Correlation of visual inspection with cytological and histopathological findings in cervical neoplasia

Correspondence: Dr. Palzum Sherpa, MBBS, MD Department of Pathology Patan Academy of Health Sciences, Lalitpur, Nepal E-mail: palzumsherpa@pahs.edu.np Background: Cervical cancer is one of the commonest malignancies and a leading cause of morbidity and mortality among women. The aim of this study was to evaluate the diagnostic value of Papanicolaou (PAP) smear and visual inspection with acetic acid as methods of cervical cancer screening.

impact of false negative rate. 4 Depending on the resources available, there are a number of screening methods like visual inspection tests, PAP smear and HPV DNA tests.
The current study is aimed at finding out the diagnostic accuracy of PAP smear at a tertiary level hospital considering histopathology results as the gold standard.The diagnostic value of PAP smear is also compared with the results of VIA, in available cases in order to determine if VIA can be used as a primary screening tool in resource limited settings.This study intends to evaluate and compare the commonly used screening modalities so that we can help clinicians reach to an early diagnosis and treatment of cervical neoplasia, thus giving women an opportunity for a better quality of life.

MATERIALS AND METHODS
This was a prospective study carried out over a period of 1 year from 2068.11.01 to 2069.11.01 at the Department of Pathology, Institute of Medicine, Tribhuvan University Teaching Hospital, Kathmandu, Nepal.Approval of the study protocol by the institutional review board of Institute of Medicine was obtained.
The study population consisted of women with histologically confirmed cervical intraepithelial neoplasia or invasive carcinoma who had undergone a prior PAP smear test.However, women with previous history of cervical cancer were excluded from the study.Detailed clinical data was obtained and noted in a structured proforma.Data was analyzed using the Statistical Package for Social Sciences (SPSS) version 16.

RESULTS
During the study period, a total of 160 patients underwent both PAP smear and cervical biopsy.Out of these 160 cases, 49 had positive results in biopsy specimen and were included in the study.Among the 49 cases, 30 had positive result and 19 had negative result in PAP smear.Three patients had positive PAP smear with negative biopsy results and 108 had negative results in both.A total of 56 patients had underwent both VIA and cervical biopsy.Among them, 31 patients had positive result in biopsy (23 VIA positive and 8 VIA negative) and were included in the study.Thirteen patients were VIA positive with negative biopsy and 12 had negative results in both (Table 1).
Minimum age of the patient was 23 years and the maximum age was 82 years.The mean age of the patient was 42 years.
HSIL was more common in the age group 31-40 years, LSIL in 41-50 years and squamous cell carcinoma in 61-70 years (Table 2).A significant statistical association of cervical intraepithelial lesion and malignancy with parity was established with a p-value of 0.024.Only 1 (2%) nulliparous woman had cervical neoplasm whereas 25 (51.02%)women with cervical neoplasm had three or more children.

DISCUSSION
The present study had a spectrum of patients ranging from 23 to 82 years of age.Mean age of the patient was 42 years.Maximum frequency (36.7%) was found in the age group 31-40 years, closely followed by 41-50 years of women constituting 32.7%.Similar results were found in studies performed by Goel et al 5 , Dhakal et al 6 and Boicea et al. 7 Thus, since cervical neoplasia is more common between 31-50 years, the screening programs should target women in this age group.
The value of PAP smear in screening for cervical cancer has long been established.VIA is an alternative method especially suited for low resource settings.The sensitivity of PAP smear in our study was 61.2% which is lower than that of VIA (74.1%).The specificity of PAP smear was 97.2% whereas that of VIA was only 48.0%.The PPV of PAP smear was 90.9%, NPV was 85.0% and diagnostic accuracy was 86.2%.VIA had a PPV of 63.8%, NPV of   11 Vedantham et al found that among control group VIA positivity was 15.5% in women with inflammation and 6.1% in women without inflammation with a p value of <0.001. 12avis et al suggested that women with cervicitis were twice as likely to have a positive VIA result as women without cervicitis. 13In a similar fashion, inflammation could also have contributed to the false positive VIA results observed in our study.
In our study, we also tried to find out whether the combination of PAP smear and VIA improves the diagnostic accuracy of screening for cervical cancer.On combining the two procedures, the sensitivity increased by 26%, NPV by 11% and diagnostic accuracy by 2%.However, the specificity decreased by 9% and PPV by 26%.Our results showed an overall improvement in the performance of the screening tests by using the two methods in combination.
Our results are in concordance with studies done by Consul et al 9 , Denny et al 14 and Sankarnarayan et al 15 , all of which demonstrated that when used in combination PAP smear and VIA had a much better diagnostic performance than each test alone.

CONCLUSION
PAP smear has a higher specificity, PPV, NPV and diagnostic accuracy but lower sensitivity than VIA.The findings of our study shows that VIA by itself is not an effective screening method and further actions based only on its result may prove unnecessary for a number of patients.A combination of PAP smear and VIA can ensure adequate screening of cervical neoplasia.