Good Morning, I am Dr. Nancy Lee, Associate Director for Science, within the Division
of Cancer Prevention and Control of the National Centers for Chronic Disease Prevention
and Health Promotion, Centers for Disease Control and Prevention (CDC) in Atlanta,
Georgia. I am pleased to be here this morning to discuss how CDC approaches cervical
cancer early detection through CDC's, National
Breast and Cervical Cancer Early Detection Program (NBCCEDP).
Background
Cervical cancer is nearly 100 percent preventable, yet according to the American Cancer
Society, an estimated 12,800 new cases of invasive cervical cancer will be diagnosed in
1999 with about 4,800 women dying of the disease. The cervical cancer death rate declined
45 percent between the periods 1972-74 and 1992-94 and the overall incidence of the
disease has decreased steadily from 14.2 per 100,000 in 1973 to 7.4 per 100,000 in 1995.
This is largely attributed to the effectiveness of Pap smear screening for cervical
cytology.
Even with this success, there remains significant disparities in the incidence and
mortality of cervical cancer among some racial and ethnic minority women, when compared to
the rate in white women. The incidence rate for all U.S. women is about 8 per 100,000;
however, the highest age-adjusted incidence rate of 43 per 100,000 occurs among Vietnamese
women, probably reflecting lack of appropriate screening. Incidence rates of 15 per
100,000 or higher also occur among Alaska Native, Korean, and Hispanic women. The death
rate of 6.7 per 100,000 in African American women continues to be more than twice that of
whites even though their incidence rate is slightly lower.
Early Detection
Cervical cancer occurs at an average age of 54; however, cervical intraepithelial
neoplasia (or CIN), the precursor lesion to cervical cancer, most often occurs in much
younger women. For a woman with CIN, her likelihood of survival is almost 100 percent with
timely and appropriate treatment. The fact that CIN occurs at a younger age tells us that
it usually takes a substantial amount of time for cervical cancer to develop. This means
that screening younger women is an important strategy that actually prevents cervical
cancer from ever developing. Furthermore, when cervical cancer is detected at its earliest
stage, the 5-year survival rate is more than 90 percent.
Risk Factors
Studies that have identified risk factors associated with cervical cancer have shown
that cervical cancer is closely linked to sexual behaviors, human papillomavirus (or HPV)
infection, immunosuppressive disorders such as HIV/AIDS, as well as a failure to receive
regular Pap smear screening. The sexual behaviors specifically associated with greater
risk are intercourse at an early age, multiple male sexual partners, and sex with a male
partner who has had multiple sexual partners. Experts agree that infection with certain
strains of the HPV is one of the strongest risk factors for cervical cancer, but the most
important risk factor for developing cervical cancer, at least from the point of view of
what we can do about it, is the failure to receive regular screening with a Pap smear.
Screening Tests
The principal screening test for cervical cancer is the Pap smear. Since its
introduction 50 years ago by Dr. Papanicolaou, the Pap smear has been widely used and is
credited with the steady decline in cervical cancer deaths in the United States
.
Nationwide estimates from 1994 indicated that well over 90 percent of all U.S. women had
received a Pap test at least once in their lives and that 80 percent had obtained one
within the preceding 3 years.
Despite the ability of the Pap test to help reduce cervical cancer mortality, the test
is far from 100 percent accurate. Approximately half of the inaccuracies are due to
inadequate collection of the Pap smear by the health care provider and the other half are
due to errors at the laboratory. Detecting a precancerous lesion such as CIN does not
always mean that a cancer has been prevented because only some of the early
precancerous lesions progress to cancer. Thus, the search for a more efficient means of
screening for cervical cancer and precancer is ongoing.
The Food and Drug Administration has approved three new technologies for Pap smears:
ThinPrep, AutoPap, and Papnet. The technologies all appear to do a somewhat better job of
detecting cervical disease than conventional Pap tests. They are rapidly being adopted by
laboratories nationwide and at least double the price of the conventional Pap test.
However, there are concerns that the extra costs associated with these technologies will
overshadow their benefits.
Two evaluations of cervical cytology were released in January: one done for the Agency
for Health Care Policy and Research, and the other published in the Journal of the
American Medical Association. Although the analyses were independently done, each
determined that new screening technologies were cost-effective only if screening was
infrequent, done every 3-4 years. They also found that the new technologies increased life
expectancy by a relatively small amount compared with conventional Pap testing.
In spite of the promise of these new technologies, the American College of
Obstetricians and Gynecologists stated last year that their routine use "[could] not be recommended based on costs and the
lack of sufficient data demonstrating whether they reduce the incidence of or improve the
survival rate from invasive cervical cancer."
The college also concluded that the main focus should remain screening women who are not
receiving regular screening, as they account for the majority of cervical cancer cases.
Screening Guidelines
There are several different recommendations from national, professional and
governmental organizations on the frequency that women should receive a Pap test. The
American Cancer Society, National Cancer Institute, American College of Obstetricians and
Gynecologists, American Medical Association, American Academy of Family Physicians, and
others developed a consensus agreement regarding cervical cancer screening. These
organizations recommended annual Pap testing for all women who have been sexually active,
or have reached the age of 18.
After three consecutive annual exams with normal findings, the Pap test could be
performed less frequently at the discretion of the physician.
The U.S. Preventive Services Task Force recommends regular Pap tests for all women who
are or have been sexually active, or who are 18 or older, and who have a cervix. The Pap
test should be performed at least every 3 years. However, the interval for each patient
should be determined by the physician, based on the woman's history of risk factors.
National Breast and Cervical Cancer Early Detection Program
Recognizing the value of appropriate cancer screening, Congress passed the Breast and
Cervical Cancer Mortality Prevention Act of 1990 (Public Law 101-354). This Act authorized
the Centers for Disease Control and Prevention (CDC) to establish a national screening
program to ensure that low income women who are uninsured or underinsured receive regular
screening for breast and cervical cancer and prompt followup when necessary. In fiscal
year 1999, with Congressional appropriations of $159 million, the CDC entered into the
ninth year of the National Breast and Cervical Cancer Early Detection Program (NBCCEDP).
This landmark program brings critical breast and cervical cancer screening services to
underserved women, including older women, women with low income, and women of racial and
ethnic minorities.
CDC supports early detection programs in all 50 states, five U.S. territories, the
District of Columbia, and 15 American Indian/Alaska Native organizations. The goal of the
national program is to establish, expand, and improve community-based screening services
for women at risk. The goal is achieved by screening medically underserved women for
breast and cervical cancer, providing appropriate and timely diagnostic evaluations for
women with abnormal screening tests and treatment services if needed, developing and
disseminating public information and education related to the detection and control of
breast and cervical cancer, improving training of health professionals in the detection of
these cancers, and finally, evaluating program activities through the establishment of
surveillance systems.
The program targets cervical cancer screening services to women who are hard to reach
and are unlikely to seek a Pap test because of cultural, language, monetary or
institutional barriers. As a major public health program, our overall concern must be to
reach the largest number of unscreened, eligible women as possible. Thus, we also consider
all women who do not receive regular Pap tests a priority population for the program.
Currently, the national program follows cervical cancer screening guidelines that are
consistent with the consensus guidelines developed by the American Cancer Society and
others.
Providing cervical and breast cancer health education and outreach services is an
essential component to the NBCCEDP. With technical guidance, our funded programs have
developed projects that are focused on specific at-risk populations and cover a wide range
of prevention and research activities. For example, many programs are involved with
developing low literacy, bilingual and culturally appropriate educational materials that
are used in a myriad of unique training and outreach programs and educational campaigns.
These various strategies used by the different programs result in the common goal of
increasing knowledge and awareness of breast and cervical cancer and promoting screening
for early detection.
CDC partners with many national organizations to address issues related to breast and
cervical cancer screening in priority populations. For instance, CDC funds the American
Social Health Association to formulate a national model for the prevention of cervical
cancer, using two counties in North Carolina as pilot sites and focusing upon economically
disadvantaged Hispanic and African-American populations and women living in hard-to-reach
urban and rural areas. This cervical cancer prevention project consists of developing and
delivering culturally appropriate media messages, educational materials, client support
services, and health education workshops in the community setting.
CDC is committed to increasing the awareness, availability and use of cervical cancer
screening services for women. The main purpose of cervical cancer screening is not to find
cancer, but to find precancerous lesions. Early detection and treatment of precancerous
cervical lesions identified by Pap screening can actually prevent cervical cancer; thus,
the success of any cervical cancer screening program depends on the early detection, case
management and treatment of precancerous cervical lesions.
The breast and cervical cancer program has provided more than 1.1 million Pap test to a
total of more than 700,000 women. With existing resources, the national program is able to
screen 12%-15 percent of the eligible population annually. Almost half of the women
screened are from minority racial and ethnic groups. Of Pap tests provided, about 3
percent were abnormal; more than 31,000 cases of precancerous lesions were ultimately
diagnosed, and 508 women were diagnosed with invasive cervical cancer. These statistics
illustrate a key point for this essential public health program. The main purpose of
cervical cancer screening is to find precancerous lesions, treat them, and cure them, so
that these women do not go on to be diagnosed with cervical cancer. Of all the women
diagnosed with cervical disease through our program, fewer than 2 percent actually had a
diagnosis of cancer. The program has potentially averted cancer in more than 31,000 women!
This underscores the success of Pap testing and emphasizes the proven strategy that we as
public health practitioners can use to fight this cancer.
As mentioned earlier, the success of any cervical cancer screening program depends on
the early detection and treatment of precancerous cervical lesions. But we must also work
hard to screen those women who are not regularly screened elsewhere. Research has shown
that they are at the greatest risk for developing cervical cancer. This is the hardest
part of our job, but one we cannot ignore. The National Breast and Cervical Cancer Early
Detection Program will continue to develop strategies to find those women and provide the
life-saving benefit of Pap smear screening.
Thank you for your interest in the cervical cancer early detection activities at CDC. I
would be pleased to answer any questions you may have.
