Diagnostic accuracy of multiparametric MRI in endometrial cancer and its adjunctive value in identifying high-risk women requiring surgical staging

Abstract

LETTER TO THE EDITOR Dear Editor, Endometrial cancer is the most common gynaecological cancer in developed countries, with a five-year survival rate of 81%. 1,2 Prognostic factors include the International Federation of Gynecology and Obstetrics (FIGO) stage, depth of myometrial invasion (MI), lymph node involvement, cervical stromal involvement, and histological grade. Total hysterectomy with bilateral salpingo-oophorectomy (THBSO), pelvic and para-aortic lymph node dissection is the standard staging procedure for endometrial cancer. 3 Decision on adjuvant therapy for endometrial carcinomas is based upon clinicopathologic factors such as FIGO stage and tumour grade. 4 Multiparametric magnetic resonance imaging (mpMRI) has been reported to have high sensitivity and specificity in the detection of deep MI. [5][6][7] We sought to evaluate the diagnostic accuracy of pelvic mpMRI in determining MI and the adjunctive value that it may add to high-grade carcinoma detected on endometrial biopsy ("high-grade endometrial biopsy") in identifying high-risk patients (deep MI or ≥ Stage 1B disease).We reviewed consecutive cases of all primary endometrial cancers on the database at the National Cancer Centre Singapore over a 5-year period from 1 January 2010 to 31 December 2014. The inclusion criteria were: patients with newly diagnosed non-metastatic primary endometrial carcinomas, preoperative pelvic mpMRI, THBSO performed with curative intent, pathological review, and management plan discussed at the Gynaecologic Oncology tumour board. Cases with synchronous tumours or insufficient data were excluded.Our MRI protocol included anatomical T1-weighted and T2-weighted sequences, combined with functional diffusion-weighted imaging and dynamic contrastenhanced (DCE) imaging. The depth of MI was measured on MRI and then dichotomised as <50% or ≥50%.All pathological specimens were reviewed by 2 gynaecologic pathologists. The microscopic depth of MI in millimetres (mm) in relation to the total thickness of the myometrium was classified as <50% or ≥50% without reference to MRI findings.A total of 171 cases were analysed. There were 72 (42.1%) cases classified as FIGO Stage ≥1B. The majority (152/171, 88.9%) were of the endometrioid