According to the Japanese and NCCN guidelines, diagnostic conization is an important method for determining the exact stage and the most accurate treatment strategy for patients with cervical cancer 7 13 14. However, as depicted by the results of the present study, there is a potential risk of cutting into a tumor in some cases and resulting in a positive margin at conization. Until now, there is no consensus on whether diagnostic conization is appropriate even when positive margins are predicted. Therefore, we evaluated the association between diagnostic conization with positive margins and patient outcomes, including lymph node metastasis in uterine cervical cancer.
The basic principles of oncologic surgery are careful tumor manipulation, resection in tumor-free margins, and avoidance of tumor spillage 15. For example, Turnbull et al. proposed the no-touch isolation technique in colon cancer surgery in 1967 16. This method involves vascularization first and then tumor removal to prevent hematogenous metastasis, and it contributed to a favorable 5-year survival rate. Hence, the method has also been applied for pancreatic and liver cancers 17 18. For uterine cervical cancer, patients who underwent minimally invasive radical hysterectomy could have shorter survival than those who underwent conventional abdominal radical hysterectomy. A possible explanation is the use of an intrauterine manipulator in the minimally invasive surgery, which might increase intrauterine pressure and spread cancer cells to the lymphovascular space 15 19 20 21. However, other reports showed that the use of manipulators is not associated with worse prognosis, and its clinical significance is still debated 22 23. Therefore, the basic principles are important, but they are not absolute factors, and other factors may have a great influence.
Diagnostic conization does not meet these principles in case of a positive margin. The risk of positive margins at conization was associated with several factors, such as menopausal status, grade and size of disease, devices used for conization, and purpose of conization (diagnostic or therapeutic) 24 25 26. According to previous studies, a positive margin at conization would mean residual disease; however, it was not associated with parametrial invasion at the time of hysterectomy 27 28 29. In the present study, we showed that positive margins may increase the rate of LVSI positivity in hysterectomy samples, although there was no statistical significance regarding pelvic lymph node metastasis. Moreover, there was no significant difference in PFS and OS between the positive and negative margin groups. Consistent with our results, a recent report also indicated that there were no significant differences in lymph node metastasis, LVSI positivity, recurrence, and death between the patients with positive and negative margins 30. Therefore, the prognostic impact of a positive margin at conization was considered to be limited.
However, in some cases, obvious lymph node enlargement and strong LVSI positivity can occur after diagnostic conization with a positive margin. Needless to say, lymph node metastasis is one of the worst prognostic factors in cervical cancer 31 32. Therefore, regardless of the lack of statistical significance, clinicians should keep in mind that there are cases with rapid progression after conization. Moreover, due to the present relatively small-scale retrospective study, it was difficult to statistically evaluate such rare cases. Therefore, further studies are needed to evaluate the potential risk of a positive margin at conization.
In conclusion, the present study provided important evidence for the association between cervical conization with positive margins and subsequent cancer progression. We showed that there were no significant differences in the lymph node metastasis rate and patient prognosis between the positive and negative margin groups. Therefore, diagnostic conization is considered acceptable even if a positive margin will occur.