Breast Cancer Screening: A Primary Care Perspective Flashcards

1
Q

Screenings, by definition, are only in people without ______________.

A

symptoms; if they have symptoms, that is a diagnostic test

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2
Q

What happens to early-stage incidence and late-stage incidence when screening protocols are implemented?

A

Early-stage incidence increases and late-stage incidence decreases.

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3
Q

Breaking down cancers into very fast, fast, slow, and very slow progressors, what cancers are you hoping to find with screening?

A

Fast

Note: Over-diagnosis occurs in the slow and very slow cancers (like prostate cancer) and screening is unlikely to catch the very fast progressors (like melanoma).

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4
Q

What is lead-time bias?

A

If you discover something earlier then it appears that people in the screened group live longer.

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5
Q

What is length-time bias?

A

You’re more likely to discover something that’s slow growing.

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6
Q

In a 2x2 table, the _____________ is on top.

A

positive (those who have the disease)

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7
Q

Why is high sensitivity important in a screening test?

A

High sensitivity means you have few false negatives, which is important if you’re going to tell people they don’t have a disease.

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8
Q

What is the SpIn mnemonic?

A

With a highly SPecific test, you’ve ruled the patient IN. This is so because with high specificity you have few false positives.

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9
Q

What is the formula for NPV?

A

(TN) / (TN + FN)

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10
Q

What is the likelihood that a woman with an abnormal mammogram has breast cancer?

A

6.6%

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11
Q

As the prevalence of a certain disease goes down, the rate of ______________ goes up.

A

false positives

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12
Q

What is the prevalence of breast cancer in women in their 40s and 50s?

A

40s: 1%
50s: 2%

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13
Q

What is the likelihood ratio?

A

(probability of test result in person with disease)
_____________________________________
(probability of same result in person without disease)

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14
Q

What are good LRs for ruling something in and out?

A

In: greater than 10
Out: less than 0.1

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15
Q

What are the formulae for LR + and LR -?

A

LR +:
(sensitivity) / (1 –specificity)

LR –:
(1 –sensitivity) / (specificity)

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16
Q

The relative risk reduction is equal to _____________.

A

1 –(relative risk)

17
Q

How many women in their 40s need to be screened to save one life from breast cancer?

A

3,334

18
Q

MRI is recommended for women whose lifetime risk of developing breast cancer is _____________.

A

greater than 20%

19
Q

Tamoxifen is recommended for women whose 5-year risk of developing breast cancer is _________.

A

greater than 3%

20
Q

The number needed to treat decreases as ______________ increases.

A

prevalence