Hormone replacement therapy and false positive recall in the Million Women Study: patterns of use, hormonal constituents and consistency of effect

INTRODUCTION: Current and recent users of hormone replacement therapy (HRT) have an increased risk of being recalled to assessment at mammography without breast cancer being diagnosed ('false positive recall'), but there is limited information on the effects of different patterns of HRT use on this. The aim of this study is to investigate in detail the relationship between patterns of use of HRT and false positive recall. METHODS: A total of 87,967 postmenopausal women aged 50 to 64 years attending routine breast cancer screening at 10 UK National Health Service Breast Screening Units from 1996 to 1998 joined the Million Women Study by completing a questionnaire before screening and were followed for their screening outcome. RESULTS: Overall, 399 (0.5%) participants were diagnosed with breast cancer and 2,629 (3.0%) had false positive recall. Compared to never users of HRT, the adjusted relative risk (95% CI) of false positive recall was: 1.62 (1.43–1.83), 1.80 (1.62–2.01) and 0.76 (0.52–1.10) in current users of oestrogen-only HRT, oestrogen-progestagen HRT and tibolone, respectively (p (heterogeneity) < 0.0001); 1.65 (1.43–1.91), 1.49 (1.22–1.81) and 2.11 (1.45–3.07) for current HRT used orally, transdermally or via an implant, respectively (p (heterogeneity) = 0.2); and 1.84 (1.67–2.04) and 1.75 (1.49–2.06) for sequential and continuous oestrogen-progestagen HRT, respectively (p (heterogeneity) = 0.6). The relative risk of false positive recall among current users appeared to increase with increasing time since menopause, but did not vary significantly according to any other factors examined, including duration of use, hormonal constituents, dose, whether single- or two-view screening was used, or the woman's personal characteristics. CONCLUSION: Current use of oestrogen-only and oestrogen-progestagen HRT, but not tibolone, increases the risk of false positive recall at screening

Predictors of outcome of mammography in the National Health Service Breast Screening Programme

Background: Little is known about the factors influencing the risk of recall for assessment invasive diagnostic procedures, and early rescreening after screening mammography. Methods: From June 1996 to March 1998 women attending screening at 10 National Health Service Breast Screening Programme (NHSBSP) centres completed a self administered questionnaire and were followed up for their screening outcome. Results: 1969 (3.3%) out of 60 443 women aged 50-64 who had never used hormone replacement therapy (HRT) were recalled for assessment but were not diagnosed with breast cancer (defined here as false positive recall). After adjustment for the variation between centres, false positive recall was decreased significantly among women who were likely to have had a previous NHSBSP mammogram (odds ratio (OR) 0.49, 95% confidence interval (95% CI) 0.38 to 0.63 for likely versus unlikely), who were postmenopausal (OR 0.65, 95% CI 0.56 to 0.76 for postmenopausal v premenopausal) and increased significantly for women reporting previous breast surgery (OR 1.64, 95% CI 1.42 to 1.89). Although false positive recall decreased significantly with parity and increasing body mass index, these effects were not large and no significant variation was found with age, education, family history of breast cancer, oral contraceptive use, sterilisation, exercise, smoking, or alcohol consumption. Altogether 655 (1.1%) women had an invasive diagnostic procedure; no personal characteristics were predictive of this outcome, 286(0.5%) were referred for early rescreening, and this was increased significantly by nulliparity and a family history of breast cancer. Interpretation: Premenopausal women, those without a previous NHSBSP mammogram, and women with previous breast surgery have an increased risk of false positive recall by the NHSBSP

Influence of personal characteristics of individual women on sensitivity and specificity of mammography in the Million Women Study: cohort study

Objectives To examine how lifestyle, hormonal, and other factors influence the sensitivity and specificity of mammography. Methods Women recruited into the Million Women Study completed a questionnaire about various personal factors before routine mammographic screening. A sample of 122 355 women aged 50-64 years were followed for outcome of screening and incident breast cancer in the next 12 months. Sensitivity and specificity were calculated by using standard definitions, with adjustment for potential confounding factors. Results Breast cancer was diagnosed in 726 (0.6%) women, 629 in screen positive and 97 in screen negative women; 3885 (3.2%) were screen positive but had no subsequent diagnosis of breast cancer. Overall sensitivity was 86.6% and specificity was 96.8%. Three factors had an adverse effect on both measures: use of hormone replacement therapy (sensitivity: 83.0% (95% confidence interval 77.4% to 87.6%), 84.7% (73.9% to 91.6%), and 92.1% (87.6% to 95.0%); specificity: 96.8% (96.6% to 97.0%), 97.8% (97.5% to 98.0%), and 98.1% (98.0% to 98.2%), respectively, for current, past, and never use); previous breast surgery v no previous breast surgery (sensitivity: 83.5% (75.7% to 89.1%) v 89.4% (86.5% to 91.8%); specificity: 96.2% (95.8% to 96.5%) v 97.4% (97.3% to 97.5%), respectively); and body mass index < 25 v ≥ 25 (sensitivity: 85.7% (81.2% to 89.3%) v 91.0% (87.5% to 93.6%); specificity: 97.2% (97.0% to 97.3%) v 97.4% (97.3% to 97.6%), respectively). Neither sensitivity nor specificity varied significantly according to age, family history of breast cancer, parity, past oral contraceptive use, tubal ligation, physical activity, smoking, or alcohol consumption. Conclusions The efficiency, and possibly the effectiveness, of mammographic screening is lower in users of hormone replacement therapy, in women with previous breast surgery, and in thin women compared with other women

Influence of personal characteristics of individual women on sensitivity and specificity of mammography in the Million Women Study: cohorty study.

Objectives: To examine how lifestyle, hormonal, and other factors influence the sensitivity and specificity of mammography. Methods: Women recruited into the Million Women Study completed a questionnaire about various personal factors before routine mammographic screening. A sample of 122 355 women aged 50-64 years were followed for outcome of screening and incident breast cancer in the next 12 months. Sensitivity and specificity were calculated by using standard definitions, with adjustment for potential confounding factors. Results: Breast cancer was diagnosed in 726 (0.6%) women, 629 in screen positive and 97 in screen negative women; 3885 (3.2%) were screen positive but had no subsequent diagnosis of breast cancer. Overall sensitivity was 86.6% and specificity was 96.8%. Three factors had an adverse effect on both measures: use of hormone replacement therapy (sensitivity: 83.0% (95% confidence interval 77.4% to 87.6%), 84.7% (73.9% to 91.6%), and 92.1% (87.6% to 95.0%); specificity: 96.8% (96.6% to 97.0%), 97.8% (97.5% to 98.0%), and 98.1% (98.0% to 98.2%), respectively, for current, past, and never use); previous breast surgery v no previous breast surgery (sensitivity: 83.5% (75.7% to 89.1%) v 89.4% (86.5% to 91.8%); specificity: 96.2% (95.8% to 96.5%) v 97.4% (97.3% to 97.5%), respectively); and body mass index <25 v ≥25 (sensitivity: 85.7% (81.2% to 89.3%) v 91.0% (87.5% to 93.6%); specificity: 97.2% (97.0% to 97.3%) v 97.4% (97.3% to 97.6%), respectively). Neither sensitivity nor specificity varied significantly according to age, family history of breast cancer, parity, past oral contraceptive use, tubal ligation, physical activity, smoking, or alcohol consumption. Conclusions: The efficiency, and possibly the effectiveness, of mammographic screening is lower in users of hormone replacement therapy, in women with previous breast surgery, and in thin women compared with other women

Mammographic surveillance in women younger than 50 years who have a family history of breast cancer: tumour characteristics and projected effect on mortality in the prospective, single-arm, FH01 study.

BACKGROUND: Evidence supports a reduction in mortality from breast cancer with mammographic screening in the general population of women aged 40-49 years, but the effect of family history is not clear. We aimed to establish whether screening affects the disease stage and projected mortality of women younger than 50 years who have a clinically significant family history of breast cancer. METHODS: In the single-arm FH01 study, women at intermediate familial risk who were younger than 50 years were enrolled from 76 centres in the UK, and received yearly mammography. Women with BRCA mutations were not explicitly excluded, but would be rare in this group. To compare the FH01 cohort with women not receiving screening, two external comparison groups were used: the control group of the UK Age Trial (106,971 women aged 40-42 years at recruitment, from the general population [ie, average risk], followed up for 10 years), and a Dutch study of women with a family history of breast cancer (cancer cases aged 25-77 years, diagnosed 1980-2004). Study endpoints were size, node status, and histological grade of invasive tumours, and estimated mortality calculated from the Nottingham prognostic index (NPI) score, and adjusted for differences in underlying risk between the FH01 cohort and the control group of the UK Age Trial. This study is registered with the National Research Register, number N0484114809. FINDINGS: 6710 women were enrolled between Jan 16, 2003, and Feb 28, 2007, and received yearly mammography for a mean of 4 years (SD 2) up until Nov 30, 2009; surveillance and reporting of cancers is still underway. 136 women were diagnosed with breast cancer: 105 (77%) at screening, 28 (21%) symptomatically in the interval between screening events, and three (2%) symptomatically after failing to attend their latest mammogram. Invasive tumours in the FH01 study were significantly smaller (p=0·0094), less likely to be node positive (p=0·0083), and of more favourable grade (p=0·0072) than were those in the control group of the UK Age Trial, and were significantly less likely to be node positive than were tumours in the Dutch study (p=0·012). Mean NPI score was significantly lower in the FH01 cohort than in the control group of the UK Age Trial (p=0·00079) or the Dutch study (p<0·0001). After adjustment for underlying risk, predicted 10-year mortality was significantly lower in the FH01 cohort (1·10%) than in the control group of the UK Age Trial (1·38%), with relative risk of 0·80 (95% CI 0·66-0·96; p=0·022). INTERPRETATION: Yearly mammography in women with a medium familial risk of breast cancer is likely to be effective in prevention of deaths from breast cancer