Visceral pleura invasion and pleural lavage tumor cytology by lung cancer: a prospective appraisal

Impact of Pleural Lavage Cytology Positivity on Early Recurrence After Surgery for Non-Small Cell Lung Cancer

OBJECTIVE

The aim of this study was to elucidate the impact of pleural lavage cytology positivity on early recurrence in patients operated on non-small cell lung cancer (NSCLC).

METHODS

This is a multicentre prospective cohort study of 684 patients undergoing an anatomical lung resection for NSCLC between October 2015 and October 2017 at 12 national centres. A pleural lavage was performed before and after lung resection. The association between the different predictors of early recurrence and PLC positivity was performed using univariate and multivariate logistic regression models. A propensity score analysis was performed by inverse probability weighting (IPSW) using average treatment effect (ATE) estimation to analyse the impact of PLC positivity on early recurrence.

RESULTS

Overall PLC positivity was observed in 15 patients (2.2%). After two years, 193 patients (28.2%) relapsed, 182 (27.2%) with a negative PLC and 11 (73.3%) with a positive PLC (p<0.001). Factors associated to early recurrence were adenocarcinoma histology (OR=1.59, 95%CI 1.06-2.38, p=0.025), visceral pleural invasion (OR=1.59, 95%CI 1.04-2.4, p=0.03), lymph node involvement (OR=1.84, 95%CI 1.14-2.96, p=0.013), advanced pathological stage (OR=2.12, 95%CI 1.27-3.54, p=0.004) and PLC positivity (OR=4.14, 95%CI 1.25-16.36, p=0.028). After IPSW, PLC positivity was associated with an increased risk of early recurrence (OR=3.46, 95%CI 2.25-5.36, p<0.001).

CONCLUSIONS

Positive pleural lavage cytology was found to be the strongest predictor of early recurrence.

Pleural Carcinoembryonic Antigen and Maximum Standardized Uptake Value as Predictive Indicators of Visceral Pleural Invasion in Clinical T1N0M0 Lung Adenocarcinoma

Background

Visceral pleural invasion (VPI) is a poor prognostic factor that contributes to the upstaging of early lung cancers. However, the preoperative assessment of VPI presents challenges. This study was conducted to examine intraoperative pleural carcinoembryonic antigen (pCEA) level and maximum standardized uptake value (SUVmax) as predictive markers of VPI in patients with clinical T1N0M0 lung adenocarcinoma.

Methods

A retrospective review was conducted of the medical records of 613 patients who underwent intraoperative pCEA sampling and lung resection for non-small cell lung cancer. Of these, 390 individuals with clinical stage I adenocarcinoma and tumors ≤30 mm were included. Based on computed tomography findings, these patients were divided into pleural contact (n=186) and non-pleural contact (n=204) groups. A receiver operating characteristic (ROC) curve was constructed to analyze the association between pCEA and SUVmax in relation to VPI. Additionally, logistic regression analysis was performed to evaluate risk factors for VPI in each group.

Results

ROC curve analysis revealed that pCEA level greater than 2.565 ng/mL (area under the curve [AUC]=0.751) and SUVmax above 4.25 (AUC=0.801) were highly predictive of VPI in patients exhibiting pleural contact. Based on multivariable analysis, pCEA (odds ratio [OR], 3.00; 95% confidence interval [CI], 1.14-7.87; p=0.026) and SUVmax (OR, 5.25; 95% CI, 1.90-14.50; p=0.001) were significant risk factors for VPI in the pleural contact group.

Conclusion

In patients with clinical stage I lung adenocarcinoma exhibiting pleural contact, pCEA and SUVmax are potential predictive indicators of VPI. These markers may be helpful in planning for lung cancer surgery.

Comparison of cytology, chest computed and positron emission tomography findings in malignant pleural effusion from lung cancer

Background

Malignant pleural effusion (MPE) is a common medical problem in lung cancer (LC). Pleural fluid cytology (PFC), chest computed tomography (CCT) and positron emission tomography (PET) findings are helpful as first line approach. The objectives of this study were to evaluate whether there is a correlation between PFC, CCT and PET in patients with MPE due to LC.

Methods

We selected patients from our electronic files. Data of PFC, pleural biopsy (PB), CCT and PET have been recorded and analyzed.

Results

A total of 101 consecutive patients (66 males, 65.3%) with a mean age of 66.2±31 years were selected. Types of LC were adenocarcinoma in 71 patients (70.2%), squamous in 13 (12.8%), small-cell in 12 (11.8%) and large cell in 5 (4.9%). CCT showed nodules in 6 (5.9%), pleural thickening in 8 (7.9%) and both in 17 (16.8%) patients. PFC was positive in 55/91 thoracentesis (60.4%) and 32/52 thoracoscopy (61.5%), while PB in 38/40 performed (95%). PET fixation was found in 32/47 (68%) patients who had MPE at diagnosis. When we associate PFC to CCT and PET findings, the yield in our study becomes 90%. No correlation was observed between CCT findings and PFC (P=0.62) between PFC and PET fixation (P=0.63) or between CCT and PET (P=0.06).

Conclusions

In our cohort of LC patients with MPE, we observed a high sensitivity for PFC, while in most of the cases no findings were observed in CCT. PET had a relative low sensitivity. However, when all 3 methods were combined the yield was 90%.

[Latest Progress of Intraoperative Pleural Lavage Cytology in Lung Cancer Surgery]

非小细胞肺癌（non-small cell lung cancer, NSCLC）根治术中胸腔冲洗液细胞学检查是一种常用的检测肿瘤进展并评估患者预后的诊断技术。长期以来大量研究者致力于阐明术中胸腔冲洗液细胞学检查结果与肺癌患者术后生存及肿瘤复发转移的关系。由于不同研究间存在明显异质性，其结论也各有不同。但能肯定的是，胸腔冲洗液肿瘤细胞检查阳性已被证实为手术患者的不良预后因素之一。本文尝试从临床意义、影响因素及可能发生机制等角度就近年来术中胸膜腔冲洗的研究进展作一综述。

Risk factors of lymph node metastasis in patients with non-small cell lung cancer ≤ 2 cm in size: A monocentric population-based analysis

Aim

This study was designed to determine the risk factors of lymph node metastasis in non‐small cell lung cancer (NSCLC) patients with tumors ≤ 2 cm, using the Shanghai Chest Hospital Lung Cancer Database.

Methods

Five hundred and eighteen patients with NSCLC ≤ 2 cm were included in this study, and were classified into lymph node‐positive and lymph node‐negative groups. Univariate and multivariate logistic regression analyses were performed to select the independent risk factors for lymph node metastasis in NSCLC patients.

Results

No evidence of metastasis was found in tumors ≤ 1 cm, all positive results were in tumors sized 1–2 cm. Imaging characteristics, including solid and part‐solid nodules, were strongly associated with lymph node metastasis (odds ratio [OR] 24.959, 95% confidence interval [CI] 5.999–103.835, P < 0.001; OR 12.559, 95% CI 3.564–44.259, P < 0.001) and subgroup logistic analysis (OR 21.384, 95% CI 5.058–90.407, P < 0.001; OR 11.632, 95% CI 3.290–41.126, P < 0.001). Greater lymph node metastasis was observed in non‐adeno non‐squamous carcinoma. The presence of pleural invasion and carcinoembryonic antigen levels indicated lymph node dissection. Similar results were revealed in subgroup analysis in tumors ≤ 2 to > 1 cm.

Conclusion

Size had a great impact on lymph node metastasis, especially tumors of 1–2 cm. Preoperative imaging, non‐adeno non‐squamous carcinoma, pleural invasion, and carcinoembryonic antigen all indicated lymph node dissection. There was no discrepancy between N1 and N2 positive lymph nodes.

Peripheral lung adenocarcinomas harboring epithelial growth factor receptor mutations with microRNA-135b overexpression are more likely to invade visceral pleura

Lung adenocarcinoma, characterized by its early and aggressive local invasion and high metastatic potential, is the most frequently observed histological type of non-small-cell lung cancer (NSCLC). Visceral pleural invasion (VPI) caused by peripheral lung adenocarcinomas is closely associated with the poor prognosis of patients with NSCLC. The association between VPI and some clinicopathological characteristics has been observed in the past few decades. However, the molecular mechanism of VPI in lung adenocarcinomas is unknown. In the present, the expression level of microRNA (miR-)135b and epidermal growth factor receptor (EGFR) mutations using the reverse transcription-quantitative polymerase chain reaction and DNA sequencing, respectively. In addition, the present study aimed at exploring the association between the miR-135b level, EGFR mutations and VPI in peripheral lung adenocarcinoma. The results of the present study demonstrated that miR-135b was significantly upregulated in lung adenocarcinoma compared with adjacent normal tissue and positively associated EGFR mutations in peripheral lung adenocarcinoma. Furthermore, it was identified that lung adenocarcinomas with EGFR mutations and miR-135b overexpression were more likely to invade visceral pleura. Taken together, these findings indicate that miR-135b overexpression is positively associated with mutations to EGFR, which may promote the development of peripheral lung adenocarcinomas by the formation of VPI. This indicates that the two factors may serve as prognostic markers and molecular targets for the treatment of peripheral lung adenocarcinomas.

Extent of visceral pleural invasion and the prognosis of surgically resected node-negative non-small cell lung cancer

Background

Visceral pleural invasion (VPI) is generally considered a poor prognostic factor in non‐small cell lung cancer (NSCLC). VPI is defined as penetration beyond the elastic layer of visceral pleura (PL1), including the visceral pleural surface without the involvement of adjacent structures (PL2) by cancer cells. The aim of this study was to evaluate the influence of the extent of VPI on NSCLC prognosis.

Methods

This was a retrospective study of 90 patients with resected node‐negative NSCLC with VPI. The overall survival (OS) and disease‐free survival (DFS) rates were estimated using the Kaplan–Meier method. Multivariate analysis for prognostic factors was performed using a Cox proportional hazards regression model. The pattern of recurrence was also compared between PL1 and PL2 groups.

Results

Seventy‐three patients had PL1. The three‐year OS rates for the PL1 and PL2 groups were 97.4% and 82.4%, respectively (P = 0.004). The two‐year DFS rates for PL1 and PL2 groups were 81.0% and 76.5%, respectively (P = 0.419). According to the multivariate analysis, PL2 was not a significant prognostic factor for survival outcome in node‐negative NSCLC with VPI compared to PL1 (hazard ratio for DFS 1.753, 95% confidence interval 0.582–5.284; P = 0.319). In this study, six patients in the PL1 and one in PL2 group developed ipsilateral pleural recurrence (P = 1.000).

Conclusion

VPI extent may not influence survival outcomes in patients with surgically resected node‐negative NSCLC with VPI.

Visceral pleural invasion in lung adenocarcinoma ≤3 cm with ground-glass opacity: a clinical, pathological and radiological study

BACKGROUND

Visceral pleural invasion (VPI) had been demonstrated as an aggressive sign in non-small cell lung cancers (NSCLC). However, its incidence and clinical relevance in early lung cancer showing ground glass nodules (GGNs) has not been clarified.

METHODS

All consecutive surgically treated patients with solitary GGNs between 2009 and 2013 were reviewed retrospectively. Inclusion criteria were defined as lesions ≤3 cm with pleura abutting on computed tomography (CT) scan and pathologically confirmed NSCLC.

RESULTS

Out of 156 enrolled patients, 38 had pathologically confirmed VPI. The incidence of VPI was 41.5% (27/65) if the tumor diameter was larger than 2.0 cm and 14.3% (13/91) if diameter was smaller than 2.0 cm (P<0.001). Further, the incidence was 17.4% (12/69) in pure GGNs and 32.2% (28/87) in part-solid GGNs (P=0.040). The tumor size and the nodule nodule-pleural relationship were significant predictors of positive VPI. In cases with pleural indentation, attachment, and closeness, the incidence was 38.1%, 25.5%, and 5.3%, respectively (P=0.001). All cases were PL0 and PL1, with no PL2 cases observed.

CONCLUSIONS

Although VPI was visible in both pure/mix GGNs, it was more common in larger (>2 cm) GGNs. The radiographic findings of nodule abutment or a pleural tag did not reliably predict or exclude VPI. In patients with GGNs, a low rate of PL2 invasion may be observed.

Prognostic Value of Pleural Lavage Cytology in Patients with Lung Cancer Resection: An Updated Meta-Analysis

OBJECTIVE

Pleural lavage cytology (PLC) is considered as a possible tool for assessing prognosis of lung cancer patients. We aimed to comprehensively review the prognosis value of PLC in patients undergoing surgical resection.

METHODS

We searched 4 electronic databases for relevant studies comparing positive PLC and negative PLC. The primary outcomes included survival rate and recurrence rate at maximum follow-up.

RESULTS

The meta-analysis included 28 studies, with a total of 20,714 patients. For the overall survival rate of all stages, the results demonstrated that positive pre-resection, post-resection and pooled PLC were associated with unfavorable survival: hazard ratio (HR) 2.89 (95% confidence interval [CI] 2.48-3.37), 2.70 (1.90-3.83), and 2.89 (2.52-3.31), respectively. For the stage I survival rate, the combined results also suggested that positive pre-resection, post-resection and pooled PLC were associated with unfavorable survival: HR 3.29 (95% CI 2.55-4.25), 4.85 (2.31-10.20), and 3.16 (2.53-3.94), respectively. Furthermore, a meta-analysis of 14 studies included 14,279 patients showed that positive pre-resection, post-resection and pooled PLC were associated with an increased risk of overall recurrence: risk ratio (RR) 2.45 (95% CI 1.91-3.15), 2.37 (1.11-5.09), and 2.37 (95% CI 2.00-2.80), respectively. Positive PLC was also associated with a high pleural recurrence (RR 4.77; 95% CI 3.13-7.26) or distant recurrence (RR 2.33; 95% CI 1.65-3.29).

CONCLUSIONS

Both positive pre- resection and post-resection PLC are associated with not only higher tumor recurrence but also unfavorable survival outcomes in patients with lung cancer resection. This technique can therefore act as a strong prognostic factor for tumor recurrence and adverse survival rates.

Pleural involvement in lung cancer

The pleural space, a sterile secluded environment in the thoracic cavity, represents an attractive metastatic site for various cancers of lung, breast and gastrointestinal origins. Whereas lung and breast adenocarcinomas could invade the pleural space because of their anatomic proximity, "distant" cancers like ovarian or gastrointestinal tract adenocarcinomas may employ more active mechanisms to the same end. A pleural metastasis is often accompanied by a malignant pleural effusion (MPE), an unfavorable complication that severely restricts the quality of life and expectancy of the cancer patient. MPE is the net "product" of three different processes, namely inflammation, enhanced angiogenesis and vascular leakage. Current efforts are focusing on the identification of cancer cell autocrine (specific mutation spectra and biochemical pathways) and paracrine (cytokine and chemokine signals) characteristics as well as host features (immunological or other) that underlie the MPE phenotype. Herein we examine the pleural histology, cytology and molecular characteristics that make the pleural cavity an attractive metastasis destination for lung adenocarcinoma. Mesothelial and tumor features that may account for the tumor's ability to invade the pleural space are highlighted. Finally, possible therapeutic interventions specifically targeting MPE are discussed.

[Place and role of the pleura in non-small cell lung cancer dissemination]

INTRODUCTION

The pleural involvement (PLI) in non-small cell lung cancer (NSCLC) has a poor prognosis, even though it might be very heterogeneous.

PATIENTS AND METHODS

A multicentric retrospective descriptive study was performed over 2329 patients who were operated for NSCLC between 1979 and 2010. The patients with PLI were classified in P(Parietal)PLI and V(visceral)PLI and then each subdivided : VPLI to peripheric (VPLI-P) and fissural (VPLI-F) and PPLI to mediastinal (PPLI-M) and costal (PPLI-C). Characteristics and survival were compared between the subgroups as well as with patients without PLI (WPLI, n=1439).

RESULTS

The sex-ratio was 2.8 (males: n=1713). The PLI patients were significantly younger, with a less sex-ratio, less R0 resections (96% versus 98.7%, P=0.000076), and less N0 (60% vs 70%, P<10(-6)) as their 5-year survival (45.7% vs 55.5%, P<10(-6)). The PLI was related to the size of NSCLC (P<10(-6)) and N2 involvement (P=0.0020). It was less frequent after neoadjuvant treatment (36.2% vs 39.1% P=0.03). In the VPLI-F or PPLI-M, pneumonectomies were more frequent (P<10(-6)). In VPLI-P (n=196/561), there were more pN1 and pN2 (P=0.0065) with a 5-year survival of 42.9% vs 54.4%, P=0.013. In multivariate analysis, the PLI was not an independent prognostic factor contrary to age, sex, type of resection, pT and pN.

CONCLUSION

The pleura play a major role in NSCLC dissemination. Its involvement affects pN, the type of surgical resection and justifies the use of neoadjuvant treatment.

Pleural lavage cytology as an independent prognostic factor in non-small-cell lung cancer patients with stage I disease and adenocarcinoma

We previously reported that cancer cells may be detected through pleural lavage cytology (PLC). In this study, we sought to re-examine the prognostic significance of the PLC status based on an extended dataset with an additional follow-up period. Pleural lavage following thoracotomy was cytologically examined in 1,317 consecutive patients who were diagnosed with NSCLC between 1987 and 2004 at the Thoracic Surgery Units of Kobe University Graduate School of Medicine and Hyogo Cancer Center. Among the investigated patients, 46 exhibited positive cytological findings. The prognosis of these patients was significantly worse compared to that of patients without positive PLC. Of the 844 pathological stage I patients, 18 had a positive PLC status and their prognosis was significantly worse compared to that of patients with stage I disease without positive PLC. In conclusion, positive PLC findings were associated with a poor prognosis and this finding was significant for patients with stage I disease. These results suggest the need for PLC status evaluation during staging and treatment planning in patients with NSCLC.

[Pleural lymphatics and effusions]

The pleural lymphatic system has a great absorption capacity. Its most known function is fluid resorption. The pleura which cover the lungs (visceral pleura), the mediastinum, diaphragm and thoracic wall (parietal pleura) are formed by a mesothelial cell layer (mesothelium). This permeable layer is in direct contact with the vascular endothelium. The mesothelium is based over a connective tissue (interstitium) containing the blood and lymphatic vessels. The primary lymphatic vessels drain interstitium but are also in direct contact with pleural space by the stoma or openings, situated in the lower parts of parietal pleura, i.e: diaphragm, over lower ribs and mediastinum but not existing in the adjacent visceral pleura. In addition, a part of interstitial pulmonary fluid entered in the pleural cavity by passing the visceral pleura would be absorbed by these openings. The resorption process is active and directly related to the function of smooth muscles of lymphatic vessels. Besides resorption, we must emphasize that this "pumping" activity is permanent and the origin of negative pressure (the pleural void) in pleural cavity, a unique property. The other resorbed elements are molecules, bacterial and cellular debris, cells, red blood and cancer cells.

Intrapleural chemotherapy improves the survival of non-small cell lung cancer patients with positive pleural lavage cytology

PURPOSE

Information regarding the treatment of pleural lavage cytology (PLC)-positive patients is still limited. This study evaluated the efficacy of intrapleural chemotherapy (IPC) in PLC-positive patients.

METHODS

Three hundred eighty-six of the 567 lung cancer patients who underwent surgery had undergone PLC after thoracotomy, following by a complete resection were evaluated. IPC was performed after surgery, and cisplatin or adriamycin was injected intrapleurally through the thoracic tube.

RESULTS

The pathological diagnosis showed that 17 patients (4.4 %) were positive for (or suspected to have) malignancy in their PLC. The univariate and multivariate analysis showed that only pleural invasion was a significant predictor of a PLC-positive status. The 5-year overall survival in PLC-positive patients was 38 % and that in PLC-negative patients was 84 %. Both the univariate (p < 0.01) and multivariate (p = 0.045) analyses showed that the status of PLC was significantly associated with the overall survival. Eight of the 17 PLC-positive patients underwent IPC. The 2-year OS rate in the patients treated with IPC was 88 % and that of those without IPC was 44 (p = 0.04).

CONCLUSION

IPC improved the postoperative survival in PLC-positive NSCLC patients, and a further prospective evaluation regarding this therapy is warranted.

Anatomy of the pleura

The pleura is a monolayer of mesothelial cells covering the lung and inner surface of the chest cavity, creating the pleural space. The mesothelial cells rest on a matrix of collagen, elastic fibers, blood vessels, and lymphatics, which allow the lung and chest to expand and contract, protected from friction by the pleural fluid and properties of the mesothelial cells. With a rich blood supply and lymphatic system just deep to the mesothelial layer, the pleura is a dynamic layer protecting the lung and pleural cavity from infection while transmitting the forces of respiration without damage to the underlying lung parenchyma.

The influence of intraoperative pleural perfusion with matrine-cisplatin or cisplatin on stromal cell-derived factor-1 in non-small cell lung cancer patients with subclinical pleural metastasis

The early diagnosis and treatment of non-small cell lung cancer (NSCLC) in patients with subclinical pleural metastasis is currently a challenge. In an effort to establish a method for the diagnosis and treatment of these patients, we conducted a single-blind study during which intraoperative pleural lavage cytology (PLC) was performed in 164 patients with NSCLC without obvious pleural effusion. Stromal cell-derived factor-1 (SDF-1) serum concentrations were analyzed using enzyme-linked immunoassay on day 1 prior to tumor resection and on day 7 postoperatively. Western blot analysis was used for the detection of CXCR4 protein expression in resected tumors. Intraoperative pleural perfusion chemotherapy, with either cisplatin or cisplatin plus matrine, was given to patients with positive PLC. A group of 30 patients with NSCLC that did not undergo intraoperative PLC were used as a control group. Of the 164 study patients, 41 (25%) patients had positive PLC. Serum SDF-1 concentrations were higher in PLC-positive patients compared with patients negative for PLC and control patients. Serum SDF-1 concentrations were also lower at postoperative day 7 in patients treated with cisplatin plus matrine compared with control patients and those perfused with cisplatin alone. A lower incidence of chemotherapy-related adverse events was observed in patients treated with cisplatin plus matrine versus those treated with cisplatin alone during the first postoperative month. Patients with positive PLC showed a higher CXCR4 protein expression than patients with negative PLC. Based on the results of this study, PLC combined with serum SDF-1 concentration measurements may be considered as an effective index to determine the risk of subclinical pleural metastasis in patients with lung cancer. In addition, cisplatin plus matrine was confirmed as an initial approach for pleural perfusion and was superior to cisplatin alone.

Commonly encountered difficulties in pathologic staging of lung cancer

CONTEXT

Lung cancer is the leading cause of cancer mortality worldwide. Despite technological, therapeutic, and scientific advances, most patients present with incurable disease and a poor chance of long-term survival. For those with potentially curable disease, lung cancer staging greatly influences therapeutic decisions. Therefore, surgical pathologists determine many facets of lung cancer patient care.

OBJECTIVE

To present the current lung cancer staging system and examine the importance of mediastinal lymph node sampling, and also to discuss particularly confusing and/or challenging areas in lung cancer staging, including assessment of visceral pleura invasion, bronchial and carinal involvement, and the staging of synchronous carcinomas.

DATA SOURCES

Published current and prior staging manuals from the American Joint Committee on Cancer and the International Union Against Cancer as well as selected articles pertaining to lung cancer staging and diagnosis accessible through PubMed (National Library of Medicine) form the basis of this review.

CONCLUSIONS

Proper lung cancer staging requires more than a superficial appreciation of the staging system. Clinically relevant specimen gross examination and histologic review depend on a thorough understanding of the staging guidelines. Common sense is also required when one is confronted with a tumor specimen that defies easy assignment to the TNM staging system.

Clinical relevance of intraoperative pleural lavage cytology in non-small cell lung cancer

BACKGROUND

Intraoperative pleural lavage cytology for patients with lung cancer has been reported to be useful in detecting subclinical pleural dissemination. However, this procedure is not necessary for the staging of lung cancer in the current TNM staging system.

METHODS

Clinical records of 1025 patients with non-small cell lung cancer who underwent surgery were retrospectively reviewed and evaluated for the clinical relevance of intraoperative pleural lavage cytology.

RESULTS

Specimens of 37 patients (3.6%) were positive for pleural lavage cytology (PLC). Patients were categorized into three groups: positive PLC group, 27 patients with positive PLC without malignant pleural effusion or pleural dissemination; pleural dissemination (PD) group, 21 patients with malignant pleural effusion or PD; negative PLC group, 977 patients with negative PLC or negative PLC without PD. The positive PLC group had a significantly higher ratio of adenocarcinomas than the negative PLC group (p = 0.014). There was a significant difference in distribution of pleural factors between the positive and negative PLC groups (p < 0.001). Survival in the positive PLC group was significantly worse than in the negative PLC group (p = 0.007), especially in pathologic stage I (p = 0.001), but significantly better than in the PD group (p = 0.038). PLC status was found to be a significant independent prognostic factor in the multivariate analysis (p = 0.016).

CONCLUSIONS

The present study demonstrates the clinical relevance of intraoperative PLC in early stage non-small cell lung cancer. The result of intraoperative PLC should be involved in the staging system of lung cancer.

Prognostic Significance of Carcinoembryonic Antigen Level in Pleural Lavage Fluid for Patients With Lung Adenocarcinoma

BACKGROUND

Prognostic indicators for non-small cell lung cancer patients traditionally include TNM staging, pleural lavage cytology, and serum carcinoembryonic antigen levels. This prospective study evaluates carcinoembryonic antigen levels in pleural lavage fluid as a potential determinant for patients with lung adenocarcinoma.

METHODS

One hundred and fifty patients underwent thoracotomy. Pleural lavage fluid was collected, and pleural lavage cytology and lavage carcinoembryonic antigen levels were determined. The control group included 40 patients with nonmalignant disease.

RESULTS

Sixteen patients (10.7%) had positive pleural lavage cytologies. These patients and those with elevated serum carcinoembryonic antigen levels generally had a poor prognosis. Thirty-seven patients (24.7%), however, showed elevated lavage carcinoembryonic antigen levels, and a significant correlation with patient survival was demonstrated. Multivariate analysis confirmed these results. We also found a correlation between positive pleural lavage cytologies and serum carcinoembryonic antigen levels and patient survival in patients with pN0 disease but not in those with pN1-2 disease. Elevated lavage carcinoembryonic antigen levels, however, correlated significantly with survival rates in patients with pN1-2 disease.

CONCLUSIONS

An elevated lavage carcinoembryonic antigen level is an independent prognostic determinant for patients with lung adenocarcinoma, even with advanced disease, and may be a more useful marker of subclinical microdissemination than pleural lavage cytology.

Visceral pleural invasion is an invasive and aggressive indicator of non-small cell lung cancer

OBJECTIVE

Although visceral pleural invasion by non-small cell lung cancer is considered a poor-prognostic factor, further information is lacking, especially in relation to other clinicopathologic prognostic factors. We assessed the relationship between visceral pleural invasion and other clinicopathologic characteristics and evaluated its significance as a prognostic factor.

METHODS

We reviewed 1074 patients with surgically resected T1/2 non-small cell lung cancer for their clinicopathologic characteristics and prognoses. The patients were divided into 2 groups according to visceral pleural invasion status (visceral pleural invasion group and non-visceral pleural invasion group). Both groups were compared with regard to age, sex, histology, tumor size, tumor differentiation, lymph node involvement, lymphatic invasion, vascular invasion, scar grade, nuclear atypia, mitotic index, serum carcinoembryonic antigen level, and survival. Univariate and multivariate analyses were conducted.

RESULTS

Visceral pleural invasion was identified in 288 (26.8%) of the resected specimens. Survival was 76.0% at 5 years and 53.2% at 10 years in the non-visceral pleural invasion group and was 49.8% at 5 years and 37.0% at 10 years in the visceral pleural invasion group. The difference between groups was highly significant ( P < .0001). Visceral pleural invasion was also significantly associated with a higher frequency of lymph node involvement. However, regardless of N status (N0 or N1/2), there was a significant difference in survival when the visceral pleura was invaded. Visceral pleural invasion was observed significantly more frequently in tumors with factors indicative of tumor aggressiveness/invasiveness: moderate/poor differentiation, lymphatic invasion, vascular invasion, high scar grade, high nuclear atypia grade, high mitotic index, and high serum carcinoembryonic antigen level. By multivariate analysis, visceral pleural invasion proved to be a significant independent predictor of poor prognosis in non-small-cell lung cancer patients with or without lymph node involvement.

CONCLUSIONS

Visceral pleural invasion is a significant poor-prognostic factor, regardless of N status. Our analyses indicated that visceral pleural invasion is an independent indicator of non-small cell lung cancer invasiveness and aggressiveness.

Complete resection in lung cancer surgery: proposed definition

OBJECTIVE

To propose an internationally accepted definition of complete resection in lung cancer surgery.

MATERIAL AND METHODS

The International Association for the Study of Lung Cancer (IASLC) Staging Committee created the Complete Resection Subcommittee in 2001 to work on an international definition of complete resection in lung cancer surgery. The previous definitions of complete resection and the rules of the International Union Against Cancer regarding the TNM residual tumor classification, together with a thorough review of the pertinent literature, and the input of the members of the IASLC Staging Committee were considered in order to get an international consensus on the definition of complete resection in lung cancer surgery.

RESULTS

Complete resection requires all of the following: free resection margins proved microscopically; systematic nodal dissection or lobe-specific systematic nodal dissection; no extracapsular nodal extension of the tumor; and the highest mediastinal node removed must be negative. Whenever there is involvement of resection margins, extracapsular nodal extension, unremoved positive lymph nodes or positive pleural or pericardial effusions, the resection is defined as incomplete. When the resection margins are free and no residual tumor is left, but the resection does not fulfill the criteria for complete resection, there is carcinoma in situ at the bronchial margin or positive pleural lavage cytology, the term uncertain resection is proposed.

CONCLUSION

The proposed definitions of complete, incomplete and uncertain resections are clear and reproducible in an international setting to study their prognostic impact prospectively.

Intraoperative Pleural Lavage: Is It a Valid Prognostic Factor in Lung Cancer?

BACKGROUND

In patients undergoing lung resection for non-small cell lung cancer (NSCLC), the primary TNM (tumor-regional lymph node-distant metastasis) staging system is the best prognostic factor. However, it is necessary to investigate other factors that could more accurately predict a patient's prognosis. In this study we evaluated the significance of positive intraoperative pre-resectional lavage in patients with NSCLC.

METHODS

We enrolled 84 patients (79 men, 5 women) aged between 36 and 81 years (mean age, 64.8 years) undergoing a major lung resection for NSCLC, with no preoperative evidence of pleural effusions. Intraoperatively, the patients were given a pre-resectional pleural lavage with physiologic saline solution. The fluid was aspirated and sent to cytology.

RESULTS

Pre-resectional pleural lavage was positive in 19 patients (22.6%). The lavage was positive in 7.3% in patients with early stage I disease (3/41) and 37.2% in patients with stage II/III disease. In the group of 16 patients with chest wall neoplastic involvement (T3), 9 had a positive lavage (56.2%; p = 0.05). No significant correlation was found between positive lavage and nodal status, visceral pleural involvement, or histologic findings. Patients with malignant cells in the pre-resectional lavage had a significantly shorter survival than patients with a negative lavage (p = 0.025).

CONCLUSIONS

A positive cytology finding of intraoperative pre-resectional pleural lavage could be an important prognostic factor in patients undergoing major lung resection for NSCLC. Patients with a positive lavage should be upstaged. However, larger series are needed to define accurately the role of this technique in early stage lung cancer.

Visceral pleural invasion in lung cancer: recognizing histologic parameters that impact staging and prognosis

Visceral pleural involvement (VPI) is a critical component in the staging of non-small cell lung carcinoma (NSCLC). Tumors < or =3 cm that involve the visceral pleura are classified as T2 lesions, underscoring the prognostic significance of this histologic parameter. Accurate staging of small NSCLCs depends on appropriately assessing the presence or absence of VPI. Elastic stains can be instrumental in detecting disruptions of the visceral pleural elastic layer by tumor, a finding that has prognostic and staging implications similar to tumor that is present on the visceral pleural surface.

Visceral pleural involvement in nonsmall cell lung cancer: prognostic significance

BACKGROUND

A tumor of any size that invades the visceral pleura is classified in the T2 category; however, the definition of the visceral pleural involvement has remained somewhat ambiguous. It is unclear whether the T2 category includes the p2 status alone or incorporates the extent of the p1 status.

METHODS

We retrospectively analyzed the survival of 474 patients with T1 and T2 nonsmall cell lung cancer to evaluate the influence of the degree of visceral pleural involvement (p0, p1, and p2) on the prognosis and to clarify the definition of the visceral pleural involvement.

RESULTS

The 5-year survival rates according to the degree of visceral pleural involvement were 68.0% in p0 (n = 345), 43.9% in p1 (n = 110), and 54.9% in p2 (n = 19; p0 versus p1, p = 0.0004; p0 versus p2, p = 0.013; and p1 versus p2, p = 0.61). The degree of visceral pleural involvement (p0 versus p1/p2) was a significant independent prognostic factor from tumor size and lymph node involvement, by multivariate analysis (relative risk = 1.47, p = 0.033). The prognosis of pN0 patients with p1 and tumor size 3 cm or less was significantly poorer than that of those with p0 and tumor size 3 cm or less (p = 0.0004), and the prognosis of patients with p1 and tumor size more than 3 cm was significantly poorer than that of those with p0 and tumor size more than 3 cm (p = 0.024).

CONCLUSIONS

The degree of visceral pleural involvement (p0 versus p1/p2) is an important component of the lung cancer staging system. Tumors with p1 and p2 status should be regarded as representing visceral pleural involvement and T2 disease.

Pleural lavage cytology in non–small cell lung cancer: lessons from 1000 consecutive resections

OBJECTIVE

Intraoperative pleural lavage cytology for lung cancer has not been widely accepted. The prognostic significance of this procedure has yet to be intensively analyzed because the reports published thus far have involved small patient populations. We therefore performed a large prospective trial of pleural lavage cytology to elucidate its importance.

METHODS

Cytologic status of pleural lavage fluid before any manipulation of the lung was examined in 1000 consecutive patients with non-small cell lung cancer but no pleural effusion who underwent tumor resection.

RESULTS

Forty-five (4.5%) of 1000 patients had positive cytologic findings. Positive cytologic findings were observed more frequently in patients with adenocarcinoma, advanced stage, higher involvement of lymph nodes, pleural involvement of the tumor, lymphatic permeation, vascular invasion, high level of serum carcinoembryonic antigen, and male sex. The survival rate for 5 years was 28% in patients with positive findings and 67% in patients with negative findings (P <.0001). Among 587 patients with stage I disease, 13 (2.2%) had positive findings, and their 5-year survival was 43%, which was significantly poor compared with that of patients with negative findings (81%, P =.0009). Multivariable analysis demonstrated that pleural lavage cytology was an independent prognostic determinant (P =.0290). Regarding the recurrence pattern in patients with positive findings, distant metastases (19/45 [42.2%]) were observed more frequently rather than local recurrences (19/45 [22.2%]).

CONCLUSIONS

Cytologic status of pleural lavage fluid immediately after thoracotomy, an independent significant prognostic factor, constitutes valuable information to detect patients at a high risk of recurrence. Therefore cytology should be performed at the time of curative resection for non-small cell lung cancer.