A 58-year-old male Chinese patient, with no smoking history (only passive smoking), was admitted to the Third military medical university affiliated first hospital (Chongqing, Chinese) because of cough and expectoration (Fig. 1). The scan of the chest and abdomen by computed tomography (CT) revealed the presence of a primary tumor (with the longest diameter measuring 52 mm) in the right lower lobe (Fig. 2a) and subcarinal lymph node metastasis (Fig. 2b). The lung biopsy revealed the presence of adenocarcinoma cells (Fig. 2c). The clinical tumor stage was evaluated as T3N2M0 (stage IIIB). The potential presence of EGFR mutations was evaluated using a pre-operation biopsy specimen and the results revealed an exon 19 deletion in the EGFR gene. Hence, the patient was subjected to a neoadjuvant therapy with the first-generation EGFR-TKI gefitinib (0.25 g). After 2 months (Jul 2017), the CT scanning of the chest performed at the Third military medical university affiliated third hospital (Chongqing, China) revealed the reduction of the right lower lobe mass (with the longest diameter measuring 31 mm) (Fig. 3a). The surgery “right lung middle lower lobe resection and mediastinum and hilum lymph node cleaning technique” was performed (Fig. 3b) (Jul 2017). The postoperative pathologic staging was pT2aN0M0 (stage IB). Subsequently, the patient was subjected to four cycles of chemotherapy composed of pemetrexed 800 mg (500 mg/m2 intravenously injected at day 1, once every 3 weeks) combined with nida's platinum 60 mg (80 mg/m2 intravenously injected at day 1-2, once every 3 weeks).
After six months (Apr 2018), the patient complained of headaches, and brain magnetic resonance imaging (MRI) revealed the progression of the disease, with three lesions in the left parietal lobe, temporal lobe, and right frontal lobe. The patient continued to be treated with the first-generation EGFR-TKI gefitinib (0.25 g), achieving a partial response after 2 Mon and all lesions were treated with Gamma Knife radiosurgery at a dose of 16Gy (measuring curve of 50%).
At 5 months after gefitinib (0.25 g) treatment (Sep 2018), the patient showed disease progression with a metastatic lesion in the right kidney. Thus, the therapy was subsequently replaced with standard pemetrexed 800 mg (500 mg/m2 intravenously injected at day 1, once every 3 weeks) combined with nida's platinum 60 mg (80 mg/m2 intravenously injected at day 1-2, once every 3 weeks) (PP regime). The patients experienced loss of appetite and general weakness after three cycles and the disease further progressed involving the left kidney with another metastasis (Nov 2018). Therefore, the treatment was adjusted according to a personalized therapy, using bevacizumab 500 mg (7.5 mg/kg intravenously injected at day 1, once every 3 weeks) combined with pemetrexed 800 mg (500 mg/m2 intravenously injected at day 1, once every 3 weeks). The patient achieved a stable disease after one cycle. However, the patient was not satisfied with the curative effect and asked to change the therapy. Thus, the treatment was adjusted one more time to enhance the curative effect, and bevacizumab 500 mg (7.5 mg/kg intravenously injected at day 1, once every 3 weeks) combined with paclitaxel liposome 240mg (135 mg/m2 intravenously injected at day 1, once every 3 weeks) was used. Blood samples were collected and the molecular testing of EGFR by amplification refractory mutation system-polymerase chain reaction detected an EGFR T790M mutation. Therefore, the patient was treated with osimertinib, and the progression of the disease was observed after 1 year and 3 months (Apr 2020). The CT scan of the chest and abdomen revealed a secondary tumor (with the longest diameter measuring 12 mm) in the right upper lobe and a steady nodule in the right kidney. Brain MRI revealed that the brain lesions have not change. Blood samples were collected again and subjected to next-generation sequencing, which revealed the presence of an EGFR T790M mutation and the original exon 19 deletion simultaneously. Subsequently, the patient was treated with hypofractionated radiotherapy in the right upper lobe (50 Gy/5 Gy/10 f) and continued the treatment with osimertinib. Unfortunately, the CT performed after 2 months (Jun 2020) revealed a disease progression due to the increase of the nodules in the right upper lobe posterior segment and right kidney compared with the previous situation. MRI revealed the enlargement of the lesions in the left after ventricle angle compared with the previous situation. Thus, the patient subsequently was treated with hypofractionated radiotherapy in the left after ventricle angle (44 Gy/4 Gy/11 f, 3 Gy/1 f) and in the right upper lobe posterior segment (50 Gy/5 Gy/10 f). After radiotherapy, he developed a stomachache, and the gastroscopy with biopsy showed a small cell carcinoma in the gastric body derived from the lung (Fig. 4a-b). Blood samples again were collected and the NGS detected an exon 19 deletion in the EGFR and T790M mutation. The pathological examination after tissue staining showed that the metastatic tumor cells were localized in the submucosa of the stomach (Fig. 4c). Therefore, the patient was subjected to a standard treatment with etoposide 130 mg (100 mg/m2 intravenously injected at day 1-3, once every 3 weeks) and los platinum 45 mg (30 mg/m2 intravenously injected at day 1, once every 3 weeks) (EP) chemotherapy and the maintenance therapy with osimertinib. Finally, the patient achieved a partial response after four cycles. The lesions in the left kidney and right kidney before chemotherapy are shown in fig. 6a-b. while the left and right kidney lesions achieved a partial response after a four-cycle treatment (Fig. 6d-e). The gastroscopy revealed that the gastric lesion was disappeared (Fig. 6c), but the biopsy of the mucosa still showed signs of a malignant tumor (Fig. 6f). The brain and lung lesions achieved a stable disease state. In addition, the patient showed a disease progression a enlarged lesion lesion in the stomach after termination of chemotherapy. The surgery “partial gastrectomy” was performed. The potential presence of an exon 19 deletion in the EGFR and TP53 mutations was evaluated using gastric postoperative specimens and blood samples.