Impact of the pretreatment prognostic nutritional index on the survival after first-line immunotherapy in non-small-cell lung cancer patients

BACKGROUND

Immunotherapy has become a standard-of-care for patients with non-small-cell lung cancer (NSCLC). Although several biomarkers, such as programmed cell death-1, have been shown to be useful in selecting patients likely to benefit from immune checkpoint inhibitors (ICIs), more useful and reliable ones should be investigated. The prognostic nutritional index (PNI) is a marker of the immune and nutritional status of the host, and is derived from serum albumin level and peripheral lymphocyte count. Although several groups reported its prognostic role in patients with NSCLC receiving a single ICI, there exist no reports which have demonstrated its role in the first-line ICI combined with or without chemotherapy.

MATERIALS AND METHODS

Two-hundred and eighteen patients with NSCLC were included in the current study and received pembrolizumab alone or chemoimmunotherapy as the first-line therapy. Cutoff value of the pretreatment PNI was set as 42.17.

RESULTS

Among 218 patients, 123 (56.4%) had a high PNI (≥42.17), while 95 (43.6%) had a low PNI (<42.17). A significant association was observed between the PNI and both the progression-free survival (PFS; hazard ratio [HR] =  0.67, 95% confidence interval [CI]: 0.51-0.88, p =  0.0021) and overall survival (OS; HR = 0.46, 95% CI: 0.32-0.67, p < 0.0001) in the entire population, respectively. The multivariate analysis identified the pretreatment PNI as an independent prognosticator for the PFS (p =  0.0011) and OS (p  < 0.0001), and in patients receiving either pembrolizumab alone or chemoimmunotherapy, the pretreatment PNI remained an independent prognostic factor for the OS (p = 0.0270 and 0.0006, respectively).

CONCLUSION

The PNI might help clinicians appropriately identifying patients with better treatment outcomes when receiving first-line ICI therapy.

Necitumumab plus gemcitabine and cisplatin in previously treated lung squamous cell carcinoma

BACKGROUND

The efficacy and safety of the anti-EGFR antibody necitumumab combined with gemcitabine and cisplatin (N + GC) in the first-line treatment of advanced lung squamous cell carcinoma (LSCC) have been proven. However, the efficacy and safety of N + GC in the second line or later treatment remain unclear.

METHODS

Eleven patients who received N + GC for advanced-stage or recurrent LSCC were enrolled. We retrospectively assessed the patients' clinical characteristics and efficacy and safety of treatment.

RESULTS

The median patient age was 73 years (range, 63-77 years). The cohort included nine (81.8%) men and two (18.2%) women. Two (18.2%) patients had postoperative recurrence, and one (9.1%), three (27.3%), one (9.1%), and four (36.4%) patients were diagnosed with stage IIIA, IIIB, IVA, and IVB disease, respectively. Concerning the best overall response, partial response was achieved in five (45.5%) patients, four (36.4%) patients displayed stable disease, and two (18.2%) patients were not evaluable. Median progression-free survival was 6.8 months (range, 1.4-10.3 months). The grade 3 or higher neutropenia, thrombocytopenia, and anemia occurred in six (54.5%), three (27.3%), and two (18.2%) patients, respectively. Additionally, grade 3 skin reaction, rash, lung infection, duodenal ulcer, and febrile neutropenia were observed in one (9.1%) patient each. Two (18.2%) patients required treatment interruption because of adverse events.

CONCLUSION

N + GC displayed good efficacy in the second line or later treatment among patients with LSCC. This study suggested that N + GC is a useful option even after second-line treatment of advanced-stage or recurrent LSCC, although the management of adverse events is essential.

Gut microbiota diversity and specific composition during immunotherapy in responders with non-small cell lung cancer

Cancer immunotherapy including immune checkpoint inhibitors (ICI) has revolutionized non-small cell lung cancer (NSCLC) therapy. Recently, the microbiota status “before” initiation of ICI therapy has been emphasized as a predictive biomarker in patients undergoing ICI therapy. However, the microbiota diversity and composition “during” ICI therapy is unknown. This multicenter, prospective observational study analyzed both saliva and feces from 28 patients with NSCLC. We performed 16S ribosomal RNA gene sequencing, then analyzed associations of oral and gut microbiota diversity or composition with ICI response. At the genus level, the alpha diversity of the gut microbiota was significantly greater in responders (n = 17) than in non-responders (n = 11) (Chao 1, p = 0.0174; PD whole tree, p = 0.0219; observed species, p = 0.0238; Shannon, p = 0.0362), while the beta diversity of the gut microbiota was significantly different (principal coordinates analysis, p = 0.035). Compositional differences in the gut microbiota were observed between the two groups; in particular, g_Blautia was enriched in responders, whereas o_RF32 order unclassified was enriched in non-responders. The progression-free survival (PFS) of patients enriched gut microbiota of g_Blautia was significantly longer [median survival time (MST): not reached vs. 549 days, p = 0.0480] and the PFS of patients with gut microbiota of o_RF32 unclassified was significantly shorter (MST: 49 vs. 757 days, p = 0.0205). There were no significant differences between groups in the oral microbiota. This study revealed a strong association between gut microbiota diversity and ICI response in NSCLC patients. Moreover, specific gut microbiota compositions may influence the ICI response. These findings might be useful in identifying biomarkers to predict ICI response.

Case report: Success of tepotinib therapy in overcoming resistance to osimertinib in a patient with EGFR-mutant lung adenocarcinoma with a potential acquired MET exon 14 skipping mutation

Osimertinib is a standard therapy for the treatment of advanced non-small cell lung cancer (NSCLC) harboring epidermal growth factor receptor gene (EGFR) mutations, but most patients with EGFR-mutant NSCLC develop secondary resistance to osimertinib. Mesenchymal-epithelial transition gene (MET) alterations and oncogene fusions have been identified as the most common mechanisms of resistance to osimertinib. However, MET exon 14 skipping mutation (METex14del) as an acquired resistance to osimertinib has rarely been reported. A non-smoking 76-year-old woman was diagnosed with lung adenocarcinoma in the right lower lobe (cT2bN2M1c [pulmonary and bone metastases], cStage IVB). The primary tumor was submitted to cobas^® EGFR Mutation Test v2 (Roche Diagnostics Ltd.), next generation sequencing (Oncomine Comprehensive Assay v3; Thermo Fisher Scientific), the AmoyDx^® Essential NGS panel (Amoy Diagnostics, Xiamen, China), all of which were positive for EGFR L858R and de novo T790M. We administered daily osimertinib (80 mg/day), and achieved a partial response. However, after 14.0 months, computed tomography showed progression of the primary tumor and lung metastases. Re-biopsy of the primary tumor was conducted, and the specimen was submitted to Archer^®MET companion diagnostic for detection of METex14del. Although the primary tumor was negative for METex14del, the re-biopsy specimen was positive for METex14del. We validated that the biopsy specimen of the primary tumor at diagnosis before osimertinib administration was negative for METex14del using local reverse transcription PCR. We administered daily tepotinib (500 mg/day) to the patient as a further-line treatment, and achieved a partial response (tumor shrinkage rate: 34.5%) after 2.0 months, who responded to tepotinib therapy for 8.0 months. We described a patient with lung adenocarcinoma harboring METex14del as a potential acquired resistance to osimertinib, who responded to subsequent tepotinib therapy. Re-biopsy and re-analysis of genetic profiles should be considered in NSCLC patients who develop osimertinib resistance.

Chronological analysis of the gut microbiome for efficacy of atezolizumab-based immunotherapy in non-small cell lung cancer: Protocol for a multicenter prospective observational study

Background

Cancer immunotherapy with immune checkpoint inhibitors (ICIs) is an innovative treatment for non‐small cell lung cancer (NSCLC). Recently, the specific composition of the gut microbiome before initiation of cancer immunotherapy has been highlighted as a predictive biomarker in patients undergoing cancer immunotherapy, mainly in the US or Europe. However, the fact gut microbiome status is completely different in races or countries has been revealed. In addition, how the microbiome composition and diversity chronologically change during cancer immunotherapy is still unclear.

Methods

This multicenter, prospective observational study will analyze the association between the gut microbiome and therapeutic response in NSCLC patients who received atezolizumab‐based immunotherapy. The aim of the present study is to clarify not only how the specific composition of the gut microbiome influences clinical response in NSCLC patients but the chronological changes of gut microbiota during atezolizumab‐based immunotherapy. The gut microbiota will be analyzed using 16S rRNA gene sequencing. The main inclusion criteria are as follows: (1) Pathologically‐ or cytologically‐confirmed stage IV or postoperative recurrent NSCLC. (2) Patients ≥20 years old at the time of informed consent. (3) Planned to treat with atezolizumab‐based immunotherapy combined with platinum‐based chemotherapy (cohort 1) and monotherapy (cohort 2) as a first immunotherapy. (4) Patients to provide fecal samples. A total of 60 patients will be enrolled prospectively. Enrollment will begin in 2020 and the final analyses will be completed by 2024.

Discussion

This trial will provide more evidence of how gut microbiota composition and diversity chronologically change during cancer immunotherapy and contribute to the development of biomarkers to predict ICI response as well as biotic therapies which enhance the ICI response.

Artificial intelligence-derived gut microbiome as a predictive biomarker for therapeutic response to immunotherapy in lung cancer: protocol for a multicentre, prospective, observational study

INTRODUCTION

Immunotherapy is the fourth leading therapy for lung cancer following surgery, chemotherapy and radiotherapy. Recently, several studies have reported about the potential association between the gut microbiome and therapeutic response to immunotherapy. Nevertheless, the specific composition of the gut microbiome or combination of gut microbes that truly predict the efficacy of immunotherapy is not definitive.

METHODS AND ANALYSIS

The present multicentre, prospective, observational study aims to discover the specific composition of the gut microbiome or combination of gut microbes predicting the therapeutic response to immunotherapy in lung cancer using artificial intelligence. The main inclusion criteria are as follows: (1) pathologically or cytologically confirmed metastatic or postoperative recurrent lung cancer including non-small cell lung cancer and small cell lung cancer; (2) age≥20 years at the time of informed consent; (3) planned treatment with immunotherapy including combination therapy and monotherapy, as the first-line immunotherapy; and (4) ability to provide faecal samples. In total, 400 patients will be enrolled prospectively. Enrolment will begin in 2021, and the final analyses will be completed by 2024.

ETHICS AND DISSEMINATION

The study protocol was approved by the institutional review board of each participating centre in 2021 (Kyushu Cancer Center, IRB approved No. 2021-13, 8 June 2021 and Kyushu Medical Center, IRB approved No. 21-076, 31 August 2021). Study results will be disseminated through peer-reviewed journals and national and international conferences.

TRIAL REGISTRATION NUMBER

UMIN000046428.

Robot-assisted thoracic surgery for intercostal cavernous hemangioma

Intercostal cavernous hemangioma is extremely rare among benign vascular tumors. Achieving a definitive diagnosis preoperatively by radiographic examination alone is difficult; surgical resection is usually needed. Occasional cases are found as giant tumors, and some grow substantially during observation without treatment. Such tumors require extended surgical resection; however, small tumors can be completely resected by tumor extirpation alone. Thus, immediate surgical resection while the tumor is small might help to avoid invasive surgery. We herein describe cases of intercostal cavernous hemangioma with no invasion to the surrounding tissues, successfully treated by complete tumor resection using robot‐assisted thoracic surgery.

Induction immunotherapy followed by surgery for hilar unicentric Castleman disease

Castleman disease is a rare disease borne of a B cell lymphoproliferative disorder of uncertain cause. Standard therapy for the unicentric type of Castleman disease localized as a single mass or single lymph‐node station is surgical extirpation. Nevertheless, in the thoracic cavity, unresectable cases or cases of incomplete extirpation of the tumor without lung scarring owing to tumor size/location have been noted. In such cases, lung resection (e.g., lobectomy, pneumonectomy) or additional therapy (immunotherapy, chemotherapy, radiotherapy) after resection is required. However, few instances of patients receiving induction immunotherapy or chemotherapy followed by surgery have been reported. Here, we describe a 21‐year‐old woman with unicentric Castleman disease originating from the left hilum. The tumor seemed to involve/be in contact with the pulmonary vein and bronchus. Tumor location indicated that initial resection was necessary to sacrifice upper and lower pulmonary lobes. To avoid these pulmonary resections, induction therapy followed by surgery was selected. Induction therapy using rituximab was very efficacious. Resection after induction therapy was completed only by tumor extirpation, and resulted in preservation of pulmonary function. Thoracic surgeons might consider induction therapy followed by resection if the tumor is resectable UCAD, but initial resection is needed and sacrifices a large amount of pulmonary function.

Cumulative experience of the anterior approach in robot-assisted thoracic surgery for lung cancer patients

Background

Robot-assisted thoracic surgery (RATS) lobectomy for lung cancer is now performed all around the world. The camera and robotic devices are generally inserted from a low position via the thorax. We previously reported our original anterior approach (AA) for performing RATS lobectomy with a camera and robotic devices inserted via the anterior chest wall. However, whether AA is comparable or superior to the conventional approach (CA) remains unclear.

Methods

A total of 108 patients who underwent RATS lobectomy were included in the current study. We compared the AA with the CA for performing RATS lobectomy in terms of the operative and postoperative features, such as total operation/console time, blood loss and postoperative complications.

Results

Eighty-seven and 21 patients underwent the AA and CA in RATS lobectomy, respectively. The console and total operation time were significantly shorter in the AA group than in the CA group for RATS lobectomy (median console time: AA vs. CA, 112 vs. 148 min, P=0.0001; median total operation time: AA vs. CA, 193 vs. 243 min, P=0.0002), especially left upper lobectomy. Intraoperative blood loss and the frequency of postoperative complications were significantly reduced in the AA group compared with the CA group (median intraoperative blood loss: AA vs. CA, 20 vs. 105 mL, P<0.0001; postoperative complications: AA vs. CA, 8.0% vs. 28.6%, P=0.0088).

Conclusions

These results suggest that our AA of RATS lobectomy can be very easily and safely performed.

Impact of Preoperative Immunonutritional Support in Patients Undergoing Elective Thoracic Surgery

Introduction:

Several immunonutritional supplements have recently been developed. However, improvements in preoperative immunonutritional conditions using these supplements have not been analyzed in patients undergoing thoracic surgery.

Methods:

This prospective, single-arm, single-institution pilot study involved patients planning to undergo thoracic surgery. Forty adults with a poor preoperative immunonutritional status were enrolled. The patients freely selected one of three oral immunonutritional supplements (IMPACT^Ⓡ, MEIN^Ⓡ, or Abound^Ⓡ) and started taking it on an outpatient basis from 7 to 14 days before thoracic surgery. The primary endpoint was the rate of improvement in three immunonutritional parameters on the hospitalization day: body mass index (BMI), prognostic nutritional index (PNI), and geriatric nutritional risk index (GNRI). These improvement rates were compared with those of a matched historical control group.

Results:

The PNI and GNRI improvement rates were significantly higher in the immunonutritional support group than in the control group (PNI: 103.1% ± 0.6% vs. 98.9% ± 1.3%, p = 0.0391; GNRI: 101.7% ± 0.8% vs. 99.3% ± 0.8%, p = 0.0266), although there was no significant difference in the BMI improvement rate (101.0% ± 0.6% vs. 100.2% ± 0.7%, p = 0.3626). The PNI and GNRI improvement rates were significantly higher in the IMPACT^Ⓡ support group than in the control group (PNI: 104.5% ± 2.4% vs. 98.9% ± 1.3%, p = 0.0212; GNRI: 101.6% ± 1.1% vs. 99.3% ± 0.8%, p = 0.0415).

Conclusions:

The present study revealed that short-term preoperative immunonutritional support can actually improve immunonutritional parameters immediately before surgery. In particular, preoperative immunonutritional support using IMPACT^Ⓡ supplementation might be the most promising agent in patients with a poor immunonutritional condition undergoing elective thoracic surgery.

Trial registration:

University Hospital Medical Information Network 000035851

Combined laparoscopic and thoracoscopic surgical repair of Bochdalek hernia in an adult: a case report

BACKGROUND

Bochdalek hernia is a rare disease in adults. Diaphragmatic hernia in adults has been repaired using minimally invasive surgery through laparoscopy or thoracoscopy. However, the literature regarding the combined use of laparoscopy and thoracoscopy for the repair of Bochdalek hernia is limited.

CASE PRESENTATION

A 26-year-old man diagnosed with Bochdalek hernia was managed through combined abdominal and thoracic endoscopic surgery. On laparoscopy, the omentum prolapsed into the left thoracic cavity through the posterolateral area of the left diaphragm. On thoracoscopy, no adhesions of the omentum were seen in the thoracic cavity. The omentum was drawn back to the abdominal cavity, and a 4 × 3-cm hernial orifice was identified. The hernia orifice was repaired through simple closure with sutures laparoscopically. The patient's postoperative course was uneventful with no recurrences within the first year post-surgery.

CONCLUSION

Combined laparoscopic and thoracoscopic surgery is a safe and effective method for Bochdalek hernial repair in adults.

Preoperative prognostic nutritional index level is associated with tumour-infiltrating lymphocyte status in patients with surgically resected lung squamous cell carcinoma

OBJECTIVES

The prognostic nutritional index (PNI) is an indicator of systemic immune-nutritional condition and is a well-known prognostic biomarker in lung cancer patients. Tumour-infiltrating lymphocytes (TILs) is a specific histological feature of cancers, influencing an individual's immunological tumour responses. However, whether PNI can reflect lung cancer patients' prognosis through local immunity such as TIL is unclear.

METHODS

We selected 64 lung squamous cell carcinoma patients who underwent curative operations. We investigated the significance of preoperative PNI level and evaluated the relationship between PNI and immune cells surrounding the lung cancer tissue using immunohistochemical analysis of a cluster of differentiation (CD)3, CD4, CD8 and CD68.

RESULTS

A low-PNI level was significantly associated with a worse postoperative prognosis (P = 0.042). The PNI (hazard ratio 2.768, 95% confidence interval 1.320-5.957; P = 0.007) was an independent prognostic factor. The low-PNI group had a significantly shorter recurrence-free survival and overall survival (P = 0.013 and P = 0.002, log-rank test) compared with the high-PNI group. A significant positive correlation between PNI components including preoperative peripheral blood lymphocyte count and serum albumin concentration, and TILs, was observed. Absolute numbers of TILs in the preoperative high-PNI group were significantly increased compared with those in the preoperative low-PNI group (CD3+ cells; P = 0.002, CD4+ cells; P = 0.049 and CD8+ cells; P = 0.024).

CONCLUSIONS

The preoperative PNI level was strongly associated with the postoperative outcome in lung cancer patients. Considering the positive relationship between preoperative PNI level and TIL status, preoperative immune-nutritional condition may influence lung cancer patients' postoperative prognosis through local immunity as well as systemic immune response.

Dramatic response to pembrolizumab with chemotherapy followed by salvage surgery in a lung cancer patient

Immune checkpoint inhibitors with chemotherapy have been shown to exhibit remarkable efficacy for advanced non-small-cell lung carcinoma and are under investigation as an induction therapy. However, the significance of preoperative therapy with pembrolizumab + chemotherapy for surgically resectable non-small-cell lung carcinoma still remains unclear. Here, we report a case of stage IIIB non-small-cell lung carcinoma that underwent salvage surgery after three cycles of pembrolizumab + carboplatin + nab-paclitaxel. Computed tomography revealed the remarkable decrease in tumor volume by 81%. A pathological examination showed that viable neoplastic cells were observed in <1% of the total tumorous lesion suggesting near pathological complete response. This case suggests that this regimen might be a good option as induction therapy for non-small-cell lung carcinoma.

ALK-positive lung cancer in a patient with recurrent brain metastases and meningeal dissemination who achieved long-term survival of more than seven years with sequential treatment of five ALK-inhibitors: A case report

The incidence of central nervous system (CNS) metastases in patients with anaplastic lymphoma kinase (ALK) fusion gene‐positive (ALK+) non‐small cell lung cancer (NSCLC) is high, ranging from approximately 20%–70%. Although ALK inhibitors (ALKis) are generally effective for CNS metastases in patients with ALK+ NSCLC, relapse with CNS metastases is frequently observed. A 37‐year‐old woman with a high level of carcinoembryonic antigen was diagnosed with right lung adenocarcinoma (pathological stage IIIA) and underwent right lower lobectomy. Despite the administration of postoperative chemotherapy, her carcinoembryonic antigen (CEA) level remained elevated. Although crizotinib was administered due to the positivity for ALK fusion, brain metastases appeared at 19.0 months after the start of treatment. Treatment with alectinib following crizotinib resulted in the complete disappearance of brain metastases. However, brain metastases relapsed, and meningeal dissemination appeared at 38.3 months after the start of treatment with alectinib. Although ceritinib, brigatinib, and alectinib rechallenge were attempted, the CNS lesions worsened. Lorlatinib was then administered, resulting in the normalization of the CEA level (4.5 ng/ml) 4.1 months after the start of lorlatinib. The brain metastases and meningeal dissemination almost disappeared. The overall time from the start of crizotinib to lorlatinib is 89.5 months at present, and the patient continues to be treated with lorlatinib without relapse. Lorlatinib was effective in this case with brain metastases and meningeal dissemination after resistance to first‐ and second‐generation ALKis. Appropriate sequential treatment with first‐, second‐ and third‐generation ALKis can lead to a long‐term survival in ALK+ patients with brain metastases and meningeal dissemination.

Does short-term cessation of smoking before lung resections reduce the risk of complications?

Background

Smoking cessation is a highly important preparation before thoracic surgery. We examined the effects of short-term smoking cessation intervention before pulmonary resection on postoperative pulmonary complications (PPCs).

Methods

A retrospective analysis of prospectively collected data was performed for 753 patients who underwent curative surgical resection for thoracic malignancy at 3 institutions. Patients with a smoking history were instructed to quit smoking. After confirming smoking cessation by at least four weeks before surgery, surgical resection was performed. Subjects were classified into three groups based on their smoking status: abstainers (anyone who had stopped smoking for at least 4 weeks but less than 2 months), former smokers (anyone who had abstained from smoking for more than two months prior to surgery), and never smokers (those who had never smoked). We examined the relationship between the preoperative smoking status and PPCs.

Results

Surgery was performed for 660 primary lung cancers and 93 metastatic lung tumors. The smoking statuses were classified as follows: abstainers (n=105, 14%), former smokers (n=361; 48%) and never smokers (n=287, 38%). The incidence of PPCs among abstainers, former smokers and never smokers was 15%, 8% and 6%, respectively (P=0.01). The mean duration of post-operative chest tube drainage among abstainers, former smokers and never smokers was 3.2, 2.2 and 2.2 days, respectively (P=0.04). The mean post-operative hospital stay among abstainers, former smokers and never smokers was 12.1, 10.6 and 10.2 days, respectively (P=0.07). There was no 30-day mortality in the cohort.

Conclusions

Short-term smoking cessation intervention did not enough reduce the PPCs as much as in former or never smokers.

Resection of Pulmonary Metastases 12 Years after Initial Surgery for a Benign Pheochromocytoma

We describe a rare case of newly discovered pulmonary metastases and surgical confirmation 12 years after initial surgery for a pheochromocytoma. A 61-year-old asymptomatic man was referred because of an abnormal shadow in the right lung field upon chest radiography. Computed tomography (CT) showed two well-demarcated tumors in the basal segment of the right lung. Twelve years previously, he underwent right adrenalectomy and was pathologically diagnosed as having a benign pheochromocytoma. Thereafter, he received a medical check-up annually. To confirm the diagnosis of two pulmonary tumors, video-assisted thoracic surgery was done and wedge resection of the right lower lobe completed. Pathology studies revealed these tumors as pulmonary metastases from the pheochromocytoma, which indicated that the true diagnosis was a malignant pheochromocytoma. Patients with a benign pheochromocytoma should continue to undergo careful monitoring for a long time after the initial surgical procedure. Thoracic surgeons should be aware of the possibility of pulmonary metastases even if >10 years have passed since initial resection of a benign pheochromocytoma.

Weakly-supervised learning for lung carcinoma classification using deep learning

Lung cancer is one of the major causes of cancer-related deaths in many countries around the world, and its histopathological diagnosis is crucial for deciding on optimum treatment strategies. Recently, Artificial Intelligence (AI) deep learning models have been widely shown to be useful in various medical fields, particularly image and pathological diagnoses; however, AI models for the pathological diagnosis of pulmonary lesions that have been validated on large-scale test sets are yet to be seen. We trained a Convolution Neural Network (CNN) based on the EfficientNet-B3 architecture, using transfer learning and weakly-supervised learning, to predict carcinoma in Whole Slide Images (WSIs) using a training dataset of 3,554 WSIs. We obtained highly promising results for differentiating between lung carcinoma and non-neoplastic with high Receiver Operator Curve (ROC) area under the curves (AUCs) on four independent test sets (ROC AUCs of 0.975, 0.974, 0.988, and 0.981, respectively). Development and validation of algorithms such as ours are important initial steps in the development of software suites that could be adopted in routine pathological practices and potentially help reduce the burden on pathologists.

Reliable detection of the presence of pulmonary carcinoma on whole-slide images by a deep learning model

9025

Background: Lung cancer is one of the leading causes of cancer-related death worldwide, and its histopathological diagnosis is crucial for deciding on optimum treatment strategies. Recently, artificial intelligence (AI) models have been widely shown to be useful in various medical fields, particularly image and pathological diagnoses; however, AI models for the pathological diagnosis of pulmonary lesions that have been validated in large-scale test sets are yet to be seen. Methods: We trained a convolution neural network based on the Efficient Net B3 architecture to classify carcinoma from whole slide images (WSIs) using a training dataset of 3640 images. WSI diagnoses were available. We used a transfer learning approach, in which the starting weights were obtained from a pre-trained model on ImageNet. The model was then trained on our dataset using multiple instance learning, a semi-supervised learning approach. To classify a WSI, the model was applied in a sliding window fashion with an input tile size of 512x512 and a stride of 256. The maximum probability was then used as a WSI diagnosis. Results: We evaluated our model on a total of 2680 WSIs originating from five independent sources (two hospitals in Japan and three public datasets from around the world). The model achieved a Receiver Operator Curve Area Under the Curves (ROC AUCs) of 0.974, 0.974, 0.996, 0.988, and 0.981, respectively. Conclusions: We successfully established a reliable AI model for differentiating between lung carcinoma and non-neoplasm with a high ROC AUC on five independent test sets. If used in clinical practice, our model could help reduce the burden on pathologists and be useful for diagnosing pulmonary lesions in areas in which there are shortages of pathologists. Further prospective multicenter studies are warranted in order to validate the results obtained in the current study.

Complete Blood Cell Count-Derived Inflammatory Biomarkers in Early-Stage Non-Small-Cell Lung Cancer

BACKGROUND

Complete blood cell count (CBC)-derived inflammatory biomarkers are widely used as prognostic parameters for various malignancies, but the best predictive biomarker for early-stage non-small-cell lung cancer (NSCLC) is unclear. We retrospectively analyzed early-stage NSCLC patients to investigate predictive effects of preoperative CBC-derived inflammatory biomarkers.

PATIENTS AND METHODS

We selected 311 consecutive patients with pathological stage IA NSCLC surgically resected from April 2006 to December 2012. Univariate and multivariate Cox proportional analyses of recurrence-free survival (RFS) were used to test the preoperative systemic immune inflammation index (SII), neutrophil-lymphocyte ratio (NLR), platelet-lymphocyte ratio (PLR), and monocyte-lymphocyte ratio (MLR).

RESULTS

Preoperative high MLR levels were significantly associated with patient sex, smoking status, and postoperative recurrence (p <0.0001, p = 0.0307, and p = 0.0146, respectively), and preoperative high SII levels were significantly correlated with postoperative recurrence (p = 0.0458). Neither NLR nor PLR were associated with any related factors. Only preoperative MLR levels (p = 0.0269) were identified as an independent predictor of shorter RFS. The relative risk (RR) for preoperative high MLR level versus low level patients was 2.259 (95% confidence interval [CI]: 1.094-5.000). Five-year RFS rates in patients with preoperatively high MLR levels were significantly lower than in those with low MLR levels (82.21% vs. 92.05%, p = 0.0062). In subgroup analysis by tumor size and MLR level, the high MLR level subgroup with tumors >2 cm had significantly shorter RFS than other subgroups (p = 0.0289).

CONCLUSIONS

The preoperative MLR level is the optimal predictor of recurrence in patients with pathological stage IA NSCLC.

Preoperative Immune-Nutritional Abnormality Predicts Poor Outcome in Elderly Non-Small-Cell Lung Cancer Patients with Comorbidities

Background: Elderly non-small-cell lung cancer (NSCLC) patients are increasing. In general, elderly patients often have more comorbidities and worse immune-nutritional condition.

Patients and methods: In total, 122 NSCLC patients aged 75 years or older, underwent thoracic surgery between January 2007 and December 2010. In all, 99 of 122 patients (81.1%) who had preoperative comorbidities were retrospectively analyzed. We evaluated the preoperative immune-nutritional condition using the controlling nutritional status (CONUT) score.

Results: We decided the best cutoff value for CONUT score was 1; as a result, 42 of 99 patients (42.4%) had abnormal preoperative CONUT score. Univariate analyses showed sex (P = 0.0099), smoking status (P = 0.0176), pathological stage (P = 0.0095), and preoperative CONUT score (P = 0.0175) significantly affected overall survival (OS). In multivariate analysis, pathological stage (relative risk (RR): 2.12; 95% confidence interval (CI): 1.10–3.90; P = 0.0268) and preoperative CONUT score (RR: 2.10; 95% CI: 1.20–3.67; P = 0.0094) were shown to be independent prognostic factors. In Kaplan–Meier analysis of OS, the preoperative abnormal CONUT score group had significantly shorter OS than did the preoperative normal CONUT score group (P = 0.0152, log-rank test); however, there were no statistical differences both in disease-free survival (DFS) and cancer-specific survival (CSS; P = 0.9238 and P = 0.8661, log-rank test, respectively). In total, 22 patients (46.8%) were dead caused by other diseases such as pneumonia or other organs malignancies.

Conclusion: Preoperative abnormal CONUT score is a poor prognostic factor for the elderly NSCLC patients with preoperative comorbidities and might predict poor postoperative outcome caused by not primary lung cancer but other diseases.

HMGB1 blockade significantly improves luminal fibrous obliteration in a murine model of bronchiolitis obliterans syndrome

BACKGROUND

Although high-mobility group box-1 (HMGB1), which is a nuclear protein, was reported to enhance the allogeneic responses in transplantation, the effect of HMGB1 on bronchiolitis obliterans syndrome (BOS) is unknown.

METHODS

A murine heterotopic tracheal transplantation model was used. Protein concentrations of HMGB1, interferon-γ (IFN-γ), interleukin (IL)-10, and IL-17 were analyzed in the isografts, allografts, controls, and HMGB1-neutralizing antibody administered allografts (n = 6; Days 1, 3, 5, 7, 14, 21, and 28). The luminal fibrous occlusion was analyzed (n = 6; Days 7, 14, 21, and 28). Infiltrating CD8 and CD4 T lymphocytes around the allografts and serum levels of IFN-γ and IL-10 were evaluated (n = 6; Day 7).

RESULTS

The HMGB1 levels in the allografts were significantly increased compared with the isografts at Day 7. HMGB1 blockade did not change the IL-17 level, but decreased the IFN-γ/IL-10 ratio in the early phase (Days 5 and 7) and significantly improved the fibrous occlusion in the late phase (Days 14, 21, and 28). HMGB1 blockade significantly suppressed the CD8 T lymphocytes infiltration and decreased the serum IFN-γ/IL-10 ratio compared with the control at Day 7.

CONCLUSIONS

HMGB1 may be a trigger of the BOS pathogenesis and candidate target for the treatment of the disease.

A phase II randomized trial of adjuvant chemotherapy with S-1 versus S-1 plus cisplatin for completely resected pathological stage II/IIIA non-small cell lung cancer

OBJECTIVES

Platinum-based combination chemotherapy is the standard postoperative adjuvant treatment for pathological stage II/III non-small cell lung cancer (NSCLC). Oral S-1 therapy has good efficacy and relatively low toxicity for the treatment of advanced NSCLC. We investigated whether long-term S-1 monotherapy is also useful as an adjuvant therapy after surgery in patients with NSCLC.

PATIENTS AND METHODS

We conducted a phase II randomized open-label multi-institutional study in patients with pathological stage II/IIIA NSCLC (7^th TNM classification) who underwent complete resection from 2009 to 2013. The primary endpoint, the 2-year disease-free survival (DFS) rate, was evaluated using the Bayesian method. Eligible patients were randomly assigned to two arms: oral S-1 monotherapy (S-1 arm) and S-1 plus cisplatin combination therapy followed by S-1 (S-1 plus cisplatin arm) both for a total of 1 year.

RESULTS

A total of 70 and 71 patients were enrolled in S-1 arm and S-1 plus cisplatin arm, respectively. The 2-year DFS rates were 52% (95% confidence interval [CI], 0.40-0.63) and 61% (95% CI, 0.48-0.70) for S-1 arm and S-1 plus cisplatin arm, respectively. Both arms met the primary endpoint. Neither DFS nor OS was significantly different between the arms (log-rank test: P =  0.1695 and P =  0.8684, respectively). The main G3/4 adverse events were loss of appetite and anemia (S-1 vs. S-1 plus cisplatin: 4.3% vs. 11.6% and 0% vs. 5.8%, respectively). The treatment completion rate did not differ between the two arms (S-1 vs. S-1 plus cisplatin: 45.7%, 95% CI, 41.9-66.3% vs. 43.5% 95% CI, 44.0-68.4%).

CONCLUSIONS

Long-term adjuvant chemotherapy with S-1 was a feasible and promising treatment for patients with completely resected NSCLC, regardless of cisplatin addition. S-1 monotherapy should be investigated further, based on its low toxicity and practical convenience.

Seasonal and meteorological impacts on primary spontaneous pneumothorax

Background

Although several studies have suggested that primary spontaneous pneumothorax (PSP) might occur in clusters, only a few studies have found seasonal variations in PSP occurrence. Some meteorological parameters might be related to the occurrence of PSP occurrence, however, the effects of weather variations on the onset of PSP are still controversial.

Methods

We examined seasonal differences in the occurrence of PSP and the meteorological risk factors for PSP. All PSP patients aged <40 years who were admitted to Kyushu Central Hospital of the Mutual Aid Association of Public School Teachers from April 2007 through March 2013 were included in the study.

Results

The incidence rates of PSP were 16.7 and 2.1 per 100,000 person-years in men and women, respectively. The frequency of PSP days among months and seasons was significantly different with a peak in September and autumn. Daily changes in maximum wind speed had positive associations with PSP days [crude OR =1.11 (95% CI: 1.02-1.21) per 1 m/s, P=0.02; multivariable-adjusted OR =1.11 (95% CI: 1.00-1.23) per 1 m/s, P=0.05].

Conclusions

PSP tends to cluster seasonally. Increased wind speed may play a role in the development of PSP.

Postoperative Management of Multiple Primary Cancers Associated with Non-small Cell Lung Cancer

BACKGROUND/AIM

Modern treatment for primary cancers has improved survival. Therefore, increased numbers of patients with multiple primary cancers (MPC) associated with lung cancer may be expected. The aim of the present study was to report MPC associated with lung cancer and discuss patients' characteristics and postoperative management.

PATIENTS AND METHODS

Overall, 973 consecutive patients who underwent surgery for non-small cell lung cancer (NSCLC) were retrospectively studied.

RESULTS

NSCLC with MPC was observed in 148 patients (15.2%). MPC comprised 24 synchronous (2.5%) and 124 metachronous (12.7%) diseases. Of the 124 metachronous patients, NSCLC was detected before cancers were detected in other organs (lung cancer first (LCF)) in 25 (20.2%) patients and subsequently in other organs after treatment (other organs, primary cancer-first (OCF)) in 99 (79.8%) patients. MPC was significantly associated with advanced age (p<0.0001) and chronic obstructive pulmonary disease (COPD) (p=0.0040). The leading sites of MPC in patients with synchronous tumors and those with OCF were the digestive organs. In contrast, the leading site of MPC in patients with LCF was the lung. In the latter, at least two primary lung cancers were detected within 5 years as well as 5 years after surgery for the treatment of the first detected lung cancer, while primary cancers of other organs were detected within 5 years.

CONCLUSION

Advanced age and COPD may represent a high-risk of MPCs. Therefore, we recommend careful follow-up to detect MPC in the lung as well as the digestive organs beyond 5 years after treatment of the first cancer.

The significant influence of having children on the postoperative prognosis of patients with nonsmall cell lung cancer: A propensity score-matched analysis

The aim of this study was to elucidate the relationship between family‐associated factors and the postoperative prognosis in patients with nonsmall cell lung cancer (NSCLC). Additionally, we investigated whether having children was associated with the postoperative maintenance of the nutritional status. We selected 438 NSCLC patients who had undergone curative lung resection between 2004 and 2011 at Kyushu University (Fukuoka, Japan), whose family‐associated factors were available. Nutritional indices, including the prognostic nutritional index (PNI), were used to estimate the change in the nutritional status for 1 year after surgery. A propensity score analysis was conducted after adjusting the following variables: sex, age, smoking history, performance status, pathological stage, and histological type. Three hundred patients (68.5%) had both children and partners. Forty‐nine patients (11.2%) only had children, and 56 (12.8%) patients only had a partner. Thirty‐three patients (7.5%) did not have a partner or children. The overall survival (OS) and disease‐free survival (DFS) of the partner‐present and partner‐absent patients did not differ to a statistically significant extent (P = .862 and P = .712, respectively). However, childless patients showed significantly shorter OS and DFS in comparison with patients with children (P = .005 and P = .002, respectively). The postoperative exacerbation of PNI was significantly greater in childless patients than in patients with children (P = .003). These results remained after propensity score matching. Childless patients had a significantly poorer postoperative prognosis than those with children. Surgeons caring for childless NSCLC patients should be aware of the poorer postoperative outcomes in this population.

Impact of Preoperative Ultrasonography Screening for Carotid Artery Stenosis in Lung Cancer Patients

BACKGROUND

Stroke is a major cause of morbidity or death after lung operations. Carotid artery screening (CAS) is useful for detecting carotid artery stenosis, which is one of the causes of stroke. This study investigated the frequency of and risk factors for preoperative carotid artery stenosis to determine whether CAS with ultrasonography contributes to preventing postoperative stroke or cardiovascular comorbidities in lung cancer patients.

METHODS

This retrospective study included 1,676 consecutive lung cancer patients who underwent surgical resection.

RESULTS

Of the 1,342 patients who underwent CAS, 173 (12.9%) had carotid artery stenosis. Significant associations with carotid artery stenosis were found for older patients (p < 0.0001), men (p < 0.0001), smoking history (p < 0.0001), history of stroke (p = 0.0037), cardiovascular diseases (p < 0.0001), hypertension (p = 0.0353), diabetes mellitus (p = 0.0037), and peripheral vascular diseases (p < 0.0001). Patients with the three independent risk factors of age, male sex, and history of cardiovascular diseases had a 6.43-fold higher prevalence of carotid artery stenosis (odds ratio, 6.43; 95% confidence interval, 3.80 to 10.89) than those with none of these factors. Propensity score-matched analysis showed that incidences of postoperative stroke and cardiovascular comorbidities were both lower in patients who underwent CAS and received appropriate anticoagulant therapy than in those who did not (p = 0.0619 and p = 0.0319, respectively).

CONCLUSIONS

Preoperative CAS is a simple and useful tool for detecting carotid artery stenosis. Administration of perioperative anticoagulant therapy to preoperative patients with lung cancer and carotid artery stenosis identified by CAS may prevent postoperative stroke and cardiovascular events.

Clinical and Genetic Implications of Mutation Burden in Squamous Cell Carcinoma of the Lung

BACKGROUND

Lung squamous cell carcinoma (LSCC) is a major histological subtype of lung cancer. In this study, we investigated genomic alterations in LSCC and evaluated the clinical implications of mutation burden (MB) in LSCC.

METHODS

Genomic alterations were determined in Japanese patients with LSCC (N = 67) using next-generation sequencing of 415 known cancer genes. MB was defined as the number of non-synonymous mutations per 1 Mbp. Programmed death-ligand 1 (PD-L1) protein expression in cancer cells was evaluated by immunohistochemical analysis.

RESULTS

TP53 gene mutations were the most common alteration (n = 51/67, 76.1%), followed by gene alterations in cyclin-dependent kinase inhibitor 2B (CDKN2B; 35.8%), CDKN2A (31.3%), phosphatase and tensin homolog (30.0%), and sex-determining region Y-box 2 (SOX2, 28.3%). Histological differentiation was significantly poorer in tumors with high MB (greater than or equal to the median MB) compared with that in tumors with low MB (less than the median MB; p = 0.0446). The high MB group had more tumors located in the upper or middle lobe than tumors located in the lower lobe (p = 0.0019). Moreover, cancers in the upper or middle lobes had significantly higher MB than cancers in the lower lobes (p = 0.0005), and tended to show higher PD-L1 protein expression (p = 0.0573). SOX2 and tyrosine kinase non-receptor 2 amplifications were associated with high MB (p = 0.0065 and p = 0.0010, respectively).

CONCLUSIONS

The MB level differed according to the tumor location in LSCC, suggesting that the location of cancer development may influence the genomic background of the tumor.

Clinical Impact and Risk Factors for Skeletal Muscle Loss After Complete Resection of Early Non-small Cell Lung Cancer

BACKGROUND

A relationship between sarcopenia diagnosed by skeletal muscle area (SMA) and poor prognosis in cancer patients has recently been reported. This study aimed to clarify the clinical significance of postoperatively decreased SMA in patients with early non-small cell lung cancer (NSCLC).

METHODS

This study selected 101 patients with pathologic stage 1 NSCLC who had undergone pre- and postoperative (~ 1 year) computed tomography scans and lobectomy between 2005 and 2010 at Kyushu University Hospital. The post/pre ratio was defined as the postoperative normalized SMA (cm²/m²) at the 12th thoracic vertebra level divided by the preoperative normalized SMA. The cutoff value for the post/pre ratio was set at 0.9.

RESULTS

The study classified 31 patients (30.7%) as having decreased SMA. Poor performance status (PS) was significantly associated with decreased SMA (p = 0.048). The patients with decreased SMA had a significantly shorter disease-free survival (DFS) (p < 0.001) and overall survival (OS) (p < 0.001) than the other patients. Decreased SMA was found to be an independent prognostic factor for DFS (p = 0.010) and OS (p = 0.0072). The independent risk factors for skeletal muscle loss included poor PS (PS ≥ 1) and obstructive ventilatory impairment [forced expiratory volume (FEV) 1% < 70%].

CONCLUSIONS

Skeletal muscle loss after surgery is significantly associated with postoperative poor outcomes for patients with early NSCLC. Patients with poor PS, obstructive ventilatory impairment, or both need careful support to maintain their skeletal muscle mass. Future prospective studies may clarify whether physical activity and nutritional support improve postoperative prognosis.

Association Between PD-L1 Expression and Metabolic Activity on 18F-FDG PET/CT in Patients with Small-sized Lung Cancer

AIM

We evaluated the metabolic characteristics of small-sized lung cancer using ¹⁸F-fluorodeoxyglucose positron-emission tomography/computed tomography (¹⁸F-FDG PET/CT) with regard to programmed cell death ligand 1 (PD-L1) expression.

MATERIALS AND METHODS

PD-L1 expression was evaluated by immunohistochemistry with the antibody clone SP142 in 263 patients with surgically resected primary small-sized lung cancer. Specimens with <5% tumor membrane staining were considered negative. We examined the association between the frequency of PD-L1 expression and the maximum standardized uptake value (SUVmax) in preoperative ¹⁸F-FDG PET/CT.

RESULTS

Among patients with non-small cell lung cancer (NSCLC), the SUVmax was significantly higher in those with PD-L1 expression than in those without (p<0.0001). However, there was no correlation between SUVmax and PD-L1 expression in patients with neuroendocrine tumors (p=0.9638). Multivariate analysis revealed that smoking and a high SUVmax were independent predictors of PD-L1 expression.

CONCLUSION

PD-L1 expression was related to high glucose metabolism in small-sized NSCLC.

Relationship Between Preoperative Sarcopenia Status and Immuno-nutritional Parameters in Patients with Early-stage Non-small Cell Lung Cancer

BACKGROUND

Although the skeletal muscle in the region of the third lumbar vertebra (L3) is generally assessed in order to judge sarcopenia, not every patient with non-small cell lung cancer (NSCLC) undergoes computed tomography including the L3 region. We hypothesized that immuno-nutritional parameters could predict the existence of sarcopenia in patients with NSCLC.

AIM

The aim of this study was to retrospectively investigate the correlation between preoperative sarcopenia and immuno-nutritional parameters in patients with early-stage NSCLC.

PATIENTS AND METHODS

We selected 147 of patients with pathological stage I NSCLC who underwent preoperative measurement of immuno-nutritional parameters and CT including the L3 region.

RESULTS

Preoperative sarcopenia was significantly associated with female gender (p=0.0003) and poor prognosis (p=0.0322). In Kaplan-Meier analysis of overall survival (OS) by preoperative sarcopenia status, the sarcopenic group had significantly shorter OS than the non-sarcopenic group (5-year OS: 87.27% vs. 77.37%, p=0.0131, log-rank test). In multivariate analysis, the preoperative sarcopenia status (hazard ratio=5.138; 95% confidence interval=2.305-11.676; p<0.0001) was an independent prognostic factor. Preoperative sarcopenia status was significantly related to controlling nutritional status score (p=0.0071) and Geriatric Nutritional Risk Index (GNRI) (p<0.0001). Spearman's correlation test showed good significant correlation between preoperative sarcopenia status and GNRI (r=0.348, p<0.0001).

CONCLUSION

The preoperative GNRI is a simple and useful predictor for existence of preoperative sarcopenia which was associated with poor outcome in patients with early-stage NSCLC.

Successful resection of a tracheal metastasis of rectal cancer: a case report

A tracheal metastasis (TM) from non-pulmonary malignancy is extremely rare, and there are very few reports regarding TM. Here, we report a case of the successful tracheal resection of TM of colorectal cancer. A 36-year-old man underwent a surgical resection for the rectal cancer. Approximately 5 years after the surgical resection of the primary rectal cancer, an isolated TM was identified. The patient was successfully treated with a tracheal resection. In conclusion, the current case suggested that the best treatment of the isolated TM might be a surgical resection.

A Case of the Resected Lymphohistiocytoid Mesothelioma: BAP1 Is a Key of Accurate Diagnosis

BACKGROUND

Malignant mesothelioma (MM) is a well-known malignant tumor that occurs in the pleura and is histopathologically classified into three subtypes. Lymphohistiocytoid mesothelioma (LHM) is considered a variant of epithelioid MM, and few cases have been reported. First case of LHM was reported by Henderson et al. in 1988. It is difficult to precisely diagnose LHM, and it is often misdiagnosed as reactive mesothelial cell proliferation.

CASE REPORT

An 82-year-old man, with the smoking history of nine pack-years, was referred to our Department due to an abnormal shadow and pleural effusion in the left lung field on the chest X-ray imaging. His occupation was a teacher through his life without any asbestos exposure. Computed tomography (CT) and ¹⁸F-fluorodeoxyglucose-position emission tomography showed a tumor which was suggestive of malignancy on the left chest wall, with the possible invasion into the left 2nd to 4th ribs. He underwent a CT-guided biopsy and a thoracentesis, but the tumor was shown to be a benign tumor indicative of a reactive mesothelial cell proliferation. Then, he underwent a surgical resection and the tumor was suspected of liposarcoma macroscopically. Histological and immunohistochemical findings were suggestive of mesothelial lesion, such as nodular histiocytic or mesothelial hyperplasia. However, loss of BAP1 and no p16 homozygous deletion in the tumor cells led to the diagnosis of LHM, not a benign lesion.

Correlation between CXCR4/CXCR7/CXCL12 chemokine axis expression and prognosis in lymph-node-positive lung cancer patients

The CXCR4/CXCR7/CXCL12 chemokine axis plays important roles in the migration of tumor cells during cancer development by modulating site‐specific distant metastasis including to regional lymph nodes. We investigated the correlation of these chemokine expressions to prognosis in lymph‐node‐positive non‐small‐cell lung cancer (NSCLC) patients. A total of 140 surgically resected specimens of primary site (PS) and metastatic lymph nodes (MLN) of NSCLC involving hilar and/or mediastinal lymph nodes (N1‐2) were collected. CXCR4, CXCR7 and CXCL12 expressions were evaluated. Cox regression analysis was performed to determine whether these chemokines were independent prognostic factors in N1‐2 NSCLC. High expression of CXCR4 in PS and CXCL12 in MLN was associated with poor overall survival (OS) (P = .025 and .033, respectively). Significant correlations between CXCR4 expression in PS and CXCL12 expression in MLN were observed (P = .040). There was significant difference in OS between 2 groups according to expressions of CXCR4 in PS and CXCL12 in MLN (P = .0033). Expression of CXCL12 in MLN was identified as an independent prognostic factor (HR 1.79, 95% CI 1.08‐3.04, P = .023). CXCL12 in MLN was mainly expressed by tumor cells compared with stromal cells (56% vs 25%, respectively, P < .0001). CXCR4/CXCL12 may play roles in tumor progression in MLN and is associated with poor prognosis of lymph‐node‐positive NSCLC patients.

Assessment of pleural air leakage using digital chest drainage system after surgical pulmonary resection: Comparison of visible alveolar air leakage with the digital value measured by a digital chest drainage system

Background

The sensitivity of postoperative pleural air leakage (PAL) after pulmonary resection is evaluated by a simple subjective grading method in clinical practice. A new electronic digital chest drainage evaluation system (DCS) recently became clinically available. This study was designed to evaluate the clinical application of the DCS in monitoring the airflow volume and managing postoperative PAL.

Methods

We prospectively enrolled 25 patients who underwent pulmonary resection. Postoperative PAL was evaluated using both conventional PAL grading based on the physician’s visual judgment (analog chest drainage evaluation system [ACS]: Level 0 = no leakage to 4 = continuous leakage) and the DCS. The DCS digital measurement was recorded as the flow volume (ml/min), which was taken once daily from postoperative day 1 to the day of chest drainage tube removal.

Results

In total, 45 measurements were performed on 25 patients during the evaluation period. Postoperative PAL was observed in five patients (20.0%) and judged as ACS Level >1. The mean DCS values corresponding to ACS Levels 0, 1, 2, and 3 were 2.42 (0.0–11.3), 48.6 (35.4–67.9), 95.6 (79.7–111.5), and 405.3 (150.3–715.6), respectively. The Spearman correlation test showed a significant positive correlation between the ACS PAL level and DCS flow volume (R = 0.8477, p < 0.001).

Conclusions

A relationship between the visual PAL level by the ACS and the digital value by the DCS was identified in this study. The numeric volume obtained by the DCS has been successful in information-sharing with all staff. The digital PAL value evaluated by the DCS is appropriate, and the use of the DCS is promising in the treatment of postoperative PAL after pulmonary resection.