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OJHAS: Vol. 3, Issue
3: (2004 Jul-Sep) |
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| Cancer Screening |
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Krishna Prasad, MD, DM,
Medical Oncologist, Department of Medicine,
Kasturba Medical College Hospital,
Attavar, Mangalore |
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Address For Correspondence |
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Dr. Krishna Prasad,
Medical Oncologist, Department of Medicine,
Kasturba Medical College Hospital,
Attavar, Mangalore-575001
INDIA
E-mail: drkrishnaprasad@hotmail.com
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| Krishna Prasad. Cancer
Screening.
Online J Health Allied Scs.2004;3:1 |
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Submitted: Oct 10,
2004; Accepted: Oct 12, 2004; Published: Oct 18, 2004 |
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| Abstract: |
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Cancer screening is a means to detect cancer early with the goal of
decreasing morbidity and mortality. At present, there is a reasonable
consensus regarding screening for breast, cervical and colorectal cances and
the role of screening is under trial in case of cancers of the lung,
ovaries and prostate. On the other hand, good screening tests are not
available for some of the commonest cancers in India like the oral,
pharyngeal, esophageal and stomach cancers.
Key Words:
Cancer screening; Tumor
markers
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Cancer screening is a means to detect cancer early, in asymptomatic
individuals with the goal of decreasing morbidity and mortality. There is a lot of public
interest, and large trials are ongoing in many of the cancers. For a screening test to be
useful, the test should detect cancer earlier than would occur otherwise and there should
be evidence that earlier diagnosis results in improved outcome. Not all cancers are
suitable for screening and only those cancers having the following characteristics are
suitable:
- Substantial morbidity and mortality
- High prevalence in a detectable
preclinical stage
- Possibility of effective and improved
treatment because of early detection
- Availability of a good screening test with
high sensitivity and specificity, low cost, and little inconvenience and discomfort.
Some cancers for which reasonable
consensus has been arrived at regarding screening for the general population are as
follows:
- Breast Cancer:
- Monthly Breast self-examination for all
women above the age of 20.
- Clinical Breast examination every 3 years
between ages 20 – 39, and yearly after 40 years.
- Mammography yearly from age 40.
It is to be noted that among the 3
recommendations only Mammography has support of randomized controlled trials.
- Cervical Cancer:
Papanicolaou smear and pelvic examination
yearly for all women who are or who have been sexually active or have reached age 18.
After 3 consecutive normal smears, it can be done less often as per the discretion of the
physician.
- Colorectal Cancer:
One of the following schedules for people
over 50 years
- Faecal Occult Blood Test yearly and
sigmoidoscopy every 5 years.
- Colonoscopy every 10 years.
Role of Digital Rectal Examination and
Barium Meal Study is controversial.
Role of screening is under trial in
the following cancers:
- Lung Cancer:
Sputum cytology, Chest X ray, CT chest
have been evaluated but no evidence of definite benefit has been found.
- Ovarian Cancer:
Pelvic examination, Transvaginal
ultrasound and serum CA-125 levels are not proven to be beneficial.
- Prostate Cancer:
Serum Prostatic Specific Antigen levels
and Digital Rectal Examination have been attractive and also highly publicized, but no
evidence of benefit is available from randomized controlled trials
There are no good screening tests
available for some of the commonest cancers in India like the Oral, Pharyngeal, Esophageal
and Stomach cancers. However the lack of effective screening tests is not the only
problem. In fact, the main problems in our country are the lack of public awareness, lack
of motivation and the lack of access to basic health infrastructure. In the face of all
these impediments, it would not be wrong to say that Cancer Screening in India is a
distant dream.
- Rimer BK, Hiatt RA. Cancer Screening. In:
Devita VT, Hellman S, Rosenberg SA, eds. Cancer The principles and Practice of oncology.
2000. 627 – 637.
- Physicians Data Query. Cancer Screening
Bethesda MD: National Cancer Institute, 1997
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