ERBB2 and cancer: Additionally, a retrospective cohort and case–control study revealed that thiamine significantly reduced cancer growth in patients with HER2-positive breast cancer in Q3 (HR, 0.38; 95% CI, 0.54–0.92) and Q4 (HR, 0.31; 95% CI, 0.10–0.99) [6] and showed a strong negative relationship with prostate cancer in patients over 50 years of age [7].