Combining miR-3654 with miR-4646-5p and carcinoembryonic antigen (CEA) resulted in the highest diagnostic efficacy for Xuanwei lung cancer, with a sensitivity of 73.3%, specificity of 93.3%, area under the curve of 0.901, and a positive predictive value of 91.7%.<h4>Conclusions</h4>Among the four miRNAs, serum miR-3654 exhibits the best diagnostic efficacy for Xuanwei lung cancer. The gene discussed is CEACAM5; the disease is lung cancer.