The analysis of this study’s results is consistent with the findings expected as recommended by the Brazilian Guidelines for Cervical Cancer Screening, which chose the S&T method as the best option for women that meet the procedure’s eligibility criteria. When performed in women with cytology suggestive of high grade, reliable colposcopy with increased findings, visible SCJ and a maximum of one centimeter from the endocervical canal (TZ type 1 or 2), lesion limited to the cervix and absence of suspicion of invasion or glandular disease, there is a low risk of negative histology or incomplete treatment. The current study only assessed women that met all the criteria for the treatment and that underwent the procedure, resulting in 8.7% negative histology or CIN 1.
Furthermore, according to the Brazilian Guidelines, in cases where this method is indicated, cervical biopsy is not recommended except in services with absence of guaranteed quality of cytology or when the colposcopist is uncertain of the findings, in which case biopsy becomes acceptable. The overtreatment rate when performed in two stages, with prior biopsy, ranges from 11 to 35%, a variability attributed to the limitation of intra- and inter-observer agreement on the biopsy and histopathology results from the excised specimen (4). These values may also be due to excisional biopsies. The colposcopy center where the current study was performed is considered a referral center in the city of Rio de Janeiro, with highly experienced professionals, and is a teaching and research institute, thus corroborating the services’ quality.
In a meta-analysis that aimed to estimate overtreatment in women undergoing S&T, in 13 studies that included 3,403 women with high-grade cytology and colposcopy, the overtreatment rate was 11.6% (5). In this study, overtreatment was defined as CIN 1 or less, as in our study, in which we found an even lower rate (8.7%). Seven studies from this same meta-analysis and including 374 women with high-grade cytology and low-grade colposcopy showed that the overtreatment rate was even higher (29.3%), as expected in this situation. Meanwhile, studies including 506 women and showing low-grade cytology and high-grade colposcopy found an overtreatment rate of 46.4%. In the group of studies with 328 women with low-grade cytology and colposcopy, overtreatment was 72.9% (5).
We emphasize that CIN 2 is considered here as a preinvasive lesion since the present Brazilian Guidelines recommends its treatment because of its unknown prognosis. Although women with this histopathologic result are not as prevalent as the other with CIN 3 (Table) someone would be concerned about the use of S&T in younger women. That´s why this approach is not recommended for women younger than 25 years old in Brazil. In fact, since recent papers had put into light the high probability of spontaneous regressions of CIN 2 the previous biopsy approach had become the first choice in women younger than 30 years old, with less marked alterations or with lesions limited to one quadrant of the ectocervix.
Importantly, the effectiveness and appropriate application of the S&T method requires adequate criteria in its indication, and agreement between the cytology and colposcopy findings is essential. In cases of disagreement between cytology and colposcopy, we believe it is prudent to perform a biopsy, with treatment reserved for confirmed cases of high-grade intraepithelial lesion, especially in young and fertile women, in order to avoid unnecessary treatment that can have a negative impact on their reproductive future, besides other unwanted effects.
Despite the observed risk of overtreatment, S&T offers other benefits for women, such as prompt resolution of the problem, diminishing both the waiting time and the number of return visits to the outpatient clinic, as well as fewer expenses for both the patient and the health service, which is thus able to increase the uptake of new women. A previous study in the same service, from 1998 to 2004, found the same negative histology rate (8.7% − 2.0% negative results and 6.7% LSIL, CIN 1, and HPV without CIN), in a sample of 298 women submitted to S&T.(8)
If one considers the CIN 1 histology rate acceptable, given the observed cytologic and colposcopic alterations in these cases, in which the excisional procedure met the diagnostic objective, the negative histology rate would be 3.3% (95%CI 1.9–4.7), reinforcing the prevailing recommendation, in which the benefits of immediate treatment outweigh the risks of losses following biopsy.
We attempted to correlate negative histology with younger patient age and the reduction of negative histology rates over time, as the result of the team’s accumulated experience. However, the results were not statistically significant, and we could thus not identify groups at risk of negative histology or the team’s greater experience as capable of avoiding this outcome (despite the absence of negative histology results in the last four years of the study).
We further emphasize that a reduction in the risk of negative histology resulting from the team’s accumulated experience, although not statistically significant, is a plausible hypothesis and deserves attention, since the negative histology rates were lower on average starting in 2007 compared to the earlier years (4.9% in recent years, versus 8.6% before 2007).