The present study aimed to investigate the diagnostic value of automatic DNA image cytometry (DNA-ICM) for diagnosing lung cancer. A total of three different types of samples from 465 cases were included: Bronchoalveolar lavage fluid (BALF), 386 samples; pleural effusion cases, 70 samples; and fine-needle aspiration procedures, 9 samples. Two methods, liquid-based cytology (LBC) and automatic DNA-ICM, were used to assess the samples, and the pathological results of 120/465 cases were reviewed. The results of DNA-ICM were compared with those of LBC and pathology. There were 57 cases of lung cancer without aneuploidy and 49 cases without evidence of malignant tumor, but with the presence of heteroploid cells. The positive diagnostic rate for BALF samples using LBC was significantly higher compared with that for DNA-ICM (P<0.05). No statistically significant difference was observed in the positive diagnostic rate between DNA-ICM and LBC in pleural effusion samples. For DNA-ICM in BALF, pleural effusion and all samples, no statistically significant differences were identified between the positive diagnostic rates of lung squamous carcinoma and lung adenocarcinoma. The positive diagnostic rate of LBC combined with DNA-ICM was not significantly improved. In non-small cell lung cancer (NSCLC) cases, the difference in the maximum value of DNA (DNAmax) was positively correlated with tumor stage (P<0.05), but no significant correlations were observed among DNA max, tumor type and tumor location. In small-cell lung cancer (SCLC) cases, no significant correlations were observed among DNAmax, tumor staging or tumor location. The differences in the DNAmax values of squamous cell carcinoma, adenocarcinoma, SCLC and NSCLC were not statistically significant. In the present study, the area under the receiver operating characteristic curve for LBC (0.936) was significantly greater compared with that for DNA-ICM (0.766) (P<0.05). DNA-ICM has medium diagnostic value in lung cancer, and the DNAmax was positively correlated with tumor stage in NSCLC. DNA-ICM may serve as a supplement to LBC, but it is not recommended as a sole procedure for lung cancer screening.
Keywords: DNA image cytometry; bronchoalveolar lavage fluid; diagnosis; liquid-based cytology; lung cancer; pleural effusion.