A comparative study of robot-assisted thoracoscopic surgery and conventional approaches for short-term outcomes of anatomical segmentectomy.

OBJECTIVES: Since anatomical segmentectomy requires meticulous dissection of the segmental pulmonary vessels and bronchus, robot-assisted thoracoscopic surgery (RATS) has been widely adopted in recent years. We investigated the usefulness of RATS segmentectomy by comparing perioperative outcomes with conventional approaches including open thoracotomy or video-assisted thoracoscopic surgery (VATS). We compared perioperative outcomes of segmentectomy between RATS and conventional approaches including open thoracotomy or video-assisted thoracoscopic surgery (VATS). METHODS: This single-institutional retrospective study comprised 231 patients with primary lung cancer who underwent segmentectomy by RATS or conventional approaches between January 2011 and December 2022. Surgical outcomes and postoperative complications were analyzed among patients whose background factors were adjusted by propensity score matching (PSM). RESULTS: Before PSM, there were significant differences in age, smoking status, and types of segmentectomy. After PSM, 126 patients (63 patients in each group) were included in this analysis. The RATS group had significantly shorter operative time (154 vs 210 min; p < 0.01), fewer bleeding amounts (10 vs 40 mL; p < 0.01), and shorter duration of chest drainage (2 vs 2 days; p = 0.04) than the conventional-approach group. There was no significant difference in the incidence of all complications; however, the incidence of postoperative pneumonia was significantly lower than in the conventional-approach group (p = 0.02). CONCLUSIONS: RATS segmentectomy is proposed to be useful. It was suggested that RATS segmentectomy may be useful with better perioperative results than the conventional approach. Further studies on oncological long-term outcomes and cost-benefit comparisons are needed.

Typical carcinoid in right middle lobe of pulmonary hypoplasia.

BACKGROUND: Pulmonary typical carcinoid occurring in hypoplasia of the right middle lobe is very rare. CASE PRESENTATION: A routine examination's chest X-ray revealed an abnormal shadow in the right middle lung field of an 82-year-old Japanese woman. A chest computed tomography scan showed a solid 2.5 × 2.0-cm nodule in the very small right middle lobe. A trans-bronchial lung biopsy of the mass in the right middle lobe was performed; it revealed atypical cells with round nuclei growing in multiple foci, and immunostaining was positive for chromogranin A, synaptophysin and CD56, suggesting pulmonary carcinoid. The preoperative clinical diagnosis of primary lung cancer, cT1cN0M0 stage IA3 was considered. A right middle lobectomy and mediastinal lymph node dissection were performed by video-assisted thoracic surgery. Intraoperatively, the middle lobe of the right lung was very small, with 1- to 2-mm-dia. pulmonary arteries and veins that were considered hypoplastic. The final histopathological diagnosis was typical carcinoid, pT2aN0M0 stage IB based on the presence of pleural invasion. CONCLUSIONS: Including the present patient, only nine cases of lung cancer occurring within pulmonary hypoplasia have been reported, most of which were typical carcinoid.

Dynamic transition of molecular subtypes in relapsed small cell lung cancer treated with multimodal therapy: A case report.

Several transcription factors in small cell lung cancer (SCLC), including achaete-scute homolog 1 (ASCL1) and neurogenic differentiation factor 1 (NEUROD1), contribute to rapid tumor growth and early metastatic dissemination. Recent studies suggested that these molecular subtypes represent neuroendocrine differentiation in dynamic SCLC evolution. In the present case, a 62-year-old man was diagnosed with limited disease SCLC originating from the right upper lobe. Biopsy specimens were positive for ASCL1 but negative for NEUROD1. Six months after concurrent chemoradiotherapy and prophylactic cranial irradiation, the primary tumor had regrown and salvage surgery was performed. The pathological diagnosis was recurred SCLC, and postoperative histopathology was positive for both ASCL1 and NEUROD1. The patient was subsequently followed up; however, he had multiple bone metastases 9 months after surgery. It was speculated that the shift to NEUROD1-high expression in tumor cells surviving concurrent chemoradiation therapy may be related to the poor outcome after combined modality treatment.

Sublobar Resection for Non-Small Cell Lung Cancer in Octogenarians: A Prospective, Multicenter Study.

BACKGROUND: Segmentectomy is a good surgical option for peripheral, early, non-small cell lung cancer (NSCLC) ≤2 cm. However, the role of sublobar resection including wedge resection and segmentectomy remains unclear for octogenarians with >2-cm but ≤4-cm early-stage NSCLC, for which lobectomy is a standard treatment. METHODS: By use of a prospective registry, 892 patients aged ≥80 years with operable lung cancer were enrolled at 82 institutions. Of these, we analyzed the clinicopathologic findings and surgical outcomes of 419 patients with NSCLC tumors of 2 to 4 cm during a median follow-up of 50.9 months between April 2015 and December 2016. RESULTS: Five-year overall survival (OS) was slightly but not significantly worse after sublobar resection than after lobectomy in the entire cohort (54.7% [95% CI, 43.2%-93.0%] vs 66.8% [95% CI, 60.8%-72.1%]; P = .09). Multivariable Cox regression analysis of OS revealed that these surgical procedures were not independent prognostic predictors (hazard ratio, 0.8 [0.5-1.1]; P = .16). The 5-year OS was comparable between 192 patients who could tolerate lobectomy but were treated by sublobar resection or lobectomy (67.5% [95% CI, 48.8%-80.6%] vs 71.5% [95% CI, 62.9%-78.4%]; P = .79). Recurrence after sublobar resection and lobectomy was locoregional in 11 (11%) of 97 and in 23 (7%) of 322 patients, respectively. CONCLUSIONS: OS might be equivalent between sublobar resection with a secure surgical margin and lobectomy for selected patients aged ≥80 years with peripheral early-stage NSCLC tumors of 2 to 4 cm who can tolerate lobectomy.

Clinical significance of MYC family protein expression in surgically resected high-grade neuroendocrine carcinoma of the lung.

OBJECTIVES: MYC family genes including MYC, MYCN, and MYCL are amplified and overexpressed as oncogenic drivers in high-grade neuroendocrine carcinoma of the lung (HGNEC), but little is known about their clinical significance. This study evaluated the prognostic impact of MYC family protein expression in patients with surgically resected HGNEC. METHODS: Immunohistochemical analyses were performed on 83 resected specimens of HGNEC using antibodies against MYC family proteins (c-MYC, n-MYC, and l-MYC). When nuclear staining of any intensity in ≥10% of tumor cells showed immunoreactivity with any one or more of c-MYC, n-MYC, or l-MYC, the specimens were defined as MYC family-positive. RESULTS: A total of 83 patients were analyzed. MYC family-positive status was observed in 33.7% (28 of 83 cases) and was not correlated with clinicopathological factors. The protein expression was mutually exclusive and no duplicate cases were observed. A log-rank test showed that MYC family-positive status was significantly associated with shorter overall survival (OS) (p = 0.003) and recurrence-free survival (RFS) (p = 0.039). According to Cox multivariate analysis, MYC family-positive status had a significant effect on shorter OS (hazard ratio [HR] = 2.217, 95% confidence interval [CI] 1.179-4.169, p = 0.014) and RFS (HR = 1.802, 95% CI 1.014-3.202, p = 0.045). In patients with pathological stage I, MYC family-positive status also showed significantly poor OS (HR = 2.847, 95% CI 1.236-6.557, p = 0.014) and RFS (HR = 2.088, 95% CI 1.006-4.332, p = 0.048) in the multivariate analysis. CONCLUSIONS: MYC family protein expression could be an independent unfavorable prognostic factor in patients with surgically resected HGNEC.

Early chest tube removal regardless of drainage volume after anatomic pulmonary resection: A multicenter, randomized, controlled trial.

OBJECTIVES: This study aimed to evaluate the safety and feasibility of early chest tube removal after anatomic pulmonary resection, regardless of the drainage volume. METHODS: We conducted a multicenter, randomized, controlled, noninferiority trial. Patients with greater than 300 mL drainage volume during postoperative day 1 were randomly assigned to group A (tube removed on postoperative day 2) and group B (tube retained until drainage volume ≤300 mL/24 hours). The primary end point was the frequency of respiratory-related adverse events (grade 2 or higher based on the Clavien-Dindo classification) within 30 days postoperatively. RESULTS: Between April 2019 and October 2021, 175 patients were assigned to group A (N = 88) or group B (N = 87). One patient in group B who experienced chylothorax was excluded from the study. Respiratory-related adverse events were observed in 10 patients (11.4%) in group A and 12 patients (14.0%) in group B (P = .008). The frequencies of thoracentesis or chest tube reinsertion were not significantly different (8.0% and 9.3% in groups A and B, respectively, P = .752). Additionally, the duration of chest tube placement was significantly shorter in group A than in group B (median, 2 vs 3 days; P < .001). No significant difference between groups A and B was found in postoperative hospital stay (median, 6 vs 7 days, P = .231). CONCLUSIONS: Early chest tube removal, regardless of drainage volume, was safe and feasible in patients who underwent anatomic pulmonary resection.

Video-Assisted Thoracoscopic Surgery Using Extracorporeal Membrane Oxygenation for Intractable Pneumothorax.

Intractable pneumothorax with poor lung function that has received multiple conservative treatments may occur. Case 1 was a 70-year-old woman with aspergilloma who was admitted for pneumothorax. Case 2 was a 68-year-old man with acute exacerbation of interstitial pneumonia who developed pneumothorax. In both cases, multiple conservative therapies were administered, but the leak continued; thus, operations using veno-venous extracorporeal membrane oxygenation (ECMO) were planned. By video-assisted thoracoscopic surgery (VATS), we obtained the optimal surgical field by lung collapse. We removed many blood clots that were used for pleurodesis, ligated the bulla in case 1, and covered the leak point with strengthening agents in case 2. For cases of intractable pneumothorax, lung collapse by ECMO is advantageous because we can check details and leak points even in blood clots or in poor condition of the lung, and we can maneuver the lung in poor condition with a clear surgical field.

Prognostic impact of surgical treatment for high-grade neuroendocrine carcinoma of the lung: a multi-institutional retrospective study.

Background: High-grade neuroendocrine carcinoma (HGNEC) of the lung, which includes small cell lung cancer (SCLC) and large cell neuroendocrine carcinoma (LCNEC), is an aggressive form of lung cancer. Although lobectomy followed by adjuvant chemotherapy is regarded as the standard therapy for this disease, it would be an uphill struggle for HGNEC patients to receive that multidisciplinary therapy perfectly. This study aimed to examine recurrence and survival outcomes in surgically treated patients with HGNEC of the lung. Methods: The medical records of 104 HGNEC patients who underwent surgical treatment in five institutions were retrospectively analyzed. Standard treatment (ST) was defined as lobectomy, bilobectomy, or pneumonectomy with mediastinal lymph node dissection followed by adjuvant platinum-doublet chemotherapy with more than two cycles. Results: Patients in the ST group (n=31; 30%) were younger and had fewer respiratory complications than those in the non-standard treatment (NST) group (n=73; 70%). A significantly higher proportion of patients in the NST group developed ipsilateral lymph node recurrence (21% vs. 3%; P=0.035) and ipsilateral or contralateral lung recurrence (15% vs. 0%; P=0.031). Five-year overall survival (OS) was 64.2% in the ST group and 38.3% in the NST group (P=0.038). NST was independently associated with worse OS in multivariate analysis (hazard ratio, 2.044; 95% confidence interval, 1.016-4.113; P=0.045). Conclusions: Surgically treated HGNEC patients who received ST had a more favorable outcome than those who received NST. Patients who receive NST may require additional treatment.

High mRNA expression of POU2F3 in small cell lung cancer cell lines predicts the effect of lurbinectedin.

BACKGROUND: Small cell lung cancer (SCLC) is a progressive disease with a poor prognosis. Recently, a method to classify SCLC by the expression status of four transcription factors, ASCL1, NEUROD1, POU2F3, and YAP1, was proposed. Here, we investigated the potential relationships between expression of these four transcription factors and the effect of lurbinectedin. METHODS: mRNA and protein expression of ASCL1, NEUROD1, POU2F3, and YAP1 were quantified in eight SCLC cell lines and analyzed for potential correlations with drug sensitivity. In addition, ASCL1, NEUROD1, POU2F3, and YAP1 expression were evaluated in 105 resected cases of high-grade neuroendocrine carcinoma of the lung, including 59 resected cases of SCLC. RESULTS: Based on the results of qRT-PCR and western blot analyses, the eight SCLC cell lines examined were classified into NEUROD1, POU2F3, and YAP1 subtypes, as well as five ASCL1 subtypes. There were no correlations between cell line subtype classification and drug sensitivity to cisplatin, etoposide, or lurbinectedin. Next, we compared relative mRNA expression levels of each transcription factor with drug sensitivity and found that the higher the mRNA expression level of POU2F3, the lower the IC50 of lurbinectedin. Evaluation of resected SCLC tissue revealed that the composition of subtypes defined by the relative dominance of ASCL1, NEUROD1, POU2F3, and YAP1 was as follows: 61% ASCL1, 15% NEUROD1, 14% POU2F3, 5% YAP1, and 5% all-negative. CONCLUSION: In our experiments, high mRNA expression of POU2F3 in SCLC cell lines correlated with the effect of lurbinectedin.

The C-reactive protein to albumin ratio is a prognostic factor for stage I non-small cell lung cancer in elderly patients: JACS1303.

PURPOSE: To establish the prognostic significance of C-reactive protein (CRP) and albumin in octogenarians with non-small cell lung cancer (NSCLC) based on the study of the Japanese Association for Chest Surgery (JACS 1303). METHODS: A total of 618 octogenarians with pathological stage I NSCLC, who underwent pulmonary resection, were included in the analysis. We conducted multivariable Cox regression analysis to evaluate the CRP to albumin ratio (CAR) as a potential prognostic factor. Other clinicopathological factors were also evaluated. RESULTS: The median age was 82 years. Operations included lobectomy (n = 388; 62.8%) segmentectomy (n = 95; 15%), and wedge resection (n = 135; 22%). Pathological stage IA was diagnosed in 380 (61.5%) patients. The 3-year (OS) and cancer-specific survival (CS) rates were 86.7% and 94.6%, respectively. OS was significantly higher for patients with low CAR (< 0.106) than for those with high CAR (≥ 0.106) (hazard ratio = 3.13, 95% confidence interval: 1.99-4.93, p < 0.0001). Univariate analysis identified sex, poor performance status, smoking status, comorbidity, solid tumor, histology, high Glasgow prognostic scale, and high CAR as significant prognostic factors. Multivariate analysis identified only the CAR as a significant prognostic factor for both OS and CS. CONCLUSIONS: Our analysis of the nationwide data demonstrated that the CAR is a useful prognostic factor for elderly patients with stage I NSCLC.

Gene expression profiling using targeted RNA-sequencing to elucidate the progression from histologically normal lung tissues to non-invasive lesions in invasive lung adenocarcinoma.

Lung adenocarcinoma (LUAD) shows heterogeneous morphological features and the stepwise progression from adenocarcinoma in situ to minimally invasive adenocarcinoma to invasive LUAD. Although multiple genetic alterations have been linked to the progression, the differences between the gene expression profiles of non-invasive lesions (non-ILs) and adjacent histologically normal lung (aNL) tissues within invasive LUAD have not been investigated. Herein, we analyzed differentially expressed genes (DEGs) specific to early-stage carcinogenesis in LUAD. Invasive LUAD tissue samples containing both non-ILs and aNL tissues were obtained from seven patients with pathological stage I LUAD, and each component was subjected to microdissection. Gene expression profiles of each component were determined using targeted RNA-sequencing. In total, 2536 DEGs, including 863 upregulated and 1673 downregulated genes, were identified in non-ILs. In non-ILs, the expression of SLC44A5, a choline transporter-like protein-coding gene, was significantly upregulated, and that of TMEM100, a gene encoding a transmembrane protein, was significantly downregulated. Reportedly, SLC44A5 plays an important role in the development and progression of hepatocellular carcinoma, whereas TMEM100 functions as a tumor suppressor in non-small cell lung cancer. Gene set enrichment analysis showed that DEGs in non-ILs were negatively enriched in cell death and immune response. Immunohistochemical analysis revealed that increased SLC44A5 expression and decreased TMEM100 expression were maintained in ILs. A protein-protein interaction (PPI) network analysis identified several upregulated and downregulated hub genes with high degrees in non-ILs. In conclusion, several new DEGs and key PPI network hub genes were identified in non-ILs, contributing to understanding of early-stage carcinogenesis in LUAD.

Predictive value of EGFR mutation in non-small-cell lung cancer patients treated with platinum doublet postoperative chemotherapy.

The mutation status of tumor tissue DNA (n = 389) of resected stage II-III non-squamous non-small-cell lung cancer (Ns-NSCLC) was analyzed using targeted deep sequencing as an exploratory biomarker study (JIPANG-TR) for the JIPANG study, a randomized phase III study of pemetrexed/cisplatin (Pem/Cis) vs vinorelbine/cisplatin (Vnr/Cis). The TP53 mutation, common EGFR mutations (exon 19 deletion and L858R), and KRAS mutations were frequently detected. The frequency of the EGFR mutation was significant among female patients. Patients with an EGFR mutation-positive status had a significantly shorter recurrence-free survival (RFS) time (24 mo vs not reached) (HR, 1.64; 95% CI, 1.22-2.21; P = .0011 for EGFR mutation status). Multivariable analysis identified both the pathological stage and EGFR mutation status as independent prognostic factors for RFS (HR, 1.78; 95% CI, 1.30-2.44; P = .0003 for disease stage; and HR, 1.57; 95% CI, 1.15-2.16; P = .0050 for EGFR mutation status). This study demonstrated that the EGFR mutation has either a poor prognostic or predictive impact on a poor response to postoperative chemotherapy with platinum doublet chemotherapy for stage II-III Ns-NSCLC patients. This result supports a role for mandatory molecular diagnosis of early-stage Ns-NSCLC for precision oncology and signifies the importance of adjuvant for the 3rd generation tyrosine kinase inhibitor rather than platinum-based chemotherapy. This study is registered with the UMIN Clinical Trial Registry (UMIN 000012237).

Prognostic Impact of Mediastinal Lymph Node Dissection in Octogenarians With Lung Cancer: JACS1303.

INTRODUCTION: The prognostic significance of mediastinal lymph node dissection (MLND) in elderly patients with non-small cell lung cancer (NSCLC) remains unclear. This post hoc analysis of a nationwide multicenter cohort study (JACS1303) evaluated the prognostic significance of MLND in octogenarians with NSCLC. MATERIALS AND METHODS: We included 622 octogenarians with NSCLC who underwent lobectomy. The median follow-up duration was 41.1 months. We compared survival and perioperative outcomes between patients who did and did not undergo MLND. RESULTS: In total, 414 (67%) patients underwent MLND (ND2 group), whereas 208 (33%) did not undergo MLND (ND0-1 group). The disease stage was more advanced in the ND2 group than in the ND0-1 group. Disease-free survival was slightly greater in the ND0-1 group with marginal significance (P= .079). In the matched cohort (N = 228), which mainly consisted of patients with clinical stage I disease (96%), there was no significant difference between the 2 groups regarding overall and disease-free survival (P= .908 and P = .916, respectively). Operative time and blood loss were significantly lower in the ND0-1 group than in the ND2 group in the entire cohort (P< .001 and P = .050, respectively) and in the matched cohort (P = .003 and P= .046, respectively). CONCLUSION: Based on a nationwide prospective database, we found limited prognostic impact of MLND, suggesting that MLND can be omitted for octogenarians with early-stage NSCLC.

A rare case of combined thymoma and a multilocular thymic cyst discovered due to chest pain.

BACKGROUND: A thymoma with chest pain and multilocular thymic cysts (MTCs) is very rare. CASE PRESENTATION: A 49-year-old man presented to another hospital complaining of an anterior chest pain. Chest computed tomography (CT) showed an anterior mediastinal tumor 60 × 30 × 55 mm in size. The boundary with the pericardium or left brachiocephalic vein seemed to be partially unclear while enhanced by the contrast medium, and so the tumor could have invaded them. No definitive diagnosis of myasthenia gravis was made although the serum anti-acetylcholine receptor antibody count was high. We performed an extended thymectomy with combined partial resection of left brachiocephalic vein, left upper lobe, and left phrenic nerve. He was discharged with no chest pain and no complications post-surgery. The tumor was pathologically type B2 thymoma with hemorrhage necrosis and MTCs, and we diagnosed Masaoka stage II because of no histological infiltration to the organs. CONCLUSIONS: We speculated that hemorrhagic necrosis due to infarction in tumor caused the inflammation to spread to the surrounding organs, which was related to the chest pain and the development of MTCs.

Comparison between robot-assisted thoracoscopic surgery and video-assisted thoracoscopic surgery for mediastinal and hilar lymph node dissection in lung cancer surgery.

OBJECTIVES: Lymph node dissection (LND) with robot-assisted thoracoscopic surgery (RATS) in lung cancer surgery has not been fully evaluated. The aim of this study was to compare LND surgical results between video-assisted thoracoscopic surgery (VATS) and RATS. METHODS: We retrospectively compared perioperative parameters, including the incidence of LND-associated complications (chylothorax, recurrent and/or phrenic nerve paralysis and bronchopleural fistula), lymph node (LN) counts and postoperative locoregional recurrence, among 390 patients with primary lung cancer who underwent lobectomy and mediastinal LND by RATS (n = 104) or VATS (n = 286) at our institution. RESULTS: The median total dissected LN numbers significantly differed between the RATS and the VATS groups (RATS: 18, VATS: 15; P < 0.001). They also significantly differed in right upper zone and hilar (#2R + #4R + #10L) (RATS: 12, VATS: 10; P = 0.002), left lower paratracheal and hilar (#4L + #10L) (RATS: 4, VATS: 3; P = 0.019), aortopulmonary zone (#5 + #6) (RATS: 3, VATS: 2; P = 0.001) and interlobar and lobar (#11 + #12) LNs (RATS: 7, VATS: 6; P = 0.041). The groups did not significantly differ in overall nodal upstaging (P = 0.64), total blood loss (P = 0.69) or incidence of LND-associated complications (P = 0.77). CONCLUSIONS: In this comparison, it was suggested that more LNs could be dissected using RATS than VATS, especially in bilateral superior mediastinum and hilar regions. Accumulation of more cases and longer observation periods are needed to verify whether RATS can provide the acceptable quality of LND and local control of lung cancer.

Survival of Octogenarians with Early-Stage Non-small Cell Lung Cancer is Comparable Between Wedge Resection and Lobectomy/Segmentectomy: JACS1303.

BACKGROUND: Anatomic resection with lymph node dissection or sampling is the standard treatment for early non-small cell lung cancer (NSCLC), and wedge resection is an option for compromised patients. This study aimed to determine whether wedge resection can provide comparable prognoses for elderly patients with NSCLC. METHODS: The study analyzed the clinicopathologic findings and surgical outcomes during a median follow-up period of 39.6 months for 156 patients with solid dominant (consolidation-to-tumor ratio > 0.5) small (whole tumor size ≤ 2 cm) NSCLC among 892 patients 80 years of age or older with medically operable lung cancer between April 2015 and December 2016. RESULTS: The 3-year overall survival (OS) rates after wedge resection and after segmentectomy plus lobectomy did not differ significantly (86.5 %; 95 % confidence interval [CI], 74.6-93.0 % vs 83.7 % 95 % CI, 74.0-90.0 %; P = 0.92). Multivariable Cox regression analysis of OS with propensity scores showed that the surgical procedure was not an independent prognostic predictor (hazard ratio [HR], 0.84; 95 % CI, 0.39-1.8; P = 0.64). The 3-year OS rates were slightly better after wedge resection for 97 patients who could tolerate lobectomy than after segmentectomy plus lobectomy (89.4 %; 95 % CI, 73.8-95.9 % vs 75.8 %; 95 % CI, 62.0-85.2 %; P = 0.14). The cumulative incidence of other causes for death was marginally higher after segmentectomy plus lobectomy than after wedge resection (P = 0.079). CONCLUSIONS: Wedge resection might be equivalent to lobectomy or segmentectomy for selected patients 80 years of age or older with early-stage NSCLC who can tolerate lobectomy.

Tumor mutation burden as a biomarker for lung cancer patients treated with pemetrexed and cisplatin (the JIPANG-TR).

The JIPANG study is a randomized phase III study of pemetrexed/cisplatin (Pem/Cis) versus vinorelbine/cisplatin (Vnr/Cis) for completely resected stage II-IIIA non-squamous non-small cell lung cancer (Ns-NSCLC). This study did not meet the primary endpoint (recurrence-free survival, RFS) but Pem/Cis had a similar efficacy to Vnr/Cis with a better tolerability. Tumor mutation burden (TMB) is thought to have a predictive value of immune checkpoint inhibitors. However, the relevance of TMB to cytotoxic chemotherapy remains unknown. This exploratory study investigates the relationship between tumor mutation profiles and clinical outcome of Pem/Cis. Formalin-fixed, paraffin-embedded tumor tissues (n = 389) were obtained from the patients. Mutation status of tissue DNA was analyzed by targeted deep sequencing. Epidermal growth factor receptor (EGFR) mutations were detected frequently in Ns-NSCLC (139/374). Patients without any EGFR mutations experienced longer RFS in the Pem/Cis arm versus Vnr/Cis arms. Pem/Cis in patients with high TMB (≥12-16 mut/Mb) tended to have improved survival. In patients with wild-type EGFR, TMB ≥ 12 mut/Mb was significantly associated with improved RFS with Pem/Cis versus Vnr/Cis (not reached vs 52.5 months; hazard ratio (HR) 0.477). It could be proposed that TMB was predictive of RFS benefit with Pem/Cis versus Vnr/Cis in Ns-NSCLC. Further investigation is required to determine whether TMB combined with EGFR mutation status could be used as a predictive biomarker.

Transformation from adenocarcinoma to squamous cell carcinoma associated with long-term administration of EGFR-TKIs.

Although patients with non-small cell lung cancer exhibiting EGFR mutations generally respond to tyrosine kinase inhibitors (TKIs), the majority of patients acquire resistance ~1 year after treatment. EGFR T790M mutations, MET or HER2 amplifications and phenotypic transformations contribute to the mechanism of EGFR-TKI resistance. The transformation of small cell lung cancer frequently occurs, although few convert to squamous cell carcinoma associated with the administration of EGFR-TKIs. The current study reports a case of EGFR-mutated adenocarcinoma of the lung that transitioned to squamous cell carcinoma in association with long-term EGFR-TKIs administration.