Weight, weight gain and behavioural risk factors in women attending a breast cancer family history, risk and prevention clinic: an observational study

Background Weight and health behaviours impact on breast cancer risk. We describe trends in weight and health behaviours in women at entry to a specialist breast cancer family history clinic in Manchester, UK, and changes after clinic entry. Methods Questionnaires were completed at clinic entry (1987–2019, n = 10,920), and updated in 2010–11 ( n = 3283). Clinic entry characteristics were compared between joining periods 1989–98, 1999–2008 and 2009–18. Partial Least Squares analysis characterised trends in weight, smoking and alcohol intake by age at entry, year of entry and birth year. Weight changes were compared over time, between joining periods. Results Obesity at clinic entry increased from 10.6% in 1989–98 to 20.5% in 2009–18. Alcohol intake above recommendations and smoking prevalence decreased from 20.1% to 13.8% and 33.5% to 16.1% respectively. Weight gain was median 9.7 (IQR 1.4–20.6) % between age 20 and clinic entry (mean duration 11.9 ± 5.6 years) and a further 4.5 (0.0–12.5) % between clinic entry and 2010–11 (31.1 ± 10.4 years). Weight gain between age 20 and clinic entry was highest in the most recent joining period. Conclusions Obesity and weight gain are common in women attending a breast cancer family history clinic suggesting a need for weight management advice and support.