Title: Development of a Machine Learning-Based Model for Predicting Positive Margins in
high-grade squamous intraepithelial lesion(HSIL) Treatment by Cold Knife Conization(CKC):
A Single-Center Retrospective Study
Version: 3 Date: 28 Apr 2024
Reviewer:  Sveinung Wergeland Sørbye
Reviewer's report:
Zhang et al. have conducted a retrospective study involving 3,343 patients who underwent
cold knife conization (CKC) for cervical high-grade squamous intraepithelial lesions (HSIL) to
identify factors contributing to positive surgical margins and to develop a machine learning-
based risk prediction model. Their analysis highlighted several independent risk factors for
positive margins, including HPV16/18 infection, multiple high-risk HPV infections, glandular
involvement, lesions across three or more quadrants, and severe cytologic test results. Logistic
regression emerged as the most effective machine learning method, achieving an accuracy of
74.7%, sensitivity of 76.7%, specificity of 74.4%, and an area under the curve (AUC) of 0.826.
The study underscores the clinical utility and consistency of the predictive model in identifying
patients at higher risk for positive margins after CKC.
The claims are properly placed in the context of the previous literature. The experimental data
support the claims. The manuscript is written clearly enough that most of it is understandable to
non-specialists. The authors have provided adequate proof for their claims, without overselling
them. The authors have treated the previous literature fairly. The paper offers enough details of
methodology so that the experiments could be reproduced.
Comments
1. In my clinical experience, most hospitals in Western countries have transitioned from
cold knife conization (CKC) to Loop Electrosurgical Excision Procedure (LEEP) to mitigate
risks such as bleeding, reduced recovery times, cervical stenosis, and cervical incompetence.
Although the risk of recurrence may be slightly higher with LEEP compared to CKC, the
underlying risk factors contributing to positive margins are likely consistent across both
methods. Consequently, I believe the findings from this study, which are based on women treated
with CKC, could also be applicable to populations treated with LEEP. This broader applicability
should be considered in the discussion of your results.
2.  In the introduction, Zhang et al. state that 'HSIL is closely related to the occurrence and
development of cervical cancer.' It is important, however, to clarify the potential outcomes
of untreated CIN2 and CIN3 lesions, which are typically categorized as HSIL. Evidence
suggests that most cases of CIN2 and CIN3 do not progress to cervical cancer if left untreated.
Specifically, only about 5% of untreated CIN2 lesions and between 12% to 33% of untreated
CIN3 lesions will progress to invasive cervical cancer, according to Ostor (1993). It may
be beneficial to include these statistics to provide a more nuanced understanding of the risk
associated with untreated HSIL.
Ostör AG. Natural history of cervical intraepithelial neoplasia: a critical review. Int J Gynecol
Pathol. 1993 Apr;12(2):186-92. PMID: 8463044.
3. In the introduction, Zhang et al. cite that 'Relevant literature shows that about 31%-50% of
HSIL patients without formal treatment will progress to cancer within 30 years.' This reference
appears to be based on McCredie (2008), which actually reports a 31.3% cumulative incidence
of invasive cancer after 30 years in a subgroup of women with large colposcopically visualized
CIN3 lesions who were managed only by punch or wedge biopsy, and 50.3% in those with
persistent disease within 24 months. It is crucial to specify that these figures pertain particularly
to CIN3 and not to all HSIL, which also includes CIN2. CIN2, as noted, has a significantly lower
progression risk to invasive cancer.
Furthermore, the context in which McCredie’s study was conducted—New Zealand between
1955 and 1976—featured less sensitive screening methods than are available today. Modern
screening techniques, such as liquid-based cytology and HPV testing, detect CIN2 and CIN3
lesions earlier when they are typically smaller, which likely contributes to a lower risk of
progression to invasive cancer today than reported in the older study. This distinction is critical
for readers to understand the current risk landscape accurately, and I recommend that this
context be included to provide a clearer picture of the risk associated with untreated HSIL in
the contemporary clinical environment.
McCredie MR, Sharples KJ, Paul C, Baranyai J, Medley G, Jones RW, Skegg DC. Natural
history of cervical neoplasia and risk of invasive cancer in women with cervical intraepithelial
neoplasia 3: a retrospective cohort study. Lancet Oncol. 2008 May;9(5):425-34. doi: 10.1016/
S1470-2045(08)70103-7. Epub 2008 Apr 11. PMID: 18407790.
4.  In the discussion, Zhang et al. highlight the issue of positive resection margins following
conization and their close relationship with the residual and recurrence of HSIL. However,
it's important to contextualize these concerns with broader epidemiological data. According to
a meta-analysis by Arbyn et al. (2017), the overall risk of residual or recurrent CIN2+ post-
treatment is 6.6%, with 23.1% of cases showing positive margins. Notably, the risk of CIN2+
recurrence is 3.5% for women with negative margins and 16.9% for those with positive margins.
This data indicates a relative risk of 4.8 for positive margins compared to negative ones. These
statistics suggest that while positive margins significantly increase recurrence risk, a substantial
number of treated women do not experience recurrence, irrespective of margin status.
Arbyn, M., Redman, C. W. E., Verdoodt, F., Kyrgiou, M., Tzafetas, M., Ghaem-Maghami, S.,
Petry, K.-U., Leeson, S., Bergeron, C., Nieminen, P., Gondry, J., Reich, O., & Moss, E. L.
(2017). Incomplete excision of cervical precancer as a predictor of treatment failure: a systematic
review and meta-analysis. The Lancet Oncology, 18(12), 1665-1679. https://doi.org/10.1016/
S1470-2045(17)30700-3.
5.  While removing more cervical tissue during treatment can decrease the risk of positive
resection margins and recurrence of CIN2+, it also increases the risk of premature births,
presenting a significant clinical trade-off. According to Kyrgiou (2016), extensive tissue removal
is linked with higher premature birth rates. Additionally, a meta-analysis by Arbyn et al. (2008)
found that cold knife conization significantly increases the risk of perinatal mortality (relative
risk 2.87, 95% CI 1.42 to 5.81), severe preterm delivery (RR 2.78, 95% CI 1.72 to 4.51), extreme
preterm delivery (RR 5.33, 95% CI 1.63 to 17.40), and the occurrence of low birth weight infants
under 2000 g (RR 2.86, 95% CI 1.37 to 5.97). Moreover, LEEP treatment prior to pregnancy
has been associated with an increased risk of preterm delivery, premature rupture of fetal
membranes, and low birth weight infants (Liu 2023). These findings underscore the necessity
of balancing effective treatment with minimizing potential harm, particularly in reproductive-
age women.
Arbyn M, Kyrgiou M, Simoens C, Raifu A O, Koliopoulos G, Martin-Hirsch P et al. Perinatal
mortality and other severe adverse pregnancy outcomes associated with treatment of cervical
intraepithelial neoplasia: meta-analysis BMJ 2008; 337 :a1284 doi:10.1136/bmj.a1284
Liu, R., Liu, C., & Ding, X. (2023). Association between loop electrosurgical excision procedure
and adverse pregnancy outcomes: a meta-analysis. The Journal of Maternal-Fetal & Neonatal
Medicine, 36(1). https://doi.org/10.1080/14767058.2023.2183769
Kyrgiou M, Athanasiou A, Paraskevaidi M, Mitra A, Kalliala I, Martin-Hirsch P, Arbyn M,
Bennett P, Paraskevaidis E. Adverse obstetric outcomes after local treatment for cervical
preinvasive and early invasive disease according to cone depth: systematic review and meta-
analysis. BMJ. 2016 Jul 28;354:i3633. doi: 10.1136/bmj.i3633. PMID: 27469988; PMCID:
PMC4964801.
6. In the manuscript, the authors have presented percentages with two decimal places. For ease
of reading and to simplify the presentation in both tables and text, I recommend rounding these
percentages to one decimal place (e.g., 74.74% to 74.7%).
7. The submitted manuscript currently lacks page numbers and line numbers. To enhance the
accuracy of the peer review process and streamline subsequent edits, I strongly recommend
implementing a line numbering system across all pages of the manuscript effective immediately.
This change will significantly aid reviewers and editors in providing precise feedback.
8. The manuscript currently includes several typographical errors, including missing spaces
—particularly noticeable before parentheses—unusual special characters, and inconsistent
punctuation. While the journal typically addresses such errors during the publishing process,
submitting a manuscript with minimal errors would facilitate a smoother final layout process
and enhance the overall quality of the publication. It would be beneficial to review and correct
these issues before submission.
Minor revisions
Title, "Development of a Machine Learning-Based Model for Predicting Positive Margins in
HSIL Treatment by Cold Knife Conization: A Single-Center Retrospective Study"
Abstract, "Objective: This study aims to analyze factors associated with positive surgical
margins following cold knife conization (CKC) in patients with cervical high-grade squamous
intraepithelial lesion (HSIL) and to develop a machine-learning-based risk prediction model.
Methods: We conducted a retrospective analysis of 3,343 patients who underwent CKC for
HSIL at our institution. Logistic regression was employed to examine the relationship between
demographic and pathological characteristics and the occurrence of positive surgical margins.
Various machine learning methods were then applied to construct and evaluate the performance
of the risk prediction model.
Results: The overall rate of positive surgical margins was 12.9%. Independent risk factors
identified included glandular involvement (OR=1.716, 95% CI: 1.345-2.189), transformation
zone III (OR=2.838, 95% CI: 2.258-3.568), HPV16/18 infection (OR=2.863, 95% CI:
2.247-3.648), multiple HR-HPV infections (OR=1.930, 95% CI: 1.537-2.425), TCT # ASC-
H (OR=3.251, 95% CI: 2.584-4.091), and lesions covering #3 quadrants (OR=3.264, 95%
CI: 2.593-4.110). Logistic regression demonstrated the best prediction performance, with an
accuracy of 74.7%, sensitivity of 76.7%, specificity of 74.4%, and AUC of 0.826.
Conclusion: Independent risk factors for positive margins after CKC include HPV16/18
infection, multiple HR-HPV infections, glandular involvement, extensive lesion coverage, high
TCT grades, and involvement of transformation zone III. The logistic regression model provides
a robust and clinically valuable tool for predicting the risk of positive margins, guiding clinical
decisions and patient management post-CKC."
Introduction, "Cervical high-grade squamous intraepithelial lesion (HSIL), which encompasses
cervical squamous intraepithelial neoplasia grades 2 (CIN2) and 3 (CIN3), is closely associated
with the development of invasive cervical cancer. It is essential to distinguish between the
progression risks of these grades. Studies suggest that if left untreated, approximately 5% of
CIN2 lesions and 12% to 33% of CIN3 lesions may progress to invasive cancer, reflecting
significant variability based on lesion severity (Ostör, 1993). Moreover, recent literature, such as
McCredie (2008), notes that the cumulative incidence of invasive cancer over 30 years can reach
31.3% in women with substantial colposcopically visualized CIN3 managed only by biopsy,
with a higher incidence in those with persistent disease. This distinction is crucial, as earlier
and more sensitive detection methods like liquid-based cytology and HPV testing are likely to
identify lesions at a stage where they pose a lower risk of progression. Given the potential for
progression, particularly in untreated CIN3, and the significantly reduced risk of 0.7% following
conventional surgical treatment, proactive surgical management of HSIL is recommended to
prevent the development of cervical cancer."
Discussion,  "Currently, cervical conization serves as a pivotal treatment strategy for HSIL.
A significant challenge in this approach is the incidence of positive resection margins, which
substantially influence the risk of residual disease and recurrence of HSIL. It has been reported
that the rate of positive resection margins following HSIL conization is 12.7% [6]. Furthermore,
according to a meta-analysis by Arbyn et al. (2017), while the overall risk of residual or recurrent
CIN2+ post-treatment is 6.6%, the occurrence of positive margins was observed in 23.1% of
cases. Importantly, the risk of recurrence for those with positive margins is significantly higher
at 16.9%, compared to only 3.5% for those with negative margins, indicating a relative risk of
4.8. This data highlights the critical need for precision in surgical technique to ensure complete
removal of the lesion, thereby reducing the likelihood of positive margins and subsequent
recurrence. Additionally, it emphasizes the importance of rigorous postoperative monitoring,
especially for patients with positive margins, to manage and mitigate the risk of HSIL recurrence
effectively.
In addressing the treatment of HSIL through conization, it is also crucial to consider the
long-term reproductive consequences associated with different surgical techniques. While
more extensive tissue removal can decrease the risk of positive resection margins and reduce
the recurrence of CIN2+, it is associated with increased risks in subsequent pregnancies.
Research, including findings by Kyrgiou (2016) and a meta-analysis by Arbyn et al. (2008),
has demonstrated that treatments like cold knife conization significantly elevate the risks of
perinatal mortality, severe and extreme preterm delivery, and the birth of low weight infants
under 2000 g. Similarly, Liu (2023) has documented that the Loop Electrosurgical Excision
Procedure (LEEP) is linked with a higher incidence of preterm delivery, premature rupture of
fetal membranes, and low birth weight infants. These adverse outcomes highlight the importance
of surgical prudence and the need for individualized treatment planning that considers both
oncologic safety and future pregnancy outcomes. Hence, while strategizing treatments for HSIL,
especially in younger women planning future pregnancies, a careful evaluation of the extent of
tissue removal is imperative to ensure optimal long-term health outcomes."
Conclusion, "In conclusion, our study identifies several independent risk factors for positive
resection margins following cold knife conization (CKC), including HPV16/18 infection,
multiple high-risk HPV (HR-HPV) infections, glandular involvement, lesions covering three or
more quadrants, TCT results of at least ASC-H, and involvement of the transformation zone
III (TZ III). The clinical prediction model developed from these findings demonstrates robust
consistency and practical value, offering significant guidance for clinicians in managing and
following up with patients postoperatively. This model not only aids in surgical planning but also
enhances post-treatment monitoring, ultimately contributing to improved patient outcomes."