Evaluation of visual inspection as a screening test for cervical cancer

Abstract

Summary Visual inspection of the uterine cervix by paramedical personnel has been proposed for the early detection of cervical cancer, as an alternative to routine cytology screening in developing countries. We evaluated the performance of this procedure in detecting precursor lesions and cancer in a study involving 2843 married women in Kerala, India. Two thresholds were used to define a positive test. In the lower one, any abnormality was considered as positive. The cut-off point for the high threshold was one or more of the high-risk findings: bleeding on touch, suspicious growth/ulcer and hard, irregular, oedematous cervix. A Pap smear was performed on all subjects, and a biopsy was done for those with moderate dysplasia and above. A combination of cytology and histology findings was used as the 'gold standard'. Using the low threshold, 1279 (45%) women were positive on visual inspection, and with the higher threshold 179 (6.3%) were positive. There were six moderate dysplasias, nine severe dysplasias, ten carcinomas in situ and 13 invasive carcinomas. With the lower threshold, sensitivity and specificity to detect moderate dysplasia and above were 65.8% and 55.3% respectively; the values for severe dysplasia and above were 71.9% and 55.3% respectively and for invasive cancer were 92.3% and 55.2% respectively. With the higher threshold, the sensitivity decreased considerably (28.9% to detect moderate dysplasia lesions, 31.3% for severe dysplasia and 53.8% for clinical cancer) and the specificity increased to approximately 94%. At a lower threshold, the sensitivity was not satisfactory, and the test was highly non-specific; at a higher threshold sensitivity was even lower. Thus, the test characteristics of visual inspection are not very promising either as a preselection procedure for cytology or as a low-technology measure for cervical cancer screening in developing countries.Keywords: cervical cancer; screening; visual inspection; developing countriesThe success of screening for cancer depends on the performance of the screening test (test validity), the programme validity and the adequacy of health services. The purpose of the screening test is to distinguish subjects who probably have a disease from those who probably do not. The screening test itself is not expected to be diagnostic; the positive findings need to be evaluated by further diagnostic procedures (Wilson and Jungner, 1968). Before using a screening test in an intervention trial or a programme, adequate information on its validity is necessary.Visual inspection of the uterine cervix by nurses and other paramedical health workers has been proposed for the early detection of cervical cancer, as an alternative to routine Pap smear screening, in the context of approaches to cervical cancer control in developing countries (Miller, 1992). This active attempt to detect disease in an early stage is based on the assumption that organized cervical cytology screening programmes are not feasible in many developing countries because of labour and resource ...

Accuracy of visual inspection with acetic acid in cervical ectopy evaluation

“…This result was in agreement with Suman (2013) [13] who reported positive VIA in also about two thirds of his sample. It was also in agreement with Wesley et al (1997) who reported in their study about evaluation of visual inspection as a screening test for cervical cancer that VIA test was positive in half of their sample. [15] On the other hand, this result was in disagreement with the findings of Kavita et al (2010) [11] who reported positive VIA test in less than one fifth of their study subjects and also with the findings of Ghaemmaghami et al (2004) [16] who reported in their study about "visual inspection with acetic acid as a feasible screening test for cervical neoplasia" that VIA test was positive in only less than one fifth of their study sample.…”

Evaluation of downstaging in the detection of cervical neoplasia in Kolkata, India

“…13,16 -20 The sensitivities for high-threshold downstaging to detect invasive cancer ranged from 58.3-71.4% with specificities ranging from 94.2-94.6% in previous studies. 18,19 In our study, the sensitivity to detect invasive cancer was 86.1% (31/36) and 72.2% (26/36) with low-threshold and high-threshold testing, respectively; the corresponding specificities were 75.6% and 93.6%.…”

“…Only 3 studies allowed evaluation of downstaging for different grades of dysplasia and the results of accuracy in these studies is given in Table VII. 16,18,19 However, the proportion of high-grade precursor lesions was very low in the study by Nene et al 18 The sensitivities for low-threshold downstaging to detect invasive cancer in previously reported studies varied from 50.0 -100.0%, with specificities ranging from 30.0 -59.0%. 13,16 -20 The sensitivities for high-threshold downstaging to detect invasive cancer ranged from 58.3-71.4% with specificities ranging from 94.2-94.6% in previous studies.…”

“…21,22 Also, it performs particularly poorly in low-resource settings, similar to the ones where these downstaging studies have been performed. 23,24 In the study by Sujathan et al, 16 only 2.2% of the women were subjected to colposcopy and biopsy; in the studies by Wesley et al 19 and Nene et al, 18 around 1% of women underwent biopsy and none had colposcopy. In the study by Rao et al, 17 no woman had a confirmatory diagnostic investigation and the distribution of cytologically diagnosed dysplasia by different grades is not provided.…”

“…[13][14][15][16][17][18][19][20] A major drawback of the previously reported studies on downstaging or unaided visual inspection is that all of them used cytology as the reference investigation (gold standard) to assess the performance of downstaging. The proportion of women subjected to colposcopy and histology was very low in these studies.…”