Concomitant use of 18F-FDG PET-CT SUVmax is useful in the assessment of Ki67 labeling index in core-needle biopsy specimens of breast cancer

Abstract

Background: Ki67 is a recognized proliferative and predictive marker in invasive breast cancer. However, results of Ki67 evaluation are affected by the method employed for sample fixation or biopsy, as well as by intratumor heterogeneity. Here, we aimed to compare the Ki67 labeling index (Ki67LI) between core-needle biopsy specimens (CNBSs) and surgically resected specimens (SRSs) of invasive breast cancer, and verify whether the discordance in Ki67LI can be reduced by analyzing the maximum standardized uptake value (SUVmax) obtained from pretreatment whole-body positron emission tomography/computed tomography (PET/CT) in combination with Ki67LI.Methods: Tumor tissues were obtained from 118 patients with invasive breast cancer. Ki67LI was evaluated in CNBSs and SRSs by immunohistochemistry. First, we directly compared Ki67LI between CNBS and SRS, "allowing a tolerance margin of 5%." We divided the Ki67LI values into three groups (Low: 0≤ Ki67LI ≤10, Intermediate: 10< Ki67LI <30, and High: 30≤ Ki67LI) and the SUVmax into three groups (SUVmax ≤4, 4< SUVmax <8, and 8≤ SUVmax). We then verified the concordance rate between CNBS and SRS in each group in combination with the SUVmax obtained by PET/CT. Results:The median Ki67LI was 17.8% (0.5-75.9%) and 17.0% (1.0-75.7%) in CNBS and SRS, respectively. The overall Ki67LI concordance rate between CNBS and SRS was 37.3% (44/118). The concordance was improved in the Low and High Ki67LI groups by applying SUVmax thresholds of 4 [82.6% (19/23), P=0.033 and 8 (92.3% (12/13), P=0.009], respectively. Conclusions: Our results indicated that CNBS Ki67LI alone was not able to reflect SRS Ki67LI with sufficient accuracy. By dividing CNBS Ki67LI into three classes in combination with SUVmax, tumor proliferation could be predicted with higher accuracy in patients with invasive breast carcinoma.

Breast Magnetic Resonance Imaging Can Predict Ki67 Discordance Between Core Needle Biopsy and Surgical Samples

“…One study linked this disagreement to tumor size >1 cm, lack of PR expression in the tumor, grade III cancer, and patient age >35 years 8 . Another study associated Ki67 discordance with lower maximum standardized uptake value (SUVmax) in whole‐body positron emission tomography/computed tomography 9 . Imaging indices are particularly attractive as markers because they can be measured noninvasively before treatment.…”

“…8 Another study associated Ki67 discordance with lower maximum standardized uptake value (SUVmax) in whole-body positron emission tomography/computed tomography. 9 Imaging indices are particularly attractive as markers because they can be measured noninvasively before treatment. MRI is already widely applied to breast cancer patients for preoperative staging, evaluation of neoadjuvant chemotherapy, and monitoring of recurrence.…”

Radiomics Methods to Differentiate Metastasis and Primary Lung Cancer of Breast Cancer Patients in PET/CT

“…Although major advances have been made in diagnosis and treatment of primary breast cancer, metastasis, typically to bone, lung, liver, and brain, is still the leading reason for mortality of cancer patients [2] . The lung is often the first site of metastasis for BC, especially among the clinically aggressive basal subtype of breast cancer [3] . A increasing opportunity for the development of second caners since the better survival is a matter of course.…”

“…Thus, the degree of 18FDG uptake seems to be more heterogeneous in comparison with many other cancers, which has been the main reason for the present investigation of the causal mechanism that determines 18 FDG uptake in breast cancer [33] . Present available literature recommends that the use of 18 F-FDG PET and PET/CT leads to significant modification of staging and treatment in diagnosed breast cancer patients [34][35][36] . Therefore, PET imaging may be applied for clinical routine use in the breast cancer initial staging.…”