Abstract 5777: Risk factors associated with Pipelle endometrial biopsy failure
Authors: Adambekov Shalkar , Lopa Samia , Elishaev Esther , Rindos Noah , Mansuria Suketu , Edwards Robert P. , Bovbjerg Dana H. , Donnellan Nicole , Linkov Faina 
Published: September 2020

Abstract
Background. Although Pipelle biopsy plays a significant role in diagnosis of endometrial cancer and benign gynecologic disease, it has a significant failure rate, with multiple reasons for failure not well characterized. Few studies have distinguished between biopsy failures due to inability to obtain a sample at all (sampling failure) and failures due to having samples with insufficient tissue for histopathological diagnosis (tissue failure).
Methods. Women undergoing a Pipelle biopsy in a tertiary care center (August 2017 to June 2019) were recruited and signed informed consent. Biopsy sampling failures were assessed by surveys administered to the clinicians immediately after procedures. Reasons for failure included: stenotic cervix, body habitus, and procedure intolerance. Biopsy tissue failures were determined by extraction of patients' pathology reports from electronic health records, which also provided data regarding demographic factors, personal history, and clinical indications for biopsy (i.e., abnormal bleeding, postmenopausal bleeding, other indications). Overall failure of Pipelle biopsy was defined as failures due to sampling failure and tissue failure. Descriptive statistics and univariate logistic regression analyses were used to identify risk factors associated with each type of biopsy failure. Two-sided P≤0.05 was considered significant. Analyses were performed using SAS version 9.4 (SAS Institute Inc., Cary, NC, USA).
Results. A total of 121 patients were included in the study. A majority were white (84.03%) and obese (median BMI = 31.70). The overall failure incidence was 29% (18% sampling failure and 11% tissue failure). Overall failure was significantly associated with patients': age (OR=1.10, P&lt;0.001); menopausal status (OR=3.46, P=0.003); and biopsy indication (ORother vs abnormal bleeding=3.20, ORpostmenopausal bleeding vs abnormal bleeding=3.05, P=0.025). Sampling failure was significantly associated with patients': age (OR=1.11, P=0.001); history of OB/GYN surgery (OR=3.84, P=0.014); history of biopsy failure (OR=10.78, P=0.009); menopausal status (OR=4.67, P=0.002); and biopsy indication (ORother vs abnormal bleeding=7.77, ORpostmenopausal bleeding vs abnormal bleeding=4.11, P=0.007). Tissue failure was significantly associated only with patients' age (OR=1.10, P=0.050).
Conclusions. Overall Pipelle failure was found to be due to both failures to obtain a sample at all, and to failures to obtain enough tissue for histopathological diagnosis. Interestingly, these two reasons for overall failure were found to have different sets of predictors, suggesting that providers may want to pursue alternative approaches in high risk patients for Pipelle biopsy failure.
Citation Format: Shalkar Adambekov, Samia Lopa, Esther Elishaev, Noah Rindos, Suketu Mansuria, Robert P. Edwards, Dana H. Bovbjerg, Nicole Donnellan, Faina Linkov. Risk factors associated with Pipelle endometrial biopsy failure [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 5777.