NEPA Vital Signs - Summer Fall 2017 - 8

LACKMEDSOC.ORG

Feature

THE

POWER

he invention of the cervical Pap test
(the "pap smear") has been one of
the triumphs of medicine, allowing
for early detection and treatment of the
precursors of cervical cancer. The most
recent data from the National Institutes
of Health show that about 4 in 100,000
women are diagnosed with cervical cancer
every year in the United States, and about 2
in 100,000 die every year of this disease. In
the US, it is currently the 14th most common
cause of cancer death in women. This is in
contrast to the early 1900s, when cervical
carcinoma ranked 3rd.
The cervical Pap test was developed in the
1920s by Dr. George Papanicolau, a pathologist at Cornell University. Dr. Papanicolau
discovered that he could diagnose cervical
cancer by scraping cells from the vagina,
smearing them on a glass slide, and looking
at the cells under the microscope. This test,
which became known as the "pap smear,"
was eventually utilized to detect cervical
cancer precursors as well. The test was
first widely utilized in Europe in the 1950s
and eventually in the United States, with
marked decreases in both cervical cancer
cases and in the number of women who
died of cervical cancer.
The Pap test is obtained in the gynecologist's or family practice physicians office,
the slide is stained in the lab (by the "pap"
stain) and it is screened by a cytotechnologist, who has received training in examining
Pap tests under the microscope. If the
cytotechnologist believes that the smear is

"negative," they can report it as negative. If
they believe that the smear is abnormal, they
send it to a pathologist for final determination. Abnormal results are investigated by
the gynecologist, who may perform a tissue
biopsy after examining the cervix.

proper follow-up would be for the various
grades. The Bethesda System has since
been universally accepted by pathologists
and clinicians.

The second advance was an improved
system for obtaining the cells from the
The Pap smear has been a good method of patient and making the slide. In the mid
screening for the precancerous changes in 1990s the ThinPrep system was develthe cervix, but there was a significant false oped to standardize how the sample was

In the US, cervical cancer is currently the
14th most common cause of cancer death
in women. This is in contrast to the early
1900s, when cervical carcinoma ranked 3rd.
negative rate in which some serious precan- obtained. Prior to this, a wooden spatula
cerous lesions were "missed." Several recent was used to scrape cells from the cervix
advances have greatly improved the test. and smear them on a glass slide. This slide
was then sprayed with fixative and sent to
The first advance was agreement by all the lab for the pap stain. The quality of the
pathologists of a unified nomenclature for smears varied greatly, sometimes making
interpreting and reporting these smears. The interpretation impossible. The ThinPrep
1st Bethesda conference, held in Bethesda, system (and other methods which have
Maryland in 1988, assigned criteria for since been developed) utilizes a brush to
interpreting the cells under the micro- gently scrape cells from the cervix. This
scope and also assigned various degrees of brush is then placed in a preservative
abnormality ("Negative," "Low Grade" or solution; the cells are then transferred by
"High Grade"). Subsequent conferences a machine onto a glass slide. The advantage
improved upon the system and also involved to this "liquid based" method is that the
gynecologists, who gave input as to what cells are always preserved well, the cells

N E PA

VITAL SIGNS

http://www.lackmedsoc.org

Table of Contents for the Digital Edition of NEPA Vital Signs - Summer Fall 2017