TYMS, MTHFR, p53 and MDR1 gene polymorphisms in breast cancer patients treated with adjuvant therapy.

PURPOSE: The distribution of TSER (TYMS), C677T (MTHFR), Arg72Pro (p53) and C3435T (MDR1) gene polymorphisms was investigated in 80 consecutive breast cancer patients treated with adjuvant chemotherapy. RESULTS: Observed allelic frequencies were: TSER, (2) 0.55 and (3) 0.45; MTHFR C677T, (C) 0.65 and (T) 0.35; p53 Arg72Pro, (Arg) 0.76 and (Pro) 0.24; MDR1 C3435T, (C) 0.51 and (T) 0.49. MTHFR C677T was found to be a strong predictor of the presence of multifocal tumour (odds ratio, 4.1; 95% CI, 1.1-15.7; P=0.035). CONCLUSION: Our data indicate that breast cancer patients with the C/C variant may present multifocal tumour most frequently.