Use of colposcopy for detection of squamous intraepithelial lesions

Introduction: Pap smear, the main tool of cervical cancer screening is not always available, but some patients are in urgent need for proper diagnostic. Aim of this article was to investigate accuracy of colposcopy for detection of squamous intraepithelial lesions of low or high grade (LGSIL, HGSIL) and to promote colposcopy as useful tool for detection of patients in need for immediate further diagnostics. Methods: Prospective multicentric study performed in B&H in 2012-2014 included 87 patients with colposcopic images related to squamous intraepithelial lesion (SIL) who formed experimental group: 56 patients with colposcopic images related to LGSIL and 31 patients related to HGSIL. Control group included 50 patients without colposcopic abnormalities. To test accuracy of colposcopy, PAP smear and histology were used. For statistical analysis χ2 was used. Results: 94.5% patients in experimental group had abnormal PAP test: 64.3% correlated to LGSIL (χ2 = 60.48 P < 0.0001), while 64.5% correlated to HGSIL (χ2 = 54.23 P < 0.0001) Odds Ratio = 490; 95% CI = 42.024 to 5713.304). HGSIL was confirmed in 27 (87%) cases by histology (CIN II/CIN III). There were no statistically significant differences between colposcopic finding and histology results (Yates-corrected χ2 = 0.33 P = .5637). Conclusions: This study showed high level of correlation between colposcopy and PAP results (63-64%) and to histology for HGSIL (87%). In absence of PAP test colposcopy could be used to select patients in need for biopsy.


IntroductIon
Squamous intraepithelial lesion (SIL) starts at the cellular level as transformation and abnormal growth of squamous cells on the surface of the cervix. In the cervical channel intraepithelial lesion 73 starts as squamous metaplasia, which includes proliferation of undifferentiated reserve cells, columnar cells and their transformation into the squamous cells. SIL begin as cellular change at low grade level (LGSIL) and during the time could advance to high grade lesion (HGSIL) and cervical cancer. When detected, SIL can be successfully treated at any stage. It is well known and scientifically proven fact that cervical cancer screening program decreases incidence of cervical cancer by detecting early stages of intraepithelial changes (SIL) using PAP test as main tool (1). For the patients with abnormal PAP smear, colposcopy is usually the next step. However, what happens if the cervical cancer screening is not available and there is lack of information about disease prevention possibility? What happens if PAP control depends only on patients' awareness of disease? In such circumstances usually, incidence of inoperable cervical cancer is very high. Where does Bosnia and Herzegovina stand in this respect?
Health system in Bosnia and Herzegovina does not provide cervical cancer screening at the any level (State level, Entity level, Cantonal level). System for education of patients does not exist. Even more, there is no cancer database. First official reports about cancer incidence including cervical cancer were published by Public Health Institute of Federation Bosnia and Herzegovina (PBIFB&H) in 2007. According to that Report cervical cancer is second most common cancer in females in the Federation Bosnia and Herzegovina (FB&H). Furthermore in the period 1996 -2007 there were 20-25/100.000 newly detected cervical cancers in Tuzla Canton. Only 20.3% of those cases were in operable stages (2).
If we do not have cervical cancer screening program and if we cannot provide a PAP test as frequently as needed (due to lack of means), could we use colposcopy to select patients who are in need for a kind of "immediate" PAP smear or even biopsy?
The aim of this article was to investigate accuracy of colposcopy for detection of squamous intraepithelial lesions (SIL) and to promote colposcopy as tool for detection of patients in need for immediate PAP smear in the health systems without screening program.

Methods study design
This was prospective multi-centric study that took a place in Obstetrics and Gynecology practice Omeragić, Tuzla, Health Centre of Tuzla, Health Centre Teašanj, Cantonal Hospitals of Mostar and Clinical Centre Banjaluka, during the period January 2012 to January 2014.

Patients
The patients in the study were selected in accordance to colposcopic criteria for squamous intraepithelial lesions.
Experimental group marked as Group A was formed by 87 patients. They were selected by means of colposcopy which showed one or more coploscopic images (markers) related to squamous intraepithelial lesion (SIL).
Colposcopic assessment of lesions was based on the following characteristics: location of the lesion related to Transformation zone (within or outside of the Transformation zone), reaction to 3-5% solution of acetic acid, color intensity, surface and borders, vascularization (inter-capillary distance), speed of emergence and time of duration.
Group A was divided in two subgroups: A1 and A2. Subgroup A1 included 56 patients with colposcopic images that are clearly defined as characteristics of LGSIL. Subgroup A2 included 31 patients with colposcopy images that are clearly defined as characteristics of HGSIL. Extensive lesion that was spread over the broad area of surface of the cervix, in the same time, was indication for biopsy.  (Figure 1).
Out of all patients in experimental group there were 56 patients with colposcopic images defined as markers for LGSIL. They formed Subgroup A1. Those patients had markers located within the transformation zone (100%). Aceto-white (AW) epithelium was the most frequently seen (53 or 94.6%) as a single marker (50 or 89.3%) or associated with vascular changes, mosaic (M) or/and punctuation (P) (3 or 5.35%).
When detected outside of Transformation zone (31 patients) more than one markers were seen most often. Aceto-white epithelium (AW) is most frequently seen, but only in two cases as a single marker (6.4%). Vascular changes (Mosaic, Punctuations) associated with AW epithelium were present in 29 (93.5%) cases. These images (markers) are defined as colposcopic criteria for HGSIL. Patients with such images formed Subgroup A2 (Table 1).
PAP smear was performed in all patients including control group. Distribution of PAP diagnosis (Bethesda categories) per groups was shown in Table 2.
Correlation between colposcopy and PAP diagnosis is shown of Figure 2.
In control group there were 17 (34%) PAP results marked as abnormal. In 12 (24%) cases it was ASC-US, atypical cells were related to inflammation or lack of hormonal activity, while only 8% had SIL.
There are no statistically significant differences between colposcopic finding and histology results (Yates-corrected χ 2 = 0.33 P =.5637) but there is a four times higher possibility that histology will show cervical intraepithelial lesion of medium grade (CIN II) and two times higher possibility that histology will show high grade dysplasia (    Colposcopy is useful method for detection of early stages of SIL. This study showed high level of correlation between colposcopy and both, PAP test and histology. In the absence of cancer screening program and regular frequency of PAP smear diagnostics or if PAP test is not available, it can be used as a non-invasive, inexpensive and accurate tool.