The Incorrect Statement is B: Smoking is NOT the Most Significant Risk Factor for Breast Cancer
Statement B is incorrect because smoking is not established as the most significant risk factor for breast cancer—in fact, one study found no association between cigarette smoking and breast cancer risk 1.
Analysis of Each Statement
Statement A: Affects 1 in 8 Women in Western Societies
This is correct. Breast cancer has high incidence rates in Western populations, with approximately 1 in 8 women developing the disease during their lifetime.
Statement B: Smoking as Most Significant Risk Factor
This is INCORRECT. The evidence directly contradicts this:
- Kabat et al. found that cigarette smoking was NOT associated with breast cancer risk in a large study of 148,030 women 1
- The established major risk factors are actually:
- Reproductive factors (nulliparity, age at first birth, parity)
- Hormonal exposures (early menarche, late menopause, exogenous hormones)
- Family history and genetic mutations (BRCA1/2)
- Ionizing radiation exposure
- Alcohol consumption (not smoking) 2
Statement C: BRCA1/BRCA2 Mutations in 5-10% of Cases
This is correct. Genetic mutations in BRCA1, BRCA2, and other DNA repair pathway genes account for approximately 5-10% of breast cancer cases 3.
Statement D: Incidence Peaks Between 60-70 Years
This is correct. Breast cancer incidence increases with age and peaks in the 60-70 age range, with rates declining after age 70 4.
Statement E: Mammography Reduces Mortality, Self-Examination Does Not
This is correct. Multiple international guidelines recommend mammographic screening for mortality reduction, with most recommending screening for women aged 40-74 years, particularly 50-69 years as the optimal age group 5. Breast self-examination has not been shown to reduce mortality in randomized trials.
Clinical Context for This Patient
For this 57-year-old nulliparous woman:
- Nulliparity itself is a risk factor for certain breast cancer subtypes, particularly ER-positive disease 1
- Her age places her in the peak incidence range
- Absence of family history reduces but does not eliminate risk, as most breast cancers occur sporadically
- She should continue regular mammographic screening as recommended by guidelines 5, 6