[Well Differentiated Liposarcoma of a Lung:Report of a Case].

A 61-year-old woman was referred for further evaluation of an intracystic nodule in her left upper lung. Computed tomography( CT) showed a 15 mm nodule in a pulmonary cyst adjacent to aortic arch and mediastinum. Fluorodeoxyglucose-positron emission tomography (FDG-PET)-CT showed little uptake of FDG in the lesion. No abnormality was found in the bronchoscopy findings. On imaging findings, the possibility of pulmonary aspergilloma was considered, but the serological findings were inconsistent, and surgical resection of the lesion was performed for both diagnosis and treatment. The final pathohistological diagnosis was well differentiated liposarcoma. No adjuvant therapy was performed and the patient has been well without recurrence for 2 years after the surgery. We report a rare case of well differentiated liposarcoma of a lung mimicking pulmonary aspergilloma.

Circulating and Tumor Myeloid-derived Suppressor Cells in Resectable Non-Small Cell Lung Cancer.

RATIONALE: Myeloid-derived suppressor cell (MDSC) expansion has been found to play a role in disease progression in patients with cancer. However, the characteristics of MDSCs in lung cancer are poorly understood. OBJECTIVES: We prospectively investigated MDSCs and inflammatory factors in tumor and peripheral blood samples from patients with resectable non-small cell lung cancer and studied their correlations with the disease prognosis. METHODS: A complex analysis of MDSC subsets and inflammatory mediators was performed using flow cytometry and a Bio-Plex assay. MEASUREMENTS AND MAIN RESULTS: A significant increase in the frequency of circulating monocytic (M)-MDSCs was observed in the patients with non-small cell lung cancer compared with the healthy donors (HDs). Moreover, the frequencies of M- and polymorphonuclear (PMN)-MDSCs were higher in tumors than in the peripheral blood of the same patients. This accumulation was associated with elevated concentrations of inflammatory mediators involved in MDSC migration to and activation in the tumor microenvironment. An analysis of the MDSC immunosuppressive pattern showed increased programmed death-ligand 1 expression on circulating cells from patients compared with HDs. Tumor PMN-MDSCs displayed higher programmed death-ligand 1 expression levels than the same cells in the peripheral blood. The frequency of CCR5 (C-C chemokine receptor 5) expression on circulating M-MDSCs was significantly higher in the patients than in the HDs. Clinical data analysis revealed negative correlations between recurrence-free survival and the frequencies of PMN-MDSCs and CCR5+ M-MDSCs in the circulation but not in tumors. CONCLUSIONS: Our findings suggest that the level of MDSCs in the peripheral blood but not in tumor tissues predicts recurrence after surgery.

Coadministration of erlotinib and curcumin augmentatively reduces cell viability in lung cancer cells.

Resistance to erlotinib in lung cancer cases includes T790M mutant epidermal growth factor receptor and c-Met gene amplification, but other unknown mechanisms account for about 30% of the resistance. Activation of the nuclear factor kappa B (NFkappaB)-related pathways in association with the reduction in ikappaB level may be one of such potential mechanisms. It is known that curcumin inhibits the inducible activation of NFkappaB at least in part by sustaining ikappaB expression level. Therefore, we evaluated the effects of coadministration of erlotinib and curcumin on lung cancer cells. We found that erlotinib and curcumin augmentatively reduced cell viability. Studies in PC9 cells showed that induction of apoptosis was involved. Expression of ikappaB was elevated in PC9 cells by curcumin administration, and pretreatment with siRNAs for ikappaB significantly attenuated the reduction in cell viability after coadministration of erlotinib and curcumin. Furthermore, coadministration of erlotinib and/or curcumin augmentatively attenuated the growth of PC9 tumors in mice. These results suggested the existence of an augmentative tumor growth inhibitory effect between erlotinib and curcumin, and this effect was at least in part mediated by the increase in the expression of ikappaB induced by curcumin.

[Results of percutaneous cryoablation for malignant lung tumors compared with radiotherapy].

Radiotherapy has been regularly applied mainly for inoperable patients with non- small cell lung cancer, and various clinical trials have been performed. On the other hand, we have applied percutaneous cryoablation for lung tumors (PCLT) since 2002. In this paper, we describe our experience of PCLT compared to the results of radiation treatment. Three-year local progression-free rates with stereotactic body radiotherapy were 79-92% in stage I A and 30-79% in stage I B. Those with proton radiotherapy were 82-89% in stage I A and 49-62% in stage I B. CTCAE grade ≥3 complications occurred in 3-28% cases, such as radiation pneumonitis. As for PCLT, 1-, 2- and 3-year local progression-free rates were 80.4%, 69.0% and 67.7%, respectively. Pneumothorax, pleural effusion, and hemoptysis occurred after 61.7%, 70.5%, and 36.8% sessions, respectively. Of all cases with pneumothorax, 17.6% required chest tube insertion and 1.7% required pleurodesis. Delayed and recurrent pneumothorax occurred in 7.8% each. CTCAE grade ≥3 complications occurred in 1.5% cases. The biggest advantage of PCLT compared with radiotherapy is the possibility to treat local recurrence at the same site as treated before. In addition, no radiation pneumonitis occurs in PCLT. Moreover, less space or budget is needed when PCLT is newly introduced in a hospital. Although high reliable clinical data is not achieved yet, PCLT is one of the promising methods in local treatment.

An effective plication technique for diaphragmatic eventration under thoracoscopy with laparoscopic image display.

Diaphragmatic eventration causes respiratory distress with the development of severe diaphragmatic compression of lung volume. While non-surgical treatment, such as physical therapy and pulmonary rehabilitation, is adequate for mild cases, surgical intervention is critical for severe diaphragmatic eventration. A 45-year-old man with respiratory fatigue was diagnosed with left diaphragmatic eventration and underwent surgery with diaphragmatic plication with double-row stapling under a video-assisted approach. Thoracoscopy with laparoscopic image display avoided visceral tissue involvement, and the double-stapling technique prevented diaphragmatic rupture and lowered the diaphragmatic level. The procedure improved the patient's respiratory function by reducing respiratory fatigue. This procedure is safe and effective for the thin and vulnerable diaphragmatic muscle.

Arterial Embolization and Cone-Beam Computed Tomography-Guided Lung Resection for Anomalous Systemic Arterial Blood Supply to Normal Lung: Two Case Reports.

Systemic arterial blood supply to a normal lung is a rare anatomical abnormality. Surgery is usually indicated because this abnormality leads to pulmonary hypertension. Herein, we report our experience and ideas for safe vessel dissection. Case 1 was a woman in her 50s. We performed a left lower lobectomy following percutaneous coil embolization. The aberrant artery with emboli was confirmed intraoperatively by cone-beam computed tomography (CBCT) to safely dissect under thoracoscopic surgery (TS). Case 2 was a man in his 40s. Following percutaneous endovascular plug occlusion, we performed a left partial resection using indocyanine green fluorescence navigation. Intraoperatively, CBCT imaging demonstrated the aberrant artery and exact position of the emboli. This combination technique of interventional radiology and TS with CBCT imaging was considered safe and more secure for the treatment of anomalous systemic arterial blood supply to a normal lung.

A Comparison of the Efficacies of OK-432 and Talc Slurry for Pleurodesis in Patients with Prolonged Air Leak after Pulmonary Resection.

PURPOSE: A prolonged air leak (PAL) is one of the common postoperative complications of pulmonary resection. The aim of this study was to evaluate the efficacy and safety of pleurodesis with sterile talc or OK-432 for postoperative air leak. METHODS: Patients with postoperative air leak who received chemical pleurodesis using sterile talc or OK-432 were retrospectively identified from medical records data. For pleurodesis with either agent, prior assessment and approval by the hospital safety department were carried out for each case, in addition to individual consent. RESULTS: Between February 2016 and June 2022, 39 patients had PALs and underwent chemical pleurodesis. Among them, 24 patients received pleurodesis with talc (Talc group) and 15 with OK-432 (OK-432 group). The leak resolved after less than two pleurodesis treatments in 22 patients (91.7%) in the Talc group compared with 14 patients (93.3%) in the OK-432 group. Pleurodesis significantly increased white blood cell counts, C-reactive protein concentration, and body temperature in the OK-432 group compared with that in the Talc group (p <0.001, p = 0.003, and p <0.001, respectively). CONCLUSIONS: Pleurodesis with talc may be an effective treatment option for postoperative air leak. Our findings suggest that talc was as effective as OK-432 and resulted in a milder systemic inflammatory response.

Suitable Patient Selection and Optimal Timing of Treatment for Persistent Air Leak after Lung Resection.

OBJECTIVES: The choice of therapeutic intervention for postoperative air leak varies between institutions. We aimed to identify the optimal timing and patient criteria for therapeutic intervention in cases of postoperative air leaks after lung resection. METHODS: This study utilized data from a prospective multicenter observational study conducted in 2019. Among the 2187 cases in the database, 420 cases with air leaks on postoperative day 1 were identified. The intervention group underwent therapeutic interventions, such as pleurodesis or surgery, while the observation group was monitored without intervention. A comparison between the intervention group and the observation group were analyzed using the cumulative distribution and hazard functions. RESULTS: Forty-six patients (11.0%) were included in the intervention group. The multivariate analysis revealed that low body mass index (p = 0.019), partial resection (p = 0.010), intraoperative use of fibrin glue (p = 0.008), severe air leak on postoperative day 1 (p < 0.001), and high forced expiratory volume in 1 s (p = 0.021) were significant predictors of the requirement for intervention. The proportion of patients with persistent air leak in the observation group was 20% on postoperative day 5 and 94% on postoperative day 7. The hazard of air leak cessation peaked from postoperative day 3 to postoperative day 7. CONCLUSIONS: This research contributes valuable insights into predicting therapeutic interventions for postoperative air leaks and identifies scenarios where spontaneous cessation is probable. A validation through prospective studies is warranted to affirm these findings.

Talc slurry pleurodesis in patients with secondary intractable pneumothorax: A phase 2 study.

BACKGROUND: Secondary pneumothorax, which occurs most commonly in the elderly, is caused by underlying diseases. Cardiac dysfunction and other organ inefficiencies may render surgical repair impossible. Such non-operative and poor-risk cases are targets for pleurodesis, which involves the instillation of chemicals or irritants to the thoracic cavity through injection, bronchoscopic bronchial occlusion, or other procedures. Sterile graded talc has been used for pleurodesis mainly in Europe and the United States; however, only a few studies and case series investigating this topic have been published. This study evaluates the efficacy and safety of talc slurry pleurodesis. METHODS: Patients with inoperable secondary intractable pneumothorax, who were not candidates for surgical repair, were recruited. Four grams of sterilized talc was suspended in 50 mL of physiological saline and injected through a tube into the pleural cavity. Additional 50 mL of saline was subsequently injected through the same channel to clean the residual saline in the injection tube. Another additional talc instillation was allowed to control persistent air leakage. The primary endpoint was the proportion of drainage tube removal within 30 days after talc pleurodesis. RESULTS: Thirty-one patients were included in this study. In 23 out of 28 patients, the drainage tube could be removed within 30 days of talc instillation (82.1 %, 95 % CI = 63.1-93.9), exceeding the threshold of 36.0 % (p < 0.0001). The most common event was pain (11/28 patients, 39.3 %). CONCLUSIONS: Talc slurry pleurodesis is effective for intractable secondary pneumothorax, with minor side effects.

Factors affecting local progression after percutaneous cryoablation of lung tumors.

PURPOSE: To evaluate factors predicting local tumor progression after percutaneous cryoablation of lung tumors (PCLT). MATERIALS AND METHODS: Seventy-one consecutive patients with 210 tumors (11 primary and 199 metastatic pulmonary neoplasms; mean maximum diameter, 12.8 mm) were treated with 102 sessions of PCLT. Rates of local tumor progression and technique effectiveness were estimated by Kaplan-Meier method. Multiple variables were evaluated with the log-rank test, followed by uni- and multivariate multilevel analyses to identify independent risk factors, and hazard ratios (HRs) and 95% confidence intervals (CIs) were estimated. All statistical tests were two-sided. RESULTS: Median follow-up period was 454 days (range, 79-2,467 d). Local tumor progression occurred in 50 tumors (23.8%). One-, 2-, and 3-year local progression-free rates were 80.4%, 69.0%, and 67.7%, respectively, and technique effectiveness rates were 91.4%, 83.0%, and 83.0%, respectively. Existence of a thick vessel (diameter≥3 mm) no more than 3 mm from the edge of the tumor was assessed as an independent factor (HR, 3.84; 95% CI, 1.59-9.30; P = .003) associated with local progression by multivariate analysis. CONCLUSIONS: Presence of a vessel at least 3 mm in diameter close to the tumor represents an independent risk factor for local progression after PCLT.

Solitary pulmonary capillary hemangioma mimicking a preinvasive malignant lesion in an asymptomatic middle-aged female patient.

Pulmonary capillary hemangiomatosis (PCH) is a rare disease characterized by a proliferation of capillaries in the alveolar septa, bronchial and venous walls, pleura, and regional lymph nodes. However, the etiology of the disease remains unknown due to its rarity. Therefore, we present a case of a solitary PCH lesion without symptoms in a 38-year-old female patient. According to computed tomography, she was diagnosed with lung carcinoma, indicated by a tiny nodule with ground-glass opacity detected in her right upper lung. However, no other lesions were detected on systemic examination. Consequently, partial lung resection was conducted, since the lesion was suspected of lung adenocarcinoma. Pathologic results showed that the thick alveolar septa were caused by capillary growth without cellular atypia and hardly any infiltration of inflammatory cells. Finally, we diagnosed the pulmonary lesion as PCH, although solitary PCH has previously been reported in a few case reports. Therefore, further case studies are essential to clarify the causes of PCH.

High-grade endometrial stromal sarcoma with YWHAE-NUTM2B fusion gene abnormality identified after 10 years of recurrent pulmonary metastases: A case report.

•Endometrial stromal sarcoma is the second most common type of uterine sarcoma.•Endometrial stromal sarcoma has undergone modifications since its proposal.•This case highlights the importance of accurately diagnosing endometrial stromal sarcoma.•Asymptomatic uterine fibroids may not be treated with therapeutic intervention or prompt regular check-ups.

Survival after Lung Metastasectomy from Esophageal Cancer: Results from a Multi-Institutional Database.

To clarify the clinical impact and to identify prognostic predictors of surgical intervention for pulmonary metastasis from esophageal cancer, a registry database analysis was performed. From January 2000 to March 2020, patients who underwent resection of pulmonary metastases from primary esophageal cancer at 18 institutions were registered in a database developed by the Metastatic Lung Tumor Study Group of Japan. An amount of 109 cases were reviewed and examined for the prognostic factors for pulmonary metastasectomy of metastases from esophageal cancer. As a result, five-year overall survival after pulmonary metastasectomy was 34.4% and five-year disease-free survival was 22.1%. The multivariate analysis for overall survival revealed that initial recurrence site, maximum tumor size, and duration from primary tumor treatment to lung surgery were selected as the significant prognostic factors (p = 0.043, p = 0.048, and p = 0.037, respectively). In addition, from the results of the multivariate analysis for disease free survival, number of lung metastases, initial recurrence site, duration from primary tumor treatment to lung surgery, and preoperative chemotherapy for lung metastasis were selected as the significant prognostic factors (p = 0.037, p = 0.008, p = 0.010, and p = 0.020, respectively). In conclusion, eligible patients with pulmonary metastasis from esophageal cancer selected based on the identified prognostic predictors would be good candidates for pulmonary metastasectomy.

Risk-adjusted hazard analysis of survival after pulmonary metastasectomy for uterine malignancies in 319 cases.

Objective: There is little evidence of the outcome of pulmonary metastasectomy for uterine tumors when comparing different histologies. This study aimed to delineate the primary histology that leads to more favorable outcomes after pulmonary metastasectomy. Methods: The database of the Metastatic Lung Tumor Study Group of Japan for 1984 to 2016 was used to analyze the outcomes of patients with gynecologic malignancies who underwent pulmonary metastasectomy. Prognostic factors and long-term outcomes were compared according to the histology of the primary uterine tumors, specifically adenocarcinoma, squamous cell carcinoma, and sarcoma. The adjusted hazard risks according to disease-free intervals (DFIs) and the number and maximum size of resected tumors were also analyzed to delineate the pattern of risk trends. Results: A total of 319 patients were included in the analysis (122 with adenocarcinomas, 113 with squamous cell carcinomas, 46 with sarcomas, and 38 with other types). The 5-year survival rate was 66.5% for the entire cohort, 71.6% for the patients with adenocarcinoma, 61.3% for those with squamous cell carcinoma, and 55.4% for those with sarcoma. Multivariate analyses identified the positive prognostic factors as DFI ≥12 months in adenocarcinoma and sarcoma and the primary site (corpus) of uterine tumors in adenocarcinoma. The nonlinear adjusted hazard risks indicated that a shorter DFI was associated with an elevated risk of death in patients with adenocarcinoma and sarcoma. Conclusions: The survival outcome after pulmonary metastasectomy varies according to primary tumor histology, and the prognostic factors differ among histologic subtypes. Surgical indications should be determined based on the prognostic factors for each histology.

Exploration of a novel prognostic model based on nomogram in non-small cell lung cancer patients with distant organ metastasis: implications for immunotherapy.

Background: Evidence for the effects of immunotherapy in non-small cell lung cancer (NSCLC) patients with distant organ metastasis is insufficient, and the predictive efficacy of established markers in tissue and blood is elusive. Our study aimed to determine the prognostic factors and develop a survival prognosis model for these patients. Methods: A total of 100 advanced NSCLC patients with distant organ metastases, who received single or combination immune checkpoint inhibitors (ICIs) in Xijing Hospital between June 2018 and June 2021, were enrolled for retrospective analysis. The major clinicopathological parameters were collected, and associated survival outcomes were followed up by telephone or inpatient follow-up for nearly 3 years to assess prognoses. The survival prognosis model was established based on univariate and multivariate Cox regression analyses to determine the candidate prognostic factors. Results: From the start of immunotherapy to the last follow-up, 77 patients progressed and 42 patients died, with a median follow-up of 18 months [95% confidence interval (CI): 15-19.9]. The median progression-free survival (PFS) and overall survival (OS) were 8 months (95% CI: 5.6-10.4) and 21 months (95% CI: 8.9-33.1), respectively. Multivariate Cox proportional hazards analysis showed Eastern Cooperative Oncology Group performance status (ECOG PS), body mass index (BMI), age-adjusted Charlson comorbidity index (ACCI), lactate dehydrogenase (LDH), and absolute neutrophil count (ANC) were correlated significantly with OS. Based on these five predictive factors, a nomogram and corresponding dynamic web page were constructed with a concordance index (C-index) of 0.81 and a 95% CI of 0.778-0.842. Additionally, the calibration plot and time-receiver operating characteristic (ROC) curve validated the precision of the model at 6-, 12-, and 18-month area under the curves (AUCs) reached 0.934, 0.829, and 0.846, respectively. According to the critical point of the model, patients were further divided into a high-risk total point score (TPS) >258, middle-risk (204< TPS ≤258), and low-risk group (TPS ≤204), and significant OS differences were observed among the three subgroups (median OS: 4.8 vs. 13.0 vs. 32.9 months). Conclusions: A feasible and practical model based on clinical characteristics has been developed to predict the prognosis of NSCLC patients with distant organ metastasis undergoing immunotherapy.

Percutaneous cryoablation of lung tumors: feasibility and safety.

PURPOSE: To evaluate the safety and feasibility of cryoablation for lung tumors as well as the incidence of, and risk factors for, complications. MATERIALS AND METHODS: This study included 193 cryoablation sessions for 396 lung tumors in 117 consecutive patients. Univariate and multivariate analyses were performed to assess risk factors for common complications. Changes in laboratory values were analyzed the day after cryoablation. RESULTS: Pneumothorax, pleural effusion, and hemoptysis occurred after 119 (61.7%), 136 (70.5%), and 71 (36.8%) sessions, respectively. Phrenic nerve palsy, frostbite, and empyema occurred after one session each (0.52%). Proximal tumor implantation was observed in one of 471 punctures (0.20%). Of 119 sessions with pneumothorax, 21 (17.6%) required chest tube insertion and two (1.7%) required pleurodesis. Delayed and recurrent pneumothorax occurred in 15 of 193 sessions each (7.8%). A greater number of cryoprobes was a significant (P = .001) predictor of pneumothorax. Male sex (P = .047) and no history of ipsilateral surgery (P = .012) were predictors for the need for chest tube insertion, and no history of ipsilateral surgery (P = .021) was a predictor for delayed/recurrent pneumothorax. Greater number of cryoprobes (P = .001) and no history of ipsilateral surgery (P = .004) were predictors for pleural effusion. Greater number of cryoprobes (P < .001) and younger age (P = .034) were predictors for hemoptysis. Mean changes in white blood cell count, platelet count, hemoglobin level, and C-reactive protein level were 2,418/µL ± 2,260 (P < .001), -2.0 × 10(4)/µL ± 3.2 (P < .001), -0.77 mg/dL ± 0.89 (P < .001), and 3.0 mg/dL ± 2.9 (P < .001), respectively. CONCLUSIONS: Percutaneous cryoablation could be performed minimally invasively with acceptable rates of complications.

Curcumin induces autophagy in ACC-MESO-1 cells.

Malignant pleural mesothelioma is known to be widely resistant to therapy and new treatment strategies are needed. Curcumin, which has a long history as a dietary spice is known to suppress the growth of multiple cancer lines, but the effects on mesothelioma cells are not well defined. In the present study we examined the effects of curcumin on ACC-MESO-1, which is a human derived mesothelioma cell line. We found that curcumin dose-dependently reduced cell viability but did not induce apoptosis. Curcumin administration increased LC3B-II/LC3B-I expression, and induced the formation of autophagosomes on electron microscopy. These changes were attenuated by RNA silencing of atg5. From these findings it was speculated that induction of autophagy was at least in part involved in the reduction of cell viability by curcumin.

Innovative segmentectomy to remove the posterior segment of the lower lobe (S¹°) of the lung.

We describe our innovative technique for performing segmentectomy of the posterior segment of the lower lobe of the lung, being segment number 10 (S¹°). In segmentectomy of S¹°, it is difficult to identify A¹° from the interlobar fissure because the pulmonary artery to S¹° (A¹°) branches from A(9+10) and runs dorsally and deeply into the lung tissue. Moreover, to reach S¹° from the interlobar fissure, the lung tissue should be cut between S6 and S8, because S¹° is not located beside the interlobar fissure. However, it is difficult to identify the boundary between the S6 and S8 without a route marker. To solve these difficulties, we divided S6 and S¹° from each other at the beginning of the procedure, which enabled A¹° to be identified easily from the dorsal side. Because S6 and S(8-10) should be divided in S¹° segmentectomy at the end, the division between S6 and S(8-10) at the beginning of procedure is not only reasonable, but makes the procedure simple.

Survival Outcomes of Complete Pulmonary Metastasectomy for Head and Neck Squamous Cell Carcinomas.

Purpose: Metastatic head and neck squamous cell carcinoma (HNSCC) is relatively poor; however, depending on the selected cases, pulmonary metastasectomy can be a practical therapeutic option. This study aimed to identify the outcomes of complete metastasectomy based on each primary site and to investigate unfavorable prognostic factors. Patients and Methods: We used the database from the Metastatic Lung Tumour Study Group of Japan. Between November 1980 and April 2017, 231 patients were deemed eligible. According to anatomy and the current epidemiology of HNSCC, the patients were divided into three groups: nasopharynx, oropharynx, and salivary gland (n = 40, Group 1), oral cavity, tongue, and paranasal sinuses (n = 69, Group 2), and larynx and hypopharynx (n = 122, Group 3). Results: The 5-year overall survival after complete pulmonary metastasectomy was 58.5%, 25.0%, and 46.9% in G1, 2, and 3, respectively (p < 0.01). Multivariate analyses revealed unfavourable prognostic factors to be G2, and pathological maximum diameter was >20 mm. Therefore, on dividing group 1 and 3 with or without diameter, the 5-year overall survival was significantly worse in HNSCC with a diameter >20 mm (n = 74) than that in the remnant (n = 88; 61.9% vs 35.5%; p < 0.01). Conclusion: According to the multi-institutional Japanese data, pulmonary metastasectomy from HNSCC indicates a potential survival benefit. Oral cavity, tongue, and paranasal sinuses cancer, and tumour size (>20 mm) were poor prognostic factors for pulmonary metastasectomy from head and neck cancer.

Development and validation of a dynamic survival nomogram for metastatic non-small cell lung cancer based on the SEER database and an external validation cohort.

Background: Limited efficacy and poor prognosis are common in patients with metastatic non-small cell lung cancer (NSCLC). An accurate and useful nomogram helps the clinician predict the prognosis of the patients. However, there has been no previous report on the nomogram specially for predicting the overall survival (OS) of metastatic NSCLC patients. Methods: A total of 18,343 patients diagnosed with metastatic NSCLC in the Surveillance, Epidemiology, and End Results (SEER) database were included and divided into the training cohort (n=12,840) and the internal validation cohort (n=5,503), and 242 patients in Renji Hospital were additionally enrolled as the external validation cohort. Demographical, clinical, and OS data were collected. A Cox proportional hazards regression model was used to develop a nomogram based on the training cohort. To validate the nomogram, we applied C-indexes, calibration curves, receiver operating characteristic (ROC) curve, decision curve analysis (DCA), and a Kaplan-Meier survival curve. Results: The multivariate Cox regression model found that there were a total of 16 independent risk factors for OS of the patients (all 16 factors showed P<0.001), which were integrated into the nomogram with a C-index of 0.702 [95% confidence interval (CI): 0.684-0.720]. The nomogram also exhibited good prognostic value in the internal validation cohort (C-index =0.699, 95% CI: 0.673-0.725) and external validation cohort (C-index =0.695, 95% CI: 0.653-0.737). The ROC and Kaplan-Meier survival curve analyses demonstrated a high discriminative ability. High-risk patients had significantly less favorable OS than low-risk patients in the SEER population and external validation cohort (both P<0.001). The DCA analysis showed that the nomogram provided better prognosis prediction than the tumor-node-metastasis (TNM) staging system. Conclusions: We constructed and validated a dynamic nomogram with 16 variables based on a large-scale population of SEER database to predict the prognosis of metastatic NSCLC patients. The nomogram is expected to provide higher predictive ability and accuracy than the TNM staging system.