SM_280b: Cancer Screening Flashcards
Cancer screening is ___
Cancer screening is performance of a procedure to detect cancer or precancerous condition before onset of symptoms
- Not the same as diagnosis
Describe factors that favor screening as a population strategy
Factors that favor screening as a population strategy
- High burden of disease (cancer is common)
- Precancerous lesion or early stage disease detectable by screening (long latency)
- Clinical intervention at this stage prevents subsequent development of cancer or improves prognosis of cancer
- Screening test with favorable test characteristics: accurate, safe, affordable and available
- Clinical outcomes are improved: requires effective treatment intervention, risks and harms of intervention are acceptably low, early treatment after screening is more effective than later treatment without screening
Describe the adenoma carcinoma sequence in colorectal cancer
Adenoma carcinoma sequence in colorectal cancer
Biases in screening are ___, ___, and ___
Biases in screening are lead-time bias, length-time bias, and compliance bias
Lead-time bias is ___
Lead-time bias is when lead time in diagnosis makes it seem that survival is prolonged but death is not delayed
Length bias is ___
Length bias is when screening detects more indolent cancers
____ is best way to avoid lead time and length time bias in cancer screening trials
Using cancer specific mortality rates is best way to avoid lead time and length time bias in cancer screening trials
Describe factors that make screening unfavorable
Factors that make screening unfavorable
- Overdiagnosis and overtreatment
- Harms of initial screening test
- Harms of false positive results
- Screening test has poor sensitivity
- Cancer is very rare
- Outcomes not improved with earlier detection
Overdiagnosis bias is when ___
Overdiagnosis bias is when screenign detects cancer (pseudodisease) that would remain subclinical before death from other causes
____ and ____ are ways to decrease the rate of false positives in screening
Screening higher risk populations and limiting the frequency of screening are ways to decrease the rate of false positives in screening
Sensitivity of screening can be improved by ___
Sensitivity of screening can be improved by increasing the frequency of screening
Screening fails to improve outcomes when ___ and ___
Screening fails to improve outcomes when there is excellent prognosis at clinical presentation or no accurate screening tests are available
Describe the USPSTF classification system
USPSTF classification system
Progression for LGSIL / CIN I to cervical cancer takes ___
Progression for LGSIL / CIN I to cervical cancer takes 15 years
- Sufficient time interval exists when precancerous condition or early stage cancer is detectable by screening
HPV ___ and ___ are associated with cervical neoplasia
HPV 16 and 18 are associated with cervical neoplasia
- Key factor is persistence of HPV infection
Describe cervical cancer screening
Cervical cancer screening (21-65 yo)
- 21-29: Pap q3 years
- 30-65: Pap q3 years or co-testing every 5 years or high risk HPV alone every 5 years
Colorectal cancer screening tests include ___ or ___
Colorectal cancer screening tests include stool based tests or direct visualization tests
Describe mammogram guidelines for average risk women
Mammogram guidelines for average risk women
- Start at age 50
- Stop age age 74
- Screen every two years
- Insufficient evidence for clinical breast exam
- Recommends against teaching women how to perform breast self-exam
Decision to undergo prostate cancer screening should be ___
Decision to undergo prostate cancer screening should be individual one
- Routine screening not recommended
