Menopausal oestrogens and breast cancer risk: an expanded case-control study

Br J Cancer. 1986 Nov;54(5):825-32. doi: 10.1038/bjc.1986.246.

Abstract

A study among 1960 post-menopausal breast cancer cases and 2258 controls identified through a nation-wide screening program enabled evaluation of effects of oestrogen use on breast cancer risk. Ever use was not associated with increased risk (RR = 1.0), but a significant trend was observed with increasing years of use, with users of 20 or more years being at a 50% excess risk. Elevations associated with long-term use were apparent across all menopause subgroups (natural, ovaries retained, ovaries removed). Hormones exerted particularly adverse effects in those initiating use subsequent to a diagnosis of benign breast disease, particularly long-term users (RR = 3.0, 95% CI 1.6-5.5). There was also some indication that effects predominated among the lower stage tumours, an observation similar to that observed for endometrial cancer. These findings support a role for oestrogens in the aetiology of breast cancer, although risk appears to be enhanced only after extended periods of use, and not to the extent observed for other hormonally-sensitive tumours.

MeSH terms

  • Adult
  • Breast Neoplasms / chemically induced*
  • Estrogens / administration & dosage
  • Estrogens / adverse effects*
  • Female
  • Humans
  • Menopause*
  • Middle Aged
  • Risk
  • Time Factors

Substances

  • Estrogens