Breast Cancer Screening Flashcards
sensitivity
Percentage of patients with disease who will be correctly identified by a screening test
specificity
Percentage of patients without disease who will be correctly identified as disease free by a screening test
PPV
Probability of having the disease given one has a positive test result
NPV
Probability of not having the disease given one has a negative test result
Prevalence
Probability of having the disease for a patient sample simulated in a 2x2 table
Most common breast cancer screening modalities
digital mammography, the clinical breast exam (lesions greater than 1 cm), and the self-breast exam
Interventions according to basic, limited, enhanced, and maximal levels of resources
Basic:
Breast health awareness (education + self-examination)
Clinical history and CBE
Limited:
Targeted outreach/education encouraging CBE for at risk groups
Diagnostic breast US +/- diagnostic mammography in women with positive CBE
Enhanced:
Diagnostic mammography
Opportunistic mammographic screening
Maximal:
Population based mammographic screening
Other imaging technologies as appropriate for high-risk groups
Mammography
- low dose radiographs of breast
- 2 views of each breast in perpendicular planes (medio-lateral and cranio-caudal views)
- 2 indications are screening and diagnostic
- Breast composition graded on a 4 point scale (A-D)
- breast cancers appear white on mammograms, but denser breast tissue is also white: makes lesion identification more difficult. (younger women= denser breasts)
A-D scale and description for mammogram
A:The breasts are almost entirely fatty (10%)
B: There are scattered areas of fibroglandular density (40%)
C: The breasts are heterogeneously dense, which may obscure small masses. (40%)
D: The breasts are extremely dense, which lowers the sensitivity of mammography. (10%)
BI-RADS Assessment categories
Categories 0-6
0: incomplete
- Need additional imaging/info
1: negative (~0% malignant)
2: benign (~0% malignant)
3: probably benign (0-2% likelihood of malignancy)
- shorter interval for follow up or next mammogram
4: suspicious (low, moderate, high) (2-95% chance of malignancy)
- Need tissue diagnosis
5: highly suggestive of malignancy (95% likelihood of malignancy)
- Tissue dx
6: known biopsy-proven malignancy
- surgical excision
Breast self-exam vs being breast aware
BSE: regular, repetitive monthly palpation to a rigorous set method performed by the woman at the same time each month
Breast aware:
a woman becoming familiar with her own breasts and the way that they will change.
-to know how their own breasts look and feel normally so that they gain confidence about noticing any change which might help detect breast cancer early
Changes in breasts that should be looked out for
- Size – if one breast becomes larger, or lower.
- Nipples – if a nipple becomes inverted (pulled in) or changesposition or shape.
- Rashes – on or around the nipple.
- Discharge – from one or both nipples.
- Skin changes – puckering or dimpling.
- Swelling – under the armpit or around the collarbone (where the lymph nodes are).
- Pain – continuous, in one part of the breast or armpit.
- Lump or thickening – different to the rest of the breast tissue.
Clinical breast exam
- examination of a patient’s breast tissue by a trained examiner
- examining the entire breast and its lymphatic drainage, palpating the breast tissue at multiple depths, and examining the breast tissue for three minutes each.
- Characterize lesions by mobility, consistency, regularity, size (is it fixed? hard? irregular? how big?)
When are MRIs appropriate? 3D mammography?
MRIs
- for pts at very high risk of developing breast cancer (like BRCA carriers)
- expensive
3D mammography
- newest
- more suitable for women with more dense breasts
American Cancer Society recommendations for women at average risk
- Women ages 40 to 44 should have the choice to start annual breast cancer screening with mammograms
- Women age 45 to 54 should get mammograms every year.
- Women age 55 and older should switch to mammograms every 2 years, or have the choice to continue yearly screening.
- Screening should continue as long as a woman is in good health and is expected to live 10 more years or longer