Risk of breast cancer in symptomatic women in primary care: a case-control study using electronic records

Br J Gen Pract. 2014 Dec;64(629):e788-93. doi: 10.3399/bjgp14X682873.

Abstract

Background: Breast cancer is the most common cancer in the UK. GPs are encouraged to refer all women whose symptoms may represent cancer, rather than selecting those at highest risk.

Aim: To identify and quantify features of breast cancer in primary care.

Design and setting: A UK case-control study using the Clinical Practice Research Database (CPRD).

Method: Possible features of breast cancer were identified in the year before diagnosis, and odds ratios calculated using conditional logistic regression. Positive predictive values (PPVs) were estimated for consulting women.

Results: A total of 3994 women aged ≥40 years with breast cancer between 2000 and 2009, and 16 873 age-, sex-, and practice-matched controls were studied. Median age at diagnosis was 63 years (interquartile range 55-74 years). Four features were significantly associated with breast cancer: breast lump (odds ratio [OR] 110; 95% confidence interval [CI] = I88 to 150), breast pain (OR = 4.2; 95% CI = 3.0 to 6.0), nipple retraction (OR = 26; 95% CI = 10 to 64), nipple discharge (OR = 19; 95% CI = 8.6 to 41): all P-values <0.01. In the year before diagnosis, 1762 (44%) of cases had a breast lump compared with 132 (0.8%) controls. The PPV of breast cancer with a breast lump was 4.8% in women aged 40-49 years, rising to 48% in women aged >70 years. PPVs were lower in women who also reported breast pain.

Conclusion: Generally, the figures support current referral practice. However, the low likelihood of cancer for all the non-lump symptoms means that the current guidance recommends investigation for possible cancer at a more liberal risk threshold than for other cancers. Although supported by patients, this may not meet current NHS criteria for cost-benefit.

Keywords: breast cancer; diagnosis; primary health care.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Breast Neoplasms / diagnosis*
  • Breast Neoplasms / epidemiology
  • Case-Control Studies
  • Early Detection of Cancer*
  • Electronic Health Records / statistics & numerical data*
  • Female
  • General Practice*
  • Humans
  • Middle Aged
  • Odds Ratio
  • Patient Acceptance of Health Care
  • Practice Guidelines as Topic
  • Practice Patterns, Physicians' / statistics & numerical data*
  • Predictive Value of Tests
  • Primary Health Care
  • Referral and Consultation / organization & administration*
  • Risk Assessment
  • United Kingdom / epidemiology