Neoadjuvant nivolumab plus chemotherapy in resectable non-small-cell lung cancer in Japanese patients from CheckMate 816.

In the open-label, phase III CheckMate 816 study (NCT02998528), neoadjuvant nivolumab plus chemotherapy demonstrated statistically significant improvements in event-free survival (EFS) and pathological complete response (pCR) versus chemotherapy alone in patients with resectable non-small-cell lung cancer (NSCLC). Here we report efficacy and safety outcomes in the Japanese subpopulation. Patients with stage IB-IIIA, resectable NSCLC were randomized 1:1 to nivolumab plus chemotherapy or chemotherapy alone for three cycles before undergoing definitive surgery within 6 weeks of completing neoadjuvant treatment. The primary end-points (EFS and pCR) and safety were assessed in patients enrolled at 16 centers in Japan. Of the Japanese patients randomized, 93.9% (31/33) in the nivolumab plus chemotherapy arm and 82.9% (29/35) in the chemotherapy arm underwent surgery. At 21.5 months' minimum follow-up, median EFS was 30.6 months (95% confidence interval [CI], 16.8-not reached [NR]) with nivolumab plus chemotherapy versus 19.6 months (95% CI, 8.5-NR) with chemotherapy; hazard ratio, 0.60 (95% CI, 0.30-1.24). The pCR rate was 30.3% (95% CI, 15.6-48.7) versus 5.7% (95% CI, 0.7-19.2), respectively; odds ratio, 7.17 (95% CI, 1.44-35.85). Grade 3/4 treatment-related adverse events were reported in 59.4% versus 42.9% of patients, respectively, with no new safety signals identified. Neoadjuvant nivolumab plus chemotherapy resulted in longer EFS and a higher pCR rate versus chemotherapy alone in Japanese patients, consistent with findings in the global population. These data support nivolumab plus chemotherapy as a neoadjuvant treatment option in Japanese patients with resectable NSCLC.

Lymphangioleiomyomatosis as a potent lung cancer risk factor: Insights from a Japanese large cohort study.

BACKGROUND AND OBJECTIVE: Lymphangioleiomyomatosis (LAM) is a rare neoplastic disease associated with the functional tumour suppressor genes TSC1 and TSC2 and causes structural destruction in the lungs, which could potentially increase the risk of lung cancer. However, this relationship remains unclear because of the rarity of the disease. METHODS: We investigated the relative risk of developing lung cancer among patients diagnosed with LAM between 2001 and 2022 at a single high-volume centre in Japan, using data from the Japanese Cancer Registry as the reference population. Next-generation sequencing (NGS) was performed in cases where tumour samples were available. RESULTS: Among 642 patients diagnosed with LAM (sporadic LAM, n = 557; tuberous sclerosis complex-LAM, n = 80; unclassified, n = 5), 13 (2.2%) were diagnosed with lung cancer during a median follow-up period of 5.13 years. All patients were female, 61.5% were never smokers, and the median age at lung cancer diagnosis was 53 years. Eight patients developed lung cancer after LAM diagnosis. The estimated incidence of lung cancer was 301.4 cases per 100,000 person-years, and the standardized incidence ratio was 13.6 (95% confidence interval, 6.2-21.0; p = 0.0008). Actionable genetic alterations were identified in 38.5% of the patients (EGFR: 3, ALK: 1 and ERBB2: 1). No findings suggested loss of TSC gene function in the two patients analysed by NGS. CONCLUSION: Our study revealed that patients diagnosed with LAM had a significantly increased risk of lung cancer. Further research is warranted to clarify the carcinogenesis of lung cancer in patients with LAM.

Postoperative management using a digital drainage system for massive air leakage after pulmonary resection.

PURPOSE: To elucidate clinical outcomes using a digital drainage system (DDS) for massive air leakage (MAL) after pulmonary resection. METHODS: A total of 135 consecutive patients with pulmonary resection air leakage of > 100 ml/min on the DDS were evaluated retrospectively. In this study, MAL was defined as ≥ 1000 ml/min on the DDS. We analyzed the clinical characteristics and surgical outcomes of patients with MAL compared with non-MAL (101-999 ml/min). Using the DDS data, the duration of the air leak was plotted with the Kaplan‒Meier method and compared using the log-rank test. RESULTS: MAL was detected in 19 (14%) patients. The proportions of heavy smokers (P = 0.04) and patients with emphysematous lung (P = 0.03) and interstitial lung disease (P < 0.01) were higher in the MAL group than in the non-MAL group. The MAL group had a higher persistence rate of air leakage at 120 h after surgery than the non-MAL group (P < 0.01) and required significantly more frequent pleurodesis (P < 0.01). Drainage failure occurred in 2 (11%) and 5 (4%) patients from the MAL and non-MAL groups, respectively. Neither reoperation nor 30-day surgical mortality was observed in patients with MAL. CONCLUSIONS: MAL was able to be treated conservatively without surgery using the DDS.

Salvage extended surgery after immune-checkpoint inhibitor treatment for advanced non-small cell lung cancer.

PURPOSE: We evaluated the surgical outcomes of salvage extended surgery after definitive medical treatment with an immune-checkpoint inhibitor (ICI) for locally advanced or unresectable non-small-cell lung cancer (NSCLC). METHODS: The subjects of this single-center retrospective analysis were 14 patients who underwent salvage surgery after ICI treatment between May, 2017 and April, 2023 at our institute. We reviewed the comprehensive surgical outcomes, including operative procedures, intraoperative findings, and postoperative morbidities. Overall survival (OS) was calculated using a Kaplan-Meier estimation. RESULTS: The initial clinical stage before medical treatment (c-stage) was stage III in eight patients, stage IV in five patients, and one patient had postoperative lung cancer recurrence. The indications for surgery were as follows: local control for relapse or residual tumor in ten patients and discontinuation of systemic therapy because of treatment-related complications in four patients. The surgical modes were segmentectomy (n = 1), lobectomy (n = 4), bilobectomy (n = 3), pneumonectomy (n = 6), and bronchoplasty (n = 7). Grade 3 or higher postoperative morbidities were observed in six patients, including only one case of 90-day mortality. CONCLUSIONS: Our series demonstrated that the surgical outcome of salvage extended surgery after ICI therapy may be positive with careful selection of the procedure and indication.

Comprehensive clinicopathological characteristics and mucin core protein expression profiles of bronchiolar adenoma.

AIMS: Bronchiolar adenoma (BA) is a novel entity in the 2021 WHO classification of lung tumours. The expression profile of mucin core proteins in BAs is not clear. The aim of this study was to clarify the expression profiles of mucins and to validate the clinicopathologic and molecular features of BAs. METHODS AND RESULTS: We examined the clinicopathological, immunohistochemical, and molecular features of 20 BAs. Our cohort comprised 10 proximal and 10 distal BAs. Only seven of 18 patients (39%) were accurately diagnosed with BA at the time of intraoperative consultation. The frequent genetic alterations were BRAF V600E (35%) and KRAS (30%) mutations, which were mutually exclusive. The expression of MUC1, MUC4, and MUC5B was observed in all cases and that of MUC5AC and MUC6 was observed in nine (45%) and five (25%) cases, respectively. MUC4 was diffusely expressed in 18 cases. In contrast, MUC1, MUC5AC, MUC5B, and MUC6 displayed a patchy expression pattern. These expression patterns were similar to that of bronchiolar epithelium in normal lung tissue. In addition, overexpression of MUC1 and MUC4 on the entire cell surface was not observed in any of the BAs, suggesting their benign nature. CONCLUSION: BA commonly exhibits diffuse MUC4 and patchy MUC1 and MUC5B expression. Its unique expression pattern is probably attributed to mucin expression specific to the bronchiolar epithelium. These results confirm the clinicopathologic and molecular characteristics of BA, including the difficulty in intraoperative frozen section diagnosis and the broad morphologic spectrum of BA derived from the bronchiolar epithelium.

Expression of paired box 9 defines an aggressive subset of lung adenocarcinoma preferentially occurring in smokers.

AIMS: A distinct subset of lung adenocarcinomas (LADs), arising from a series of peripheral lung cells defined as the terminal respiratory unit (TRU), is characterised by thyroid transcription factor 1 (TTF-1) expression. The clinical relevance of transcription factors (TFs) other than TTF-1 remains unknown in LAD and was explored in the present study. METHODS AND RESULTS: Seventy-one LAD samples were subjected to high-throughput transcriptome screening of LAD using cap analysis gene expression (CAGE) sequencing data; CAGE provides genome-wide expression levels of the transcription start sites (TSSs). In total, 1083 invasive LAD samples were subjected to immunohistochemical examination for paired box 9 (PAX9) and TTF-1 expression levels. PAX9 is an endoderm development-associated TF that most strongly and inversely correlates with the expression of TTF-1 TSS subsets. Immunohistochemically, PAX9 expression was restricted to the nuclei of ciliated epithelial and basal cells in the bronchi and bronchioles and the nuclei of epithelial cells of the bronchial glands; moreover, PAX9 expression was observed in 304 LADs (28%). PAX9-positive LADs were significantly associated with heavy smoking, non-lepidic subtype, EGFR wild-type tumours and PD-L1 expression (all P < 0.0001). All these characteristics were opposite to those of TRU-type LADs with TTF-1 expression. PAX9 expression was an independent prognostic factor for decreased overall survival (P = 0.022). CONCLUSIONS: Our results revealed that PAX9 expression defines an aggressive subset of LADs preferentially occurring in smokers that may arise from bronchial or bronchiolar cells.

Comparison of ASCL1, NEUROD1, and POU2F3 expression in surgically resected specimens, paired tissue microarrays, and lymph node metastases in small cell lung carcinoma.

Subtypes of small cell lung carcinoma (SCLC) are defined by the expression of ASCL1, NEUROD1, and POU2F3 markers. The aim of our study was to explore the extent to which the intratumoral heterogeneity of ASCL1, NEUROD1, and POU2F3 may lead to discrepancies in expression of these markers in surgical samples and their matched tissue microarray (TMA) and lymph node (LN) metastatic sites. METHODS AND RESULTS: The cohort included 77 patients with SCLC. Immunohistochemical examinations were performed on whole slides of the primary tumour, paired TMAs, and metastatic LN sites. Samples with H-scores >50 were considered positive. Based on the ASCL1, NEUROD1, and POU2F3 staining pattern, we grouped the tumours as follows: ASCL1-dominant (SCLC-A), NEUROD1-dominant (SCLC-N), ASCL1/NEUROD1 double-negative with POU2F3 expression (SCLC-P), and negative for all three markers (SCLC-I). In whole slides, 40 SCLC-A (52%), 20 SCLC-N (26%), 15 SCLC-P (20%), and two SCLC-I (3%) tumours were identified. Comparisons of TMAs or LN metastatic sites and corresponding surgical specimens showed that positivity for ASCL1, NEUROD1, and POU2F3 in TMAs (all P < 0.0001) or LN metastatic sites (ASCL1, P = 0.0047; NEUROD1, P = 0.0069; POU2F3, P < 0.0001) correlated significantly with that of corresponding surgical specimens. CONCLUSION: The positivity for these markers in TMAs and LN metastatic sites was significantly correlated with that of corresponding surgical specimens, indicating that biopsy specimens could be used to identify molecular subtypes of SCLC in patients.

Efficacy of Adjuvant Chemotherapy for Stage II/III Nonsmall Cell Lung Cancer with Epidermal Growth Factor Receptor Mutations.

BACKGROUND: Adjuvant cisplatin-based chemotherapy improves the survival of patients with resected pathological stage II/III nonsmall cell lung cancer (NSCLC). However, the efficacy in patients with epidermal growth factor receptor (EGFR) mutations remains controversial. METHODS: This retrospective study included 353 patients with resected pathological N1/N2 stage II/III NSCLC between 2010 and 2016. Mutant EGFR (mEGFR) was detected in 76 patients. Adjuvant chemotherapy (AC) was administered to 151 patients. We compared cancer-specific survival (CSS) and recurrence-free survival (RFS) between AC and surgery-alone (SA) groups, including patients with wild-type EGFR (wEGFR) and mEGFR. Using multivariate analysis, we evaluated the prognostic factors in patients with wEGFR and mEGFR. RESULTS: The median follow-up time was 4.7 years. In patients with wEGFR, the differences in CSS and RFS between the AC (n = 114) and SA (n = 163) groups were significant (CSS: 66.8% [5 years] vs. 49.4% [5 years], p = 0.001; RFS: 54.2% [5 years] vs. 39.2% [5 years], p = 0.013). The significant prognostic factors were AC (vs. SA; p < 0.0001), diffusing capacity of the lung for carbon monoxide > 60% (p = 0.028), tumor size (p < 0.001), lymphatic permeation (p = 0.041), and pN1 (vs. pN2; p < 0.001). However, the differences in CSS and RFS between the AC (n = 37) and SA (n = 39) groups were not significant (CSS: 64.0% [5 years] vs. 58.1% [5 years], p = 0.065; RFS: 45.0% [5 years] vs. 33.8% [5 years], p = 0.302). Multivariate analysis identified no significant prognostic factors in patients with mEGFR. CONCLUSION: We demonstrated the efficacy of AC in patients with mEGFR and wEGFR. The efficacy of AC may be lower in patients with mEGFR than in those with wEGFR.

The balance between lung regulatory T cells and Th17 cells is a risk indicator for the acute exacerbation of interstitial lung disease after surgery: a case-control study.

BACKGROUND: Acute exacerbation (AE) of interstitial lung disease (ILD) (AE-ILD) is a life-threatening condition and the leading cause of 30-day mortality among patients who underwent pulmonary resection for lung cancer in Japan. This study was conducted to clarify the characteristics of the immune environment of lung tissues before the onset of AE-ILD. METHODS: This retrospective matched case-control study compared the immune phenotypes of helper T cells in lung tissues from patients with and without AE-ILD after surgery. In total, 135 patients who underwent surgical resection for lung cancer and were pathologically diagnosed with idiopathic interstitial pneumonia (IIP) at our institute between 2009 and 2018 were enrolled. Thirteen patients with AE-IIP and 122 patients without AE (non-AE) were matched using a propensity score analysis, and 12 cases in each group were compared. We evaluated the percentages of T helper (Th)1, Th2, Th17, regulatory T (Treg), and CD8 cells in CD3+ T cells and the Th1:Th2, Th17:Treg, and CD8:Treg ratios in patients with AE by immunostaining of lung tissues in the non-tumor area. RESULTS: We found a significant difference in the lung Th17:Treg ratio between the AE and non-AE groups (1.47 and 0.79, p = 0.041). However, we detected no significant differences in the percentages of lung Th1 (21.3% and 29.0%), Th2 (34.2% and 42.7%), Th17 (22.3% and 21.6%), Treg (19.6% and 29.1%), and CD8+ T cells (47.2% and 42.2%) of CD3+ T cells between the AE and non-AE groups. CONCLUSION: The ratio of Th17:Treg cells in lung tissues was higher in participants in the AE group than in those in the non-AE group. CLINICAL TRIAL REGISTRATION: This study was approved by the ethics committee of our institute (2,016,095).

Risk factors for bronchopleural fistula based on surgical procedure and sex in 4794 consecutive patients undergoing anatomical pulmonary resection.

PURPOSE: Bronchopleural fistula (BPF) is a lethal complication, even in the modern era. Therefore, we investigated the details of patients with BPF to select an appropriate surgical strategy. METHODS: This retrospective study included 4794 consecutive patients who underwent anatomical pulmonary resection between 2008 and 2022. We evaluated the predictors of BPF using a multivariable analysis and investigated the mortality and clinical course after BPF in detail. RESULTS: BPF was observed in 32 patients (0.67%). In the multivariable analysis, the predictors for BPF were male sex (odds ratio [OR], 6.91), the body mass index (OR, 2.40), the vital capacity (%VC) (OR, 2.93), surgery performed (right lower lobectomy [OR, 10.92], right middle and lower lobectomy [OR, 6.97], and right pneumonectomy [OR, 16.68]), and additional resection of surrounding organs (OR, 3.47). Among the risk factors, surgery performed and male sex were very strong risk factors, with the frequency itself very low in females (0.1%). The 90-day mortality was 15.6%, and the 5-year overall survival in patients with BPF was 28.1%. CONCLUSION: Our study revealed that independent risk factors and consideration of the surgical methods and sex might help determine whether or not special attention should be given to the bronchial stump, which will be of great help in surgical strategies.

Predictive factors inhibiting recovery of the respiratory function after anatomical pulmonary resection.

PURPOSE: Some patients have worse actual observed postoperative (apo) respiratory function values than predicted postoperative (ppo) values. The present study therefore clarified the predictive factors that hinder the recovery of the postoperative respiratory function. METHODS: This study enrolled 255 patients who underwent anatomical pulmonary resection for lung cancer. A pulmonary function test (PFT) was carried out before surgery and at one, three, and six months after surgery. In each surgical procedures, the forced expiratory volume in 1 s (FEV1) ratio was calculated as the apo value divided by the ppo value. In addition, we investigated the predictive factors that inhibited postoperative respiratory function improvement in patients with an FEV1 ratio < 1.0 at 6 months after surgery. RESULTS: The FEV1 ratio gradually improved over time in all surgical procedures. However, 49 of 196 patients who underwent a PFT at 6 months after surgery had an FEV1 ratio < 1.0. In a multivariate analysis, right side, upper lobe, segmentectomy and pleurodesis for prolonged air leakage were independent significant predictors of a decreased FEV1 ratio (p = 0.003, 0.006, 0.001, and 0.009, respectively). CONCLUSION: Pleurodesis was the only controllable factor that might help preserve the postoperative respiratory function. Thus, the intraoperative management of air leakage is important.

S-1 + Cisplatin with Concurrent Radiotherapy Followed by Surgery for Stage IIIA (N2) Lung Squamous Cell Carcinoma: Results of a Phase II Trial.

BACKGROUND: To date, no clinical trials on the use of induction therapy before surgery have focused solely on lung squamous cell carcinoma (LSCC). We report the results of the Personalized Induction Therapy-2 (PIT-2) trial, a multicenter phase II study, performed to investigate the efficacy and safety of S-1 + cisplatin with concurrent thoracic radiotherapy (TRT) followed by surgery in patients with stage IIIA (N2) LSCC. METHODS: Patients with pathologically proven stage IIIA (N2) LSCC received induction therapy comprising three cycles of S-1 + cisplatin with concurrent TRT (45 Gy in 25 fractions) followed by surgery. S-1 was administered orally at a dose of 40 mg/m2 twice daily on days 1-14, in addition to intravenous infusion of cisplatin (60 mg/m2) on day 1. The primary endpoint was 2-year progression-free survival (PFS) rate. RESULTS: Of 45 registered patients, 43 underwent induction therapy. Of the 43 patients, 39 (91%) underwent surgery (35 lobectomies, 3 pneumonectomies, and 1 wedge resection). The 2-year PFS, 2-year overall survival, objective response rate, and pathological complete response rates were 67% (90% confidence interval [CI] 54-78%), 70% (95% CI 53-81%), 86% (95% CI 76-96%), and 39% (95% CI 23-54%), respectively. No new treatment-related adverse events occurred during the induction therapy. One case of 90-day postoperative mortality involving a patient who underwent right pneumonectomy and developed pneumonia after discharge occurred. CONCLUSIONS: Induction therapy using S-1 + cisplatin with concurrent TRT followed by surgery is a feasible and promising treatment approach for stage IIIA (N2) LSCC.

Outcomes of lung cancer surgery for patients with interstitial pneumonia and coronary disease.

PURPOSE: To evaluate the surgical outcomes of lung cancer patients with idiopathic interstitial pneumonia (IIP) and/or coronary artery disease (CAD). METHODS: The subjects of this retrospective study were 2830 patients who underwent surgical resection for lung cancer between 2009 and 2018. Seventy-one patients (2.6%) had both IIP and CAD (FC group). The remaining patients were divided into those with IIP only (group F), those with CAD only (group C), and those without IIP or CAD (group N). We compared mortality and overall survival (OS) among the groups. RESULTS: The 90-day mortality and OS were poorer in group FC than in groups C and N, but equivalent to those in group F. Multivariate analyses revealed that IIP (odds ratio [OR] 3.163; p = 0.001) and emphysema (2.588; p = 0.009) were predictors of 90-day mortality. IIP (OR 2.991, p < 0.001), diabetes (OR 1.241, p = 0.043), and a history of other cancers (OR 1.347, p = 0.011) were all predictors of OS. CONCLUSIONS: Short-term and long-term mortality after lung cancer surgery were not dependent on coexistent CAD but were related to IIP. Thus, computed tomography (CT) should be done preoperatively to check for IIP, which is a risk factor for surgical mortality.

Development of an optimal protocol for molecular profiling of tumor cells in pleural effusions at single-cell level.

Liquid biopsy analyzes the current status of primary tumors and their metastatic regions. We aimed to develop an optimized protocol for single-cell sequencing of floating tumor cells (FTCs) in pleural effusion as a laboratory test. FTCs were enriched using a negative selection of white blood cells by a magnetic-activated cell sorting system, and CD45-negative and cytokeratin-positive selection using a microfluidic cell separation system with a dielectrophoretic array. The enriched tumor cells were subjected to whole-genome amplification (WGA) followed by genome sequencing. The FTC analysis detected an EGFR exon 19 deletion in Case 1 (12/19 cells, 63.2%), and EML4-ALK fusion (17/20 cells, 85%) with an alectinib-resistant mutation of ALK (p.G1202R) in Case 2. To eliminate WGA-associated errors and increase the uniformity of the WGA product, the protocol was revised to sequence multiple single FTCs individually. An analytical pipeline, accurate single-cell mutation detector (ASMD), was developed to identify somatic mutations of FTCs. The large numbers of WGA-associated errors were cleaned up, and the somatic mutations detected in FTCs by ASMD were concordant with those found in tissue specimens. This protocol is applicable to circulating tumor cells analysis of peripheral blood and expands the possibility of utilizing molecular profiling of cancers.

Diffuse expression of MUC6 defines a distinct clinicopathological subset of pulmonary invasive mucinous adenocarcinoma.

Invasive mucinous adenocarcinoma (IMA) of the lung is a unique variant of lung adenocarcinoma. Aberrant mucin expression is associated with cancer development and metastasis. However, the clinicopathological significance of mucin expression in IMA is not fully understood. Herein, we evaluated the clinicopathological, immunohistochemical, and molecular characteristics of 70 IMA tumors. EGFR, KRAS, GNAS, and TP53 mutations were assessed by PCR-based sequencing. Next-generation sequencing was used to assess cases without EGFR/KRAS mutations. A NanoString-based screening for fusions was performed in all IMAs without mitogenic driver mutations. Expression of mucins (MUC1, MUC2, MUC4, MUC5AC, and MUC6) was evaluated by immunohistochemistry and categorized as follows: negative (<10% of tumor cells), patchy expression (<90% of tumor cells), or diffuse expression (≥90% of tumor cells). Immunohistochemical testing for transcription factors (TTF-1, CDX2, HNF1ß, HNF3α, HNF3ß, and HNF4α) was also performed. As expected, KRAS mutations were the most common (in 67% of cases), followed by small numbers of other alterations. Patchy or diffuse expression of MUC1, MUC2, MUC4, MUC5AC, and MUC6 was observed in 52% or 6%, 3% or 0%, 30% or 3%, 26% or 73%, and 59% or 27% of cases, respectively. Furthermore, all IMAs were generally positive for HNF1ß (100%), HNF3α (100%), HNF3ß (100%), and HNF4α (99%) but were positive less often for TTF-1 (6%) and CDX2 (9%). Overall, there was no significant correlation between mucin expression and transcription factor expression. Unexpectedly, diffuse expression of MUC6 was significantly associated with KRAS-wild-type tumors (p = 0.0008), smaller tumor size (p = 0.0073), and tumors in female patients (p = 0.0359) in multivariate analyses. Furthermore, patients with tumors exhibiting diffuse MUC6 expression had significantly favorable outcomes. Notably, none of these patients died of the disease. Our data suggested that diffuse expression of MUC6 defines a distinct clinicopathological subset of IMA characterized by wild-type KRAS and possibly less aggressive clinical course.

Histological characteristics of lung adenocarcinoma with uncommon actionable alterations: special emphasis on MET exon 14 skipping alterations.

AIMS: In the evolving era of precision medicine, increasing emphasis is placed on detecting molecular alterations driving the development of specific cancers and targeting them with matched therapies that can yield the best outcomes for patients. Lung adenocarcinomas with uncommon actionable alterations, including MET exon 14 skipping (METex14), ERBB2 and BRAF mutations, are rare and poorly characterised cancers. METHODS AND RESULTS: To more clearly understand the histopathological features of lung adenocarcinoma with uncommon actionable alterations, we compared the histological features of 678 cases with mitogenic driver alterations from 996 surgically resected lung adenocarcinomas. Genomic data from our cohort revealed METex14, ERBB2 and BRAF mutations in 13, 16 and 15 cases, respectively. Patients who had lung adenocarcinoma with METex14 were often elderly females. Histological features such as clear cell features (23%), hyaline globules (31%) and nuclear pleomorphism (39%) were the most frequently identified in METex14-positive cases; among those, three cases (23%) had tumour cells with bizarre giant or multilobulated nuclei. Additionally, the micropapillary pattern was the most frequently identified in ERBB2-mutated lung adenocarcinoma (31%). Lung adenocarcinoma with BRAF mutations tended to be less invasive, and the BRAF V600E mutation was identified in only one case with lepidic adenocarcinoma. Immunohistochemically, all METex14, ERBB2 and BRAF-positive tumours, except for invasive mucinous adenocarcinoma, were positive for thyroid transcription factor 1 (TTF-1). CONCLUSIONS: Our data from Japanese patients showed that lung adenocarcinoma with METex14 had unique clinicopathological characteristics: tumour cells with marked nuclear pleomorphism, hyaline globules and expression of TTF-1 in elderly women who never or lightly smoked.

Surgical challenges in multimodal treatment of N2-stage IIIA non-small cell lung cancer.

Locally advanced non-small cell lung cancer, especially mediastinal lymph node metastasis-positive stage IIIA-N2 cancer, is a heterogeneous disease state characterized by anatomically locally advanced disease with latent micrometastases. Thus, surgical resection or radiotherapy alone has historically failed to cure this disease. During the last three decades, persistent efforts have been made to develop a suitable treatment modality to overcome these problems using chemotherapy and/or radiotherapy with surgical resection. However, the role of surgical resection remains unclear, and the standard treatment for stage IIIA-N2 disease is concurrent chemoradiotherapy. In general, adjuvant chemotherapy is indicated for completely resected pathological stage IB disease or lymph node metastasis-positive pathological stage II or IIIA disease. Platinum-based doublet cytotoxic chemotherapy is currently the standard regimen. Additionally, post-operative radiotherapy might be indicated for post-operatively proven mediastinal lymph node metastasis; i.e. clinical N0-1 and pathological N2 disease. With the remarkable progression that has recently been made in the field of chemotherapy, such as advances in molecular targeting agents and immune checkpoint inhibitors, the basic policy of chemotherapy has been shifting to personalized treatment based on the individual patient's oncogene driver mutation status, immune status and other parameters. The same trend is being seen in the treatment of stage IIIA-N2 disease. We should consider the past and upcoming results of several clinical trials to optimize the coming era of personalized treatment.

Recent advances and future perspectives in adjuvant and neoadjuvant immunotherapies for lung cancer.

The superior efficacy of immune checkpoint inhibitors for the treatment of advanced non-small cell lung cancer has inspired many clinical trials to use immune checkpoint inhibitors in earlier stages of lung cancer worldwide. Based on the theoretical feasibility that neoantigens derived from a tumor tissue are present in vivo, some clinical trials have recently evaluated the neoadjuvant, rather than the adjuvant, use of immune checkpoint inhibitors. Some of these trials have already produced evidence on the safety and efficacy of immune checkpoint inhibitors in a neoadjuvant setting, with a favorable major pathologic response and few adverse events. In the most impactful report from Johns Hopkins University and the Memorial Sloan Kettering Cancer Center, the programed death-1 inhibitor nivolumab was administered to 21 patients in a neoadjuvant setting. The authors reported a major pathologic response rate of 45%, with no unexpected delay of surgery related to the adverse effects of nivolumab. The adjuvant as well as the neoadjuvant administration of immune checkpoint inhibitors has also been considered in various clinical trials, with or without the combined use of chemotherapy or radiotherapy. The development of appropriate biomarkers to predict the efficacy of immune checkpoint inhibitors is also underway. The expression of programed death ligand-1 and the tumor mutation burden are promising biomarkers that have been evaluated in many settings. To establish an appropriate method for using immune checkpoint inhibitors in combination with surgery, the Lung Cancer Surgical Study Group of the Japan Clinical Oncology Group will manage clinical trials using a multimodality treatment, including immune checkpoint inhibitors and surgery.

Evaluation of solid portions in non-small cell lung cancer-the solid part is not always measurable for clinical T factor.

BACKGROUND: Solid component size on thin-section computed tomography is used for T-staging according to the eighth edition of the Tumor Node Metastasis classification of lung cancer. However, the feasibility of using the solid component to measure clinical T-factor remains controversial. METHODS: We evaluated the feasibility of measuring the solid component in 859 tumours, which were suspected cases of primary lung cancers, requiring surgical resection regardless of the procedure or clinical stage. After excluding 126 pure ground-glass opacity tumours and 450 solid tumours, 283 part-solid tumours were analysed to determine the frequency of cases where the measurement of the solid portion was difficult along with the associated cause. Pathological invasiveness was also evaluated. RESULTS: The solid portion of 10 lesions in 283 part-solid nodules was difficult to measure due to an underlying lung disease (emphysema and pneumonitis). The solid portion of 62 lesions (21.9%) without emphysema and pneumonitis was difficult to measure due to imaging features of the tumours. Among the 62 patients, five had no malignancy and one with a tumour size of 33 mm had nodal metastasis. There were 56 lesions with a tumour size of ≤30 mm, wherein nodal metastases, vascular and/or lymphatic invasions were not observed. CONCLUSION: For one-fifth of the part-solid tumours, measurement of the solid component was difficult. Moreover, these lesions had low invasiveness, especially in T1. The measurement of the solid portion and the classification of T1 in 1-cm increments may be complex.

Molecular and clinicopathological features of colorectal adenocarcinoma with enteroblastic differentiation.

BACKGROUND: Colorectal adenocarcinoma with enteroblastic differentiation (CAED) is a rare subtype of colorectal malignancy with expression of enteroblastic markers (glypican 3, SALL4, AFP); however, the clinicopathological and epidemiological features are not fully elucidated. AIMS: The aims of this study were to elucidate and establish the molecular and clinicopathological characteristics of CAED. MATERIALS AND METHODS: In addition to three cases recently diagnosed as CAED, colorectal carcinoma (CRC) with expression of enteroblastic markers were selected by using immunohistochemistry (IHC) on tissue microarrays of 988 advanced CRC. We employed next-generation sequencing (NGS) and Sanger sequencing for the detection of genetic alterations. IHC for p53 and HER2, HER2-FISH and MSI status was also investigated. Survival analyses for clinicopathological parameters were performed using Kaplan-Meier methods. RESULTS: Thirty-nine cases (4.0%) were positive for at least one enteroblastic marker. Histological evaluation of the total of 42 cases revealed that 10 contained tumour cells with clear cytoplasm. Enteroblastic marker-positive cases had aggressive behaviour and poor prognosis. NGS revealed TP53 as the most frequently mutated gene. The rate of HER2-positive cases and MSI-H cases was 9.5% (four of 42) and 12.2% (five of 41), respectively. Among these 42 cases, there were no molecular and clinicopathological differences according to the presence of tumour cells with clear cytoplasm. CONCLUSIONS: Enteroblastic marker-positive CRC could be grouped together as CAED regardless of clear cell cytoplasm. Using this definition, the frequency of CAED is 4.0% and has a poorer prognosis than that for conventional CRCs. HER2 targeted therapy would be a meaningful treatment for CAED, and CAEDs contain both MSI-H and MSI-stable CRCs, although the MSS phenotype is dominant.