Prognostic significance of immunotherapy in postoperative recurrent non-small cell lung cancer without EGFR mutations or ALK rearrangements.

Background: Limited reports exist regarding postoperative recurrent non-small cell lung cancer (NSCLC) without major driver mutations [epidermal growth factor receptor (EGFR) mutations or anaplastic lymphoma kinase (ALK) rearrangements] treated with immune checkpoint inhibitors (ICIs) when programmed cell death ligand 1 (PD-L1) is expressed in a real-world setting. The aim of this study was to evaluate the effect of ICIs for those NSCLC. Methods: We enrolled 255 patients with postoperative recurrent NSCLC lacking EGFR mutations or ALK rearrangements who underwent lobectomy or more extensive resection between 2012 and 2021. Factors associated with post-recurrence survival (PRS) were determined using the Cox proportional hazards model. PRS was analyzed using Kaplan-Meier curves and compared using the log-rank test. Results: Multivariable analysis demonstrated that squamous cell carcinoma, pathological stage III, and an Eastern Cooperative Oncology Group (ECOG) performance status ≥2 were significantly associated with worse PRS. Conversely, ICI use at first line was associated with improved PRS. Patients who used ICIs during the first line and subsequent therapies had better PRS than those who received chemotherapy alone. Among patients who used ICIs, there was no significant difference in response rate at the first line, nor in PRS among those with PD-L1 expression ≥50%, 1-49%, and <1% in surgically resected specimens. Conclusions: ICI use at any treatment line improved the PRS of NSCLC patients without major driver mutations, irrespective of PD-L1 expression, in a real-world setting.

Comparison of SP263 and 22C3 pharmDx assays to test programmed death ligand-1 (PD-L1) expression in surgically resected non-small cell lung cancer.

BACKGROUND: Atezolizumab, one of the immune checkpoint inhibitors, has been approved as an adjuvant treatment following resection and platinum-based chemotherapy in patients with stage II-IIIA non-small cell lung cancer with 1% or more programmed death ligand-1 (PD-L1) expression. The Food and Drug Administration (FDA) has approved SP263 as a companion diagnostic assay for adjuvant treatment with atezolizumab; however, in clinical practice, the 22C3 assay is most commonly used for advanced non-small cell lung cancer. Therefore, our study aimed to compare two PD-L1 assays, SP263 and 22C3, to evaluate whether 22C3 could replace SP263 when deciding whether to administer adjuvant atezolizumab. METHODS: We retrospectively and prospectively analyzed 98 patients who underwent surgical resection at Kanagawa Cancer Center (Japan). An immunohistochemistry assay was performed for all the cases with both SP263 and 22C3. We statistically analyzed the concordance of PD-L1 expression between SP263 and 22C3 assays. RESULTS: The concordance between the two assays using Cohen's kappa was κ = 0.670 (95% CI: 0.522-0.818) at the 1% cutoff and κ = 0.796 (95% CI: 0.639-0.954) at the 50% cutoff. The Spearman correlation coefficient of 0.874 (p < 0.01) indicated high concordance. PD-L1 expression with 22C3 resulted slightly higher than that with SP263. CONCLUSIONS: This study showed a high concordance of PD-L1 expression with the SP263 and 22C3 assays. Further studies examining the therapeutic effects of adjuvant atezolizumab are required.

Right S3 segmentectomy for lung cancer with partial anomalous pulmonary venous return in the right upper pulmonary vein: A case report.

Partial anomalous pulmonary venous return (PAPVR) is a rare congenital malformation where the pulmonary vein partially refluxes into the venous system. Here, we present the first robotic-assisted right S3 segmentectomy in a 70-year-old male with early-stage lung cancer and PAPVR in the right upper pulmonary vein. The patient, with suspected primary lung cancer (11 mm diameter, pure solid appearance in right S3 segment), exhibited clinical stage T1bN0M0 stage IA2. Preoperative computed tomography revealed severe lung emphysema, and right V1-3 returned directly to the superior vena cava. However, no signs of right-sided heart failure were observed, and echocardiogram was normal with a pulmonary-to-systemic blood flow ratio of 1.4. Successful robot-assisted right S3 segmentectomy with hilar nodal dissection was performed, and the patient was discharged on the sixth postoperative day without complications. One year postoperatively, there has been no recurrence of lung cancer or respiratory/right-sided heart failure symptoms.

Impact of RBM10 and PD-L1 expression on the prognosis of pathologic N1-N2 epidermal growth factor receptor mutant lung adenocarcinoma.

Background: Impact of RNA-binding motif protein 10 (RBM10) and programmed death-ligand 1 (PD-L1) on the postoperative prognosis of patients with epidermal growth factor receptor gene mutation (EGFR-Mt) lung adenocarcinoma with pathological lymph node metastasis is still unclear. Methods: Patients who underwent curative surgery for pN1-N2 EGFR-Mt lung adenocarcinoma (n=129) harboring the EGFR exon 19 deletion mutation (Ex19) (n=66) or EGFR exon 21 L858R mutation (Ex21) (n=63) between January 2010 and December 2020 were included in this retrospective study. The prognoses of patients with low/high cytoplasmic RBM10 expression and PD-L1 negativity/positivity based on immunohistochemistry (IHC) of resected specimens were compared using the log-rank test. The effects of RBM10 and PD-L1 expression on overall survival (OS) were examined via multivariable analysis using the Cox proportional hazards regression model. The effects of RBM10 and PD-L1 expression on progression-free survival (PFS) of EGFR-tyrosine kinase inhibitors (TKIs) therapy among patients with recurrent pN1-N2 EGFR-Mt lung adenocarcinoma (n=67) were examined using log-rank tests. Results: The RBM10 low expression group showed significantly better 5-year OS than the RBM10 high expression group (89.4% vs. 71.5%, P=0.020), and the PD-L1 negative group tended to have longer 5-year OS than the PD-L1 positive group (86.4% vs. 68.4%, P=0.050). Multivariable analysis showed that high RBM10 expression [hazard ratio (HR), 3.12; 95% confidence interval (CI): 1.19-8.17; P=0.021] and PD-L1 positivity (HR, 3.80; 95% CI: 1.64-8.84; P=0.002) were independent poor prognostic factors for OS. PFS of patients with relapse and first-line EGFR-TKI treatment was significantly better in the PD-L1-negative group than in the PD-L1-positive group (34.5 vs. 12.1 months, P=0.045). PFS of patients with Ex21 relapse and first-line EGFR-TKI treatment was significantly better in the RBM10 low expression group than in the RBM10 high expression group (25.5 vs. 13.0 months, P=0.025). Conclusions: High RBM10 expression and PD-L1 positivity are poor prognostic factors for OS in patients with pN1-N2 EGFR-Mt lung adenocarcinoma after curative surgery. In patients with recurrent pN1-N2 EGFR-Mt lung adenocarcinoma, PD-L1 and RBM10 expression may influence response to EGFR-TKIs.

Wedge resection vs. segmentectomy for lung cancer measuring ≤ 2 cm with consolidation tumor ratio > 0.25.

Objectives: We aimed to clarify the differences in prognosis between wedge resection and segmentectomy performed for cN0 non-small cell lung cancer (NSCLC) measuring ≤ 2 cm, with consolidation tumor ratio (CTR) > 0.25. Methods: This multicenter study included 570 patients with cN0 NSCLC (tumor size ≤ 2 cm, CTR > 0.25) who underwent wedge resection (n = 244) and segmentectomy (n = 326) between January 2010 and December 2018. After propensity score matching (PSM, 1:1 method), 182 patients were matched for clinical characteristics (age, sex, laterality, smoking index, tumor size, CTR, carcinoembryonic antigen value, positron-emission tomography-documented maximum standardized uptake value, clinical stage, and tumor disappearance rate) and intergroup comparison of disease-free survival (DFS) and overall survival (OS). Using Gray's test, an intergroup comparison of the cumulative incidence of lung cancer-specific mortality was performed. Results: After PSM, similar DFS (5-year DFS, 79.9% vs. 87.1%, p = 0.103) and OS (5-year OS, 88.7% vs. 88.9%, p = 0.719) rates were observed in the wedge resection and segmentectomy groups. We observed no significant intergroup differences in lung cancer-specific mortality (5-year cumulative incidence: 4.6% vs. 3.5%; p = 0.235). Subgroup analysis revealed no specific subgroup demonstrating improved DFS or OS after undergoing wedge resection or segmentectomy. Conclusion: DFS, OS, and lung cancer-specific mortality were comparable between wedge resection and segmentectomy of cN0 NSCLC-tumor size ≤ 2 cm and CTR > 0.25. Large-scale prospective clinical trials are warranted to compare the prognoses of wedge resection and segmentectomy for these tumors.

Prognostic Significance of the Maximum Standardized Uptake Value on the Prognosis of Clinical Stage IA Lung Adenocarcinoma Based on the 8th Edition TNM Classification.

BACKGROUND: There are few reports on the utility of the maximum standardized uptake value (SUVmax) for predicting the prognosis of early-stage lung adenocarcinoma based on the latest tumor-node-metastasis (TNM) classification. This study aimed to determine whether clinicopathologic factors, including the SUVmax, affect prognosis in these patients. PATIENTS AND METHODS: We enrolled 527 patients with c-stage IA lung adenocarcinoma who underwent lobectomy or greater resection between 2011 and 2017. Recurrence-free survival (RFS) and overall survival (OS) were analyzed using Kaplan-Meier curves and compared using the log-rank test. Factors associated with RFS and OS were determined using the Cox proportional hazards model. RESULTS: RFS was significantly different based on tumor stage. In contrast, there was no significant difference in OS between patients with stage IA2 and IA3 disease (p = 0.794), although there were significant differences in OS between patients with stage IA1 and IA2 disease (p = 0.024) and between patients with stage IA1 and IA3 disease (p = 0.012). Multivariate analysis demonstrated that SUVmax was independently associated with both RFS and OS among patients with c-stage IA lung adenocarcinoma (RFS, p = 0.017; OS, p = 0.047). Further, even though there was no significant difference in OS between patients with stage IA2 and IA3 disease (n = 410), SUVmax was able to stratify patients with high and low RFS and OS among these patients (RFS, p < 0.001; OS, p < 0.001). CONCLUSION: SUVmax was an important preoperative factor to evaluate prognosis among patients with c-stage IA lung adenocarcinoma as well as the current TNM classification.

Involvement of 27-hydroxycholesterol on the progression of non-small cell lung cancer via the estrogen receptor.

The oxysterol 27-hydroxycholesterol (27HC) promotes the proliferation of breast cancer cells as a selective estrogen receptor modulator (SERM), but it is mostly produced by alveolar macrophages in vivo. The present study evaluated hypothesis that 27HC may also promote the proliferation of lung cancer cells. In the tumor and nontumor regions of lung tissue from 23 patients with non-small cell lung cancer (NSCLC) who underwent lung cancer surgery, we compared the 27HC content and its synthetic and catabolic enzyme expressions (CYP27A1 and CYP7B1), the expressions of the estrogen receptor (ER) gene and its target gene cMYC by using high-performance liquid chromatography-electrospray ionization-tandem mass spectrometry (HPLC-ESI-MS/MS), real-time RT-PCR, and immunohistochemical staining. In addition, we evaluated the effects of 27HC and ß-estradiol (E2) treatments on the proliferation of a cultured lung cancer cell line (H23 cells) expressing ERß. In squamous cell carcinoma and in adenocarcinoma, the 27HC content was significantly higher in the tumor region than in the nontumor region, and in cancer grade III than in the other cancer grades. CYP27A1-positive macrophages were histologically detected in the nontumor regions of both cancer types, whereas the gene and protein expressions of ERß, as well as the CYP7B1 and cMYC genes, were significantly increased in the tumor tissues. In cultured H23 cells, proliferation was significantly increased by 27HC and E2 treatments for 48 h. Similar to breast cancer, the present results supported idea that the 27HC produced from alveolar macrophages promotes the proliferation of lung cancer cells highly expressing ER through the SERM action. Therefore, 27HC should be an important target for cancer therapy of NSCLC.

Significance of very-low-voltage coagulation plus coverage with polyglycolic acid sheet after bullectomy for primary spontaneous pneumothorax.

BACKGROUND: The purpose of this study was to clarify the efficacy of the combination of low-voltage coagulation plus staple line coverage with a polyglycolic acid sheet after bullectomy for primary spontaneous pneumothorax to prevent a postoperative recurrence. METHODS: A total of 143 patients who underwent bullectomy for primary spontaneous pneumothorax between January 2014 and December 2019 were enrolled in this study. We classified the patients into two groups based on additional procedures after bullectomy, namely, low-voltage coagulation for the margin of the staple line plus coverage with a polyglycolic acid sheet (Group A) and staple line coverage with a polyglycolic acid sheet alone (Group B). We evaluated perioperative factors and recurrence-free survival after surgery in the two groups. RESULTS: Nine patients in Group B developed postoperative recurrences. In contrast, there was no postoperative recurrence in Group A. According to the Kaplan-Meier curves, the 2-year recurrence-free survival rates of the patients were 100% and 90.3%, in Group A and Group B, respectively. The log-rank test showed a significant difference between the two groups (p = 0.031). CONCLUSION: Low-voltage coagulation for the margin of a staple line plus coverage with a polyglycolic acid sheet is a useful option as an additional technique after bullectomy for primary spontaneous pneumothorax to prevent a postoperative recurrence.

Effect of epidermal growth factor receptor gene mutation on the prognosis of pathological stage II-IIIA (8th edition TNM classification) primary lung cancer after curative surgery.

OBJECTIVES: This retrospective study aimed to elucidate the effect of epidermal growth factor receptor (EGFR) gene mutations on the prognosis of patients with pathological stage II-IIIA primary lung cancer after curative surgery. MATERIALS AND METHODS: We enrolled 539 patients with p-stage II-IIIA (8th edition tumor-node-metastasis [TNM] classification) lung cancer who underwent curative resection at Kanagawa Cancer Center between January 2010 and December 2020 and whose tumors were tested for EGFR mutations. Relapse-free survival (RFS) and overall survival (OS) of patients with EGFR-mutant lung cancer (Mt, n = 126) including EGFR exon 21 L858R point mutation and EGFR exon 19 deletion mutation and EGFR mutation-wild lung cancer (Wt, n = 413) were analyzed using Kaplan-Meier curves and compared using a log-rank test. Cox regression analysis was performed to evaluate the effects of EGFR gene mutations on RFS and OS at each stage. RESULTS: There were 56/256 patients with p-stage II EGFR-Mt/Wt and 70/157 patients with p-stage IIIA EGFR-Mt/Wt. The 5-year RFS rate of patients with EGFR-Mt/Wt was 46.6%/52.0% (p = 0.787) for p-stage II and 17.4%/29.7% (p = 0.929) for p-stage IIIA. The 5-year OS rate was 92.0%/65.7% (p = 0.001) for p-stage II and 56.0%/39.3% (p = 0.016) for p-stage IIIA. EGFR-Mt was not an independent prognostic factor for OS of patients with p-stage IIIA lung cancer (hazard ratio [HR], 0.95; 95% confidence interval [CI], 0.51-1.76; p = 0.872); however, EGFR-Mt was an independent favorable prognostic factor for OS of patients with p-stage II lung cancer (HR, 0.59; 95% CI, 0.36-0.96; p = 0.034). CONCLUSION: The OS of lung cancer patients with p-stage II or IIIA, classified according to the 8th edition TNM classification, was remarkably favorable. Incorporating EGFR mutations to the anatomical TNM classification may lead to a more accurate prognosis prediction.

Prognostic Significance of Ground-Glass Opacity Components in 5-Year Survivors With Resected Lung Adenocarcinoma.

BACKGROUND: Reports on the prognosis for 5-year survivors with lung adenocarcinoma after resection are sparse. This study aimed to identify factors associated with overall survival (OS) and cancer-specific survival (CSS) for 5-year survivors with completely resected lung adenocarcinoma, and to determine whether preoperative imaging factors, including the presence of ground-glass opacity (GGO) components, affect late recurrence in long-term survivors. METHODS: Complete resection of lung adenocarcinoma was performed for 1681 patients between January 2000 and December 2013. Of these patients, 936 who survived 5 years or longer after surgery were identified, and factors associated with OS and CSS were determined using the Cox proportional hazard model. RESULTS: Multivariable analysis demonstrated that lymph node metastasis (p < 0.01) and absence of GGO components (p < 0.01) were independently associated with OS and CSS for the 5-year survivors. The absence of GGO components was significantly associated with OS (p < 0.01) and CSS (p < 0.01) also for the 5-year survivors with stage 1 disease (n = 782) and for the 5-year survivors without recurrence (n = 809). The incidence of recurrence anytime during the 10-year postoperative follow-up period differed significantly between the 5-year survivors with and without GGO components. CONCLUSIONS: The absence of GGO components was significantly associated with an unfavorable prognosis for the 5-year survivors with completely resected lung adenocarcinoma regardless whether they had recurrences not.

Comparison of the amino acid profile between the nontumor and tumor regions in patients with lung cancer.

Energy metabolism in cancer cells is reprogrammed to meet the energy demands for cell proliferation under strict environments. In addition to the specifically activated metabolism of cancer, including the Warburg effect and glutaminolysis, most amino acids (AAs) are utilized for gluconeogenesis. Significant increases in AAs and energy metabolites in the tumor region occur in gastric and colon cancers. However, a different AA-related energy metabolism may exist in lung cancer because of the abundant blood supply to lung tissue. This study compared the profiles of AAs and their related metabolites in energy metabolism, analyzed by an HPLC-MS/MS system, between tissues from nontumor and tumor regions collected from 14 patients with non-small cell lung cancer (NSCLC). In the energic metabolism precursor categories, the glucogenic AAs, which included the pyruvate precursors (Ser, Gly, Thr, Ala, and Trp), the α-ketoglutarate precursors (Glu, Gln, and Pro) and the succinyl-CoA precursors (Val, Ile, and Met) were significantly increased in the tumor region compared to in the nontumor region. However, no significant differences existed between the two regions in the ketogenic AAs (Leu, Lys, and Tyr). These differences were not observed between the subgroups with and without diabetes mellitus in the two regions. The metabolites on the left-hand side of the TCA cycle were significantly higher in the tumor region, but no differences in metabolites in the right-hand side. The mRNA expressions of major AA transporters and cancer proliferation factors were also significantly increased in the tumor region, compared to these in their counterparts. In lung cancer, glucogenic AAs that are actively transported from circulating fluids would be predominantly utilized for gluconeogenesis, with and without diabetes mellitus. The characteristics of the AA-related metabolism would be associated with tissue-specific cell proliferation in patients with NSCLC.

Significant prognostic determinants in lung cancers of the superior sulcus: comparable analysis of resected and unresected cases.

OBJECTIVE: In this study, we aimed to identify prognostic determinants and to comparably analyze clinical features of patients with both resected and unresected superior sulcus tumors (SSTs). METHODS: The data of 56 patients who underwent any treatment for an SST from 2004 through 2016 in our hospital were reviewed. Overall survival (OS) rates were estimated using the Kaplan-Meier method. Univariate and multivariate analyses were performed to determine independent prognostic factors for patients with resected and unresected SST separately. RESULTS: The number of patients with resected and unresected SSTs was 24 (43%) and 32 (57%), respectively. Of the 24 patients who underwent surgery, 20 received induction therapy, with 32% achieving pathological complete response. Complete resection (R0) was performed in 22 patients (92%). On multivariate survival analysis, preoperative serum carcinoembryonic antigen (CEA) level (median 8.3 ng/ml, p = 0.021) was identified as the independent determinant of OS in surgical patients; whereas, initial treatment response (complete response or partial response, p = 0.032) was the independent OS indicator in non-surgical patients. The 5-year OS of the patient with resected and unresected SST was 68.8% and 29.1% (p = 0.008), respectively. CONCLUSION: Significant prognostic factors differ among patients stratified by the presence of surgical resection for SSTs. Preoperative CEA level in surgical candidates and initial treatment response in non-surgical patients were the independent factors associated with OS. Surgical candidates are expected to have more favorable survival than patients with unresectable SSTs.

Prognostic impact of solid-part tumour volume doubling time in patients with radiological part-solid or solid lung cancer.

OBJECTIVES: The measurement of part-solid and whole tumour sizes in patients with non-small-cell lung cancer (NSCLC) using computed tomography (CT) has been widely accepted for assessing clinical outcomes. Although the volume doubling time (VDT) of a tumour is useful for distinguishing high-risk nodules from low-risk ones, it remains to be clarified whether separate calculation of whole-tumour VDT and solid-part tumour VDT (SVDT) greatly affects the survival rate of patients with radiologically node-negative part-solid or solid NSCLC. METHODS: The study included 258 patients with NSCLC who had radiologically node-negative, part-solid or solid tumours and who had at least 2 preoperative CT scans taken more than 30 days apart followed by radical lobectomy and systemic lymph node dissection between January 2012 and December 2015. Univariable and multivariable analyses of recurrence-free survival were performed using the Cox proportional hazards regression model. RESULTS: The mean whole-tumour VDT and SVDT were 375 and 458 days, respectively. Multivariable analyses demonstrated that whole-tumour VDT (P = 0.003), SVDT (P < 0.001), solid-part tumour size, whole-tumour size and comorbidities significantly affected the recurrence-free survival. Using the receiver operating characteristic curve, the cut-off value of the SVDT for recurrence was 215 days, and the 5-year recurrence-free survival rates for patients with SVDT >215 days and those with SVDT <215 days were 85.7% and 43.0%, respectively (P < 0.001). CONCLUSION: The calculation of SVDT in patients with node-negative, part-solid or solid NSCLC is highly useful for predicting postoperative survival outcomes.

Computed Tomography Histogram Approach to Predict Lymph Node Metastasis in Patients With Clinical Stage IA Lung Cancer.

BACKGROUND: Quantitative computed tomography (CT) histogram analysis of tumors is reported to help distinguish between invasive and less invasive lung cancers. This study aimed to clarify whether CT histogram analysis of tumors can be used to classify patients with clinical stage 0 to IA non-small cell lung cancer according to pathologic lymph node (pN) status. METHODS: Predictive factors associated with pN metastasis were identified from the derivation dataset including 629 patients with clinical stage 0 to IA non-small cell lung cancer who underwent complete resection with lymph node dissection (surgeries between 2008 and 2013). The validation dataset including 238 patients (surgeries between 2014 and 2015) were subsequently reevaluated. Clinicosurgical factors, including CT histogram analysis of tumors (CT value percentiles 2.5, 25, 50, 75, and 97.5, skewness, and kurtosis) were assessed. RESULTS: Seventy-three patients (12%) in the derivation cohort and 35 patients (15%) in the validation cohort had positive nodes. The pN status significantly affected survival in the entire population: 5-year overall survival of 93.1% vs 71.1% and 5-year disease-free survival of 85.9% vs 43.1% for negative vs positive (both P < .001). On multivariate analysis in the derivation cohort, the 75th percentile CT value (P < .001), age (P = .003), and comorbidities (P = .006) were significantly associated with pN metastasis. The area under the curve and the cutoff level of the 75th percentile CT value relevant to pN metastasis were 0.729 and 1.5 HU, respectively, and the threshold value provided accuracy of 71% for the validation cohort. CONCLUSIONS: Histogram analysis of CT imaging metrics of tumors contributes to noninvasive prediction of pN metastasis in patients with clinical stage 0 to IA non-small cell lung cancer.

Prognostic factors for surgically resected non-small cell lung cancer with cavity formation.

BACKGROUND: Small pulmonary nodules have been detected frequently by computed tomography (CT). Lung cancers with cavity formation are also easily detected. There are a few reports focused on the cavity wall, although cancer cells exist along the cavity wall, not inside. We evaluated the impact of cavity wall thickness on prognosis and assessed the clinicopathological features in non-small cell lung cancer (NSCLC) with cavity formation. METHODS: Between 2005 and 2011, 1,313 patients underwent complete resection for NSCLC. Of these cases, we reviewed 65 patients (5.0%) diagnosed with NSCLC with cavity formation by chest CT. We classified the patients into three groups based on the maximum cavity wall thickness, namely, ≤4 mm (Group 1, 8 patients), >4 and ≤15 mm (Group 2, 33 patients), and >15 mm (Group 3, 24 patients). RESULTS: The number of patients with pathological whole tumor size >3 cm was 2 (25%) in Group 1, 17 (52%) in Group 2, and 23 (96%) in Group 3 (P<0.001). Cases with lymph node metastasis were 0 (0%) in Group 1, 5 (15%) in Group 2, and 10 (42%) in Group 3 (P=0.016). The 5-year overall survival (OS) rates were 100% in Group 1, 84.0% in Group 2, and 52.0% in Group 3, with significant differences between Group 1 and Group 3 (P=0.044) and between Group 2 and Group 3 (P=0.034). In univariate analysis, neither whole tumor size nor lymph node metastasis was a prognostic factor for OS (P=0.51, P=0.27). Only cavity wall thickness was a significant prognostic factor by multivariate analysis (P=0.009). CONCLUSIONS: Maximum cavity wall thickness was an important prognostic factor in NSCLCs with cavity formation, comparable with other established prognostic factors.