LITERATURE REVIEW
2.1 Conceptual Framework
2.1.1 Concept of Cervical cancer screaming
Worldwide, cervical cancer is diagnosed annually in more than 500,000 female students and it is known to account for 270,000 deaths20. In 2009, estimated new cases and deaths from cervical cancer in the United States of America were 11,270 and 4,070 respectively21. eighty percent of deaths resulting from cervical cancer occur in developing countries22. The highest age standardized incidence rate of cervical cancer has been reported in southern Africa, Eastern Africa, South America, Central America, the rater are over 40 percent per 100,000 female students23. The incidence is increasing in sub-Saharan Africa with age-standardized rates of 35.7 percent per 100,000 in Bamako, Mali and 41.7 percent in Kyadondo, Uganda. In Nigeria, it is the commonest malignancy of female genital tract. The estimated incidence is 25 percent per 100,000 and 8,000 new cases are expected to occur yearly24. However, the knowledge, attitude and perceptions concerning cancer screening is still low.
2.1.2 Pathogenesis of Cervical Cancer
Cervical cancer arises in the so-called transformation zone of the uterine cervix. This is the area which undergoes physiological metaplasia from glandular to squamous epithelium at the onset of adolescence. Human Papiloma Virus (HPV) is very common after the onset of sexual activity, and when it persists, the viral oncoprotein produce perturbation of the cell-cycle controls, resulting in CIN. At their mildest (CIN 1), these lesions are generally no more than manifestation of HPV infection, but at their most severe (CIN 3), the risk of progression to cancer, if not detected and treated, is high. Fortunately, the transmission to cancer usually takes years, thus allowing the opportunity for detection by exfoliative cytology. The peak incidence of HPV occurs at the age of 20, the peak incidence/detection of CIN 3 occur about age 30, and the peak incidence of cancer occurs in the 40s. It is estimated that without secondary preventions, cervical cancer would occur in around 1% of female students who acquire an HPV infection. Although for every cancer that occurs, a far larger number of CIN lesions develop, of which the majority probably regress. Most of the pre-malignant and marlignart lesions are of squamous type but around 15% are of glandular. HPV 16 and 18 are the dominant oncotypes in the squamous but type 18 is relating more important in glandular lesion2.
2.1.3 Risk Factors for Cervical Cancer
The most important risk factors in the development of cervical cancer is infection with a high risk strain of human papilloma virus (HPV). The virus cancer risk works by triggering alterations in the cells of the cervix, which can lead to development of cervical intraepithelial neoplasia that can lead to cancer. There are numerous types of HPV, but some are classified as high risk types (16, 18, 31, 33, 35, 39, 45, 51, 52, 56, 58, 59, 68, 73 and 82), low risk types are 6, 11, 40, 42, 43, 44, 54, 61, 70, 72, 81). However, types 16 and 18 are generally acknowledged to cause about 70% of cervical cancers cases3.
Other risk factors increasing risk of exposure to the disease are:
Early age of first sexual intercourse 3,4.
Multiple sexual partner
Male sexual partners who themselves have multiple sexual partners 3,4
Early age at first birth4.
Low social class4
Immunosuppressed states like HIV/AIDS, lymphoma’s 4
Multiparity
2.1.4 Clinical Features of Cervical Cancer
Most of the time, early cervical cancer has no symptoms. Symptoms that may occur include:
Continuous vaginal discharge which may be pale, watery, pink, brown, bloody or fowl smell.
Abnormal vaginal bleeding between periods, after intercourse or after menopause.
Periods become heavier and last longer than usual.
Any bleeding after menopause.
However in advanced cervical cancer, symptoms may include:
Loss of appetite
Weight loss
Fatigue
Pelvic pain
Leg pain
Heavy bleeding from the vagina
Leaking of urine or faeces per vaginum
Bone fracture 5
2.1.5 Cervical Cancer Screening Methods
Cervical screening has been demonstrated to be effective in reducing the mortality and morbidity of cervical carcinoma6. The following are types of screening method.
1. Papanicolaou Smears (Pap Smear)
A pap smear is a cytological test designed to detect abnormal cervical cells. The procedure involved scrapping cells from the cervix and the fixing them on a glass slide. The slide are taken to a cytology laboratory and evaluated by a trained cytology technician. This multistage process can take several weeks before the results are available to the client. Studies of cytology-based programs have resulted in a broad range of sensitivity and specificity data, the Pap smear is considered to be specific with regard to detection of high grade lesion and cancer.
Visual Inspection with Acetic Acid (VIA)
This involves swabbing the cervix with an acetic acid (3-5%) solution prior to visual examination. The difference in absorption of precancerous cells structure and absorption rates make abnormal cells temporarily turn white when exposed to the solution. On the alternative, the use of iodine based solution as a means of staining normal cells brown, leaving the abnormal cells yellow or unstained appearance. The advantage of this screening method is that it is a promising approach for use in low resource setting, it is relatively simple, non-physicians can perform the procedure provided they receive adequate training, results can be available immediately. Accuracy of VIA has been found to be reasonable from several studies. However, the drawback to VIA is, it is less effective in screening female students in their fifties because of tendency of the squamuo-columnar junction to recede into the cervical as making observation of lesson difficulty8.
Visual Inspection with Magnifications (VIAM)
This uses the aviscope to examine the cervix after application of acetic acid. A small Indonesian evaluation of an early version of the device indicated that VIAM may achieve sensitivity and specificity of over 90 percent in identifying pre-invasive cervical lesion. Preliminary findings from an ongoing study in Calcutta, India, indicate that VIAM has a sensitivity of 69 percent and specificity of 82 percent9.
New-Screening Technologies
Several effective strategies for cervical cancer prevention have been identified, including cervical cytology using either conventional or liquid based methods. High risk Human Papilloma Virus (HPV) DNA testing, and a variety of iterations of direct visual inspection of the cervix follen application of acetic acid or lugol’s iodine.
The new screening technologies with their benefits and limitations is given in the table below10.
Technology
Benefits
Limitations
HPV genotyping
Discrimination of HPV 16/18 from other high risk types may have greater positive predictive value. May differentiate sequential infection with different types from persistent infection with the same type. Useful for test of cure amenable to use with self sampling. Compatible with many collections buffers. Objective output.
Moderate to high complexity even with standardized commercial reagents. Very difficult to establish consensus primetbased genotyping denovo with adequate quality control. Algorithms may be too complicated to be readily translated into clinical practice. High cost.
HPV MRNA
Potential to increase specificity. Objective output.
Moderate to high complicity RNA less stable, not compatible with some common collection buffers. Compatibility with selfsampling unknown. High cost.
HPV Viral Load
Potential to increase specificity. Objective and quantitative output.
High complexity not prognostic (except HPV-16) require type-specific quatitation.
HPV Integration
Potential to increase specificity. Objective output.
Moderate complexity for DNA methods. Very high complexity to detect integrated transcripts integrated DNA may not be transcriptionally active. Requires type specific assay. Common occurrence of mixed episomal of integrated HPV in cervical intraepithelial nerplasia. High cost.
P 16-enzyme linked immunosorbent assay
Single analyte (P 16 protein) to detect infection with any high-risk HPV. May increase specificity by detecting active infection. Objective output cost may be lower than HPV DNA/RNA/St
Moderate complexity. Compatibility with self sampling unknown. Not compatible with all collection buffers order of sampling may affect performance. Low specificity.
Methylation profile
As a marker of disease and not infections. Compatible with urine sampling. Objective output.
High complexity. Sensitivity limited; questionable reproductivity. High cost.
TERC-gain
As a marker of disease and not infection, may increase specificity. Subjective output (requires expert interpretation) may be useful as a prognostic marker.
High complexity. High cost.
E 6 strip test
Low cost. Objective output. Results available at time of screening visit.
Unknown compatibility with self sampling. At present, only detects HPV-16. Compatibility with self collection unknown.
Cervical cancer is the most common malignancy among female students in developing countries.11 Carcinoma of the cervix is a global public health problem responsible for an estimated 258,000 deaths in the year 2001 worldwide.12 The estimated incidence in Africa is 70/100,000 – 100/100,000 population. The commonest cancer in men is Kaposi sarcoma (15.5%) with cancer of the cervix representing 22.2% of all cancers among female students. Most cases present at advanced stages when curative measures may be unsuccessful.13 The incidence of cervical cancer in Nigeria is 25/100,000, while reported prevalence rates for human papiloma virus (HPV) in the general population and human papiloma virus (HPV) in female students with cervical cancer are 26.3% and 24.8% respectively. High risk HPV types 16, 31, 35, 56 were found with infections involving more than one HPV type and high prevalence of HPV in all age groups.13,14 The recorded decrease in incidence and mortality rates of 70-80% of cervical cancer in western countries over the years is largely due to widespread screening. The papanicolaou (pap) smear introduced in 1943 for the detection of precancerous and cancerous changes in the cervix is widely recognized as the most effective cancer screening test yet devised and serves as a model for screening for other malignancies.16 Pap smear screening has a specificity of approximately 90%. It is better for high grade and invasive lesions. The test is less specific for low grade (CIN) and partly due to its inability to distinguish between low grade CIN from HPV infection. The sensitivity of the papsmear screening has been reported to range from 40-70 percent.17 In general, awareness about cervical cancer, availability of effective screening programmes and improvement of existing health services could reduce its burden among female students. One of the huge differences between in its incidence and mortality between developed and developing countries is lack of awareness among the population, health care providers, policy makers.18
2.1.6 Uptake of cervical cancer screening
Cervical cancer screening is acknowledged as currently the most effective approach for cervical cancer control, and it is associated with reduced incidence and mortality from the disease.83 In developed countries, cervical cancer prevention programmes have been shown to be effective in reducing the incidence of and mortality from cervical cancer, while in developing countries, where these programmes exist, they have failed to meet their objectives due to logistical, financial and social problems.95
The uptake of cervical cancer screening in many developing countries such as Tanzania is still poor due to various factors. Demographic characteristics include education, age, and marital status. In regards to education level, several studies have found that female students with high screening rates have a high level of education.96,97 However, female students with high education may not necessarily seek screening,98 thus, additional factors must be considered. Rates of screening are substantially lower in younger female students aged 20-29
years and elderly female students aged 60 years and above.96,99
Also, unmarried and widowed female students are less likely than married female students or female students living with a partner to obtain screening.96 However, some studies have found that single female students are more likely than married female students to have pap screening.99, 100
Screening is a universally accepted early detection strategy; yet, the utilization of screening in many developing countries is still poor.101 Although some reasons for poor uptake have been studied, the most significant ones that can directly inform public policy are not yet known.83 Female students who were less educated were less likely to participate in screening, a finding that is consistent with previous reports.102,103 Previous research on the relationship between socioeconomic factors and the use of health services has shown that education influences screening behaviour through its effects on income and through its association with individual knowledge about cancer screening.104 One key issue is to determine how to obtain high levels of attendance, which is essential to achieving adequate coverage. Barriers to screening uptake include a lack of knowledge about the disease, a lack of familiarity with the concept of prevention, the geographical and economic inaccessibility of care, the poor quality of services and a lack of support from husbands and families.105,106 Evidence indicates that to minimize these barriers, strategies in low-resource settings should be socially and culturally appropriate.105,107 The type of screening test did not appear to be a significant predictor of compliance. Cervical cancer screening in a large population-based programme carried out in a developing country; information on these variations is essential to help identify underserved female students. Our service delivery strategy was designed to reduce the main barriers to screening, including the poor quality of health resources, economic and social inaccessibility, lack of knowledge about preventing cervical cancer, difficulties in paying for services and the social stigma associated with reproductive health problems.107, 108,109
Bhagwan Nene et al in their study found satisfactory general level of participation (79%), female students with a specific socio-demographic profile were still less likely to participate in the programme. The lowest rate of participation was found among nulliparous female students. In addition, female students who used contraception were more likely to participate. Having had a higher number of pregnancies, using family planning, having contact with the health-care system have been found to be associated with an increased use of screening services,110,111,112 indicating that previous contacts with reproductive health services may increase awareness, making female students more responsive to cervical cancer Increasing age has been found to be associated with a decreased use of screening services in several studies carried out in different settings.95,113 This has been confirmed in rural India in a study that screened with visual inspection with acetic acid.7
It has been suggested that older female students may be less responsive to awareness activities because they believe that detection and treatment make no difference them. Therefore, strategies to promote cervical cancer screening should pay particular attention to incorporating messages specifically targeted at older female students. Our finding that married female students are more likely to be screened is consistent with previous studies in India and other low-resource settings.110,113
Two proposed reasons are: first, married female students may receive more frequent obstetric or gynaecological care, making them more responsive to reproductive health care,114 and second, a key factor in a woman‟s decision to participate in cervical cancer prevention services is her husband‟s positive emotional support.107
In Nigeria sporadic screening is being carried out using opportunist method for those who visit certain clinics. Also, there is no standard policy or protocol for cervical cancer screening in Niger which is very similar to that of Nigeria which is sporadic or opportunistic. It is more worrisome as all sexually active female students are at risk for the development of cervical cancer. Where the services are available, many female students seem not to be aware of the services. Services are mainly available in some secondary and tertiary health facilities at a cost that make it not accessible and affordable to many female students. Over the years awareness and uptake of services has remained poor despite all the studies on cervical cancer screening. Various studies indicate that cervical cancer screening services is poorly utilized and the awareness of the need for it is very low but can be treated if
detected early.115, 116
The barriers identified by Mutyaba117 were “ignorance about cervical cancer, cultural constraint/beliefs about illness, economic factors, domestic gender power relations, alternative authoritative sources of reproductive health knowledge and unfriendly health care services” Female students in developing countries like Nigeria seem to utilize reproductive health services more during pregnancy. They also use reproductive health services for post natal check up and family planning or when faced with various gynaecological problems. It is important to ensure that these female students are screened in order to reduce incidence of cervical cancer. Their visit to the clinics provides opportunity to give them information on the importance of the screening and where to get the services. The researchers observed that many female students attending various health facilities have not been screened. Thus the need to explore the factors influencing utilization of cervical screening services among female students in selected Health facilities in Nigeria.
Makwe et al.81 in their study of knowledge and attitude assessment among female nurses in tertiary hospital Lagos found that almost all (99.4%) of the respondents had heard of cervical cancer, while about 85% of them had heard of HPV infection. Only a quarter (25.3%) of respondents had heard of the HPV vaccines, and of those only 26.7% knew the vaccines were for the prevention of cervical cancer. Most (70.2%) of the nurses expressed a desire to be vaccinated and 120 (67.4%) supported the vaccination of preadolescent girls. Those who expressed a willingness to be vaccinated were more likely to recommend HPV vaccination for preadolescent girls. About 90% of the nurses who had heard of HPV infection knew that it could be transmitted through sexual intercourse, while only eleven (7.3%) knew it could be transmitted by skin-to-skin contact. Less than half of the respondents who had heard of genital HPV infection knew that it could be prevented by vaccination (31.8%) and condom use (33.1%).Most (74.7%) of the respondents had never heard of the HPV vaccines. Among the 45 nurses who had heard of the vaccines, only twelve (26.7%) knew they were for the prevention of cervical cancer, while 30 (66.7%) respondents thought they were for the prevention of HPV infection.81
Aswathy et al.82 in their study of knowledge in India found that almost three quarter of the study population (584, 72.1%) were aware of cervical cancer as a type of cancer affecting female students. Three quarter of the population (600, 74.2%) knew that it could be detected early by a screening test, but only 47 (5.8%) could name the Pap test as the screening method of cervical cancer. Though 56 (6.9%) had ever done Pap test, only 5.8 per cent could recall the name of the screening test. Only about half (395, 48.8%) of the female students were aware of symptoms of cervical cancer. The cardinal symptoms of cervical cancer mentioned included bleeding (289, 35.7%) and pain (70, 8.6%).
Other incorrect responses included lump, stomachache, and pain in legs (9.1%). On being asked about timing of Pap test, majority of female students (726, 89.7%) did not know when it should be done, 23 (2.8%) said it should be done only when there is any problem and 60 (7.4%) said it should be done after age of 30 yr. On periodicity, 12 (1.5%) said it should be done monthly, 20 (2.5%) said 1-2 yearly and 23 (28%) every 2 to 3 years. Scoring of knowledge levels showed that 92.8 per cent had poor knowledge on the various aspects like symptoms, risk factors, screening test.82 The knowledge factors included no symptoms (91, 37.1%), not being aware of the Pap test (28, 11.4%), not necessary (4, 3.1%). Resource factors included lack of time (18, 7.3%), financial reasons (14, 5.7%) and lack of facility in the area (3, 1.2%). Two female students said they „did not get a chance to do it′. Different psychosocial factors included lack of interest (3, 1.2%) fear of procedure
(3, 1.2%), and embarrassment (1, 0.4%). However, 18 (7.3%) did not specify any definite reason.82
Lyimo et al.83 in their study in Tanzania found a low level of knowledge of cervical cancer and its prevention, among the study participants and less than a quarter (n = 75, 21.2%) of the participants had a medium level, and less than a quarter (n = 68, 19.2%) had a high level of knowledge. Of the 80 female students who reported having been screened, those with the highest level of knowledge about cervical cancer and its prevention were more likely than those with low and medium levels of knowledge to have been screened.83
Urasa et al.84 in their study of knowledge of cervical cancer and screening found that the participating nurses know correctly causes and transmission in 46%, symptoms in 32.1% and adequate risks in only 7.3 %. More than 80% of nurses aged less than 30 years had adequate knowledge of causes of cervical cancer and transmission of HPV compared to only 36.4% and 47.1% for the 30 – 40 and above 40 age groups respectively. However, the association with cadre, department and work experience was not significant. There was a significant association between the nurses' cadre and knowledge level of symptoms of cervical cancer; 43.3% of the registered nurses had adequate knowledge of symptoms of cervical cancer compared to only 21.4% of enrolled nurses.84
Kahesa et al.85 in their study of knowledge found out that More than half (53%) of the female students had never heard of cervical cancer. When questioned about perceived barriers for attending health check-ups, 57% stated that difficult access to health service would be a hindering factor. In addition, 31% of the female students stated they were reluctant to go for any test in absence of disease. Lack of medical advice and fear of being diagnosed as having cancer were additionally mentioned as a barrier by 12% and 13% of the female students.85
Oyedunni et al.86 in their study of knowledge found that 51.7% of participant opined that regular pap smear can be used to prevent cervical cancer, 30.8% reported early diagnosis, 13.9% mentioned avoidance of multiple sexual partners and 11.9% early treatment. Other ways of prevention mentioned included avoidance of sexual intercourse (8.0%), health education (6.6%), and reduction in exposure to radiation (3.4%).86The overall analysis of knowledge of respondents showed that 84.9% had average knowledge score, 14.3% had poor knowledge and 0.8% had very good knowledge score. Respondents‟ overall mean knowledge score was 22.8±4.1. These levels of knowledge were found not to influence the utilization of cervical screening services.86
When the participants were asked about cervical screening techniques, 399 (79.3%) would like to know about screening procedures, 387 (76.9%) about its efficacy in the detection of cervical cancer, 336 (66.8%) wanted to know the age limit for cervical cancer screening, 367 (73.0%) about the side effects of the screening technique while 377(75.0%) would want to know what is next line of action after the screening.86 Four hundred and twenty-eight (85.1%) of the respondents were aware of at least one screening centre in the city of Ibadan. Majority, 465 (92.4%) of the respondents were aware of the test called pap smear and 360 (77.4%) of these correctly stated what the test was used for the detection of cancer of the cervix and 455 (90.5%) confirmed pap smear to be a diagnostic test. When asked at what age a woman should commence screening for cervical cancer, 81.7% mentioned that when a woman starts having sex and 62 (12.3%) gave an age range of 15-39 years. When asked how often the screening should be done, 30.2% said twice a year and 38.0% of the respondents said once a year.86
Abotchie, et al.87 in their study found that in general respondents seemed to understand that cervical cancer screening had benefits. Over 64 percent believed that the test could find cervical changes before they became cancerous while 78.5% thought those changes could be easily cured. Among the perceived barriers to screening, the most prevalent perceived barrier was that only half of respondents believed that the purpose of cervical cancer was to diagnose cancer, the second commonest reported barrier (40.6%) was the belief that their partner would not allow them to obtain cervical cancer screening, the following barriers were also important; cost (23.2%), not knowing where to go (24.3%), and belief that everyone would think they were sexually active (24.6%). Encouragingly, few believed that a pap test would be painful (9.4%). While more than 68% perceived that young female students were susceptible to cervical cancer, a lower percentage (52.5%) believed that they themselves were at risk for cervical cancer.