28 february 2024

Impact of Alcohol Consumption on Breast Cancer Incidence and Mortality: The Women’s Health Study

Background: Alcohol intake is associated with breast cancer (BC) risk, but estimates of greatest public health relevance have not been quantified in large studies with long duration.

Materials and Methods: In this prospective cohort study of 39,811 women (median 25 years follow-up), we examined the association between alcohol consumption and BC incidence and mortality with adjusted hazard ratios (HRs), cubic splines, absolute risks, number needed to harm (NNH), and population-attributable fractions.

Results: We documented 2,830 cases of BC, including 237 BC deaths. Each additional alcoholic drink/day was associated with a 10% higher rate (HR = 1.10, 95% confidence intervals [CIs]: 1.04-1.16) of total BC in a linear manner (p = 0.0004). The higher rate was apparent for estrogen receptor (ER)(+) (HR = 1.12, 95% CI: 1.06-1.18) but not ER(-) tumors (HR = 0.95, 95% CI: 0.82-1.10), with a statistically significant difference between these associations (p = 0.03). We constructed models comparing BC incidence among 100,000 women followed for 10 years. Compared to a scenario where all women rarely or never consumed alcohol, we expect 63.79 (95% CI: 58.35-69.24) more cases (NNH = 1,567) had all women consumed alcohol at least monthly and 278.66 (95% CI: 268.70-288.62) more cases (NNH = 358) had all women consumed >1 drink/day. Approximately 4.1% of BC cases were attributable to consumption exceeding one drink/month.

Conclusion: Alcohol consumption is associated with a linear dose-response increase in BC incidence even within recommended limits of up to one alcoholic drink/day, at least for ER(+) tumors. Our estimates of risk differences, attributable fraction, and NNH quantify the burden that alcohol consumption imposes on women in the general population.

ClinicalTrials.gov Identifier: NCT00000479.

Additional Info

  • Authors

    Mostofsky E.; Lee I. M.; Buring J. E.; Mukamal K. J.
  • Issue

    Periodical: J Womens Health (Larchmt) - Edition: 20240228
  • Published Date

    28 february 2024