170 studied populations, belonging to four distinct linguistic families and inhabiting different geographic zones, revealed wide diversity of about 22 major haplogroups of M. The tribal populations belonging to the same linguistic family but inhabiting different geographical regions (Dravidian and Austro-Asiatic speakers) exhibited differences in their haplogroup diversity. The northern and southern region castes showed greater diversity than the castes of other regions.

A microsatellite guided insight into the genetic status of adi, an isolated hunting-gathering tribe of northeast India.

Tibeto-Burman populations of India provide an insight into the peopling of India and aid in understanding their genetic relationship with populations of East, South and Southeast Asia. The study investigates the genetic status of one such Tibeto-Burman group, Adi of Arunachal Pradesh based on 15 autosomal microsatellite markers. Further the study examines, based on 9 common microsatellite loci, the genetic relationship of Adi with 16 other Tibeto-Burman speakers of India and 28 neighboring populations of East and Southeast Asia. Overall, the results support the recent formation of the Adi sub-tribes from a putative ancestral group and reveal that geographic contiguity is a major influencing factor of the genetic affinity among the Tibeto-Burman populations of India.

Genetic kinship among an isolated Adi tribe of Arunachal Pradesh: isonymy in the Adi Panggi.

Isolated tribes in remote areas are important for genetic studies, and one such little known subtribe of the Adi tribe, namely, the Adi Panggi (Pangi) of the Upper Siang District of Arunachal Pradesh, India, was studied for surname distribution to deduce the deviation from random mating and genetic kinship between villages. The estimates of homonymy (homozygosity) vary between villages; husbands show wider variation (0.009 to 0.23) than wives (0.005 to 0.054). The remote villages of Sumsing and Sibum and Geku Town show lower entropy among husbands' surnames than among Panggi wives. The highest equivalent surname number was found among Sibum husbands (9.9), Panggi wives (12.6), and Panggi and non-Panggi wives (13.5). The estimates of unbiased random isonymy among husbands and wives together show the smallest values in Sibum (0.05) and the highest values in Sumsing and Ramku (0.16). The random and nonrandom components of the inbreeding coefficient show avoidance of inbreeding among the Panggi villages (-0.012 to -0.27) except in Sibum (0.012). Genetic kinship between villages based on the Mij distance shows different clusters of villages among husbands and wives. Both the Panggi wives and the Panggi and non-Panggi wives show a similar pattern of clustering between villages. The wide homonymy variation between villages among the patrilocal Adi Panggi indicates differential genetic kinetics among husbands and wives, avoidance of inbreeding, and female-oriented differential gene flow with little effect on the overall intervillage genetic kinship.

Intertribal and temporal allele-frequency variation at the ABO locus among Tibeto-Burman-speaking Adi subtribes of Arunachal Pradesh, India.

We studied the distribution of ABO blood group frequencies of the Galo and Mishing subtribes of the Adi tribal cluster in East Siang District, Arunachal Pradesh, India, in order to investigate the intertribal and temporal allelic variation. Blood groups O and AB showed higher frequencies (28.4%, 27.4%) in the Galo, whereas group O (45%) was predominant in the Mishing. Allele r is significantly different in the Galo (44.6%) and Mishing (60.3%). The chi-square test indicated significant deviations from Hardy-Weinberg equilibrium. Adi tribes show high heterogeneity and indicate significant temporal variation in ABO genotype frequencies in the Galo, Mishing, and Padam, whereas the Panggi, a small isolated subtribe of Adi, show similar and stable frequencies.

Genetic heterogeneity among three Adi tribes of Arunachal Pradesh, India.

We studied the distribution of ABO blood groups among three little known subtribes of the Adi tribe, namely, the Panggi, Komkar, and Padam, of the East and Upper Siang districts of Arunachal Pradesh, India. Blood group O was the predominant group in the Komkar and Padam, whereas group A was the predominant group in the Panggi. Blood group AB was found to be the least frequent group in all three studied populations. The populations showed significant differences in blood groups A (43% in Panggi, 23% in Komkar, and 18% in Padam) and O (33% in Panggi, 54% in Komkar, and 61% in Padam). The chi-square test indicated significant deviation from Hardy-Weinberg equilibrium, suggesting high heterogeneity among the tribes.