CYP19A1 and cancer: Nevertheless, some single-nucleotide CYP19A1 polymorphisms are associated with decreased performance in memory tests in women69 and aromatase inhibitors used for cancer treatment have a negative impact on cognition in some patients,70 with subtle effects on hippocampal-dependent verbal and visual memory.71 In contrast, treatment with the aromatase inhibitor letrozole does not impair the development of cognitive performance in boys.72