Download Cancer Screening

Cancer Screening
경희의대 부속병원
종양혈액내과
조 경 삼
Cancer screening
Definition
Means of detecting disease early in
asymptomatic people with the goal of
decreasing morbidity and mortality
Screening examinations, tests, or
procedures are usually not diagnostic,
but indicate that a cancer may be
present
Lung cancer screening
• Chest radiographs
• Sputum cytology
– No reduction in lung cancer mortality
• NCCN (National Comprehensive
Cancer
Network) lung cancer
screening
guideline :
clinical trial, spiral CT (ex: I-ELCAP)
for high risk persons
• 기간 : 1993 – 2005 (median: 2001)
• 대상 : high risk persons
– ≥ 40 years
– History of smoking
– Occupational exposure (to asbestos,
beryllium, uranium, or radon)
– Exposure secondhand smoke
• Baseline and annual screening
• Baseline screening :
– Positive result :
– Lung cancer :
• Annual screening :
– Positive result :
– Lung cancer :
31,567명
4,186명 (13%)
405명 + 5명
27,456명
1,460명 (5%)
74명
• Total : lung cancer, 484명 : Stage I, 412명
• 10 year survival rate(stage I) : 88%
• Surgical resection (stage I): 302명, 92%
Detection rate
• Baseline screening : 1.3%
• Annual screening :
0.3%
• Original I-ELCAP
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≥ 60 years
Former or current smoker
Baseline screening : 2.7%
Annual screenig :
0.6%
Problems
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Definition of “high risk”
Systematic case-control observation
Lead time biases
Overdiagnosis
False positive
Cost-effectiveness
Cancer screening
Definition
Means of detecting disease early in
asymptomatic people with the goal of
decreasing morbidity and mortality
Screening examinations, tests, or
procedures are usually not diagnostic,
but indicate that a cancer may be
present
Scientific basis
• There must be a test or procedure
that will detect cancers early
• There must be evidence that
treatment at an earlier stage of
disease will result in an improved
outcome
• Decrease in cause-specific mortality
childhood neuroblastoma
prostate cancer
Assessment of screening tests
• A randomized, controlled screening
trial
• Internally controlled trials
• Cohort or case-control analytic
observational studies
• Multiple time series studies
• Opinions of respected authorities
Evaluation of a screening test
• Screening
test result
Positive
Negative
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Truth(diagnosis)
Cancer(+)
Cancer(-)
TP
FP
FN
TN
Sensitivity = TP/(TP+FN) X 100
Specificity = TN/(TN+FP) X 100
Positive predictive value (PV+) = TP/(TP+FP) X 100
Negative predictive value (PV-) = TN/(TN+FN) x 100
Measures of an improved
outcome
• A decrease in cause-specific
mortality
• Reduction in incidence of advanced
stage cancers
• An increase in survival
• A shift in stage
Biases of screening tests
• Lead-time bias : no change in
natural history ---prolonged survival time
• Length bias : slow-growing less
aggressive ---over diagnosis
• Selection bias : differ from general
population ---healthy volunteer effect
Cancers suitable for screening
• Substantial morbidity and mortality
• High prevalence in a detectable preclinical
state
• Possibility of effective and improved
treatment because of early detection
• Availability of a good screening test with high
sensitivity, specificity, low cost, little
inconvenience and discomfort:
breast, cervix, skin, colon-rectum, prostate
Benefits of cancer screening
• Improved prognosis for those with
screen-detected cancers
• The possibility of less radical
treatment
• Reassurance for those with
negative test results
• Resource saving
Potential drawbacks of screening
• Screening intervention itself
• Further investigation of persons with
positive test results
• Treatment of persons with a truepositive result
Disadvantages of cancer
screening
• Economic and psychological
consequences of FP and FN
• Potential for overdiagnosis
• Potential carcinogenic effects of
screening
• Unnecessary treatment with side
effects
Appropriate cancer screening
• Early detection of asymptomatic
or unrecognized disease
• By the application of inexpensive
tests or examinations
• In a large number of persons
Detection methods
• Observation:
skin, lip, mouth, larynx, external genitalia, cervix
• Palpation:
Breast, mouth, salivary gland, thyroid, anus,
rectum, prostate, testes, ovaries,
LN in the neck, axilla, groin,
• Endoscopy, x-rays, MRI, ultrasound
• Laboratory tests: pop smear, occult blood test
Screening recommendations(I)
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Sigmoidoscopy:
>50: periodically (USPSTF)
Fecal occult blood: >50: every year (USPSTF)
DRE:
>40: every year (ACS)
PSA:
>50: every year (ACS)
Papanicolaou test: 18-65: every 1-3 years
Pelvic exam:
same as Pap test (ACS)
Endometrial tissue sampling:
at menopause, obese, estrogen use (ACS)
Screening
recommendations(II)
• Breast self-exam: >20: every month (ACS)
• Breast clinical-exam:
>50: every year
(USPSTF)
• Mammography:
50-75: every 1-2 years
40-49:
(ACS)
• Complete skin exam:
20-39: every 3 years
(ACS)
Breast Cancer
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Breast self examination
Clinical breast examination
Mammography
MRI
• Age : over 50 : 20-30% decrease
Cervical cancer
• Pappanicolaou smears
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Sexually active for 3years, or 21 years
Interval : 1 to 3 years
Over 30 : 3 normal tests : 2-3years
Over 70 : no abnormal results for
previous 10 years
Colorectal cancer
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Fecal occult blood tests
Digital rectal examination
Rigid and flexible sigmoidoscopy
Barium contrast studies
Colonoscopy
Ovarian cancer
• Adnexal palpation
• Transvaginal ultrasound
• Serum CA-125
• Genetic ovarian cancer syndrome
Prostate cancer
• Digital rectal examination
• Serum PSA
• Impotence and urinary incontinence
• At least 10 years life expectancy
NCCN guidelines for screening
(http://www.nccn.org)
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Guidelines for Detection, Prevention, & Risk Reduction of Cancer
Breast Cancer Risk Reduction
Breast Cancer Screening and Diagnosis
Cervical Cancer Screening
Colorectal Cancer Screening
Genetic/Familial High-Risk Assessment: Breast and Ovarian
Breast and/or Ovarian Genetic Assessment
Hereditary Breast and/or Ovarian Cancer
Li-Fraumeni Syndrome
Cowden Syndrome
Prostate Cancer Early Detection
Genetic testing for cancer
risk
• Familial melanoma
p16INK4
melanoma, pancreatic
$400-600
• Hereditary breast or ovarian BRCA1
Breast, ovary, others
$400-2,000
• Hereditary breast
BRCA2
Breast, others
$400-2,000
• Hereditary nonpolyposis colon MSH2, MLH1, PMS2
Colon, uterine, others
$400-2,000
• Li-Fraumeni syndrome
p53
Brain, sarcoma, others
$500-700
Genetic testing
Individuals who are considering genetic
testing for cancer susceptibility should
be given the opportunity to consider the
physical, social, and legal risks
balanced against the potential benefits
of genetic testing for cancer risk,
including the uncertainties of the state
of our knowledge of cancer risk and
effective interventions
국내 암환자의 스크리닝(1)
• 자궁경부암 : 30세 -- 2년 – 자궁질경부
도말세포검사
• 위암 : 40세--2년 – 위내시경 또는 위장조영술
• 간암 : B, C, 만성 간질환 -- 6개월 – 복부초음
파,
AFP
• 유방암 : 40세 -- 1-2년 -- 유방촬영술
• 대장암 : 50세 -- 5-10년 – 대장내시경,
조영바륨검사
국내 암환자의 스크리닝(2)
문제점
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종양 표지자 (tumor markers)
대상 : 개인 또는 다수
Cost effectiveness
No evidence of studies