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Breast Cancer Screening Eve Espey, M.D. University of New Mexico Objectives To explain the epidemiology of breast cancer among US women To understand screening modalities and current breast cancer screening recommendations To discuss strategies to reduce risk of developing breast cancer
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Breast Cancer Screening Eve Espey, M.D. University of New Mexico
Objectives • To explain the epidemiology of breast cancer among US women • To understand screening modalities and current breast cancer screening recommendations • To discuss strategies to reduce risk of developing breast cancer
Epidemiology of Breast Cancer • 2003: 211,300 new cases of breast cancer and 39,800 deaths • 32% of all newly diagnosed cancers in women are cancers of the breast • Most common cancer diagnosed in women • Most feared health condition by women
Leading Sites of Cancer Incidence and Death in Women (1997 Estimates) CANCER CANCER RANK INCIDENCE DEATHS 1 Breast Lung 192,200 66,000 2 Lung Breast 79,800 40,200 3 Colon/Rectum Colon/Rectum 64,800 27,900 4 Corpus Uteri Ovary 34,900 14,200
Cancer Mortality Rate Ratio for Females, 1994-98, AI/AN Compared to U.S. All Races All Sites Lung Colon/Rect. Ill Def/Unk. Breast Stomach Liver Pancreas Kidney Ovary Esophagus Cervix Gallbladder .5 .75 1 1.5 2 *AI/AN rate statistically different from US All Races death rates
Breast Cancer Mortality RatesFemales, 1994-98 All IHS (14.1) * All US (24.2) Rate per 100,000 per year, adjusted to 1970 U.S. population Figure 26 ** Denotes a rate significantly higher (* lower) than the U.S. rate.
Risk Factors for Breast Cancer • Female gender • Age over 50
Putting Breast Cancer Risk in Perspective • The “1 in 9” statistic • Cohort of 1000 women • By age 85: • 33 dead from breast cancer • 99 will have diagnosis of breast ca • 203 dead from CV disease
Putting Breast Cancer Risk in Perspective • 1 woman in 9 develops breast cancer • That woman has a 50% chance of being diagnosed after age 65 • That woman has a 60% chance of surviving breast cancer and dying of another cause
Fear of Breast Cancer • Survey of 1000 women age 45-64 • Condition they feared most: • Breast cancer: 61% • Cardiovascular disease: 9%
Other Major Risk Factors • Family History • 1st degree relative • Premenopausal • Bilateral cancer • Personal History • Breast cancer • Carcinoma in situ • Atypical hyperplasia
Minor Risk Factors • Late age at first pregnancy • Nulliparity • High socioeconomic status • Exposure to high dose radiation • Hyperplasia on breast biopsy
Risk factors for BRCA 1 and BRCA 2 • Breast and ovarian cancer • 2 or more relatives < 50 with breast cancer • Male breast cancer • > or = 1 relative < 50 with breast cancer + Ashkenazi Jew • Ovarian cancer + Ashkenazi Jew
Breast cancer and HRT • 5 years of ERT does not increase risk • 5 years of HRT increases risk by 26%
Unproven Risk Factors • Oral contraceptives • Obesity • High fat diet
Breast Cancer Screening • Breast self exam (BSE) • Clinical breast exam (CBE) • Mammography
USPSTF and Canadian TFPHCRating of evaluations • A: Strong recommendation to include the service • B: Recommendation to include the service • C: No recommendation either for or against • D: Recommendation against routine provision of the service • I: Evidence insufficient
Breast self exam:Canadian Task force on Prevention • Fair evidence of no benefit • Good evidence of harm • Overall fair evidence that routine teaching of BSE should be excluded from the annual exam • D recommendation June, 2001
USPSTF: 2002Should we recommend BSE? BSE: insufficient evidence to recommend for or against • “I” recommendation
Studies evaluating BSE • 2 RCTs, 1 quasi RCT, 3 case-control studies • No difference in breast cancer mortality • No difference in stage of cancer at diagnosis • More provider visits: 8% vs. 4% • More benign biopsies
ACOG Practice Bulletin: Breast cancer screening April, 2003 • Despite a lack of definitive data for or against breast self-examination, breast self-examination has the potential to detect palpable breast cancer and can be recommended.
Costs of BSE • $700 per competent frequent self-examiner • Opportunity cost: limited time for counseling • Anxiety, worry, depression
Disadvantages of Screening Age 40-49 1/3 of women undergoing annual screening mammography between 40-49 will have an abnormal mammo requiring: • Further imaging studies • FNA or core biopsy • Excisional biopsy
Does mammography work? • 2001: Cochrane review by Olsen and Gotzsche found no reduction in mortality • 5 of 8 trials seriously flawed • 3 “sound” trials showed no benefit • Methodological flaws negate findings of benefit
Does mammography work? • 2002: USPSTF reviewed Cochrane findings • Only 1 trial seriously flawed • Flaws “problematic” but unlikely to negate findings of benefit • Downgraded recommendation (A to B) but included all women > 40
Mortality is declining • 1990-1999: breast cancer mortality has decreased by 17%
New screening technologies • Full-field digital mammography • Computer-assisted detection • MRI • Ultrasound
Screening Mammogram ReportsBirads • Birads 0: Incomplete study • Birads 1: Normal, routine follow-up • Birads 2: Benign finding, routine follow-up • Birads 3: Probably benign finding, 6 month follow-up • Birads 4: Suspicious finding, consider biopsy • Birads 5: Highly suspicious, biopsy required
Limitations of Mammography • Palpable masses must be evaluated despite NEGATIVE results
Gail Model • http://bcra.nci.nih.gov/brc/ • Calculates 5 year risk of developing breast cancer • Age • Age at menarche • # of breast biopsies • Age at first live birth • Number of first degree relatives with breast cancer
Reducing the risk of breast cancer • Chemoprevention • Tamoxifen and raloxifene: • 38% decrease in breast cancer incidence?? Reduction in mortality • Tamoxifen • Endometrial cancer, DVT • Raloxifene • DVT
Chemoprevention • NSAIDs?? • 2 or more tabs/wk of ASA/ibuprofen led to a 21% decrease in breast cancer risk in the WHI trial
Reducing the risk of breast cancer • Prophylactic surgery • Bilateral mastectomy • Reduces risk by 90% • Bilateral oophorectomy • Lifestyle • Reduction in fat intake, exercise, weight loss, reduction in alcohol
Summary • Take down your shower card for BSE • Encourage mammography • Work up palpable masses • Don’t worry quite so much…