Download Cancer Screening Cancer screening

Screening and Early
Diagnosis in Oncology
Başak Oyan-Uluç, MD
Yeditepe University Hospital
Department of Medical Oncology
Prevention
Onset of disease
Healthy
Primary
Elimination of
risk factor
• Cessation of
smoking
• Colonoscopy
• Vaccination
• Lifestyle
modifications
Clinical
diagnosis
Asymptomatic
Clinical course
Secondary
Early diagnosis
and treatment
• Colonoscopy
• Mamography
• Pap smear
Tertiary
Reducing
complications
(rehabilitation)
Cancer Screening
• Cancer screening: Early detection of asymptomatic
or unrecognized disease by the application of
inexpensive tests or examinations in a large number
of people.
• Main objective: To reduce morbidity and mortality
from a particular cancer among people screened.
• Screening procedure itself
– Not diagnostic
– Detects people with cancer risk
– Positive or suspicious findings must be evaluated further to
determine diagnosis and appropriate treatment.
Screening vs. Diagnosis
Screening
Diagnosis
Applied to asymptomatic
groups
Applied to symptomatic
individuals
Lower cost per test
Higher cost, all necessary tests
applied to identify disease
Lower yield per test
Increased probability of case
detection
Lower adverse consequences of Failure to identify true positive
error
can delay treatment, worsen
prognosis
Ideal screening program
Patient features
• High impact: Morbidity,
mortality, economy
• High incidance and high
prevelance
• Predictable corse and biology
• High prevelance of preclinic
phase
• Effective treatment exists
Requirements of
screening test
• Diagnosing disease at
preclinical phase
• Acceptable sensitivity and
specificy
• Acceptable to people
• Simple anf cheap
• Safe
Quality of primary or secondary prevention (Cheap, effective, safe)
Benefits of Screening
• Improved prognosis for those with earlydetected cancers
• Less radical treatment
• Reassurance for those with negative test
results
• Reduction of treatment costs
Hazards of screening
• The potential for overdiagnosis (Labelling phenomenon)
• The potential carcinogenic effects of screening (i.e. Radiation
risk with mammography)
• The economic consequences of false-negatives
Cervical Cancer-Pap Smear
1.
Long preinvasive period
2.
Increased morbidity and mortality in invasive period
3.
Treatable if early diagnosis
4.
PAP smear: Sensitive, low cost, easy to apply, safe
Cancers suitable for screening
• Although there are more than 100 different cancers,
most of them lack proven screening interventions
• Cancers that have widely accepted screening
interventions
•
•
•
•
Breast
Cervix
Colorectal
Prostate ?
• Hepatocellular cancer in patients with risk factor
• Lung cancer in people with defined risk factors
Breast Cancer Screening
• Most common cancer in females
• Average risk
• Increased risk
–
–
–
–
–
Prior thoracic RT (eg. Mantle)
Women who have a lifetime risk of >%20
Strong family history of genetic predisposition
LCIS/atypical hyperplasia
Prior history of breast cancer
Breast Cancer Screening
Average risk women
Widely accepted techniques for breast cancer
screening includes
– Brest self-examination: Monthly after age 20
– Clinical breast examination:
• Age 20-39: Every 1-3 years
• Every year after age 40
– Mamography: Every year after age 40
• Decrease mortality by 20-30%
Cervical Cancer Screening
• Second most common cancer in females
worldwide particularly in the underdeveloped
regions
• The incidence has declined in many
countries due to the improved standard of
living throughout the world
Cervical Cancer Screening
• Pap test: Introduced in 1930s by Dr. Papanicolaou
• Screening should begin at age 21
• Discontinuation of screening
– At age 65-70, if 3 negative tests and no abnormal tests in
preceeding 10 years
• Screening not discontinued in
–
–
–
–
In-uterine DES exposure
Personal history of servical cancer
Immune insuffiency (eg. HIV)
HPV DNA (+)
Cervical Cytologic Screening Guidelines from the American College of
Obstetricians and Gynecologists, 2009
Sawaya G. N Engl J Med 2009;10.1056/NEJMp0911380
Colorectal Cancer Screening
• Causes morbidity and mortality in both men
and women
• Second leading cause of death due to cancer
• The natural history of colon cancer with
relatively long time from biologic onset to
development of carcinoma makes it a good
candidate for screening
Risk groups for screening
• Average risk
–
–
–
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Age ≥ 50 y
No inflammatoy bowel disease
No history of adenoma or colorectal cancer
Negative family history
• Increased risk
– Personal history of
• Adenoma/sessile serrated polyp
• Inflammatoy bowel disease
• Colorectal cancer
– Positive family history
• High risk syndromes
– Lynch syndrome/Hereditary nonpolyposis colorectal cancer (HNPCC)
– Polyposis syndromes (familial adenomatous polyposis, PeutzJeggers syndrome, Juvenile polyposis syndrome, hyperplastic
polyposis syndrome)
Screening tests for colorectal cancer
Average risk
Starts at age 50
1. Colonoscopy every 10 years
•
•
preferred if available
For every 1% increase in complete colonoscopy rate, the hazard of
death decreased by 3%.
2. Annual FOBT+Flexible sigmoidoscopy every 5 years
Annual Fecal occult blood test (FOBT)
•
•
Testing of stool for occult blood to detect colorectal cancer at an early
stage
Variation is observed in estimates of the sensitivity but its lower cost and
increased specificity to detect right-isded colonic lesions make it a good
screening test
Flexible sigmoidoscopy every 5 years
•
•
•
In contrast to FOBT, has a high sensitivity and specificity
Involves the use of a 60 cm flexible sigmoidoscope
Detects left sided lesions
Prostate Cancer Screening
• Most commonly diagnosed cancer among
men and is the second leading cause of male
cancer deaths
• Two main screening modalities
• Serum prostate specific antigen (PSA)
• Digital rectal examination (DRE)
Prostate Cancer Screening
• Benefit of screening is controversial
• Prostate cancer is common and potentially lethal; however,
more patients die with, rather than from, the disease.
• Incidence: 1/6
Mortality: 1/30
• Screening detects more cases of organ-confined disease, but
there is no proof that this detection saves lives.
• In more instances, prostate cancer is not the cause of elevated
PSA level.
NEJM 2009; 360:1310
NEJM 2009; 360:1320
Prostate Cancer Screening
• Localized treatment of prostate cancer is effective
but is associated with complications than can
include impotence and incontinence (~ 50%).
• It is likely that prostate cancer screening using the
PSA level is beneficial in a subset of men; however,
the characteristics of the subset have not been
defined.
Prostate Cancer Screening
• Discuss benefit and harms of screening with
the patient
• In men with a life expectancy of >10 years,
start annual screening at age 40y with:
– PSA
– Digital rectal examination
• In last years it is recommended to offer a
baseline DRE and PSA at age 40 y.
Prostate Cancer Screening
• DRE
• Most widely used and oldest technique for
detection of prostate cancer
• Wide ranges of sensitivity (33%-69%) and
specificity (49%-97%)
• Serum PSA level
• Allows earlier detection of prostate cancer
• Normal PSA values are found in 1/3 of localized tumors
(false negative)
• Often elevated in men with noncancerous conditions
such as benign prostatic hyperplasia (false positive)
Prostate Cancer Screening
• NCCN recommendation
– DRE yearly starting at age 40
– PSA yearly starting at age 40
Lung Cancer Screening
Target population:
• Age: 55-74 years +
• Smoked ≥ 30 pack/year +
• Continue to smoke or have quitted smoking
within 15 years
Screeninig method: Low dose thorax CT
Hepatocellular Carcinoma
Cirrhosis
No cirrhosis
•
•
•
•
• Hepatitis B carrier
• Non-alcoholic
steatohepatitis
Hepatitis B, C
Alcohol
Genetic hemocromatosis
Non-alcoholic
steatohepatitis
• Autoimmune hepatitis
• Primary biliary cirrhosis
Diagnosis rate:
%92
False (+): %7.5
Ultrasonography
Alpha-feto protein (AFP)
Every 6-12 months
People not to be screened
• Life expectancy <5 years
• People who do not wish to undergo
additional diagnostic tests or who do not
want any treatment
Future of Screening
• Compliance: Encourage people to adhere the
proven cancer screening modalities
• New and better methods: With the discovery
of cancer susceptibility genes (e.g. BRCA-1
susceptibility gene for breast cancer) lifetime
risk for an individual to develop a specific
cancer could be estimated.