Comprehensive diagnosis and individualized treatment of multiple primary lung cancer: A case report

With the popularity of low-dose CT, the detection rate of multiple primary lung cancer (MPLC) has gradually increased. However, to the best of our knowledge, no unified standard for diagnosing MPLC currently exists. Therefore, the differentiation of this tumor type from lung cancer intrapulmonary metastasis (IM) can aid the diagnosis of MPLC. The treatment strategies and prognosis of these two tumor types are different. The present report documents the case of a 45-year-old female patient with MPLC with >20 lesions in both lungs. Enhanced chest CT imaging indicated IM, prompting admission to the hospital for clarification of the pathology of the lung lesions and for receiving drug therapy. However, whole-body PET-CT revealed an anterior left upper lobe lesion with increased F¹⁸-fluorodeoxyglucose (FDG) metabolism (maximum standardized uptake value=7.3). No abnormal increases in FDG metabolism were found in the other multiple lesions. The data led to a diagnosis of MPLC. Following multidisciplinary discussions, an individualized treatment plan for this patient was developed. The patient was treated with a two-stage surgery (first surgery on the left lung, second surgery on the right lung) according to the protocol, coupled with adjuvant chemotherapy (700 mg pemetrexed combined with 45 mg lobaplatin) between surgeries. For 56 months after the first surgical treatment, the patient did not experience disease progression. The patient's disease-free survival period is ongoing. In this case, the multiple lesions did not show significant similarities in their histopathological and genomic characteristics. The integration of radiological, histopathological and genomic features by a multidisciplinary team facilitated a more accurate diagnosis of MPLC. This has the potential to become an option for the differential diagnosis of MPLC in the future. In addition, an individualized treatment design would be more beneficial to patients with MPLC, especially those with a large number of lesions in both lungs. The present study reports a case of the diagnosis and individualized treatment of MPLC with multiple lesions in both lungs, which provides a reference for the diagnosis and treatment of similar patients.