Amal Chandra Kataki

Investigation on the Role of p53 Codon 72 Polymorphism and Interactions with Tobacco, Betel Quid, and Alcohol in Susceptibility to Cancers in a High-Risk Population from North East India

The association of TP53 codon 72 polymorphism with cancer susceptibility remains uncertain and varies with ethnicity. Northeast India represents a geographically, culturally, and ethnically isolated population. The area reports high rate of tobacco usage in a variety of ways of consumption, compared with the rest of Indian population. A total of 411 cancer patients (161 lung, 134 gastric, and 116 oral) and 282 normal controls from the ethnic population were analyzed for p53 codon 72 polymorphism by polymerase chain reaction-restriction fragment length polymorphism. No significant difference in genotypic distribution of p53 between cases and controls was observed. Results suggested betel quid chewing as a major risk factor for all the three cancers (odds ratio [OR]=3.54, confidence interval [CI]=2.01-6.25, p<0.001; OR=1.74, CI=1.04-2.92, p=0.03; and OR=1.85, CI=1.02-3.33, p=0.04 for lung, gastric, and oral cancers, respectively). Tobacco smoking was associated with risk of lung and oral cancers (OR=1.88, CI=1.11-3.19, p=0.01 and OR=1.68, CI=1.00-2.81, p=0.04). Interactions between p53 genotypes and risk factors were analyzed to look for gene-environment interactions. Interaction of smoking and p53 genotype was significant only for oral cancer. Interactions of betel quid with p53 genotypes in lung cancer showed significant increase for all the three genotypes, indicating a major role of betel quid (OR=5.90, CI=1.67-20.81, p=0.006; OR=5.44, CI=1.67-17.75, p=0.005; and OR=5.84, CI=1.70-19.97, p=0.005 for Arg/Arg, Arg/Pro, and Pro/Pro, respectively). In conclusion, high incidence of these cancers in northeast India might be an outcome of risk habits; further, tissue- and carcinogen-specific risk modification by p53 gene is probable.

Evaluation of carcinoma cervix using magnetic resonance imaging: Correlation with clinical FIGO staging and impact on management

Aim: To evaluate carcinoma of the cervix using magnetic resonance imaging (MRI), correlate with clinical approach of International Federation of Gynecology and Obstetrics (FIGO) staging system and to study the impact of MRI findings on patient management.

Hybrid Capture 2 Assay Based Evaluation of High-Risk HPV Status in Healthy Women of North-East India

BACKGROUND High risk HPV (HR-HPV) testing has been recommended as an effective tool along with cytology screening in identification of cervical intraepithelial lesions (CINs) and prevention of their progress towards invasive cervical cancer. The aim of this study was to assess the HR-HPV DNA status by Hybrid Capture 2 (HC2) assay in healthy asymptomatic women of North-East India. MATERIALS AND METHODS This study examined cervical cell samples of forty three (n=43) healthy women by HC2 assay. A High Risk HPV DNA kit (Qiagen) was used which can detect 13 high risk HPV types: 16, 18, 31, 33, 35, 39, 45, 51, 52, 56, 58, 59 and 68. RESULTS The mean relative light units (RLU) for samples was in the range of 141-5, 94, 619. HR-HPV DNA was confirmed in 16% (7/43) of participant women samples. Among demographic and clinical parameters, menstrual irregularity (p=0.039) and infection history (p=0.028) has shown statistically significant differences between the HR-HPV-positive and negative groups. In the HR-HPV positive group, two women were confirmed for CINs after colposcopy and histopathologic examination. CONCLUSIONS We suggest that there may be an association between irregular menstruation and infection history of the urogenital tract with HR-HPV DNA prevalence in North-East Indian asymptomatic women. HC2 assay can be a valuable tool for HR-HPV screening.

Genomic Alterations in Breast Cancer Patients in Betel Quid and Non Betel Quid Chewers

Betel Quid (BQ) chewing independently contributes to oral, hepatic and esophageal carcinomas. Strong association of breast cancer risk with BQ chewing in Northeast Indian population has been reported where this habit is prodigal. We investigated genomic alterations in breast cancer patients with and without BQ chewing exposure. Twenty six BQ chewers (BQC) and 17 non BQ chewer (NBQC) breast cancer patients from Northeast India were analyzed for genomic alterations and pathway networks using SNP array and IPA. BQC tumors showed significantly (P<0.01) higher total number of alterations, as compared with NBQC tumors, 48±17% versus 32±25 respectively. Incidence of gain in fragile sites in BQC tumors were significantly (P<0.001) higher as compared with NBQC tumors, 34 versus 23% respectively. Two chromosomal regions (7q33 and 21q22.13) were significantly (p<0.05) associated with BQC tumors while two regions (19p13.3–19p12 and 20q11.22) were significantly associated with NBQC tumors. GO terms oxidoreductase and aldo-keto reductase activity in BQC tumors in contrast to G-protein coupled receptor protein signaling pathway and cell surface receptor linked signal transduction in NBQC tumors were enriched in DAVID. One network “Drug Metabolism, Molecular Transport, Nucleic Acid Metabolism” including genes AKR1B1, AKR1B10, ETS2 etc in BQC and two networks “Molecular Transport, Nucleic Acid Metabolism, Small Molecule Biochemistry” and “Cellular Development, Embryonic Development, Organismal Development” including genes RPN2, EMR3, VAV1, NNAT and MUC16 etc were seen in NBQC. Common alterations (>30%) were seen in 27 regions. Three networks were significant in common regions with key roles of PTK2, RPN2, EMR3, VAV1, NNAT, MUC16, MYC and YWHAZ genes. These data show that breast cancer arising by environmental carcinogens exemplifies genetic alterations differing from those observed in the non exposed ones. A number of genetic changes are shared in both tumor groups considered as crucial in breast cancer progression.

Association of interleukin-1β -511 C/T polymorphism with tobacco-associated cancer in northeast India: a study on oral and gastric cancer.

The IL-1β -511 C/T polymorphism is associated with increased IL-1 production and with increased risk of developing cancers. In this study, 251 patients (125 with gastric cancer [GC] and 126 with oral cancer [OC]) and 207 normal controls from northeast (NE) India were genotyped for the IL-1β -511 C/T polymorphism by PCR-restriction fragment length polymorphism (RFLP) and sequencing. Analysis of results showed betel-quid chewing to be a major risk factor (OR = 2.01, 95% CI = 1.05-3.87; P = 0.035) for OC. Inheritance of the IL-1β -511 CT or TT resulted in a 2.6- to 3.05-fold increase in the risk of developing OC relative to that of participants who possessed the reference genotype (OR = 2.57, 95% CI = 1.06-6.22; P = 0.036 and OR = 3.05, 95% CI = 1.22-7.63; P = 0.017), after adjusting for potential confounders. The dominant genetic model also confirmed the presence of the T allele as a significant risk factor for OC (OR = 2.72, 95% CI = 1.15-6.42; P = 0.02). In GC, interaction of the CT genotype with tobacco and betel-quid chewing habits conferred a significant 78% and 89% reduced risk of cancer, respectively. In conclusion, for the NE Indian population, the IL-1β -511 CC and CT genotypes were significantly associated with increased risk of OC. However, the interaction of the CT genotype with risk habits may play a preventive role for GC but not for OC.

Aptamer-Assisted Detection of the Altered Expression of Estrogen Receptor Alpha in Human Breast Cancer

An increase in the expression of estrogen receptors (ER) and the expanded population of ER-positive cells are two common phenotypes of breast cancer. Detection of the aberrantly expressed ERα in breast cancer is carried out using ERα-antibodies and radiolabelled ligands to make decisions about cancer treatment and targeted therapy. Capitalizing on the beneficial advantages of aptamer over the conventional antibody or radiolabelled ligand, we have identified a DNA aptamer that selectively binds and facilitates the detection of ERα in human breast cancer tissue sections. The aptamer is identified using the high throughput sequencing assisted SELEX screening. Biophysical characterization confirms the binding and formation of a thermodynamically stable complex between the identified DNA aptamer (ERaptD4) and ERα (Ka = 1.55±0.298×108 M-1; ΔH = 4.32×104±801.1 cal/mol; ΔS = -108 cal/mol/deg). Interestingly, the specificity measurements suggest that the ERaptD4 internalizes into ERα-positive breast cancer cells in a target-selective manner and localizes specifically in the nuclear region. To harness these characteristics of ERaptD4 for detection of ERα expression in breast cancer samples, we performed the aptamer-assisted histochemical analysis of ERα in tissue samples from breast cancer patients. The results were validated by performing the immunohistochemistry on same samples with an ERα-antibody. We found that the two methods agree strongly in assay output (kappa value = 0.930, p-value <0.05 for strong ERα positive and the ERα negative samples; kappa value = 0.823, p-value <0.05 for the weak/moderate ER+ve samples, n = 20). Further, the aptamer stain the ERα-positive cells in breast tissues without cross-reacting to ERα-deficient fibroblasts, adipocytes, or the inflammatory cells. Our results demonstrate a significant consistency in the aptamer-assisted detection of ERα in strong ERα positive, moderate ERα positive and ERα negative breast cancer tissues. We anticipate that the ERaptD4 aptamer targeting ERα may potentially be used for an efficient grading of ERα expression in cancer tissues.

Prognosis of vulval cancer with lymph node status and size of primary lesion: A survival study

Introduction: Squamous cell cancer of the vulva is a rare disease with an annual incidence of two to three per 100,000 women. Lymph node metastasis is the most important prognostic factor for the recurrence and survival in vulval carcinoma. Materials and Methods: It is a retrospective study of 18 cases, operated in our institute from 2006 to 2009 and followed up till July, 2012. These patients were divided into two group of node positive and node negative and compared for recurrence and survival. Result: Ten patients had lymph node metastasis and eight had no lymph node metastasis. Recurrence rate was 40% and 12.5% in node positive and negative groups, respectively. Adjuvant radiation when given to node negative bulky tumor showed no recurrence compared to one out of two in the non-irradiated group. Survival was only 25% in node positive recurrent cases. Conclusion: Lymph node positivity added a great risk for future recurrence. Prophylactic radiation in node negative, bulky tumor is helpful.

Evaluation of hypopharyngeal carcinoma using high-resolution ultrasound: comparison with CT.

To evaluate the role of sonography (US) in assessing hypopharyngeal carcinoma when compared with CT.

Synchronous primary cancers of the head and neck region and upper aero digestive tract: Defining high‑risk patients

BACKGROUND Patients with cancers in the head and region are at increased risk of developing synchronous primary cancers. AIM To see the epidemiology of synchronous cancers of the head and region and identification of high-risk factors for the development of synchronous primary in the head and neck cancers. MATERIALS AND METHODS Data of head and neck cancer patients from January 2010 to December 2011 were obtained from the hospital cancer registry for retrospective analysis of patients with synchronous cancers. All synchronous malignancies were analyzed for distribution of sites, association with smoking history, stage of index head, and neck tumor and the average age of patients at presentation with synchronous cancers. The Chi-square test for association of upper aero digestive tract (UADT) and smoking and statistical formula of median for calculating the average age have been employed for analysis. RESULTS Incidence of synchronous primaries has been found to be 1.33%, majority were seen at the oropharynx (39.2%) and 60.7% synchronous occurred at the esophagus, 0.81% of all head and neck cancers developed synchronous primary at the esophagus. Approximately, 65% of all synchronous primaries were in Stage III and Stage IV disease and 88.2% esophageal synchronous had Stage II disease. Association of UADT synchronous cancers with smoking is highly significant, relative risk = 1.95 95% confidence interval for relative risk 1.05-3.64 P = 0.00010981 (P < 0.05) and the average age is 62.4 years in males and 57.8 years in females. CONCLUSION Patients who are at the high-risk for the development of synchronous primary tumors in the cancers of the head and neck region are patients with oropharyngeal carcinoma, smoking population, patients over the age of 62 years in males, and 57 years in females and in patients with higher staged index tumor.

Alcohol and Tobacco Increases Risk of High Risk HPV Infection in Head and Neck Cancer Patients: Study from North-East Region of India

Background Human papilloma virus (HPV) associated Head and Neck Cancers (HNCs) have generated significant amount of research interest in recent times. Due to high incidence of HNCs and lack of sufficient data on high-risk HPV (hr-HPV) infection from North -East region of India, this study was conceived to investigate hr-HPV infection, its types and its association with life style habits such as tobacco, alcohol consumption etc. Methods A total of one hundred and six primary HNC tumor biopsy specimens were collected. These samples were analyzed for hr-HPV DNA (13 HPV types) using hybrid capture 2 (HC2) assay and genotyping was done by E6 nested multiplex PCR (NMPCR). Results The presence of hr-HPV was confirmed in 31.13% (n = 33) and 24.52% (n = 26) of the HNC patients by nested multiplex PCR (NMPCR) and HC2 assay respectively. Among hr-HPV positive cases, out of thirteen hr- HPV types analyzed, only two prevalent genotypes, HPV-16 (81.81%) followed by HPV-18 (18.18%) were found. Significant association was observed between hr-HPV infection with alcohol consumption (p <0.001) and tobacco chewing (p = 0.02) in HNC cases. Compared to HPV-18 infection the HPV-16 was found to be significantly associated with tobacco chewing (p = 0.02) habit. Conclusions Our study demonstrated that tobacco chewing and alcohol consumption may act as risk factors for hr-HPV infection in HNCs from the North-East region of India. This was the first study from North-East India which also assessed the clinical applicability of HC2 assay in HNC patient specimens. We suggest that alcohol, tobacco and hr- HPV infection act synergistically or complement each other in the process of HNC development and progression in the present study population.