Breast cancers among very young premenopausal women (United States)

Cancer Causes Control. 2003 Mar;14(2):151-60. doi: 10.1023/a:1023006000760.


Objective: To assess risk factors for breast cancer among very young compared to older premenopausal women.

Methods: Between 1990 and 1992 a population-based case-control study conducted in Atlanta, GA, Seattle/Puget Sound, WA, and central NJ interviewed 3307 premenopausal women aged 20-54 years. Logistic regression models estimated adjusted relative risks (RR) and 95% confidence intervals (CI) for each of three 10-year age groups.

Results: Among the youngest age group (<35 years, n = 545), significant predictors of risk included African-American race (RR = 2.66: 95% CI 1.4-4.9) and recent use of oral contraceptives (RR = 2.26; 95% CI 1.4-3.6). Although these relationships were strongest for estrogen receptor-negative (ER-) tumors (RRs of 3.30 for race and 3.56 for recent oral contraceptive use), these associations were also apparent for young women with ER+ tumors. Delayed childbearing was a risk factor for ER+ tumors among the older premenopausal women (Ptrend < 0.01), but not for women <35 years in whom early childbearing was associated with an increased risk, reflecting a short-term increase in risk immediately following a birth. Family history of early-onset breast cancer was more strongly associated with risk among women <35 years (RR = 3.22) than those 45-54 years (RR = 1.51). Risk factors for premenopausal breast cancer not significantly modified by age at diagnosis included early age at menarche, low body mass index, and heavy alcohol consumption.

Conclusion: These findings suggest the possibility that women who develop breast cancers at very young ages may be etiologically as well as clinically distinct.

Publication types

  • Comparative Study
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Adult
  • Age Factors
  • Alcohol Drinking / adverse effects
  • Breast Neoplasms / epidemiology*
  • Breast Neoplasms / etiology
  • Carcinoma in Situ / epidemiology*
  • Carcinoma in Situ / etiology
  • Case-Control Studies
  • Continental Population Groups
  • Contraceptives, Oral, Hormonal / adverse effects
  • Female
  • Humans
  • Logistic Models
  • Middle Aged
  • Premenopause*
  • Risk Factors
  • United States / epidemiology


  • Contraceptives, Oral, Hormonal