CCND1 and breast cancer: Results: No significant difference was found between patient and control groups in distribution of genotypic and allelic frequencies in CCND1 genotype, yet CCND1 A870G (rs9344) GG genotype was far less prevalent in breast cancer patients younger than 55 years (OR=0.62, 95%CI=0.43–0.89, P=0.0362), with first menarche earlier than 12.2 years (OR=0.61, 95% CI=0.42–0.87, P=0.0241), with menopause earlier than 49.0 years (OR=0.57, 95%CI=0.39–0.82, P=0.0093), or showing triple-negative breast cancer (OR=0.28, 95%CI=0.13–0.62, P=0.0006).