Takatoshi Fujishita

Clinical Significance of PD-L1 Protein Expression in Surgically Resected Primary Lung Adenocarcinoma.

Introduction The clinicopathological features of carcinomas expressing programmed death ligand 1 (PD‐L1) and their associations with common driver mutations, such as mutations in the EGFR gene, in lung adenocarcinoma are not clearly understood. Here, we examined PD‐L1 protein expression in surgically resected primary lung adenocarcinoma and the association of PD‐L1 protein expression with clinicopathological features, EGFR mutation status, and patient outcomes. Methods The expression of PD‐L1 protein in 417 surgically resected primary lung adenocarcinomas was evaluated by immunohistochemical analysis. The cutoff value for defining PD‐L1 positivity was determined according to the histogram of proportions of PD‐L1–positive cancer cells. Results Samples from 85 patients (20.4%) and 144 patients (34.5%) were positive for PD‐L1 protein expression according to 5% and 1% PD‐L1 cutoff values, respectively. Fisher’s exact tests showed that PD‐L1 positivity was significantly associated with male sex, smoking, higher tumor grade, advanced T status, advanced N status, advanced stage, the presence of pleural and vessel invasions, micropapillary or solid predominant histological subtypes, and wild‐type EGFR. Univariate and multivariate survival analyses revealed that patients with PD‐L1 positivity had poorer prognoses than those without PD‐L1 protein expression at the 1% cutoff value (disease‐free survival p < 0.0001, overall survival p < 0.0001). Conclusions PD‐L1 protein expression was significantly higher in smoking‐associated adenocarcinoma and in EGFR mutation–negative adenocarcinoma. PD‐L1 protein expression was associated with poor survival in patients with lung adenocarcinoma. The PD‐L1/programmed cell death 1 pathway may contribute to the progression of smoking‐associated tumors in lung adenocarcinoma.

PD-L1 Is Upregulated by Simultaneous Amplification of the PD-L1 and JAK2 Genes in Non–Small Cell Lung Cancer

Objectives The programmed death ligand 1(PD‐L1)/programmed cell death protein 1 (PD‐1) pathway is one of the most important checkpoint pathways for mediating tumor‐induced immune suppression through T‐cell exhaustion. Recently, targeted therapies using monoclonal antibodies against components of this pathway have been shown to reduce tumor burden in patients with non–small cell lung cancer (NSCLC). However, the prognostic significance of PD‐L1 expression is controversial and the precise mechanisms of PD‐L1 gene activation in lung cancer have yet to be clarified. Methods We investigated copy number alterations (CNAs) in the PD‐L1 gene by real‐time PCR in 94 surgically resected lung cancer samples to find possible associations between PD‐L1 CNA and lung cancer biology. Janus kinase 2 gene (JAK2) CNA and its influence on the PD‐L1/PD‐1 pathway were also assessed. Results Five samples were shown to have PD‐L1 gene amplification, whereas 89 samples did not. The patients with PD‐L1 amplification had worse prognoses than did those without PD‐L1 amplification. Genetic amplification of the PD‐L1 gene was correlated with JAK2 gene amplification. The lung cancer cell line HCC4006 was found to harbor both JAK2 and PD‐L1 amplification. Flow cytometry analyses revealed the level of PD‐L1 protein expression to be higher in HCC4006 cells than in other NSCLC cell lines. Expression of the PD‐L1 protein was significantly reduced by the JAK2 inhibitor TG‐101348 and the signal transducer and activator of transcription 3 (STAT‐3) inhibitor BP‐1‐102, but not by the STAT1 inhibitor fludarabine. Conclusions Our data suggest that expression of PD‐L1 protein is upregulated by the simultaneous amplification of the PD‐L1 and JAK2 genes through JAK‐STAT signaling in NCSLC.

Predictive impact for postoperative recurrence using the preoperative prognostic nutritional index in pathological stage I non-small cell lung cancer

BACKGROUND The most effective treatment for early-stage non-small cell lung cancer (NSCLC) is surgical resection. Nevertheless, up to 20% of patients, even those with stage I NSCLC, relapse after surgery and die. The prognostic nutritional index (PNI) is used to assess immunonutritional conditions or is a predictor of postoperative recurrence in patients with digestive malignancies. However, the usefulness of the PNI for lung cancer is still unknown. We retrospectively analyzed clinicopathological features of stage I NSCLC patients to identify predictors of recurrence and to investigate effects of preoperative PNI levels. METHODS We selected 141 consecutive stage I NSCLC patients who were treated from August 2005 to August 2010. We measured their preoperative PNI levels in uni- and multivariate Cox regression analyses of recurrence-free survival. RESULTS A low PNI was significantly associated with sex (P=0.0117), preoperative serum carcino embryonic antigen levels (P=0.0228), and postoperative recurrence (P<0.0001). In multivariate analysis, PNI (RR: 9.243; 95% CI: 3.662-25.823; P<0.0001), pleural invasion (RR: 8.664; 95% CI: 2.510-38.056; P=0.0005), and intratumoral blood vessel invasion (RR: 3.151; 95% CI: 1.259-7.681; P=0.0152) were independent prognostic factors. The low-PNI group had a significantly shorter recurrence-free survival than the high-PNI group, regardless of pathological T factors (T1a, P=0.0422; T1b, P<0.0001; T2a, P=0.0098). CONCLUSIONS The preoperative PNI level is a simple and novel predictor of recurrence in stage I NSCLC patients, and might help identify patients who will need multimodality therapy such as induction or adjuvant therapy.

Clinical implications of sarcopenia in patients undergoing complete resection for early non-small cell lung cancer

OBJECTIVES Sarcopenia is characterized by progressive and generalized loss of skeletal muscle mass and strength. We aimed to investigate sarcopenia in patients with stage I non-small cell lung cancer (NSCLC) who underwent complete resection, and the relationship of sarcopenia with clinicopathological factors. METHODS All consecutive patients who underwent lung resection between January 2005 and December 2008 were enrolled in this retrospective study. Eligible patients were assigned to one of 2 groups according to the presence or absence of sarcopenia, as assessed by the sum of cross-sectional areas of skeletal muscles in the region of the third lumbar vertebra (L3) on preoperative computed tomography (CT). RESULTS Sixteen of 52 male (30.8%) and 22 of 38 female (57.9%) patients were identified with sarcopenia (p=0.01). Patients with sarcopenia were more likely to have a low body mass index (BMI) (p<0.0001). Kaplan-Meier analysis showed that patients with sarcopenia had a significantly worse outcome than patients without sarcopenia (5-year-survival: 72.8% vs 85.8%, respectively, p=0.028). Multivariate analysis found that sarcopenia was a significant independent prognostic factor (hazard ratio: 7.09, p=0.0008). CONCLUSIONS Sarcopenia identified on a cross-sectional CT image of the L3 level was associated with poor outcome with completely resected early-stage NSCLC.

The prognostic impact of the amount of tobacco smoking in non-small cell lung cancer—Differences between adenocarcinoma and squamous cell carcinoma

BACKGROUNDS The purpose of this study was to investigate the relationship between the level of tobacco smoking and the clinicopathological features of non-small cell lung cancer (NSCLC) patients, individually for adenocarcinoma (Ad) and squamous cell carcinoma (Sq). PATIENTS AND METHODS We retrospectively reviewed the clinical records of 1825 consecutive lung cancer patients who underwent surgery in our department. Among these, the data sets of 750 Ad patients and 364 Sq patients who received lobectomy or more extensive resection were available. RESULTS In Ad patients, those who had never smoked (never-smokers) (n=309) were more likely to be female, to have less advanced stage tumors, and to have a significantly better prognosis than those who had ever smoked (ever-smokers) (n=441) (5-year OS: never-smokers, 67.9%; ever-smokers, 53.7%, p<0.0001). In Sq patients, the never-smokers (n=15) were more likely to be female than the ever-smokers (n=349). Among ever-smokers, the light-smokers (PY≤30; n=56) were associated with more female patients, more advanced stage tumors, and significantly worse prognoses than were the heavy smokers (PY>30; n=292) (p=0.0003). The multivariate survival analysis showed that light smoking was related to a worse prognosis compared with heavy smoking (HR=2.06, 95% CI 1.43-2.98, p=0.0001). CONCLUSIONS The never-smokers had a significantly better prognosis than ever-smokers among Ad patients, whereas the light-smokers had a significantly worse prognosis than heavy smokers among Sq patients. There may be factors other than tobacco carcinogens that influence the development of Sq in never and/or light smokers.

Surgical results of resectable small cell lung cancer.

The standard of care for patients with small cell lung cancer (SCLC) is chemotherapy and radiotherapy, even for patients with limited disease. To define the role of surgical resection in patients with limited SCLC, we investigated the outcomes of patients diagnosed with limited‐stage disease (LD) SCLC.

A novel method of using bioabsorbable materials for the surgical repair of flail chest.

F lail chest is a critical condition that is mostly caused by multiple rib fractures secondary to blunt traumatic injury. The resulting malfunction of the mechanics of breathing can lead to respiratory compromise and requirement for intensive care. Compared with conservative management, surgical repair by open reduction and internal fixation had been the preferred therapeutic approach because of its efficacy, as demonstrated by shorter ventilator days, intensive care unit days, and hospital days; improved quality of life; and cost benefits. Several materials have been used for surgical rib fixation; however, each material has pros and cons. Metallic materials such as titanium rib clips or implants have often been used because of stability, but were associated with risks of the remnant inside the body, which would necessitate surgical removal. On the other hand, bioabsorbable rib pins have been used for intramedullary fixation of rib fracture; however, it is difficult to apply the pins in cases wherein the edge of the fractured rib is sharp or distorted. Super Fixorb MX mesh-type plate, a bioabsorbable mesh sheet composed of hydroxyapatite and poly-L-lactide acid, has a characteristic of being absorbed by the body in a few years while inducing osteoconduction. The mesh has already been applied in the field of oral-maxillofacial surgery or orthopedic surgery because of its useful properties. Here, we present a novel technique of immobilizing the ribs in flail chest by applicating a bioabsorbable sheet. This surgical procedure could provide excellent stability to the ribs by fixating multiple bone fractures without any residues.

Association of MTH1 expression with the tumor malignant potential and poor prognosis in patients with resected lung cancer

OBJECTIVES The oxidized purine nucleoside triphosphatase, mutT homolog 1 (MTH1), physiologically sanitizes 8-oxo-dGTP in the nucleotide pool. Previous studies indicated that MTH1 is associated with tumor proliferation and invasion in non-small cell lung cancer (NSCLC) cell lines; however, the role of MTH1 in patients with NSCLC remains unclear. MATERIALS AND METHODS Two patient cohorts that underwent surgery for NSCLC in our institution were investigated retrospectively. In one cohort consisting of 197 patients, the associations between MTH1 expression and clinicopathological factors or prognosis were analyzed. In another cohort consisting of 41 patients, the relationship between MTH1 expression in the tumors and serum oxidative stress levels (evaluated by the diacron-reactive oxygen metabolites [d-ROMs] test) or antioxidant capacity in the patients (evaluated by the biological antioxidant potential (BAP) test) was analyzed. A total of 238 patients were assessed for MTH1 protein levels using immunohistochemistry. RESULTS Among the 197 patients in the former cohort, 111 (56.3%) exhibited high MTH1 expression, while 86 (43.7%) exhibited low MTH1 expression. Male sex, smoking habit of ≥20 pack-years, squamous cell carcinoma, pathological stage ≥ II, tumor diameter ≥30mm, lymph node metastases, pleural invasion, lymphatic permeation and vascular infiltration were significantly associated with high MTH1 expression (p<0.05). The high MTH1 expression group had a significantly worse prognosis than that of the low MTH1 expression group (5-year overall survival: 81.6% vs. 92.3%, p=0.0011; 5-year disease-free survival: 55.0% vs. 83.7%, p=0.0002). d-ROMs and BAP test values were significantly higher in the high than in the low MTH1 expression group (p<0.05). CONCLUSION This study showed that MTH1 protein expression was closely related to factors associated with a high malignant potential and poor patient survival. MTH1 may be a novel therapeutic target for NSCLC.

A Rare Case of a Bronchial Anomaly Running in the Hilar Region from the Right Lower Lobe to the Middle Lobe

A 77-year-old male was referred to our department due to lung cancer (cT3N0M0) of the right lower lobe. During right lower lobectomy, a thin duct structure was recognized in the hilar region between the middle and lower lobes that was identified to be a supernumerary bronchus upon a review of the preoperative chest CT images. Although bronchial anomalies are rare, it is important to carefully view preoperative images for any such anomalies in order to more safely perform surgery.