EP390 - An Analysis of Colorectal Involvement During Cytoreductive Surgery for Advanced Gynecologic Cancer

Purpose/Background: Currently, there is limited literature related to the relationship between advanced-stage gynecologic cancer and secondary colorectal involvement. This study aims to identify which factors predict colon involvement in advanced gynecologic cancers. At a high-volume academic medical center, colorectal surgeons are often asked to be available during cytoreductive surgeries due to the uncertainty of whether a colon resection will be required. By examining patient demographics, tumor characteristics, treatment course, and disease stage, this study seeks to better anticipate which patients will require colon resection and improve preoperative and surgical planning.

Methods/Interventions: This retrospective chart review was conducted at a tertiary care academic hospital including patients who underwent cytoreductive debulking surgeries for gynecologic cancer between 2015 and 2021. Patients were identified using electronic medical records. Inclusion criteria consisted of patients over the age of 18 with a primary gynecologic cancer who were boarded by the gynecology service for debulking surgery. Exclusion criteria included patients with baseline colorectal carcinoma, defined as those with a prior history of colorectal cancer or a primary colorectal malignancy with secondary gynecologic involvement. Both descriptive and inferential statistics were performed, with significance set at p < 0.05.

Results/Outcomes: Among 556 patients, 491 (88.3%) had no colonic involvement and 65 (11.7%) had colonic involvement. On univariate analysis colonic involvement was significantly associated with age < 50 (p < 0.05), ovarian/fallopian tube primary (as opposed to uterine or other; p< 0.001), histologic subtype with a serous component (p < 0.001), higher TNM stage (p < 0.001), ASA 3+ status (p < 0.01), higher CA-125 (p < 0.001), receiving neoadjuvant therapy (p < 0.05), having a preoperative CT scan (p=0.023), recent colonoscopy (p < 0.001), and lower BMI (p=0.038). (Figure 1). In addition, in our logistic regression models using a total of 13 variables, we found that the TNM staging indicating the presence of distant metastasis (OR 3.70, 1.05 to 13.6, p=0.044), endoscopy within 3 years (OR 4.15, 1.40 to 12.9, p=0.011), and a CA125 level between 101-500 (OR 4.26, 1.11 to 17.3, p=0.037), were independent predictors of colon involvement (p < 0.05).

Conclusion/Discussion: Identifying predictive values that increase likelihood of colonic involvement for gynecologic cancer may help surgeons better preoperatively counsel and predict bowel resections for these patients. Our data demonstrated strong correlations within multiple sub groups that increased the predictive value of colonic involvement, as well as a logistic regression model establishing independent predictors of colonic involvement. Further data is needed to increase the power of the study, and we hope to enhance our model to include a surgical risk prediction calculator in the future.

An Analysis of Colorectal Involvement During Cytoreductive Surgery for Advanced Gynecologic Cancer