- • Starting at age 21 or no more than 3 years after
becoming sexually active, women should have a Papanicolaou (Pap)
smear on a yearly basis until they have had three consecutive normal
tests, after which the screening interval can be increased to every
- • All women whose test samples show cellular abnormalities,
persistent atypical squamous cells, or atypical squamous cells of
unclear significance that test positive for high-oncogenic-risk human
papillomavirus (HPV) require referral for colposcopy and biopsy.
Cervical cancer is the second most common cancer in women worldwide.
An estimated 466,000 new cases of cervical cancer are diagnosed
each year, resulting in 231,000 deaths. The majority of these cases
occur in countries that have limited or no effective screening programs.
In the United States and other developed countries, rates of cervical
cancer have markedly diminished over the past 30 years as a result
of Pap smear screening. Despite this, more than 10,000 cases of
cervical cancer are diagnosed in the United States each year, leading
to almost 4000 deaths. Countries that initiate Pap screening experience
decreases in cancer rates compared with countries that do not. For
example, in the mid-1960s, Finland, Sweden, and Iceland all initiated
Pap smear screening whereas Norway did not. In the subsequent 20
years, the incidence of cervical cancer did not change in Norway
but dropped 50% in the other countries.
Despite widespread screening in the United States, about 50% of
all women with cervical cancer have not had a Pap smear in the preceding
3 years and another 10% have not been screened in the past
5 years. Over 50 million Pap smears are obtained each year in the
United States, and 7% (3.5 million) of these are abnormal.
A woman who never has a Pap smear has a 3.5% risk for developing
cervical cancer; this is reduced to 0.8% with Pap smear
screening. Infection with high-oncogenic-risk HPV is found in most,
if not all, cervical cancers. Detection of high-oncogenic-risk HPV
types from cervical samples is now a part of routine clinical management
to identify women with abnormal Pap smears who need further treatment
In 1928 George Papanicolaou initiated the sampling of vaginal
cells, speculating that these cells would predict which women would
develop cervical cancer. His initial findings were not appreciated
by the general medical community, but he persevered and, together
with Dr Herbert Traut, published a monograph in 1943 that eventually
resulted in Pap smears becoming the standard of care in cervical
cancer screening. The procedure they outlined was modified in 1947
by Ayre, who collected cervical cells directly using a wooden spatula.
Although the Pap smear (also called the Pap test) has reduced
the incidence of cervical cancer by almost 75%, it is difficult
to collect and read a Pap smear in a uniform manner. This lack of
uniformity led to widespread confusion about what constituted an
abnormal test result. The development of common ...