Rare but clinically important salivary gland-type tumor of the lung: A review.

Salivary gland-type tumor (SGT) of the lung, which arises from the bronchial glands of the tracheobronchial tree, was first recognized in the 1950s. SGT represents less than 1% of all lung tumors and is generally reported to have a good prognosis. Mucoepidermoid carcinoma (MEC) and adenoid cystic carcinoma (ACC) are the two most common subtypes, comprising more than 90% of all SGTs. The reported 5-year survival rate of patients with SGT is 63.4%. Because this type of tumor develops in major bronchi, patients with SGT commonly present with symptoms of bronchial obstruction, including dyspnea, shortness of breath, wheezing, and coughing; thus, the tumor is usually identified at an early stage. Most patients are treated by lobectomy and pneumonectomy, but bronchoplasty or tracheoplasty is often needed to preserve respiratory function. Lymphadenectomy in the surgical resection of SGT is recommended, given that clinical benefit from lymphadenectomy has been reported in patients with MEC. For advanced tumors, appropriate therapy should be considered according to the subtype because of the varying clinicopathologic features. MEC, but not ACC, is less likely to be treated with radiation therapy because of its low response rate. Although previous researchers have learned much from studying SGT over the years, the diagnosis and treatment of SGT remains a complex and challenging problem for thoracic surgeons. In this article, we review the diagnosis, prognosis, and treatment (surgery, chemotherapy, and radiotherapy) of SGT, mainly focusing on MEC and ACC. We also summarize reports of adjuvant and definitive radiation therapy for ACC in the literature.

The Lung Cancer Surgical Study Group of the Japan Clinical Oncology Group: outstanding contribution and entering a new phase.

The Lung Cancer Surgical Study Group (LCSSG) of the Japan Clinical Oncology Group (JCOG) was organized in 1986 and initially included 26 collaborative institutions, which has increased to 52 institutions currently. JCOG-LCSSG includes thoracic surgeons, medical oncologists, pathologists, and radiotherapists. In the early period, the JCOG-LCSSG mainly focused on combined modality therapies for lung cancer. Since the 2000s, the JCOG-LCSSG has investigated adequate modes of surgical resection for small-sized and peripheral non-small cell lung cancer and based on the radiological findings of whole tumor size and ground-glass opacity. Trials, such as JCOG0802, JCOG0804, and JCOG1211, have shown the appropriateness of sublobar resection, which has significantly influenced routine clinical practice. With the introduction of targeted therapy and immunotherapy, treatment strategies for lung cancer have changed significantly. Additionally, with the increasing aging population and medical costs, tailored medicine is strongly recommended to address medical issues. To ensure comprehensive treatment, strategies, including surgical and nonsurgical approaches, should be developed. Currently, the JCOG-LCSSG has conducted numerous clinical trials to adjust the diversity of lung cancer treatment strategies. This review highlights recent advancements in the surgical field, current status, and future direction of the JCOG-LCSSG.

Updated review of perioperative treatment for non-small-cell lung cancer in the new era of immune checkpoint inhibitors: past, present, and future.

The perioperative treatments for non-small cell lung cancer (NSCLC) should control both local and microscopic systemic disease, because the survival of patients with NSCLC who underwent surgical resection alone has been dismal except in stage IA patients. One way to improve surgical outcome is the administration of chemotherapy before or after the surgical procedure. During the last two decades, many clinical studies have focused on developing optimal adjuvant or neoadjuvant cisplatin-based chemotherapy regimens that can be combined with surgical treatment and/or radiotherapy. Based on the results of those clinical studies, multimodality therapy has been considered to be an appropriate treatment approach for locally advanced NSCLC patients. When nodal involvement is discovered postoperatively, adjuvant cisplatin-based chemotherapy has conferred an overall survival benefit. More recently, neoadjuvant and/or adjuvant use of immunotherapy adding to the cisplatin-based chemotherapy has been revealed to improve survival of the patients with locally advanced NSCLC in many large-scale clinical trials; although, optimal treatment strategies are still evolving.

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.

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.

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.

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.

New revisions and current issues in the eighth edition of the TNM classification for non-small cell lung cancer.

In the eighth edition of the TNM classification of lung cancer, the prognostic impact of tumor size is emphasized as a descriptor of all T categories. Especially in lung cancer where tumor size is 5 cm or less, the 1-cm cutoff point significantly differentiated the survival outcome. In addition, the new staging categories were assigned, namely, Tis (adenocarcinoma in situ) and T1mi (minimally invasive adenocarcinoma). Furthermore, the measurement of a radiological solid component size excluding the ground glass opacity component or pathological invasive size without a lepidic component was proposed for deciding the cT/pT categories for lung adenocarcinoma. The N descriptors were kept the same as in the eventh edition on the whole, however, quantification of nodal disease had a prognostic impact based on the number of nodal stations involved in the eighth edition, i.e. N1a as a single N1 station, N1b as a multiple N1 station, N2a1 as a single N2 station without N1 (skip metastasis), N2a2 as a single N2 station with N1 disease, and N2b as a multiple N2 station. In the M descriptors, subclassification was performed based on the location or numbers of distantly metastatic lesions, i.e. M1a as any intrathoracic metastases, M1b as a single distant metastatic lesion in one organ, and M1c as multiple distant metastases in either a single organ or multiple organs. Survival analysis of the eighth edition of the TNM classification clearly separated the distinct groups, however, unsolved issues still remain that should be discussed and further revised for the forthcoming TNM staging system.

Surgical resection for clinical-Stage I radiological pure-solid lung cancer that met the current high risk criteria.

OBJECTIVE: We assessed whether surgical resection is acceptable for radiological invasive non-small cell lung cancer (NSCLC) that met the current high-risk criteria. METHODS: We reviewed 500 clinical-Stage I NSCLCs with a radiological pure-solid appearance. High-risk criterion was defined as follows: (1) preoperative FEV1% ≤ 50% or DLco% ≤ 50%, (2) age > 75y with 50% < FEV1% < 60% or 50% < DLco% < 60%, and (3) three or more severe general comorbidities. RESULTS: The high-risk group comprised 184 (37%) patients. The percentages for elderly, male, smoker, non-adenocarcinoma histology were significantly higher than those of the normal-risk group (P < 0.001). Lobectomy was performed in 148 (80%) patients. Overall survival (OS) was significantly worse in the high-risk group (59.4% vs 73.1%, P = 0.004), however, a multivariate analysis revealed that high-risk was not associated with poor survival (P = 0.519). Furthermore, there were no significant differences between the high-risk and normal-risk groups regarding cancer-specific survival (74.5% vs 79.2%, P = 0.569). Postoperative morbidity rates were significantly different between the two study arms (45% vs 25%, P < 0.001), however, the 30-day and 90-day mortality rates for the high-risk group were 1.6% and 3.8%, respectively. In the high-risk patients, the difference in survival between lobectomy and sublobar resection was not significant (69.4% vs 78.6%, P = 0.716), and was also proven in the propensity-score matched patients (82.1% vs 76.0%, P = 0.623). CONCLUSIONS: Conventional high-risk criteria are not always appropriate prognostic variables, and lung cancer specific survival or short-term mortalities for high-risk patients were fully acceptable. Surgical therapy including lobectomy should not be readily excluded from radical local management even when a patient meets the high-risk criteria.

Is cancer history really an exclusion criterion for clinical trial of lung cancer? Influence of gastrointestinal tract cancer history on the outcomes of lung cancer surgery.

Objective: Exclusion of patients with a history of other cancer treatment except in situ situation has been considered to be inevitable for clinical trials investigating survival outcome. However, there have been few reports confirming these influences on surgical outcome of lung cancer patients ever. Methods: Multi-institutional, individual data from patients with non­small cell lung cancer resected between 2000 and 2013 were collected. The patients were divided into two groups: those with a history of gastrointestinal tract cancer (GI group) and those without any history (non-GI group). We compared the outcomes with well-matched groups using propensity scoring to minimize bias related to the nonrandomness. The influence of gastrointestinal tract cancer stage, disease-free interval, and treatment method for gastrointestinal tract cancer on the surgical outcome of non­small cell lung cancer was examined. Results: We analyzed 196 patients in the GI group and 3732 in the non-GI group. In unmatched cohort, multivariate analyses showed that a history of gastrointestinal tract cancer did not affect overall survival or recurrence-free survival. Independent predictors of poor prognosis included older age, male sex, high carcinoembryonic antigen levels and advanced clinical stage of non­small cell lung cancer. The two groups in the matched cohort demonstrated equivalent overall survival and recurrence-free survival, even in patients with clinical stage I. Gastrointestinal tract cancer stage, disease-free interval and treatment method for gastrointestinal tract cancer were not associated with outcomes. Conclusions: History of early gastrointestinal tract cancer completely resected is not always necessary for exclusion criteria in clinical trial of lung cancer.

Surgical Management of Multifocal Ground-Glass Opacities of the Lung: Correlation of Clinicopathologic and Radiologic Findings.

Background We evaluated the clinicopathologic characteristics and oncologic outcome in patients who underwent surgical resection for multifocal ground-glass opacities (GGOs) of the lung. Methods We examined 131 patients who underwent surgical resections for multiple clinical-N0 lung cancers. Multifocal GGOs were defined as tumors showing GGO dominance with a consolidation/tumor ratio (CTR) < 0.5 for all, whereas solid lesions were defined as having at least one tumor that showed CTR ≥0.5. Results Multifocal GGOs were found in 53 (40.5%) patients. A significantly large number of GGOs with a median of 3 per patient (range 2-41) was observed in multifocal GGOs (p < 0.0001). A multivariate analysis demonstrated tumor size ≤ 20 mm (p = 0.0407) and multifocal GGOs (p = 0.0345) were significantly associated with the survival. Regarding surgical managements for multifocal GGOs, the 5-year overall survival (OS) of multiple synchronous or staged limited resection only (n = 26) versus anatomical resection with or without additional limited resection (n = 27) was not significantly different (100% and 91.9%, p = 0.2287). The total number of resected multifocal GGOs was 278, most of which revealed adenocarcinoma or precancerous lesions. Unresected or new GGOs developed in 19 (35.8%) patients, all of which remained pure-GGO of < 10 mm in size without any interventions. The 5-year OS of multifocal GGOs and solid lesions were 94.4% and 80.6% (p = 0.0096), with a median follow-up time of 60 months. Conclusion Surgical interventions combined with limited surgery or adequate follow-up management based on the findings on thin-section CT could provide acceptable oncologic outcomes for multifocal GGOs.

The impact on the prognosis of unsuspected N2 disease in non-small-cell lung cancer: indications for thorough mediastinal staging in the modern era.

PURPOSE: Predicting the prognosis of advanced non-small-cell lung cancer (NSCLC) patients who present with clinically unsuspected N2 is very different due to the heterogeneity of this cohort. Thus, this study was undertaken to identify the clinicopathological features and survival of patients with clinical N0 or N1 and pathological N2, namely, unsuspected N2. METHODS: Among 239 patients with pathological N2 NSCLC, we reviewed the cases of 92 (38.5 %) patients who showed unsuspected N2. The prognosis was investigated using the Kaplan-Meier method and a Cox regression model. RESULTS: The 5-year overall survival (5yOS) of the patients with unsuspected N2 was 51.2 %. Based on a multivariate analysis, age and 18F-fluorodeoxyglucose (FDG) uptake in the lymph nodes were significant prognostic factors of unsuspected N2 (p = 0.0081, 0.0228, respectively). The 5yOS of PET-negative unsuspected N2 (n = 68) was 58.9 %, whereas that of PET-positive unsuspected N2 (n = 24) was 29.7 % (p = 0.0026). Furthermore, the 5yOS of PET-negative unsuspected N2 was significantly better than that of both clinical and pathological N2 s (i.e., suspected N2; n = 60; 5yOS, 42.1 %; p = 0.0051), while no significant difference was observed between PET-positive unsuspected N2 and suspected N2 (p = 0.6325). CONCLUSIONS: A preoperative evaluation of the lymph nodes by PET/CT has a potential benefit in predicting the prognosis. A thorough evaluation of the lymph nodes is, therefore, needed if the lymph nodes show an FDG uptake, even in cases that show a clinical N0 status on thin section CT scans.

Clinicopathological characteristics of lung cancer mimicking organizing pneumonia on computed tomography-a novel radiological entity of pulmonary malignancy.

OBJECTIVE: Lung cancer could be misdiagnosed as benign due to its atypical radiological findings or difficulty in the histological diagnosis. We intended to elucidate the clinicopathological features of such lung cancers. METHODS: Between 2008 and 2011, we performed surgical resection for 564 consecutive patients with lung adenocarcinoma. Findings on thin-section computed tomography were reviewed for all patients, 13 of whom were found to have lung cancer mimicking organizing pneumonia. The radiological and clinicopathological features of lung cancer mimicking organizing pneumonia and other adenocarcinomas were evaluated. RESULTS: Among 13 patients with lung cancer mimicking organizing pneumonia, 4 were men. The median age was 70 years (range 62-81 years). Six patients were followed up for more than 1 year (range 1-108 months) as their lesions were misdiagnosed as organizing pneumonia. Preoperative carcinoembryonic antigen was significantly high (P = 0.025), and maximum tumor dimension was significantly large for lung cancer mimicking organizing pneumonia (30 vs. 23.6 mm, P = 0.001). Pathologically, there was no vascular invasion (P = 0.012) and only one lymphatic invasion (P = 0.064). One case of lymph node metastasis to the N2 node was found due to misdiagnosis as organizing pneumonia for 9 years. CONCLUSIONS: Basically, lung cancer mimicking organizing pneumonia was less invasive and showed slow growth. However, nodal metastasis could be found. Thus, radiological diagnosis based on the findings of thin-section computed tomography is valuable to avoid delay in diagnosis.

The oncological outcomes of segmentectomy in clinical-T1b lung adenocarcinoma with a solid-dominant appearance on thin-section computed tomography.

PURPOSE: We investigated the surgical outcomes of clinical-T1b lung adenocarcinomas patients whose tumors had a solid-dominant radiological appearance and who were treated with segmentectomy or lobectomy. METHODS: We examined 154 surgically resected clinical-T1b lung adenocarcinomas with a "solid-dominant" appearance on thin-section computed tomography (CT). The preoperative thin-section CT images of all cases were reviewed. "Solid-dominant" was defined as 0.5≤ consolidation/tumor ratio (CTR) <1.0. RESULTS: Pathological nodal metastasis, lymphatic invasion, vascular invasion, and pleural invasion were found in 7 (4.5 %), 27 (18 %), 21 (14 %), and 15 (10 %) patients with clinical-T1b solid-dominant lung adenocarcinoma, respectively. Lobectomy and segmentectomy were performed in 123 (80 %) and 31 (20 %) cases, respectively. The 3-year overall survival (OS) and relapse-free survival (RFS) of patients with clinical-T1b solid-dominant lung adenocarcinoma were 95.5 and 92.4 %, respectively. The 3-year RFS and OS did not differ significantly between the patients who underwent lobectomy or segmentectomy (3-year RFS, 92.3 vs. 93.4 %, p = 0.8713; 3-year OS, 95.3 vs. 96.6 %, p = 0.7603). Segmentectomy was not found to be a prognostic factor for RFS (p = 0.8714), or OS (p = 0.7613). CONCLUSIONS: Segmentectomy can achieve acceptable oncological outcomes (both in terms of OS and RFS), which are similar to those achieved with standard lobectomy, in patients with clinical-T1b solid-dominant lung adenocarcinoma.

Surgical intervention strategy for postoperative chylothorax after lung resection.

PURPOSE: The optimal surgical management of postoperative chylothorax has not been established. Thus, we evaluated the treatment strategy for postoperative chylothorax and identified associated predictors of surgical intervention. METHODS: The subjects of this retrospective study were 50 patients who suffered postoperative chylothorax, representing 4 % of 1235 patients who underwent pulmonary resection between 2008 and 2012. The chylothorax patients were classified into two groups based on their postoperative management: a conservative group and a surgical group. The following parameters were investigated to establish the predictors of surgical intervention for chylothorax: mode of surgery, preoperative complications, intraoperative management, and postoperative clinical status. RESULTS: Forty-one (82 %) patients were treated conservatively and 9 (18 %) underwent reoperation, as direct or concomitant ligation of the thoracic duct at the point of leakage. The frequency of postoperative chest tube drainage just after initial surgery was significantly greater in the surgical group than the conservative group before oral intake was restarted (448 ± 189 vs. 296 ± 117 ml/12 h, respectively; p = 0.003). Furthermore, it was a significant predictor of reoperation based on a multivariate analysis (p = 0.010). CONCLUSIONS: The amount of chest tube drainage just after surgery and before oral intake was a useful predictor to help us decide on the need for early surgical intervention for postoperative chylothorax.

Predictors of pathological non-invasive lung cancer with pure-solid appearance on computed tomography to identify possible candidates for sublobar resection.

PURPOSE: This study aimed to establish favorable predictors for patients with clinical stage IA radiological pure-solid lung cancer to identify possible candidates for sublobar resection. METHODS: We examined 275 patients with surgically resected clinical stage IA radiological pure-solid lung cancer. Pathological grade PL0, Ly0, V0, or N0 disease was defined as non-invasive pure-solid lung cancer (NIPS). RESULTS: Nodal involvement was observed in 63 (23 %) patients with clinical stage IA pure-solid lung cancer, while NIPS was identified in 77 (28 %). Multivariate analysis revealed that air bronchogram (p = 0.0328), clinical T1a (p = 0.0041), and SUVmax (p = 0.0002) were significant clinical predictors of NIPS. When these clinical predictors were combined and the relevant patients' disease was classified as favorable, the frequency of nodal involvement was only 4 %. Furthermore, the 3-year overall survival (OS) of the patients with "favorable" clinical stage IA pure-solid lung cancer was 100 % despite their operative modes. In contrast, the 3-year OS even for patients with clinical stage IA disease, if they had neither of these clinical predictors, was 74.1 %. CONCLUSIONS: Tumor size, the presence of air bronchogram, and the SUVmax level were significant favorable predictors of pathological non-invasive status, and patients with these clinical predictors could be candidates for sublobar resection for clinical stage IA pure-solid lung cancers.