Correlation between apparent diffusion coefficient and Ki-67 in different pathological types of lung cancer.

Abstract

BackgroundComputed tomography (CT) is common and valuable non-invasive method to evaluate proliferative activity in lung cancer; however, magnetic resonance (MR) is rarely used in lung cancer. To evaluate whether there were different expression levels of Ki-67 in different pathological types of lung cancer and the correlation between Ki-67 index and apparent diffusion coefficient (ADC) value.MethodsThe clinical and pathological data of 165 patients with lung cancer confirmed by needle biopsy or surgery were retrospectively evaluated, among whom 54 underwent MR examination. The level of Ki-67 was tested using the international standard IHC 2-step method. Kruskal-Wallis H test was used to compare the different expression level of Ki-67 index of adenocarcinoma, squamous cell carcinoma, and small cell carcinoma, and the least significant difference (LSD) method was used for pair-group comparison. Spearman correlation coefficient was used to analyze the correlation between Ki-67 index and ADC value. All statistical tests were bilateral, and P<0.05 was considered statistically significant.ResultsThe median of Ki-67 index in adenocarcinoma, squamous cell carcinoma, and small cell carcinoma were 20 (10, 30), 40 (40, 60), and 70 (60, 80), respectively. There was a statistical difference in the expression level of Ki-67 index in the 3 different pathological types of lung cancer (H=103.762, P=0.000). In 54 cases of lung cancer with MR examination, there was a significant negative correlation between average ADC value and expression level of Ki-67 index (r=−0.506, P=0.000), while there was no correlation between ADC value and Ki-67 index in distinguishing different pathological types of lung cancer.ConclusionsThe expression level of Ki-67 index was different among different pathological types of lung cancer. The ADC value is correlated with Ki-67 index in lung cancer, which can be used to evaluate the proliferative activity of lung cancer.