Download 11- Breast Screening Pros and Cons

Breast Cancer Screening….Pros
and Cons
Dr. Khaled Abulkhair
MSc, PhD Clinical Oncology, Mansoura University
Medical Oncology SCE, Royal College, UK
Ass. Professor of Clinical Oncology, Mansoura University, Egypt
Questions
• Would you follow the current NCCN
Guidelines ordering Mammographic screening
for breast cancer for average risk lady aged 40
years or more?
• What is the ultimate goal of screening?
FACTS:
• Cancer develops in the body very silently.
• Cancer is the cause of 12% of all deaths.
• Until it comes to a certain stage patients lead a
normal life without any complaints.
• Initially it produces mild symptoms as found in
other diseases.
• Cancer detected at early stage produces better
results on treatment and even cure .
• Advanced disease leads to financial
and
psychological burden.
How To Detect Cancer Early
As simple as…..The Seven Danger Signals
The American Cancer Society uses the word C-A-U-T-I-O-N to
help recognize the seven early signs of cancer:
1. Change in bowel or bladder habits.
2. A sore that does not heal.
3. Unusual bleeding or discharge.
4. Thickening or lump in the breast, testicles, or elsewhere.
5. Indigestion or difficulty swallowing.
6. Obvious change in the size, color, shape, or thickness of a
wart, mole, or mouth sore.
7. Nagging cough or hoarseness.
These signs don't necessarily mean you have cancer, but it's
important to have them checked out
Do we trust the public to catch upon these signals? We need a
test …. many theories, questions and plans:
• What we will call it? Screening…..
• Did we make a mistake replacing the concept of early
detection by Screening ??????
• Why we are doing it? To help the public’s fight against cancer
• Did the test really help the public??? After 20 years of
screening we are still not sure!
Questions?
• Is early detection of cancer an easy job?
• Is early detection equals screening?
• What are the needed requirements for
effective screening?
• Cost / Benefits?
• Do we need to import recommendations
from other countries or carefully select
what is suitable for our community?
He is not a woman!
Yes
Non Conclusive
False
Positive
Screening
• Screening refers to the use of simple tests across a
healthy population in order to identify individuals
who have disease, but do not yet have symptoms.
• Examples include breast cancer screening using
mammography and cervical cancer screening using
cytology screening methods, Prostate cancer and
PSA, Lung cancer and CT etc.
• Based on the existing evidence, mass population
screening can be advocated only for breast and
cervical cancer, using mammography screening and
cytology screening, in countries where resources
are available for wide coverage of the population.
Definitions in simple
Screening MAM is usually studied in comparison to the gold
standard for diagnosing cancer (Biopsy).
1. High Sensitivity: to be sure that as few as possible with
cancer get through undetected.
2. High Specificity: to be sure that as few as possible without
cancer are subject to further diagnostic tests
3. Positive predictive value: the portion turned out to have
cancer in those who give a positive test result.
4. Negative predictive value: the portion turned out to be
free of cancer in those who give a negative test result.
5. Prevalence: If the prevalence of the disease is very low,
even the best screening test will not be an effective public
health programs.
6. Acceptability: the extent to which those for whom the test
is designed agree to be tested.
Requirements for effective screening as per WHO:
• Screening programs should be undertaken only when
their effectiveness has been demonstrated.
• Screening tests should fulfill the following criteria:
i.
ii.
The screening test should meet acceptable levels of
accuracy and cost.
The screening test and follow-up requirements should be
acceptable to individuals at risk and to their health-care
providers.
• when resources (personnel, equipment, etc.) are
sufficient to cover nearly all of the target group.
• when facilities exist for confirming diagnoses and for
treatment and follow-up of those with abnormal results.
• And when prevalence of the disease is high enough to
justify the efforts and costs of screening.
Basically……
• A disease of a relatively high prevalence and
constitutes a major health problem e.g. Breast
Cancer.
• Organizational body to review the cost
benefits, requirements and evaluate the
program under utilization.
• A good screening Test:
Perfect Screening Test
•
•
•
•
Simple
Cheap
cost /benefit
Non invasive and widely
accepted
• High sensitivity /specificity
• Low false positive /false
negative
GOOD AND BAD
• Major financial burden
on mass application
• False negative!
• False positive! Anxiety
• Over diagnosis
• Over treatment
• Etc.
Breast Cancer Screening Using
Mammography
What are the benefits of screening
mammograms?
• Early detection of breast cancer with screening
mammography means that treatment can be started
earlier in the course of the disease, possibly before it has
spread! Remember this point
• Results from randomized clinical trials and other studies
show that screening mammography can help reduce the
number of deaths from breast cancer among women ages
40 to 70, especially for those over age 50.
• However, studies to date have not shown a benefit from
regular screening mammography in women under age 40
or from baseline screening mammograms (mammograms
used for comparison) taken before age 40.
USA: The American Cancer Society
recommends that annual screening begin at
age 40 for women at average risk
Who is offered breast
screening/how often?
We currently invite all
women between 50 - 70
years old for breast
screening.
We offer breast screening
every three years
Nordic Countries
Including:
(Denmark, Finland, Iceland, Norway and Sweden)
 The recommendations is that screening begin
at age 50 with two year intervals for
subsequent exams.
 Each Country adopts its own guidelines!
Inconsistency Among Different Guidelines
 Which Guidelines Should
We follow?
 Is There A Strong Evidence
Behind these Guidelines? If
so……..
 Why there is a great
difference between
different guidelines?
 How come UK doctors are
sure they will not miss
cancer cases by long
interval Q3 years?
 Are there any harms behind
screening mammogram????
The potential Harms Of Mammogram?
• Finding cancer early does not always reduce a
woman’s chance of dying from breast cancer.
• False-negative results. Overall, screening
mammograms miss about 20 % of breast cancers
that are present at the time of screening e.g.
dense breasts. Remember it depends up on
“what the picture shows”.
• False-positive results. False-positive results occur
when radiologists decide mammograms are
abnormal but ultimately no cancer is actually
present……Anxiety till Cancer excluded
Continued……..
• Over-diagnosis: Can find very early indolent cancers especially
in elderly and cases of DCIS that may never cause symptoms or
threaten a woman’s life, leading to “over-diagnosis” of breast
cancer.
• Over-treatment: Treatment of these indolent cancers and
cases of DCIS is not needed and leads to “overtreatment.” This
exposes women unnecessarily to the adverse effects associated
with cancer therapy.
• For every 14,000 women screened regularly for 10 years, one
woman may develop breast cancer she will die from because of
the radiation from the mammograms (NHS).
• QUALY? COST?
Methods:
• Quality adjusted life years (QALYs), combining life years gained
from screening with losses of quality of life from false positive
diagnoses and surgery. The setting was England.
• The outcomes of 100 000 women aged 50 were modelled in two
cohorts, one screened the other not.
• The outcome measures were deaths from breast cancer, deaths
from all other causes, and the number of women having false
positive diagnoses and surgery, which they combined into the
main outcome—quality adjusted life years (QALYs).
They concluded that…
• What is already known on this topic:
 Mammographic screening for breast cancer saves lives but
also imposes losses in quality of life from false positive
results and unnecessary treatment .
 It has been suggested that the harms outweigh the benefits,
but this has not been quantified.
• What this study adds:
 By combining the life years saved with the quality of life
losses in quality adjusted life years QALYs, this study
combined the benefits and harms into a single measure.
 Overall, their study supports the suggestion by Gøtzsche and
Nielsen, 2009 that mammographic breast cancer screening
could be causing more harm than good after 10 years.
• Methods: 8 Randomised trials comparing mammographic screening
with no mammographic screening. They included 600,000 women in the
analyses.
• Conclusions:
1. Screening is likely to reduce breast cancer mortality. A reasonable
estimate is a 15% reduction corresponding to an absolute risk
reduction of 0.05%.
2. Screening led to 30% overdiagnosis and overtreatment, or an absolute
risk increase of 0.5%.
3. For every 2000 women invited for screening throughout 10 years, one
will have her life prolonged and 10 healthy women, who would not
have been diagnosed if there had not been screening, will be treated
unnecessarily.
4. Furthermore, more than 200 women will experience important
psychological distress for many months because of false positive
findings.
U.K: NHS
• From NHS For every 400 women screened regularly for
10 years, one less will die from breast cancer i.e. one life
saved!
• Cost of a screening mammogram range from € 80-120.
• Simple Calculation: 400 x 100 € x 4 (times of screening
over 10 years) = € 160.000 to save one life!
• Cost would be in billions of Euros if a significant number
of women complied.
• Around one in 20 women are called back because their
mammograms show that more tests are needed (False
Positive).
• For each 1000 screened women; 8 will be diagnosed
with breast cancer. Two of them will have DCIS (potential
over diagnosis / over treatment).
• On 29 Oct 2012 Professor Sir Mike Richards, the NHS's National
Cancer Director, initiated the review last year due to a number
of academic reports which suggested the benefits of screening
programs were being oversold and the harms underplayed.
• While the panel concluded that the £96 million campaign does
save lives, they said it caused significant harm too.
• After looking at 10 trials involving almost 600,000 women, they
estimated the NHS program saves 1,300 lives a year.
• However, they also calculated it resulted in another 4,000
receiving treatment for early-stage cancers that would never
spread and cause them a problem.
Conclusions: The contrast between the time
differences in implementation of mammography
screening and the similarity in reductions in mortality
between the country pairs suggest that screening did
not play a direct part in the reductions in breast
cancer mortality.
The benefit of screening is still highly criticized in
countries with high Prevalence e.g. USA, UK and
Nordic countries
This criticism involved not only the clinical
outcome but also the cost.
• What about our countries?
• What would be the real benefit?
• What would be the cost?
• world breast cancer incidence.svg
Again….Simple Calculations!
• With our current incidence in Middle east
Countries of about 1/2 - 1/3 that of western
countries:
• I assume that we may need to spend 2-3 folds
to save the same one life i.e.
• Saving one Life = € 160.000 x 2 = € 320,000 =
3,200,000 L.E
Saving a single life worth Billions to us!
But Do We really want to save lives?!!!
• What vision they are talking
about? It is a blind world!
• During the 60 mint of this
activity… 300 child will dye in
hunger!!!!
• FAO ( Food Agriculture
Organization) stated that
Every day 925 millions
worldwide experience
hunger
• € 160,000/1,500,000 L.E!!!!
• How many thousands of lives
they can save?
• A real Hypocrisy in medicine!
• They implemented screening for a high
prevalence disease in their countries not ours.
• If we really need to screen think about
different cancer.
• world Liver.svg
What Age Should We Start Screening At?
• If we start at 40 years following NCCN
guidelines…the median age of diagnosis of
breast cancer in western data is about 60 years
i.e. they start about 15 - 20 years earlier.
• Other countries start at 50 i.e. 10 years earlier .
• Median Age of Breast Cancer in the middle
east is around 45-50 years!
Data on female patients with invasive breast carcinoma reported
from different regions in Saudi Arabia show that most patients are
in the age group of 40 - 50 years and were predominantly
premenopausal.
Data from Egypt
WHO Statements:
1. Policies on early cancer detection will differ markedly
between countries.
2. An industrialized country may conduct screening programs for
cervical and breast cancer. Such programs are not, however,
recommended in the least developed countries in which there
is a low prevalence of cancer and a weak health care
infrastructure.
3. The recommended early detection strategies for low- and
middle-income countries are awareness of early signs and
symptoms and screening by clinical breast examination in
demonstration areas.
4. Mammography screening is very costly and is recommended
for countries with good health infrastructure that can afford a
long-term programs.
5. Further, only organized screening programs are likely to be
fully successful as a means of reaching a high proportion of
the at-risk population.
My Point Of View:
1. I am not against screening
but against imposing the
“high technology” of the
developed world on
countries that:
• Lack resources / Lack
Awareness
To achieve adequate
coverage of the population.
• Having lower incidence.
• Different disease
characteristics.
2.
Major success improving mortality in cancer patients were mainly
achieved in cancers with fast growing nature where screening
does not help!
 Decreasing mortality: How can we separate the effect of
screening from the effect of improving treatment strategy in
breast cancer over the last 20 years?
3. A necessary condition for benefit by early detection requires that
the disease tends to be diagnosed in an earlier stage (we still have
≥ 70% of breast cancer patients diagnosed at advanced stages).
Awareness may be more needed than Screening?
4. The general consensus is that randomized clinical trials are the only
way to evaluate screening programs for potential benefit. Do We
Have Such Trials?
5. Important factor to consider is the efficacy of MAM in young
population below 40 years as with our patients. Doubtful benefits
for western population. What about ours?
Important Points To Remember
•
•
•
•
Not all cancers can be screened for.
Screening tests are not perfect.
Early detection is not an easy job.
It is becoming more difficult every day to justify MAM
screening. It is based on “what the picture shows” thus it
misses at least 25% of cancer! False Negative
• Easily, you can find data just saying the opposite of what I
presented.
• However, till we have our own data I do not believe adopting
mass screening MAM is the best way for our countries.
• I believe Screening is not an equal term for early detection!
• CBE is still a valid option by WHO & NCCN guidelines.
• Knowing your body well is still a very important and valid
option.
• Talk to your doctor if having new findings; which may not be
anything to worry about, in which case you’ll lose nothing. But
if it’s something serious, you could have everything to gain.
• Breast awareness can not be over emphasized!
Wherever You Find Young People Fighting For A
Better Life Help Them As Much As You Can…. If You
Cannot Help….. Please Do Not Be an Obstacle In
Their Way