Risk factors for breast cancer in nulliparous women

F. Fioretti, A. Tavani, C. Bosetti, C. La Vecchia, E. Negri, F. Barbone, R. Talamini, S. Franceschi

Research output: Contribution to journalArticlepeer-review


The relation between hormonal and lifestyle factors and breast cancer risk in nulliparae was investigated using data from two case-control studies conducted in Italy between 1983 and 1994. The study included 1041 nulliparae with histologically confirmed incident breast cancer and 1002 nulliparous controls admitted to hospital for a wide range of acute, non-neoplastic, nonhormone-related diseases. In premenopausal nulliparae, there was an inverse relation with age at menarche [odds ratios (OR) 0.45; 95% confidence intervals (CI) 0.24-0.86 for ≥ 15 years vs <12], while no association emerged in postmenopausal. Breast cancer risk increased with age at menopause, the OR being 1.91 (95% CI 1.26-2.90) for nulliparae reporting age at menopause ≥ 53 years compared with <45. Abortion was not related to breast cancer risk, the OR being 0.92 for any spontaneous, 0.97 for any induced and 0.77 for ≥ 2 total abortions compared to none. The OR was 1.75 (95% CI 1.03-2.97) for women reporting their first abortion at age ≥ 30 years compared with <30. Oral contraceptives and hormone replacement therapy in menopause were moderately related to risk. The OR was 2.71 (95% CI 1.85-3.95) in nulliparae with a family history of breast cancer and 1.60 (95% CI 1.20-2.14) in those with a history of benign breast disease. Compared with nulliparae reporting a low physical activity, the OR was 0.79 (95% CI 0.54-1.16) for those reporting intermediate/high activity. Breast cancer risk increased with total energy intake, the OR being 1.65 (95% CI 0.99-2.75) in the highest tertile; beta-carotene was inversely related to risk (OR 0.60, 95% CI 0.38-0.95) for the highest tertile. Thus, most risk factors for breast cancer in nulliparae were similar to those in women generally.

Original languageEnglish
Pages (from-to)1923-1928
Number of pages6
JournalBritish Journal of Cancer
Issue number11-12
Publication statusPublished - 1999


  • Breast neoplasms
  • Case-control studies
  • Diet
  • Oral contraceptives
  • Reproductive factors
  • Risk factors

ASJC Scopus subject areas

  • Cancer Research
  • Oncology


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