Miao Y, et al. - Researchers intended to investigate the clinical features and CT or FDG-PET characteristics which, when assessed conjointly, may help differentiate anaplastic lymphoma kinase (ALK) rearrangement from epidermal growth factor receptor (EGFR) mutations in treatment naïve advanced lung adenocarcinoma of Chinese patients. Findings demonstrated that younger age, lower serum carcinoembryonic antigen (CEA) level, larger tumor volume, well-defined tumor border, and non-brain metastasis were more likely in treatment naïve advanced lung adenocarcinomas with ALK rearrangement vs EGFR mutation. In addition, data indicated that in the absence of genetic analysis, bubble lucency and higher FDG uptake of lesion and lymph nodes may help distinguish ALK rearrangement from EGFR mutation.

Methods

• Clinical and radiological characteristics of 145 patients with treatment naïve advanced lung adenocarcinoma were retrospectively reviewed.
• In order to perform a comparison between patients with ALK rearrangement and those with EGFR mutation, the one-way ANOVA, the Mann-Whitney test, chi-square test and logistic regression were used.

Results

• This study included a total of 145 patients with advanced lung adenocarcinoma, of those, only 6 had both ALK rearrangement and EGFR mutation, the sample size was too small to analysis.
• It was revealed by univariate analysis that, compared with patients with EGFRmutation, those with ALK rearrangement were younger (P=0.001) and with lower serum carcinoembryonic antigen (CEA) level (P=0.008).
• Findings demonstrated that more of tumors with ALK rearrangement were well defined (P=0.023) and have bubble lucency (P=0.026) compared with those with EGFR mutation (P=0.026).
• Data showed that in patients with ALK rearrangement, lymphadenopathy was more frequent (P=0.167).
• Researchers noted that 26 patients received FDG-PET/CT, among this population, lesion standardized uptake values (SUV) >6.95 and lymph nodes SUV_max >6.25 were more often seen in ALKrearrangement group (P=0.011, both).
• Multivariate analysis demonstrated that ALK rearrangement than EGFR mutation was more likely in patients younger than 50 years (RR=9.878, 95% CI: 2.318–42.090, P=0.002), with lower CEA level than 4.95 μg/L (RR=8.166, 95% CI: 1.085–31.983, P=0.003) and without brain metastasis (RR=7.304, 95% CI: 1.099–48.558, P=0.040).
• Additionally, data highlighted that tumor diameter less than 36 mm were prone to be EGFR mutation (RR=0.078, 95% CI: 0.017–0.356, P=0.001).