Association of SLC14A1C/T Polymorphisms in Patients with Bladder Cancer in Comparison with Healthy Controls

Transitional cell carcinoma of the urinary bladder is one of the most common malignancies affecting the urinary tract. Genomic instability is one of the most important common features of urothelial cancers of the bladder. Gene polymorphisms of the SLC14A1 gene are known to be related to carcinogenesis of the bladder in humans. Similarly, the use of tobacco products including chewing and smoking is an established risk factor for bladder cancer in both men and women. The primary aim of the study was to assess the relationship between bladder cancer and polymorphisms of the SLC14A1 gene (rs17674580) in our patients with image and histologically confirmed bladder cancer and secondarily to assess if use of tobacco products in these patients further accentuated the risk of bladder cancer.

All patients aged ≥18 years with images (ultrasonography/computed tomography) and histologically confirmed bladder cancer formed the study group. Age- and gender-matched individuals aged ≥18 years, genetically unrelated, formed the controls. A 2-mL blood sample was collected from patients as well as controls, for genotyping of SLC14A1C/T gene polymorphisms. Demographic data were obtained from all the participants, and individuals who smoked once a day for more than 5 years were defined as smokers. Similarly, patients who chewed tobacco for more than 5 years were defined as tobacco users.

During the study period, 107 patients (84 males and 23 females) with image and histologically confirmed bladder cancer formed the study group. The mean age of the patients with bladder cancer was 58.47 ± 14.5 years and that of the controls was 60.01 ±  12.5 years. Among patients with bladder cancer, 28 (26.2%) showed no polymorphisms (rs17674580) of the SLC14A1 gene, whereas 79 (73.8%) patients showed polymorphisms. Heterozygous variations (CT) were noted in 46 (42.9%) patients, whereas homozygous variations were noted in 33 (30.9%) patients with the odds ratio being 2.772 (1.459-3.247) and 3.349 (1.610-6.922), respectively. The use of tobacco (smoking/chewing) was also found to modulate risks of bladder cancer in SLC14A1 variants.

Gene polymorphisms of SLC14A1C/T are associated with a high risk of bladder cancer in our group of patients in South India. Moreover, the use of tobacco, be it smoking or chewing, further increases the risk of bladder cancer in these patients.