Challenges in Robotic Lung Lobectomy through the Anterior Approach.

PURPOSE: Robot-assisted thoracic surgery (RATS) has become popular because of its minimally invasive nature and reduced burden on surgeons. The anterior approach (AA) is beneficial because it utilizes the same field of view and procedures as thoracotomy and video-assisted thoracic surgery, although the disadvantages are less well-known. METHODS: We retrospectively examined 35 consecutive patients who underwent RATS lobectomy via the AA, focusing on clinical factors and postoperative complications. RESULTS: The study included 12 males and 23 females with a median console time of 177 (120-346) min, median blood loss of 0 (0-100) mL, and median stapler usage of 5 (2-10) units. Postoperative complications, classified as Clavien-Dindo grade ≥III, included three cases of grade IIIa (prolonged air leakage) and one case each of grade IIIb and grade IVa (middle lobe torsion and ventricular arrhythmia). The influence of stapling device operation cannot be ruled out in prolonged air leakage and middle lobe torsion. A moderate correlation (correlation coefficient = 0.492, p = 0.003) was observed between console time and the number of staplers used. CONCLUSION: Although no severe incidence of vascular injury was observed with the AA, complications related to the use of stapling devices were noted.

A Phase 2 Single-Arm Study of Osimertinib for Radiotherapy-Naive Central Nervous System Metastasis NSCLC: Results for the First-Line Cohort of the OCEAN Study (LOGIK 1603/WJOG 9116L).

Introduction: Osimertinib may be effective in treating central nervous system (CNS) metastasis, but its efficacy in treating radiation therapy (RT)-naive metastasis is unclear. The OCEAN study assessed the efficacy of osimertinib against RT-naive CNS metastasis in patients previously treated (T790M cohort) and untreated patients (first-line cohort) with EGFR mutation. Here, we report the results of the first-line cohort. Methods: Previously untreated patients with RT-naive CNS metastasis and EGFR mutation-positive NSCLC were treated with osimertinib. The brain metastasis response rate (BMRR), progression-free survival (PFS), and overall survival in the first-line cohort were secondary end points. Results: A total of 26 patients were enrolled in the study between September 2019 and July 2020. The median age was 72.0 years with 80.8% female. There were 20 patients who had multiple CNS metastases. BMRR assessed by PAREXEL criteria was 76.9% (90% confidence interval [CI]: 63.3%-90.5%), BMRR assessed by Response Evaluation Criteria in Solid Tumors was 76.9% (95% CI: 54.0%-99.8%), and median PFS of CNS metastasis was 22.0 months (95% CI: 9.7 mo-not reached). The overall response rate was 64.0% (95% CI: 45.2%-82.8%), median PFS was 11.5 months (95% CI: 6.9 mo-not reached), and median survival time was 23.7 months (95% CI: 16.5 mo-not reached). Paronychia and increased creatinine level were the most frequent nonhematological toxicities observed in 13 patients (50%). Grade three and higher adverse events were less than 10%, and there were no treatment-related deaths. Pneumonitis was observed in five patients (19.2%). Conclusions: These results suggest that osimertinib is effective in untreated patients with RT-naive asymptomatic CNS metastasis in a clinical practice first-line setting. Trial registration: UMIN identifier: UMIN000024218. jRCT identifier: jRCTs071180017.

Osimertinib as first-line treatment for recurrent lung cancer patients with EGFR mutation.

Background: Although osimertinib was approved as adjuvant therapy for lung cancer patients with EGFR mutation in various countries, there is still some ongoing debate as osimertinib has been approved based on disease-free survival (DFS) rather than overall survival (OS). We curated a case series in which we documented patterns of recurrence and efficacy and safety of osimertinib after recurrence. Methods: Patients who received osimertinib as first-line treatment for postoperative recurrence between September 2018 and January 2023 were included. Clinicopathological factors, duration of osimertinib treatment (DoT), and adverse events were collected and analyzed. Results: Twenty patients received osimertinib [male, n=6; median age, 75 years (range, 55-85 years)]. The EGFR mutation type was L858R in 11 patients and exon 19 deletion in eight patients. The performance status (PS) was 0 or 1 in all but two patients, who had symptomatic brain metastasis and were therefore PS 3. The first site of postoperative recurrence was locoregional in five patients and distant in 15 patients, including seven with brain metastasis. As of February 2023, 10 patients were still on osimertinib, including three with brain metastasis. Patients with brain metastasis or poor PS had a considerably shorter DoT than their counterparts. Three patients with symptomatic brain metastasis or leptomeningeal metastasis initially responded to osimertinib, but all died of disease progression. Five patients discontinued osimertinib due to serious adverse effects (pneumonitis, drug eruption, and heart failure). Conclusions: Although osimertinib exerts great disease control, even in patients with brain metastasis or poor PS, their presence was associated with a poor prognosis, even with osimertinib treatment. Therefore, adjuvant osimertinib is recommended unless contraindicated.

Giant benign intrathoracic schwannoma: a decade-long progression towards fatality.

BACKGROUND: Intrathoracic neurogenic tumors arise from sympathetic nerve trunks and intercostal nerves; more than 90% are benign. Schwannomas are the most common histological variety, but fatalities due to giant schwannomas are rare. CASE PRESENTATION: We report a case of a 65-year-old woman who presented with chest pain and cough. Computed tomography (CT) revealed a large left chest wall mass of 130-mm in size, and the patient was referred to our department. Tumor biopsy was performed under local anesthesia, and a diagnosis of schwannoma was made. Ten years previously, a 30-mm tumor had been noted in the left third intercostal space by a previous doctor, but follow-up had been interrupted owing to depressive disorder. Although we planned to perform intercostal artery embolization followed by chest wall tumor resection, the patient did not consent to surgery due to uncontrolled depression. After four months, she developed respiratory failure caused by compression due to an enlarged tumor and died. Autopsy also revealed a benign schwannoma with no malignant findings. CONCLUSIONS: Although schwannomas are benign tumors, there are some very rare cases in which they can become huge and life-threatening. Therefore, a benign tumor should not be neglected, and if surgery is not possible at the time of diagnosis, a regular follow up is necessary, in order not to miss the right timing for surgery.

Five-Year Overall Survival Analysis of the JIPANG Study: Pemetrexed or Vinorelbine Plus Cisplatin for Resected Stage II-IIIA Nonsquamous Non-Small-Cell Lung Cancer.

Clinical trials frequently include multiple end points that mature at different times. The initial report, typically based on the primary end point, may be published when key planned co-primary or secondary analyses are not yet available. Clinical Trial Updates provide an opportunity to disseminate additional results from studies, published in JCO or elsewhere, for which the primary end point has already been reported.The JIPANG study is an open-label phase III trial evaluating the efficacy of pemetrexed plus cisplatin (PemP) versus vinorelbine plus cisplatin (NP) as adjuvant chemotherapy in patients with stage II-IIIA nonsquamous non-small-cell lung cancer (NSCLC). Here, we report the long follow-up overall survival (OS) data. Eligible patients were randomly assigned to receive either PemP or NP. The primary end point was recurrence-free survival (RFS), and the secondary end point included OS. This analysis was performed using data collected 5 years after the last patient enrollment. Among 804 patients enrolled, 783 patients were eligible (384 for NP and 389 for PemP). The updated median RFS was 37.5 months in the NP arm and 43.4 months in the PemP arm with a hazard ratio of 0.95 (95% CI, 0.79 to 1.14). At a median follow-up of 77.3 months, the OS rates at 3 and 5 years were 84.1% and 75.6% versus 87.0% and 75.0% with a hazard ratio of 1.04 (95% CI, 0.81 to 1.34). This long-term follow-up analysis showed that PemP had similar efficacy to NP in both RFS and OS for this population, with one of the longest OS data compared with the historical data.

Significance of programmed death-ligand 1 expression in resected lung cancer and its relationship with EGFR mutation.

BACKGROUND: Several studies have reported that the high expression of programmed death-ligand 1 (PD-L1) within tumor cells predicts a poor prognosis. However, the relationship between the PD-L1 expression and lymph node metastasis or driver mutations in lung cancer remains poorly understood. METHODS: A total of 356 consecutive patients who underwent surgical resection for primary lung cancer were included in the study. There were 268 adenocarcinomas including 100 EGFR mutations, 67 squamous cell carcinomas (Sq), and 21 other histologies. The high expression of PD-L1 was defined as a tumor proportion score (TPS) of ≥50. The relationship between the PD-L1 expression and clinicopathological factors and recurrence-free survival (RFS) was analyzed. RESULTS: The PD-L1 expression was high in 75 patients. It was significantly related to smoking history, Sq histology, driver mutation negative, elevated serum carcinoembryonic antigen levels, and lymph node metastasis. Among patients with driver mutations, a high PD-L1 TPS was found in patients with EGFR G719X mutation. A significant difference in RFS was observed in adenocarcinoma patients. A multivariate analysis of adenocarcinoma cases revealed that tumor size and lymph node metastasis were independent prognostic factors for poor RFS, while the PD-L1 expression was not. A logistic regression analysis revealed that the absence of driver mutations, lymph node metastasis, and a history of smoking were significantly associated with the high expression of PD-L1. CONCLUSION: Lymph node metastasis was positively related with the high expression of PD-L1, resulting in poor RFS. A high PD-L1 TPS was observed in patients with the EGFR G719X mutation.

The efficacy of thoracoscopic surgery for descending necrotizing mediastinitis.

OBJECTIVES: Thoracotomy is a reliable approach for descending necrotizing mediastinitis (DNM), and the use of video-assisted thoracic surgery (VATS), a minimally invasive procedure, has been increasing. However, which approach is more effective for DNM treatment is controversial. METHODS: We analysed patients who underwent mediastinal drainage via VATS or thoracotomy, using a database with DNM from 2012 to 2016 in Japan, which was constructed by the Japanese Association for Chest Surgery and the Japan Broncho-esophagological Society. The primary outcome was 90-day mortality, and the adjusted risk difference between the VATS and thoracotomy groups using a regression model, which incorporated the propensity score, was estimated. RESULTS: VATS was performed on 83 patients and thoracotomy on 58 patients. Patients with a poor performance status commonly underwent VATS. Meanwhile, patients with infection extending to both the anterior and posterior lower mediastinum frequently underwent thoracotomy. Although the postoperative 90-day mortality was different between the VATS and thoracotomy groups (4.8% vs 8.6%), the adjusted risk difference was almost the same, -0.0077 with 95% confidence interval of -0.0959 to 0.0805 (P = 0.8649). Moreover, we could not find any clinical and statistical differences between the 2 groups in terms of postoperative 30-day and 1-year mortality. Although patients who underwent VATS had higher postoperative complication (53.0% vs 24.1%) and reoperation (37.9% vs 15.5%) rates than those who underwent thoracotomy, the complications were not serious and most could be treated with reoperation and intensive care. CONCLUSIONS: The outcome of DNM treatment does not depend on thoracotomy or VATS.

Phase 2 study of osimertinib in combination with platinum and pemetrexed in patients with previously untreated EGFR-mutated advanced non-squamous non-small cell lung cancer: The OPAL Study.

BACKGROUND: This multicenter phase 2 trial evaluated the safety and efficacy of osimertinib and platinum-based chemotherapy (OPP) in patients with previously untreated EGFR-mutated advanced non-squamous non-small cell lung cancer (NSCLC). PATIENTS AND METHODS: Patients received osimertinib 80 mg once daily (QD), with either cisplatin 75 mg/m2 (arm A) or carboplatin (area under the curve [AUC] = 5; arm B), plus pemetrexed 500 mg/m2 for four cycles and maintenance therapy of osimertinib 80 mg QD with pemetrexed 500 mg/m2 every 3 weeks. The primary end-points were safety and objective response rate (ORR), and the secondary end-points were complete response rate (CRR), disease control rate (DCR), and progression-free survival (PFS). RESULTS: In total, 67 patients (34 in arm A and 33 in arm B) were enrolled between July 2019 and February 2020. At the data cutoff (28th February 2022), 35 (52.2%) patients had discontinued the protocol treatment, including 10 (14.9%) due to adverse events. No treatment-related deaths occurred. In the full analysis set, the ORR, CRR, and DCR were 90.9% (95% confidence interval [CI], 84.0-97.8), 3.0% (0.0-7.2), and 97.0% (92.8-100.0), respectively. Based on updated survival data (data cutoff on August 31, 2022, median follow-up time: 33.4 months), the median PFS was 31.0 months (95% CI, 26.8 months-not reached) and median overall survival was not reached. CONCLUSIONS: This is the first study to show that OPP has excellent efficacy with acceptable toxicity in previously untreated EGFR-mutated advanced non-squamous NSCLC patients.

[Segmentectomy for Lung Cancer Using Indocyanine Green( ICG)].

The most important issues in the segmentectomy for lung cancer, are the accurate establishment of the suture line and to reduce local recurrence at the resection margin. There are two methods:bronchial dominance as an indicator and intravenous indocyanine green (ICG) as an indicator of blood flow dominance. We have been performing identification by ICG since 2020. After the pulmonary arteriovenous and bronchus are resected, ICG is injected intravenously, and the borders between fluorescent and non-fluorescent area is identified using a ICG thoracoscope, and are resected using an electro-surgical unit or stapler. After that, additional ICG is administered, pulmonary blood flow is checked, and if an uncontaminated area is identified, an additional resection is performed. We have retrospectively reviewed 16 cases of ICG method for lung cancer( all at clinical stageⅠ) performed since January 2020, and no recurrence has been observed. We present the details of these cases and report the usefulness of the ICG fluorescence system.

Cyclin-dependent kinase (CDK) 4/6 inhibition in non-small cell lung cancer with epidermal growth factor receptor (EGFR) mutations.

BACKGROUND: Lung cancer is the leading cause of cancer death worldwide, and EGFR mutation is the most common genetic alteration among Asian patients with lung adenocarcinoma. While osimertinib has been shown to be effective in lung cancer patients with EGFR mutation, the majority of patients eventually develop acquired resistance to treatment. We explored the significance of the cyclin D1 expression in patients with EGFR mutation and the potential efficacy of adding abemaciclib, a cyclin-dependent kinase (CDK) 4/6 inhibitor, simultaneously with osimertinib in vitro. MATERIALS AND METHODS: Immunohistochemical staining, using an anti-cyclin D1 antibody, of specimens from 83 patients with EGFR mutation (male, n = 27; pStage 0-I, n = 71) who were treated by surgical resection between 2017 and 2020, and the relationship between the cyclin D1 expression and clinicopathological factors was analyzed. Additionally, the combined effect of osimertinib and abemaciclib in lung cancer cell lines were analyzed using a growth inhibition test, and the signaling pathway underlying the combined effect was investigated. RESULTS: Cyclin D1 was negative in 18.1% of patients with EGFR mutation, and cyclin D1 negativity was associated with pStage ≥ II (p = 0.02), lymph node metastasis (p = 0.001), and lymphatic invasion (p = 0.01). The cyclin D1-negative group had significantly shorter recurrence-free survival (p = 0.02), although this difference disappeared when limited to pN0 patients. In EGFR mutated cell lines, the combination of osimertinib and abemaciclib demonstrated synergistic effects, which were thought to be mediated by the inhibition of AKT phosphorylation. CONCLUSION: Combination therapy with CDK4/6 inhibitors and EGFR-TKIs may be a promising approach.

Tracheal injury from dog bite in a child.

BACKGROUND: Dog bites associated with the head and neck area in children are a common problem. Most of the lacerations are found in the upper lip and the nose region, and tracheal injury is rare [1]. Tracheal injury requires prompt and accurate diagnosis and treatment to rescue the patient. Especially in children, securing the airway is often more difficult than in adults because of their short neck and narrow trachea. In this report, we experienced a pediatric case of multiple dog bites with tracheal injuries in the neck. CASE PRESENTATION: We report the case of a 3-year-old girl who presented with multiple dog bites. There were multiple wounds on the head, face, neck, and anterior chest, and air leakage was observed from the cervical wound at the time of transfer. It was difficult to perform oral endotracheal intubation, therefore, we extended the neck wound, probed the trachea with finger, and inserted a tracheal tube directly from the cervical wound in the emergency room. Tracheoplasty and another wound cleansing were performed in the operating room. The patient was discharged on the 18th day after surgery, without further complications. CONCLUSION: Tracheal injury from a dog bite is rare. It is important to prompt and accurate diagnosis and treatment. Children should be especially careful because of their short necks and narrow tracheas.

MET kinase inhibitor reverses resistance to entrectinib induced by hepatocyte growth factor in tumors with NTRK1 or ROS1 rearrangements.

BACKGROUND: Entrectinib is an effective drug for treating solid tumors with NTRK gene rearrangement and non-small cell lung cancer (NSCLC) with ROS1 gene rearrangement. However, its efficacy is limited by tolerance and acquired resistance, the mechanisms of which are not fully understood. The growth factors produced by the tumor microenvironment, including hepatocyte growth factor (HGF) produced by tumor-associated fibroblasts, critically affect the sensitivity to targeted drugs. METHODS: We investigated whether growth factors that can be produced by the microenvironment affect sensitivity of NTRK1-rearranged colon cancer KM12SM cells and ROS1-rearranged NSCLC HCC78 cells to entrectinib both in vitro and in vivo. RESULTS: Among the growth factors assessed, HGF most potently induced entrectinib resistance in KM12SM and HCC78 cells by activating its receptor MET. HGF-induced entrectinib resistance was reversed by the active-HGF-specific macrocyclic peptide HiP-8 and the MET kinase inhibitor capmatinib in vitro. In addition, HGF-producing fibroblasts promoted entrectinib resistance in vitro (culture model) and in vivo (subcutaneous tumor model). The use of capmatinib circumvented entrectinib resistance in a subcutaneous tumor model inoculated with KM12SM and HGF-producing fibroblasts. CONCLUSION: Our findings suggest that growth factors in the tumor microenvironment, such as HGF, may induce resistance to entrectinib in tumors with NTRK1 or ROS1 rearrangements. Our results further suggest that optimally co-administering inhibitors of resistance-inducing growth factors may maximize the therapeutic efficacy of entrectinib.

Aspergillus Nodule in a Patient With Autoimmune Pulmonary Alveolar Proteinosis.

Although autoimmune pulmonary alveolar proteinosis (APAP) is more likely to be associated with infectious diseases, clinical case-based evidence is too limited to confirm this. We describe a case of a man in his late forties diagnosed with APAP nine years prior to the current presentation. A nodule in the right upper lobe gradually increased from 8 to 12 mm over a period of 6 months and was suspicious of malignancy. The pathological analyses revealed Aspergillus nodule without any malignant features. This study aims to report a case of Aspergillus nodule with APAP and discuss the differential diagnosis of solitary lung nodule developed in APAP.

Phase II study of S-1 plus cisplatin with concurrent radiotherapy for locally advanced thymic carcinoma: Results of the LOGIK1605/JART-1501 study.

BACKGROUND: Combination chemotherapy is used to treat advanced thymic carcinoma; however, the effects are insufficient. METHODS: Previously untreated patients with unresectable locally advanced thymic carcinoma received two cycles of 80 mg/m2 /day S-1 orally on days 1-14 plus 60 mg/m2 /day cisplatin intravenously on day 1, and concurrent radiotherapy (60 Gy). RESULTS: Three patients were enrolled into the study. Toxicity and survival were assessable in all patients, but the treatment response was only assessable in one patient. The study was terminated because of poor case recruitment. The patients' characteristics were as follows: male/female = 2/1; PS 0/1 = 2/1; median age (range) = 59 (55-72); and stage III/IV = 2/1. The patient in which the treatment response was assessed exhibited SD (response rate: 0%). In both nonevaluable cases, the second course of chemotherapy was judged to be post-protocol treatment because it was delayed by ≥14 days, but a CR and PR were achieved after the end of the study, respectively. G4 leukopenia/neutropenia and G3 febrile neutropenia occurred in one patient each (33%). The median time to tumor progression was 17.6 months, and the 1-, 2-, 3-, and 4-year survival rates were 67, 33, 33, and 33%, respectively. The median overall survival time was not reached, and the 1-, 2-, 3-, and 4-year survival rates were 100, 67, 67, and 67%, respectively. CONCLUSIONS: Although it was difficult to recruit patients, there was a long-term survivor >4 years who appeared to have achieved a CR, indicating that such chemoradiotherapy may be effective against locally advanced thymic carcinoma.

A prospective observational study of postoperative adjuvant chemotherapy for non-small cell lung cancer in elderly patients (≥ 75 years).

BACKGROUND: To examine the effects of postoperative adjuvant chemotherapy for elderly (≥ 75 years of age) patients with completely resected non-small cell lung cancer (NSCLC), we conducted a multi-institutional and prospective observational study. METHODS: Patients were recruited between January 2014 and December 2017, and assigned to two cohort groups based on the patients' choice either to receive postoperative adjuvant chemotherapy (Cohort B) or not (Cohort A). All the patients were observed for 2 years after enrollment. The primary endpoint was the postoperative change of Karnofsky Performance Status (KPS) at 2 years. The secondary endpoints were postoperative recurrence-free survival (RFS) and overall survival (OS) at 2 years, and the completion rate of the adjuvant chemotherapy. RESULTS: Two hundred and seventy-two patients were enrolled (Cohort A, n = 225; Cohort B, n = 47). At any time point after surgery, no marked difference of KPS was observed between Cohort B and Cohort A. The RFS at 2 years was 70.8% (95% confidence interval [CI], 64.3-76.4) in Cohort A and 76.0% (95% CI 60.8-85.9) in Cohort B. The OS at 2 years was 85.9% (95% CI 80.4-89.9) in Cohort A and 89.1% (95% CI 75.8-95.3) in Cohort B. The completion rate of planned chemotherapy was 49.9% (95% CI 34.1-63.9%). CONCLUSIONS: The elderly patients were not likely to choose to receive postoperative adjuvant chemotherapy; however, no significant adverse effect on postoperative KPS was identified. TRIAL REGISTRATION: Clinical Trial Registration ID: UMIN000020736.

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).

Randomized Phase III Study of Gefitinib Versus Cisplatin Plus Vinorelbine for Patients With Resected Stage II-IIIA Non-Small-Cell Lung Cancer With EGFR Mutation (IMPACT).

PURPOSE: To investigate the efficacy of gefitinib as an adjuvant therapy for non-small-cell lung cancer patients with EGFR mutation. PATIENTS AND METHODS: IMPACT (WJOG6410L; University Hospital Medical Information Network Clinical Trials Registry: UMIN000006252), a randomized, open-label, phase III study, included patients with completely resected pathologic stage II-III non-small-cell lung cancer harboring EGFR mutations (exon 19 deletion or L858R) during September 2011 to December 2015. Patients were randomly assigned to receive gefitinib (250 mg once daily) for 24 months or cisplatin (80 mg/m2 on day 1) plus vinorelbine (25 mg/m2 on days 1 and 8; cis/vin) once every 3 weeks for four cycles. The primary end point was disease-free survival (DFS). RESULTS: Overall, 234 patients were randomly assigned. Among 232 eligible patients (116 each; excluding two who withdrew consent), the median DFS was 35.9 and 25.1 months in the gefitinib and cis/vin groups, respectively. However, Kaplan-Meier curves crossed around 4 years after surgery with no statistically significant difference (stratified log-rank P = .63; hazard ratio by stratified Cox proportional hazards model = 0.92; 95% CI, 0.67 to 1.28). Overall survival (OS) was also not different (stratified log-rank P = .89; hazard ratio = 1.03; 95% CI, 0.65 to 1.65), with the 5-year OS rates being 78.0% and 74.6% in the gefitinib and cis/vin groups, respectively. Treatment-related deaths occurred in 0 and three patients in the gefitinib and cis/vin groups, respectively. CONCLUSION: Although adjuvant gefitinib appeared to prevent early relapse, it did not prolong DFS or OS. However, similar DFS and OS may justify adjuvant gefitinib in the selected patient subsets, especially those deemed ineligible for platinum-doublet adjuvant therapy; however, this was not a noninferiority trial.

Clinical significance of part-solid lung cancer in the eighth edition TNM staging system.

OBJECTIVES: The ground-glass component of part-solid tumour (PST) was eliminated as a clinical T (cT) descriptor in the eighth edition of the tumour, node and metastasis (TNM) staging system. We aimed to validate the new cT descriptor and investigate the prognostic impact of PST in the new staging system. METHODS: Non-small-cell lung cancer (NSCLC) patients (n = 1061) who underwent lung resection and were available for the assessment of thin-section computed tomography images were retrospectively reviewed. Tumours with a solid component (SC) size-to-whole tumour size (STR) ratio of 0, those with 0 < STR < 1 and those with an STR of 1 were defined as pure ground-glass tumours, PSTs and solid tumours (STs), respectively. RESULTS: Tumours with an SC diameter of >30 mm were less frequently observed among PSTs than among STs (4.83% vs 32.6%, P < 0.001). The postoperative 5-year survival of NSCLC patients with ground-glass tumour, PST and ST was 97.6%, 89.0% and 76.3%, respectively. In the survival analysis of patients with an SC diameter ≤30 mm, significant differences were observed among PST and ST (5-year survival, 90.7% vs 74.6%, P < 0.001). The multivariable analysis showed that age <70 years old, female sex, procedures with a lobectomy or more, SC size, pN0 disease and PST were independent predictors of a better survival among all PST and ST patients. CONCLUSIONS: Among patients with cT1 tumours, those with PST showed a significantly better survival than did those with ST. Small-sized PST tumours may not be suitable for the new cT descriptor.

High Incidence of C797S Mutation in Patients With Long Treatment History of EGFR Tyrosine Kinase Inhibitors Including Osimertinib.

INTRODUCTION: Although treatment with osimertinib confers survival benefits in patients with lung cancer with the EGFR T790M mutation, the mechanism of acquired resistance to osimertinib remains poorly understood. We conducted a prospective observational study to identify the mechanism on the basis of repeated tissue biopsies. METHODS: Patients with EGFR-mutated advanced lung cancer with a T790M mutation detected on a tissue biopsy underwent a rebiopsy after developing acquired resistance to osimertinib. Nucleic acids extracted from the biopsy samples were subjected to targeted resequencing (Oncomine Comprehensive Assay), and circulating cell-free DNA (ccfDNA) was analyzed by CAncer Personalized Profiling by deep Sequencing (AVENIO ctDNA Surveillance Kit). RESULTS: Between November 2016 and March 2020, a total of 87 patients were screened. Among them, 44 developed acquired resistance. Of these, 19 samples from rebiopsies and 12 from preosimertinib biopsies were able to be analyzed by an Oncomine Comprehensive Assay. A ccfDNA analysis was performed in 16 patients. Regarding the mechanisms of acquired resistance, structural change in EGFR, namely, C797S, G796S, or L792V, was the most frequent alteration, being observed in 57.9% of the cases. MET gain was observed in 31.6% of the cases, and gains in cell cycle genes were observed in 26.3% of the cases. In addition, we identified GAS6 gain and an ATM mutation in a patient with small-cell transformation and a BRAF V600E mutation in a patient with oligoprogressive disease. CONCLUSIONS: A repeated tissue biopsy and a ccfDNA analysis were useful in analyzing the mechanisms underlying acquired resistance. A long treatment history of EGFR TKIs may result in a high percentage of EGFR structural change.

A Phase II Study of Osimertinib for Radiotherapy-Naive Central Nervous System Metastasis From NSCLC: Results for the T790M Cohort of the OCEAN Study (LOGIK1603/WJOG9116L).

OBJECTIVES: Osimertinib has been reported to be effective against central nervous system (CNS) metastasis from activating EGFR mutation-positive NSCLC. Nevertheless, the true antitumor effects of osimertinib alone for CNS metastasis are unclear because the aforementioned studies included previously irradiated cases, in which tumor shrinkage can occur later owing to the effects of radiotherapy (RT). This study aimed to evaluate the efficacy of osimertinib against RT-naive CNS metastasis from sensitizing EGFR mutation-positive NSCLC. METHODS: The OCEAN study was a two-cohort trial, involving 66 patients (T790M cohort [n = 40] and first-line cohort [n = 26]) with RT-naive CNS metastasis from sensitizing EGFR mutation-positive NSCLC. The patients were treated once daily with 80 mg osimertinib. The primary end point was brain metastasis response rate (BMRR) according to the PAREXEL criteria. In this report, we present the results for the T790M cohort with analysis of drug concentrations and plasma circulating tumor DNA. RESULTS: The median age of the patients was 69 years, and 30% of them were males. Eight patients (20%) were symptomatic, and most had multiple CNS metastases (78%). Among the eligible 39 patients, the BMRR (PAREXEL criteria), median brain metastasis-related progression-free survival (PFS), median overall survival, overall response rate, and median PFS were 66.7% (90% confidence interval: 54.3%-79.1%), 25.2 months, 19.8 months, 40.5%, and 7.1 months, respectively. The BMRR according to the Response Evaluation Criteria in Solid Tumors criteria was 70.0% (n = 20). The brain metastasis-related PFS of patients with EGFR exon 19 deletion was significantly longer than that of exon 21 L858R (median = 31.8 versus 8.3 mo; log-rank p = 0.032). The treatment-related pneumonitis was observed in four patients (10%). On or after day 22, the median trough blood and cerebrospinal fluid concentrations of osimertinib were 568 nM and 4.10 nM, respectively, and those of its metabolite AZ5104 were 68.0 nM and 0.260 nM, respectively. The median blood to cerebrospinal fluid penetration rates of osimertinib and AZ5104 were 0.79% and 0.53%, respectively. The blood trough concentration at day 22 was not correlated with the efficacy of osimertinib against CNS metastasis. Plasma T790M and C797S mutations were detected in 83% and 3% of the patients before treatment, 11% and 3% of the patients on day 22, and 39% and 22% of the patients at the detection of progressive disease, respectively. CONCLUSIONS: This study evaluated the efficacy of osimertinib against RT-naive CNS metastasis from T790M-positive NSCLC. The primary end point was met, and the results revealed the efficacy of osimertinib in patients with CNS metastasis harboring EGFR T790M mutations especially for EGFR-sensitizing mutation of exon 19 deletion.