Pathological Pleural Invasion is a Risk Factor for Late Recurrence in Long-Term Survivors of Non-small Cell Lung Cancer after Complete Resection.

BACKGROUND: Information regarding late recurrence after pulmonary resection for non-small cell lung cancer (NSCLC) is limited. This study aimed to analyze the risk factors for late recurrence after surgery for NSCLC in the current era. PATIENTS AND METHODS: We conducted a retrospective study of patients who underwent complete resection for pathological I-III NSCLC between 2006 and 2015. Late recurrence was defined as a recurrence that met the following conditions: (1) the patient underwent chest computed tomography (CT) at or after 54 months after surgery and recurrence was not detected at that time, and (2) recurrence that occurred more than 5 years after surgery. The factors influencing late recurrence, relapse-free survival (RFS), and overall survival (OS) after surgery were analyzed. RESULTS: A total of 1275 with 5-year relapse-free survival after surgery were enrolled in this study. The mean age of the patients was 66.4 years and 54% of the patients were men. The median interval between surgery and the latest follow-up examination was 98 months. In total, 35 patients (2.7%) experienced late recurrence and 138 patients have died thus far. The cumulative recurrence, RFS, and OS rates at 10 years were 3.9%, 84.9%, and 86.3%, respectively. A multivariate analysis revealed that pleural invasion was an independent risk factor for late recurrence. Pleural invasion was a poor prognostic factor for both RFS and OS. CONCLUSIONS: Pleural invasion was a predictor of late recurrence. Age > 67 years, preoperative serum carcinoembryonic antigen (CEA) > 5 ng/ml, non-adenocarcinoma, and pleural invasion were poor prognostic factors for RFS.

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.

Development of a multivariable prediction model for prolonged air leak after lung resection.

OBJECTIVES: Prolonged air leak (PAL) is a common complication of lung resection. Research on predictors of PAL using a digital drainage system (DDS) remains insufficient. In this study, we investigated the predictive factors of PAL to establish a novel early postoperative prediction model for PAL. METHODS: A retrospective cohort study and validation study were conducted. We examined patients who underwent lung resection with DDS at our institute. The relationship between the clinical factors and measurements of the DDS, including the difference between the set and measured intrapleural pressure (named: additional negative pressure [ANP]) at postoperative hour (POH) 3, with PAL was analyzed. RESULTS: A total of 494 patients were enrolled, 29 of whom had PAL. Percent forced expiratory volume in 1 s <60%, ANP <1 cmH2O, air leak flow >20 mL/min and pleural adhesion findings at surgery were independent predictors of PAL according to a multivariable analysis. The PAL rate was clearly stratified according to our novel risk scoring system, which simply notes the presence of the above four factors, that is, the rate increases when the score increases. The area under the curve (AUC) of the receiver operating characteristic (ROC) analysis for this scoring system was 0.818. Analysis of the validation cohort (n = 133) revealed that this scoring system showed a sufficient ability to predict PAL. CONCLUSIONS: ANP at POH 3 is an independent predictor of PAL. Thus, the risk-scoring system proposed in this study is useful for predicting PAL in the early postoperative period.

Progressive changes in the protein expression profile of alveolar septa in early-stage lung adenocarcinoma.

BACKGROUND: Adenocarcinomas show a stepwise progression from atypical adenomatous hyperplasia (AAH) through adenocarcinoma in situ (AIS) to invasive adenocarcinoma (IA). Immunoglobulin superfamily containing leucine-rich repeat (ISLR) is a marker of tumor-restraining cancer-associated fibroblasts (CAFs), which are distinct from conventional, strongly α-smooth muscle actin (αSMA)-positive CAFs. Fibroblast activation protein (FAP) has been focused on as a potential therapeutic and diagnostic target of CAFs. METHODS: We investigated the changes in protein expression during adenocarcinoma progression in the pre-existing alveolar septa by assessing ISLR, αSMA, and FAP expression in normal lung, AAH, AIS, and IA. Fourteen AAH, seventeen AIS, and twenty IA lesions were identified and randomly sampled. Immunohistochemical analysis was performed to evaluate cancer-associated changes and FAP expression in the pre-existing alveolar structures. RESULTS: Normal alveolar septa expressed ISLR. The ISLR level in the alveolar septa decreased in AAH and AIS tissues when compared with that in normal lung tissue. The αSMA-positive area gradually increased from the adjacent lung tissue (13.3% ± 15%) to AIS (87.7% ± 14%), through AAH (70.2% ± 21%). Moreover, the FAP-positive area gradually increased from AAH (1.69% ± 1.4%) to IA (11.8% ± 7.1%), through AIS (6.11% ± 5.3%). Protein expression changes are a feature of CAFs in the pre-existing alveolar septa that begin in AAH. These changes gradually progressed from AAH to IA through AIS. CONCLUSIONS: FAP-positive fibroblasts may contribute to tumor stroma formation in early-stage lung adenocarcinoma, and this could influence the development of therapeutic strategies targeting FAP-positive CAFs for disrupting extracellular matrix formation.

Utility of needle biopsy in centrally located lung cancer for genome analysis: a retrospective cohort study.

BACKGROUND: It is essential to collect a sufficient amount of tumor tissue for successful next-generation sequencing (NGS) analysis. In this study, we investigated the clinical risk factors for avoiding re-biopsy for NGS analysis (re-genome biopsy) in cases where a sufficient amount of tumor tissue could not be collected by bronchoscopy. METHODS: We investigated the association between clinical factors and the risk of re-genome biopsy in patients who underwent transbronchial biopsy (TBB) or endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) and required re-genome biopsy in cases enrolled in LC-SCRUM Asia, a prospective nationwide genome screening project in Japan. We also examined whether the frequency of re-genome biopsy decreased between the first and second halves of the enrolment period. RESULTS: Of the 572 eligible patients, 236 underwent TBB, and 134 underwent EBUS-TBNA. Twenty-four TBBs required re-genome biopsy, and multivariate analysis showed that the risk of re-genome biopsy was significantly increased in lesions where the tumor lesion was centrally located. In these cases, EBUS-TBNA should be utilized even if the lesion is a pulmonary lesion. However, it should be noted that even with EBUS-TBNA, lung field lesions are at a higher risk of re-canalization than mediastinal lymph node lesions. It was also found that even when tumor cells were detected in rapid on-site evaluation, a sufficient amount of tumor tissue was not always collected. CONCLUSIONS: For centrally located pulmonary mass lesions, EBUS-TBNA, rather than TBB, can be used to obtain tumor tissues that can be analyzed by NGS.

Mediastinal lymph node dissection in older patients with non-small cell lung cancer.

PURPOSE: We evaluated the impact of omitting mediastinal lymph node dissection (MLND) from the surgical treatment of non-small cell lung cancer (NSCLC) in older patients. METHODS: We collected data retrospectively on 2475 patients who underwent pulmonary resection for NSCLC at our hospital between June, 2006 and December 2018. The subjects of this analysis were 209 patients aged ≥ 75 years who underwent lobectomy for cN0-1 NSCLC. The patients were divided into two groups based on whether they underwent MLND (ND2 group) or not (group ND0-1). RESULTS: There were more patients aged ≥ 80 years in the ND0-1 group than in the ND2 group (p < 0.001). Patients in the ND0-1 group had clinically earlier stage lung cancers than those in the ND2 group (p = 0.053). We matched patient characteristics in the ND0-1 and ND2 groups by age, tumor diameter, cN, histology, and radiological findings. There were no significant differences in overall survival between the groups (p = 0.295). More patients in the ND2 group suffered complications (41.6% vs. 27.3%, p = 0.061) and arrhythmia episodes than those in the ND0-1 group (14.3% vs. 3.9%, p = 0.021). CONCLUSION: MLND in older patients may not extend survival but it could lead to complications. Thus, the omission of MLND may be considered for patients of advanced age.

Non-adjacent interlobar lymph node metastasis distant from small-sized peripheral non-small cell lung cancer.

PURPOSE: The optimal extent of lymph node dissection (LND) during segmentectomy is unclear. During segmentectomy, it is more challenging to dissect the non-adjacent interlobar lymph node (non-aiLN) away from the primary tumor than to dissect the adjacent interlobar lymph node (aiLN), as injury to the preserved parenchyma and bronchus may occur. We examined whether dissection of non-aiLNs was required during intentional segmentectomy. METHODS: This retrospective cohort study included 310 patients who underwent lobectomy and mediastinal LND for non-small cell lung cancer of ≤ 2 cm at the Osaka International Cancer Institute during January 2006 to December 2015. We investigated LN metastasis distribution and evaluated metastases in non-aiLNs distant from the primary lesion. RESULTS: Six (1.9%) patients had iLN metastasis. Patients with iLN metastasis did not have primary lesions in the right upper lobe or left upper segment. Of the six patients with iLN metastasis, three had non-aiLN metastasis with a tumor diameter of ≥ 15 mm, with high positron emission tomography standard uptake values (> 3.5). Two patients had multiple LN metastases, and one had solitary LN metastasis. CONCLUSION: Non-aiLN dissection may be unnecessary during segmentectomy of the right upper lobe or left upper segment; however, it should be considered during lower-lobe segmentectomy.

[Dealing with Pleural Adhesion in Video-assisted Thoracoscopic Surgery].

The adhesion between the visceral and parietal pleura makes video-assisted thoracoscopic surgery (VATS) difficult or impossible. When performing VATS without conversion to thoracotomy due to pleural adhesion, it is important to( ⅰ) evaluate the presence and extent of the adhesion preoperatively, (ⅱ) carefully perform detachment, and( ⅲ) adequately repair the injured visceral pleura. We evaluate visceral sliding with the help of chest ultrasonography and plan the best approach to make utility inci-sions, camera port, and third-port incisions. Considering the difficulty in repairing the injured visceral pleura under VATS, we perform extra-pleural detachment of adhesions around the injured visceral pleura, which can facilitate the repair of the pleural injury. For repairing pleural injury, we use free mediastinal fat tissue as biological pledgets to support suturing. In this report, we present the approaches and techniques we follow to perform VATS for patients with pleural adhesion.

Preoperative AminoIndex Cancer Screening (AICS) abnormalities predict postoperative recurrence in patients undergoing curative resection for non-small cell lung cancer.

BACKGROUND: AminoIndex™ Cancer Screening (AICS (lung)) was developed as a screening test for lung cancer using a multivariate analysis of plasma-free amino acid (PFAA) profiles. According to the developed index composed of PFAA, the probability of lung cancer was categorized into AICS (lung) ranks A, B, and C in order of increasing risk. The aim of the present study was to investigate the relationship between the preoperative AICS (lung) rank and surgical outcomes in patients who underwent curative resection for non-small cell lung cancer (NSCLC). METHODS: Preoperative blood samples were collected from 297 patients who underwent curative resection for NSCLC between 2006 and 2015. PFAA concentrations were measured. The relationship between the preoperative AICS (lung) rank and clinicopathological factors was examined. The effects of the preoperative AICS (lung) rank on postoperative outcomes were also analyzed. RESULTS: The AICS (lung) rank was A in 93 patients (31.3%), B in 82 (27.6%), and C in 122 (41.1%). The AICS (lung) rank did not correlate with any clinicopathological factors, except for age. Based on follow-up data (median follow-up period of 6 years), postoperative recurrence was observed in 22 rank A patients (23.7%), 15 rank B (18.3%) and 49 rank C (40.2%). In the univariate analysis, preoperative AICS (lung) rank C was a worse factor of recurrence-free survival (p = 0.0002). The multivariate analysis identified preoperative AICS (lung) rank C (HR: 2.17, p = 0.0005) as a significant predictor of postoperative recurrence, particularly in patients with early-stage disease or adenocarcinoma. CONCLUSION: Preoperative AICS (lung) rank C is a high-risk predictor of postoperative recurrence in patients undergoing curative resection for NSCLC.

Improvement strategies for successful next-generation sequencing analysis of lung cancer.

Aim: We aimed to improve the success rate of NGS (next-generation sequencing) analysis through improved strategies of lung cancer sampling. Materials & methods: The improvement strategies are as follows. Surgically resected specimens were preferentially submitted in cooperation with pathologists and surgeons. In bronchoscopic samples, the size of the sample collection device and the number of samples collected was increased. Results: The strategies increased the success rate of NGS analysis of DNA from 69.3 to 91.1%, and that of RNA from 64.6 to 90.0%. Discussion: The introduction of strategies aimed at improving the success of NGS analysis resulted in an improvement in the success rate and brought us closer to the delivery of effective precision medicine in cancer therapy.

[Perioperative Management for Patients Undergoing General Thoracic Surgery with Metabolic or Endocrine Disorders].

By improvement of surgical procedures and advances in perioperative management, the patients with various comorbidity diseases have been able to undergo pulmonary resection. In particular, the patients with endocrine and metabolic disorders are relatively frequent and often underwent pulmonary resection. Most of them are chronic diseases and often controlled for a long time. However, they sometimes have drastic changes due to surgical stress during perioperative periods. Failure to properly perioperative management for them may result in postoperative morbidity or mortality. Therefore, we have to well know perioperative changes by surgical stress for them. Among endocrine and metabolic disorders, following is frequent, diabetes, hyperthyroidism and hypothyroidism, steroid administration. We describe perioperative management of them. When operating on them, it is important to ① proper evaluation before surgery, ② careful postoperative management, and ③ close coordination with the department of endocrinology and anesthesiology.

Outcomes of initial surgery in patients with clinical N2 non-small cell lung cancer who met 4 specific criteria.

PURPOSE: The role of surgery for patients with non-small cell lung cancer (NSCLC) with clinical mediastinal lymph node metastasis (N2) remains controversial. We specified 4 criteria for performing initial surgery in these patients (single-station N2, non-bulky N2, N2 with regional mode of spread, and N2 without N1) and examined the outcomes to validate the treatment options. METHODS: Between September 2002 and December 2010, of 1290 patients who underwent complete resection for NSCLC, 808 patients underwent initial standard resection, including 779 patients with cN0-1 and 29 with cN2. We compared the outcomes, and evaluated patients with cN2-pN2. RESULTS: The median follow-up was 45.5 months (3-119 months). Seventy (9.0 %) and 24 (82.8 %) patients had p-N2 in the cN0-1 and cN2 groups, respectively (p < 0.0001). The 5-year disease-free survival (DFS) rates in the cN0-1 and cN2 groups were 73.3 and 50.6 %, respectively (p = 0.0053), and the 5-year overall survival (OS) rates were 81.3 and 71.1 %, respectively (p = 0.051). The 5-year DFS and OS of patients with cN2-pN2 were 52.5 and 72.6 %, respectively. CONCLUSIONS: Patients with clinical N2 disease based on our criteria represent a highly specific group with a favorable prognosis. Resection should therefore be the initial treatment for these patients.

[A Case of Synchronous Double Cancers of the Liver and Pancreas Treated Using Pancreaticoduodenectomy and Liver Resection].

A 50-year-old woman had a 12mm liver tumor at segment 4 and was diagnosed with hemangioma. Two years later, the liver tumor had grown to 27mm in diameter, and a new pancreatic tumor was detected using CT examination. The pancreatic tumor was suspected of being pancreatic carcinoma, based on the results of endoscopic-ultrasound-guided fine-needlebiopsy( EUS-FNA)of the pancreas. The liver tumor was diagnosed as adenocarcinoma using liver biopsy. Because of its slow growth and the solitary liver tumor, synchronous pancreatic cancer and intrahepatic cancer were suspected. We therefore performed pancreaticoduodenectomy with portal vein resection and partial liver resection of segment 4. Upon histological analysis, carcinoma in situ was detected in the liver tumor and the patient was diagnosed with synchronous double cancers of the liver(cholangiocellular carcinoma)and pancreas(invasive ductal carcinoma). Our case indicated that it is very difficult to distinguish cholangiocellular carcinoma from metastatic liver tumor using diagnostic images. We should therefore consider the possibility of cholangiocellular carcinoma when a solitary tumor in the liver is detected at the same time as pancreatic cancer.

Assessment of mutational profile of Japanese lung adenocarcinoma patients by multitarget assays: a prospective, single-institute study.

BACKGROUND: Integration of mutational profiling to identify driver genetic alterations in a clinical setting is necessary to facilitate personalized lung cancer medicine. A tumor genotyping panel was developed and the Shizuoka Lung Cancer Mutation Study was initiated as a prospective tumor genotyping study. This study reports the frequency of driver genetic alterations in Japanese lung adenocarcinoma patients, and clinicopathologic correlations with each genotype. METHODS: Between July 2011 and January 2013, 411 lung adenocarcinoma patients admitted to the Shizuoka Cancer Center were included in this study with their written informed consent. Surgically resected tissues, tumor biopsies, and/or body cavity fluids were collected and tested for 23 hotspot sites of driver mutations in 9 genes (EGFR, KRAS, BRAF, PIK3CA, NRAS, MEK1, AKT1, PTEN, and HER2), gene amplifications in 5 genes (EGFR, MET, PIK3CA, FGFR1, and FGFR2), and ALK, ROS1, and RET fusions. RESULTS: Genetic alterations were detected in 54.3% (223 of 411) of all patients. The most common genetic alterations detected in this study were EGFR mutations (35.0%) followed by KRAS mutations (8.5%) and ALK fusions (5.0%). Concurrent genetic alterations were detected in 22 patients (5.4%), and EGFR mutations were observed in 16 patients as the most common partner for concurrent genetic alteration. Significantly more concurrent genetic alterations were observed in older patients. CONCLUSIONS: This is one of the largest reports of a prospective tumor genotyping study on Japanese patients with adenocarcinoma. These data suggest that mutational profiling data using a multimutational testing platform would be valuable for expanding the range of molecular-targeted therapeutics in lung cancer.

Prospective genetic profiling of squamous cell lung cancer and adenosquamous carcinoma in Japanese patients by multitarget assays.

BACKGROUND: Despite considerable recent progress in the treatment of lung adenocarcinoma, there has been little progress in the development of efficacious molecular targeted therapies for squamous cell lung cancer. In addition to the recent comprehensive genome-wide characterization of squamous cell lung cancer, it is also important to genotype this form of cancer. We therefore conducted the Shizuoka Lung Cancer Mutation Study to analyze driver mutations in patients with thoracic malignancies. Here we report the results of genotyping in patients with squamous cell lung cancer. METHODS: Based on the biobanking system, in conjunction with the clinic and pathology lab, we developed a genotyping panel designed to assess 24 mutations in 10 genes (EGFR, KRAS, BRAF, PIK3CA, NRAS, MEK1, AKT1, PTEN, HER2 and DDR2), EGFR, MET, PIK3CA, FGFR1 and FGFR2 copy numbers, and EML4-ALK and ROS1 translocations, using pyrosequencing plus capillary electrophoresis, quantitative polymerase chain reaction (PCR) and reverse-transcription PCR, respectively. RESULTS: A total of 129 patients with squamous cell lung cancer and adenosquamous carcinoma were enrolled in this study between July 2011 and November 2012. We detected genetic alterations in 40% of all cases. Gene alterations included: EGFR mutations, 6%; KRAS mutations, 4%; PIK3CA mutations, 13%; NRAS mutations, 1%; KIF5b-RET fusion gene, 1%; EGFR copy number gain, 5%; PIK3CA copy number gain, 15%; and FGFR1 copy number gain, 5%. Twelve patients (9%) harbored simultaneous genetic alterations. Genetic alterations were detected more frequently in surgically-resected, snap-frozen samples than in formalin-fixed, paraffin-embedded samples (50% vs. 29%). In addition, patients aged ≤70 years old and never-smokers showed high frequencies of genetic alterations. CONCLUSIONS: This study represents one of the largest prospective tumor-genotyping studies to be performed in Asian patients with squamous cell lung cancer. These results suggest that incorporation of genetic profiling into lung cancer clinical practice may facilitate the administration of personalized cancer treatments in patients with squamous cell lung cancer.

Results of surgical treatment for non-small cell lung cancer with positive sputum cytology: experience from a single institution.

BACKGROUND: Little is known about the prognostic value of positive sputum cytology in patients with non-small cell lung cancer (NSCLC). PATIENTS AND METHODS: We retrospectively examined the clinicopathological data of 30 patients who had undergone complete resection for NSCLC with positive sputum cytology between September 2002 and June 2011. RESULTS: Distant recurrence occurred significantly more frequently in the patients with adenocarcinoma (Ad) than in those with squamous cell carcinoma (p = 0.01). The most frequent metastatic site after surgery was the brain, occurring in five patients with Ad. The 5-year disease-free survival (DFS) and overall survival (OS) rates of the 30 patients were 53 and 49%, respectively. In multivariate analyses, radiographic feature of pneumonic-type shadow and pathological N (pN) 1-2 status were the independent factors significantly correlated with poor DFS (p = 0.009, 0.001, respectively), whereas pN 1-2 status was the only independent factor significantly correlated with poor OS (p = 0.009). CONCLUSION: Surgical outcome for NSCLC with positive sputum cytology was unfavorable at our institution. Close surveillance after a curative resection is mandatory for those patients presenting with radiographic feature of pneumonic-type shadow as those with lymph node metastases because they are at high risk for recurrence.

Acute exacerbation of interstitial lung disease with lung cancer after surgery: evaluation with 2-[18]-fluoro-2-deoxy-D-glucose positron emission tomography.

PURPOSE: Interstitial lung disease (ILD) has been associated with primary lung cancer and an increased risk of postoperative acute exacerbation (AE). The effectiveness of 2-[18]-fluoro-2-deoxy-D-glucose ((18)F-FDG) positron emission tomography (PET) for staging lung cancer is well established. This study investigates the association of FDG uptake on PET in patients with AE of ILD. METHODS: The subjects of this retrospective study were 1309 patients with lung cancer, who underwent pulmonary resection at Shizuoka Cancer Center between September, 2002 and January, 2011. ILD was diagnosed with chest computed tomography in 95 patients, 81 of whom underwent (18)F-FDG PET before surgery. Six patients suffered from AE after surgery (AE group), while the remaining 75 (non-AE group) did not. We investigated the clinico-pathological findings and the results of FDG uptake on PET using the value of the I/M ratio, which is the ratio of the peak of standardized uptake value (SUV) of the ILD area to the mean SUV of the mediastinum. RESULTS: There was no significant difference in clinico-pathological findings, but a significance difference in the I/M ratio (P = 0.0102). CONCLUSION: The FDG uptake in PET may be a predictive factor for AE of ILD in patients who have undergone lung cancer surgery.

Metastatic pathways to the lower zone by segment in patients with clinical T1 lower lobe non-small cell lung cancer.

OBJECTIVE: Segmentectomy and mediastinal lymph node dissection (LND) may increasingly be used for non-small cell lung cancer (NSCLC). Lymph node metastasis (LNM) distribution varies by lower lobe segments; however, its segment-specific spread to the lower zone (#8, 9) (LZ) in lower lobe NSCLC is seldom reported. METHODS: In total, 352 patients with clinical T1 lower lobe NSCLC who underwent lobectomy with systematic or lobe-specific LND were included for analysis between January 2006 and December 2018. RESULTS: Fifty-eight (16.2%) patients had LNM (pN1: 24, pN2: 34), and nine (2.6%) had LZ metastasis. LZ metastasis was significantly more frequent in tumors with diameter > 2 cm, tumors without ground-glass opacity on radiological findings, left lung cancer, and basal segment lung cancer (respectively, p = 0.039, 0.006, 0.0177, 0.0024). None of the S6 NSCLC patients had LZ metastasis. Two patients with right basal segment NSCLC had LZ metastases (tumor on S10) as well as N1 lymph node and subcarinal zone metastasis. Seven (8.4%) patients with left basal segment NSCLC had LZ metastasis (tumor on S8: 3, tumor on S10: 4). Of them, three patients with left basal NSCLC had isolated LZ metastasis. CONCLUSIONS: The LND of the LZ can be omitted for clinical T1 patients with S6 NSCLC. In addition, the LND of the LZ may be omitted in right basal NSCLC if intraoperative confirmation of negative N1 and subcarinal zone lymph nodes is obtained; however, it is necessary for left basal segment NSCLC.

Outcomes and prognostic factors of repeat pulmonary metastasectomy.

OBJECTIVES: Information on prognostic factors after repeat pulmonary metastasectomy (PM) is limited, and outcomes after a third PM are not well documented. METHODS: A single-institute retrospective study was conducted. Between 2000 and 2020, 68 patients underwent repeat PM for pulmonary metastases from various cancers. Outcomes and prognostic factors for the second PM and outcomes after the third PM were analysed. RESULTS: This study included 39 men and 29 women. The mean age at second PM was 53.2 years old. The primary tumours were soft tissue sarcoma in 24 patients, colorectal cancer in 19 and osteosarcoma in 10. The interval between the first PM procedure and detection of pulmonary metastasis after the first PM (months) was ≤12 in 37 patients and >12 in 31 patients. At the second PM, 20 patients underwent lobectomy or bilobectomy, and 48 underwent sublobar resection. Complete resection was achieved in 60 patients, and 52 patients experienced recurrence after the second PM. The 5-year relapse-free survival and overall survival rates after the second PM were 27% and 48%, respectively. Multivariable analysis revealed that the interval between the first PM and the subsequent detection of pulmonary metastasis (≤12 months) was a poor prognostic factor for both relapse-free survival and overall survival after the second PM. Seventeen patients underwent a third PM, 3 of whom achieved a 3-year disease-free survival. CONCLUSIONS: Patients with a period of >12 months between the first PM and the subsequent detection of pulmonary metastases showed favourable outcomes and are thus considered good candidates for second PM. A third PM may be beneficial for selected patients.