title: Allele frequency of ABO blood group antigen and the risk of esophageal cancer.
abstract: BACKGROUND
  ABO blood group and risk of squamous cell carcinoma of esophagus have been reported by many studies, but there is no discipline that had provided association with the genotype and gene frequency by population statics.
  
  
  METHODS
  We conducted a case-control study on 480 patients with squamous cell carcinoma of the esophagus and 480 noncancer patients. ABO blood group was determined by presence of antigen with the help of monoclonal antibody. Chi-square test and odds ratio (OR) with 95% confidence intervals (CIs) were calculated by statistical methods, and gene frequencies were calculated by Hardy-Weinberg model.
  
  
  RESULTS
  We observed significant associations between ABO genotype and squamous cell carcinoma of esophagus. OR (95% CIs) was 1.69 (1.31-2.19) for presence of B antigen allele relative to its absence (P < 0.0001); in female subgroup OR (95% CIs) observed at 1.84 (1.27-2.65) was statistically significant (P = 0.001). SCC of esophagus shows significant difference in comparison to general population; blood group B is found to be higher in incidence (P = 0.0001). Increased risk of cancer was observed with absence of Rh antigen (P = 0.0001). Relatively increased gene frequency of q[B] allele is observed more significantly in female cancer patients (P = 0.003).
  
  
  CONCLUSIONS
  Statistically significant association between squamous cell carcinoma of the esophagus and ABO and Rh genotype is identified by this study. Sex and anatomical site of cancer also present with statistically significant relative association. However, larger randomised trials are required to establish the hypothesis.
authors: Sardar Patel Medical College, Bikaner 334003, India.
authors: Narender
authors: 0000-0002-2427-647X
authors: N
authors: Kumar
authors: Department of Radiation Oncology, Sardar Patel Medical College, Bikaner 334003, India.
authors: Akhil
authors: 0000-0001-6006-2631
authors: A
authors: Kapoor
authors: Medical Oncology Division, Department of Oncology, Sardar Patel Medical College, Bikaner 334003, India.
authors: Ashok
authors: A
authors: Kalwar
authors: Department of Radiation Oncology, Sardar Patel Medical College, Bikaner 334003, India.
authors: Satya
authors: S
authors: Narayan
authors: Department of Radiation Oncology, Sardar Patel Medical College, Bikaner 334003, India.
authors: Mukesh Kumar
authors: MK
authors: Singhal
authors: Medical College & S.S.G. Hospital, Vadodara 390001, India.
authors: Akhender
authors: A
authors: Kumar
authors: Government Medical College, Kota 324005, India.
authors: Abhishek
authors: A
authors: Mewara
authors: Department of Radiation Oncology, Sardar Patel Medical College, Bikaner 334003, India.
authors: Megh Raj
authors: MR
authors: Bardia
mesh_terms: D000017:ABO Blood-Group System; D000483:Alleles; D001789:Blood Group Antigens / Q000737:chemistry / Q000235:genetics*; D002294:Carcinoma, Squamous Cell / Q000235:genetics* / Q000276:immunology; D016022:Case-Control Studies; D004938:Esophageal Neoplasms / Q000235:genetics* / Q000276:immunology*; D005260:Female; D005787:Gene Frequency; D006801:Humans; D008297:Male; D016017:Odds Ratio
chemical_list: D000017:ABO Blood-Group System; D001789:Blood Group Antigens