Identifying a low-risk group for parametrial involvement in microscopic Stage IB1 cervical cancer using criteria from ongoing studies and a new MRI criterion

Background: There are currently three ongoing studies on less radical surgery in cervical cancer: ConCerv, GOG-278, and SHAPE. The aim of this study was to evaluate the performance of the criteria used in ongoing studies retrospectively and suggest a new, simplified criterion in microscopic Stage IB1 cervical cancer. Methods: A retrospective analysis was performed in 125 Stage IB1 cervical cancer patients who had no clinically visible lesions and were allotted based on microscopic findings after conization. All patients had magnetic resonance imaging (MRI) after conization and underwent type C2 radical hysterectomy. We suggested an MRI criterion for less radical surgery candidates as patients who had no demonstrable lesions on MRI. The rates of parametrial involvement (PMI) were estimated for patients that satisfied the inclusion criteria for ongoing studies and the MRI criterion. Results: The rate of pathologic PMI was 5.6% (7/125) in the study population. ConCerv and GOG-278 identified 11 (8.8%) and 14 (11.2%) patients, respectively, as less radical surgery candidates, and there were no false negative cases. SHAPE and MRI criteria identified 78 (62.4%) and 74 (59.2%) patients, respectively, as less radical surgery candidates; 67 patients were identified as less radical surgery candidates by both sets of criteria. Of these 67 patients, only one had pathologic PMI with tumor emboli. Conclusions: This study suggests that the criteria used in three ongoing studies and a new, simplified criterion using MRI can identify candidates for less radical surgery with acceptable false negativity in microscopic Stage IB1 disease.