Running head: CERVICAL CANCER SCREENING 1
Discussion Blue Print: Cervical Cancer Screening
San Francisco State University
School of Nursing
Carissa Bergman, Ida Lollis, Krystal Tigno
N720 Epidemiology and Biostatistics
May 8, 2013 CERVICAL CANCER SCREENING 2
Discussion Blue Print: Cervical Cancer Screening
Background and Significance
Cervical Cancer is defined as a cancer that grows in the cervix and is usually slow growing and may be without any symptomatic etiology. Majority of cervical cancers are caused by the human papilloma virus (HPV), a disease spread during sexual activity with another individual. Although HPV usually does not cause any symptoms and resolves on its own, there is a chance that this virus can lead to cervical cancer.
According to the Department of Health and Human Services cervical cancer is highly preventable with proper screening. The use of Pap smear as the main screening tool detects early cervical cellular changes and has become the staple test for cervical cancer prevention in the recent past. Since the early 1970’s till the late 1990’s cervical cancer death rate has dramatically dropped 45% largely with the use of Pap smear screening becoming a regular part of preventative medical exams. For those individuals who have an abnormal pap smear and are diagnosed with early cervical cancer, the 5-year survival rate is more than 90%. These statistics show the Pap smear evaluation as highly important tool to combat a cervical cancer
Prevalence and Incidence of cervical cancer in the population
Although all women are at risk for cervical cancer, the median age of diagnosis is 48 years and it is rarely found in women under the age of 30. Recent statistics show the prevalence of the disease dropping from 14.2 to 7.4 per 100,000 over a 20 year span due to the introduction of frequent the Pap smear tool.
Although the medical community has come a long way with the use of such techniques, as of 2013 there are still 12,340 new documented cases of invasive cervical cancer a year and of those over 4,030 of those females died from this disease. CERVICAL CANCER SCREENING 3
Secondary Prevention
The secondary prevention of cervical cancer by way of regular screenings has been very successful overall. The Papanicolaou cervical smear (Pap test) has greatly added to this success since its introduction in the 1950s. Secondary methods for the prevention of cervical cancer are now the backbone of managed care, however their success is dependent upon patient collaboration and adherence (Mac Donald, 2008). This represents a major weakness since about twenty percent of the population targeted by these screenings goes unscreened. Added to this are weaknesses in the specificity and sensitivity of cervical cancer screening methods. There is also a heavy financial burden of secondary prevention for cervical cancer especially with follow-up of abnormal test results. Repeat screenings, biopsy/colposcopy, and HPV DNA testing all increase cost of secondary prevention (Mac Donald, 2008).
Sensitivity, Specificity, PPV, and NPV
A meta-analysis of the literature found by the Agency for Health Care Policy and
Research found a lot of variability in the sensitivity and specificity of the Pap smear test. The specificity of the traditional Pap test rated high at between 97- 100%, while the sensitivity was low at between 29-56%. Evidently the traditional test does a better job of detecting high-grade dysplasia and it less suited for the detection of low-grade lesions (Lie & Jones, 2003). Because of the slow growing nature of cervical cancer and repeated screenings it is probable that the sensitivity is higher. Newer techniques that use liquid-based cytology have been developed to increase the sensitivity of the screening. It is not clear whether this result in a more sensitive test, but there is an advantage that HPV testing can be done on the same preparation (NCI, 2013).
The positive predicative value (PPV) of the Pap test reflects the accuracy with which an abnormal result is able to predict cervical neoplasia. Studies have found a high PPV in the CERVICAL CANCER SCREENING 4 discovery of gynecological malignancies when malignant cytology is found by a Pap test.
However it was also found that previous treatment for cervical dysplasia or even pregnancy could influence the false positive rates of this test (Uyar et al., 2003)
The negative predicative value (NPV) gives us the accuracy in which a negative test result is able to predict the absence of disease. One study, which looked at the accuracy of the
Pap test in women who were HIV positive, focused on the negative predicative value of the test.
The researcher found annual pap testing to be a safe screening measure, and that those patients with more than one consecutive negative test could safely go for longer intervals between tests
(Stewart et al, 2012).
Compare and Contrast of Guidelines
The two guidelines that we found were titled Screening for cervical cancer: U.S.
Preventive Service Task Force recommendation statement (Guideline 1), and the American
Cancer Society, American Society for Colposcopy and Cervical Pathology, and American
Society for Clinical Pathology screening guidelines for the prevention and early detection of cervical cancer (Guideline 2). Both of the guidelines that we found were very similar, with only minor differences found in the specificity of their goals. Both of these guidelines were revisions of previously established guidelines and were both revised and reissued within a month of each other, May and June of 2012. Neither of the guidelines was adapted from other sources.
Development and Funding
Guideline 1 was developed by the US. Preventative Services Task Force. This task force is a group made up of an independent expert panel of numerous doctors from all over the United
States. Guideline 2 was developed by the organizations within its title, the American Cancer
Society-Disease Specific Society, the Society for Clinical Pathology-Professional Association, CERVICAL CANCER SCREENING 5 and the American Society for Colposcopy and Cervical Pathology-Medical Special Society.
These organizations are also comprised of a number of different doctors from across the United
States. Guideline 1 was funded solely by the government and Guideline 2 was funded through the collaborative organizations. Surrounding financial disclosures and conflicts of interest, both guidelines took the time to examine possible disclosures and eliminate conflicts of interest with its participating members.
Guideline 1 focuses on cervical cancer, while Guideline 2 looks at cervical cancer, but also cervical intraepithelial neoplasia (CIN). CIN is not necessarily diagnosed as cancer, but is seen as the morphology in new cell growth of the cervical tissue. Guideline 1 is focused on prevention and screening, while Guideline 2 adds diagnosis as a focus of its guidelines. Both guidelines are intended to be used by the same type of medical personnel which include: advanced practice nurses, nurses, physician’s assistance and physicians.
The Who and What
The only differences in the guideline’s objectives are that Guideline 2 is a bit more specific and really emphasizes on the detection of the neoplastic changes and management of monitoring those changes. The target population for both guidelines is women. Guideline 1’s target population focuses on all women with a cervix. Guideline 2 is much more specific and target women who are age 21 and older. Guideline 2 can miss a lot of women who are under the age of 21, sexually active and thus, at risk for cervical cancer. Guideline 1 seems to look at women who may not be at risk at all. Either way, all women appear to be covered with a combination of both guidelines. When looking at levels of prevention, Guideline 1 focuses on primary and secondary levels of prevention, and Guideline 2 covers all three levels of CERVICAL CANCER SCREENING 6 prevention. Guideline 2 really goes into secondary prevention in establishing a follow up schedule after a woman has been diagnosed with cervical neoplasia or cervical cancer.
Major Outcomes
Guideline 1 looks to ask and be able to answer a lot of questions regarding when to start screening, what are the benefits, and what are the risks of testing. Guideline 2 looks at a lot of statistics surrounding incidence, prevalence and patient outcomes.
Methods Used to Collect Evidence
Guideline 1 used a total of three sources to collect evidence. It’s primary and secondary sources were hand-searches of published literature. Its tertiary source was a search of electronic databases. Guideline 2 used only electronic data bases as a method to collect evidence. In either case an expert consensus was used to assess the quality and the strength of the evidence that was gathered and used. Both guidelines used meta-analysis and systematic reviews to analyze the evidence gathered.
Recommendation Formation and Rating
Both guidelines used expert censuses as a method to formulate recommendations. In addition to that, Guideline 1 also utilized balance sheets. Balance sheets are a method used to measure the net benefit of any given recommendation by subtracting the harm from the benefit.
Guideline 1 used a rating scheme that ranged from A-D and the letter I. “A” was determined to be a high level of certainty that the recommendation offered a substantial benefit and thus, practitioners and those implementing the guidelines would be encouraged to offer or provide the service. “B” was determined to offer moderate benefits. “C and D” decrease in their net benefits and are offered with special under certain circumstances. “I” was determined to be insufficient. CERVICAL CANCER SCREENING 7
Insufficient meaning that there is quite a bit of uncertainty surrounding the benefits and risks of the effects. Guideline 2 only had two categories in its rating scheme; strong and weak.
Validation and Implementation
Both methods used peer reviews to acquire validation. However, Guideline one used a comparison with guidelines from other groups, an external peer review, and an internal peer review. Guideline 2 only used a peer review, but it was not stated whether or not the review was internal or external. Only Guideline 1 developed an implementation plan.
Conclusion
We found the guidelines from the U.S. Preventative Task Force (Guideline 1) and the
American Cancer Society (Guideline 2) to be somewhat similar in their recommendations. Both guidelines were revised in 2012. Although funding came from different sources, one government and one collaborative, financial disclosures and conflicts of interest were sufficiently addressed.
Guideline 2 may be slightly more useful to medical personnel since the focus on diagnosis has been included and therefore can provide more guidance with follow-up procedures. CERVICAL CANCER SCREENING 8
Resources
CDC: cervical cancer statistics. Retrieved on 4/30/13.
http://www.cdc.gov/cancer/cervical/statistics/
Department of Health and Human Services. Retrieved on 4/30/13.
http://www.hhs.gov/asl/testify/t990316b.html
Lie, D., Jones, Gordon. (2003). Standard of Care for Pap screening. Retrieved from
http://www.medscape.com/viewarticle/450617
MacDonald, C.F. (2008). Assessing secondary prevention methods for cervical cancer: costs and
benefits on managed care. Retrieved from
http://www.ncbi.nlm.nih.gov/pubmed/18611086
National Cancer Institute. Retrieved on 4/30/13.
http://www.cancer.gov/cancertopics/types/cervical
Stewart, M.L., D’Souza, G., Fang, T et al. (2012). Negative predicative value of Pap testing:
Implications for screening intervals for woman with HIV. Retrieved from
http://journals.lww.com/greenjournal/Abstract/2012/10000/Negative_Predictive_Value_o
f_Pap_Testing_.9.aspx
Uyar, D.S., Eltabbakh, G.H., Mount, S.L. (2003). Positive predicative value of liquid-based and
conventional cervical Papanicolaou smears reported as malignant. Retrieved from
http://www.sciencedirect.com/science/article/pii/S0090825802001026