Impact of positive pleural lavage cytology on survival in patients having lung resection for non–small-cell lung cancer: An international individual patient data meta-analysis

Prediction of Pleural Lavage Cytology According to Thin-Section Computed Tomography in Non-Small-Cell Lung Cancer

BACKGROUND

Although the positive rate of preresection pleural lavage cytology (PLC) is low, it is an important indicator of poor prognosis for non-small-cell lung cancer patients with frequent pleural dissemination (PD) recurrence. Thin-section computed tomography (TSCT) can reveal relationships between a primary tumor and the pleura at 1 to 2 mm intervals, and this is associated with visceral pleural invasion (VPI). However, its association with PLC remains unclear. Therefore, we aimed to improve PLC efficiency and predict PD recurrence by understanding the relationship between PLC and preoperative TSCT findings.

PATIENTS AND METHODS

Between January 2014 and December 2018, we reviewed 978 patients with non-small-cell lung cancer who underwent PLC tests during complete resection surgery. Preoperative TSCT findings were evaluated, and factors with the highest specificity (proportion of patients with radiologically to pathologically diagnosed positive PLC) were investigated. We also evaluated their relationships with VPI and PD recurrence.

RESULTS

PLC positive was identified in 55 (5.6%) of the 978 patients. The two TSCT findings predicting PLC results, "the absence of pleural findings," ie, tumor not attached to pleura or without pleural tag, and "consolidation-to-tumor ratio ≤0.5", had a specificity of 100% (95% confidence interval: 90.4%-100%); additionally, all cases with these findings were VPI negative and had no PD recurrence. And 24% of the cohort had either of these findings.

CONCLUSION

The absence of pleural findings and/or consolidation-to-tumor ratio ≤0.5 of primary tumor on preoperative TSCT can predict PLC negativity with very high probability; therefore, PLC can be omitted for such patients.

The International Association for the Study of Lung Cancer Lung Cancer Staging Project: Proposals for Revision of the Classification of Residual Tumor After Resection for the Forthcoming (Ninth) Edition of the TNM Classification of Lung Cancer

INTRODUCTION

The goal of surgical resection is to completely remove a cancer; it is useful to have a system to describe how well this was accomplished. This is captured by the residual tumor (R) classification, which is separate from the TNM classification that describes the anatomic extent of a cancer independent of treatment. The traditional R-classification designates as R0 a complete resection, as R1 a macroscopically complete resection but with microscopic tumor at the surgical margin, and as R2 a resection that leaves gross tumor behind. For lung cancer, an additional category encompasses situations in which the presence of residual tumor is uncertain.

METHODS

This paper represents a comprehensive review of evidence regarding these R categories and the descriptors thereof, focusing on studies published after the year 2000 and with adjustment for potential confounders.

RESULTS

Consistent discrimination between complete, uncertain, and incomplete resection is revealed with respect to overall survival. Evidence regarding specific descriptors is generally somewhat limited and only partially consistent; nevertheless, the data suggest retaining all descriptors but with clarifications to address ambiguities.

CONCLUSION

On the basis of this review, the R-classification for the ninth edition of stage classification of lung cancer is proposed to retain the same overall framework and descriptors, with more precise definitions of descriptors. These refinements should facilitate application and further research.

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.

Long-Term Survival of American Joint Committee on Cancer 8th Edition Staging Descriptors for Clinical M1a Non-Small Cell Lung Cancer

BACKGROUND

The American Joint Committee on Cancer (AJCC) 8th edition TNM staging manual for non-small cell lung cancer (NSCLC) M1a descriptors includes tumors presenting with malignant pleural or pericardial effusion (ie, M1a-Effusion), pleural or pericardial nodule(s) (ie, M1a-Pleural), or separate tumor nodule(s) in a contralateral lobe (ie, M1a-Contralateral).

RESEARCH QUESTION

Is M1a NSCLC presenting with malignant pleural or pericardial effusion associated with worse survival compared with other types of M1a NSCLC?

STUDY DESIGN AND METHODS

Patients with cT1-4, N0-3, M1a NSCLC (satisfying a single M1a descriptor of M1a-Effusion, M1a-Pleural, or M1a-Contralateral), according to AJCC eighth edition staging criteria, in the National Cancer Database from 2010 to 2015 were included. Overall survival was evaluated by using Kaplan-Meier analysis, multivariable-adjusted Cox proportional hazards modeling, and propensity score matching.

RESULTS

Of the 25,716 patients who met study eligibility criteria, 12,756 (49.6%) presented with M1a-Effusion tumors, 3,589 (14.0%) with M1a-Pleural tumors, and 9,371 (36.4%) with M1a-Contralateral tumors. In multivariable-adjusted analysis, compared to M1a-Effusion tumors, both M1a-Pleural tumors (hazard ratio, 0.68; 95% CI, 0.64-0.71; P < .001) and M1a-Contralateral tumors (hazard ratio, 0.66; 95% CI, 0.64-0.69; P < .001) were associated with better overall survival. No significant differences were found in overall survival between patients with M1a-Pleural tumors vs M1a-Contralateral tumors. In a propensity score-matched analysis of 5,581 patients with M1a-Effusion tumors and 5,581 patients with other M1a tumors (ie, M1a-Contralateral or M1a-Effusion), those with M1a-Effusion tumors had worse 5-year overall survival than patients with other M1a tumors (M1a-Effusion 6.4% [95% CI, 5.7-7.1] vs M1a-Other 10.6% [95% CI, 9.7-11.5]; P < .001).

INTERPRETATION

In this national analysis of AJCC 8th edition cT1-4, N0-3, M1a NSCLC, tumors with malignant pleural or pericardial effusion were associated with worse overall survival than tumors with either pleural or contralateral pulmonary nodules. These findings may be taken into consideration for the upcoming ninth edition of the AJCC lung cancer staging guidelines.

Intraoperative rapid diagnosis of pleural lavage cytology in non-small cell lung cancer

OBJECTIVE

Positive pleural lavage cytology (PLC +) is a poor prognostic factor for non-small cell lung cancer (NSCLC). However, data on the impact of intraoperative rapid diagnosis of PLC (rPLC) are lacking. Therefore, we evaluated the efficacy of rPLC before resection during surgery.

METHODS

A total of 1,838 patients who underwent rPLC for NSCLC between September 2002 and December 2014 were studied retrospectively. We assessed the clinicopathological factors between rPLC findings and the impact on survival of patients with curative resection.

RESULTS

The rPLC + status was observed in 96 (5.3%) among 1,838 patients. The rPLC + group had more unsuspected N2 (30%) than the rPLC- group (p < 0.001). The 5-year overall survival (OS) of patients who underwent lobectomy or more extensive resection with rPLC + , negative rPLC (rPLC-), and microscopic pleural dissemination (PD) and/or malignant pleural effusion (PE) were 67.3, 81.3, and 11.0%, respectively. In the rPLC + group, the prognosis of patients with pN2 was equal to that of pN0-1 (5-year OS: 77.9% vs. 63.4%, p = 0.263). Undetectable dissemination in the first evaluation immediately after starting surgery was found in 9% of rPLC + patients by additional evaluation of the thoracic cavity.

CONCLUSIONS

Patients with rPLC + have more favorable survival than those with microscopic PD/PE after surgery. Curative resection should be performed in patients with rPLC + , even if N2 is detected during surgery. However, the rPLC + group often has N2 upstaging; therefore, systematic nodal dissection should be performed in rPLC + patients for exact staging. rPLC may contribute to preventing oversight PD by re-evaluation during surgery.

Staging by Thoracoscopy in potentially radically treatable Lung Cancer associated with Minimal Pleural Effusion (STRATIFY): protocol of a prospective, multicentre, observational study

INTRODUCTION

Recurrence rate following radical therapy for lung cancer remains high, potentially reflecting occult metastatic disease, and better staging tools are required. Minimal pleural effusion (mini-PE) is associated with particularly high recurrence risk and is defined as an ipsilateral pleural collection (<1/3 hemithorax on chest radiograph), which is either too small to safely aspirate fluid for cytology using a needle, or from which fluid cytology is negative. Thoracoscopy (local anaesthetic thoracoscopy (LAT) or video-assisted thoracoscopic surgery (VATS)) is the gold-standard diagnostic test for pleural malignancy in patients with larger symptomatic effusions. Staging by Thoracoscopy in potentially radically treatable Lung Cancer associated with Minimal Pleural Effusion (STRATIFY) will prospectively evaluate thoracoscopic staging in lung cancer associated-mini-PE for the first time.

METHODS AND ANALYSIS

STRATIFY is a prospective multicentre observational study. Recruitment opened in January 2020. The primary objective is to determine the prevalence of detectable occult pleural metastases (OPM). Secondary objectives include assessment of technical feasibility and safety, and the impact of thoracoscopy results on treatment plans, overall survival and recurrence free survival. Inclusion criteria are (1) suspected/confirmed stages I-III lung cancer, (2) mini-PE, (3) Performance Status 0-2 (4), radical treatment feasible if OPM excluded, (5) ≥16 years old and (6) informed consent. Exclusion criteria are any metastatic disease or contraindication to the chosen thoracoscopy method (LAT/VATS). All patients have LAT or VATS within 7 (±5) days of registration, with results returned to lung cancer teams for treatment planning. Following an interim analysis, the sample size was reduced from 96 to 50, based on a lower-than-expected OPM rate. An MRI substudy was removed in November 2022 due to pandemic-related site setup/recruitment delays. These also necessitated a no-cost recruitment extension until October 2023.

ETHICS AND DISSEMINATION

Protocol approved by the West of Scotland Research Ethics Committee (Ref: 19/WS/0093). Results will be published in peer-reviewed journals and presented at international meetings.

TRIAL REGISTRATION NUMBER

ISRCTN13584097.

Overall 5-year survival rate and disease-free survival after segmentectomy versus lobectomy in patients with non-small cell lung cancer

Objectives

Anatomical lobectomy has always been the standard operative treatment of early-stage non-small cell lung cancer. However, there have been emerging evidences suggesting that a subanatomical resection, such as segmentectomy, may yield the same treatment results, even in patients with higher-stage non-small cell lung cancer. This study aimed to compare overall 5-year survival rate and disease-free survival between lobectomy and segmentectomy in patients with non-small cell lung cancer.

Methods

The retrospective study included 380 patients who underwent surgery for non-small cell lung cancer at Ramathibodi Hospital between 1st January 2016 and 31st December 2020. Of 380 patients, 307 patients underwent lobectomy, while the other 73 patients underwent segmentectomy. Operative, admission, and follow-up data were collected from electronic medical records. Missing data were collected by telephone calls to patients or their relatives in deceased cases. Overall and disease-free survival were analyzed.

Results

Median overall 5-year survival time after lobectomy and segmentectomy seemed to be different but not statistically significant (18.5 months versus 5.8 months, p = 0.127). Median disease-free survival time after lobectomy and segmentectomy was also similar (8.6 months versus 4.5 months, p = 0.511). Two deaths occurred during perioperative period, one from lobectomy group due to acute massive pulmonary embolism (0.3%) and the other from segmentectomy group due to acute exacerbation of chronic obstructive pulmonary disease with respiratory failure (1.4%).

Conclusion

Lobectomy and segmentectomy result in similar overall 5-year survival rate and disease-free survival between these two comparison groups. Therefore, segmentectomy may be a potential alternative for operative treatment of non-small cell lung cancer. However, a larger and randomized-controlled trial may be needed to further validate these results.

Pleural invasion, epidermal growth factor receptor mutation and carcinoembryonic antigen level affect pleural lavage cytology-positive status in non-small-cell lung cancer

OBJECTIVES

Pleural invasion (pl) is strongly associated with the pleural lavage cytology (PLC) status. We analysed tumours with pl and evaluated the relationship between the PLC status and pl.

METHODS

We retrospectively reviewed 428 surgically treated patients who had been diagnosed with non-small-cell lung cancer with pl and had their PLC status examined between 2000 and 2016. We investigated the influence of a PLC-positive status on the prognosis and searched for the factors predictive of a PLC-positive status.

RESULTS

Seventy-eight (18%) patients were PLC positive. The recurrence-free survival of PLC-positive patients was significantly worse than that of PLC-negative patients in pl1 and pl2, but not in pl3 (5-year recurrence-free survival rate, PLC positive versus PLC negative: pl1, 22.0% vs 60.0%, P = 0.002; pl2, 30.4% vs 59.7%, P = 0.015; pl3, 50.0% vs 59.6%, P = 0.427). A multivariable analysis showed that the degree of pl (pl2-3 versus pl1) [odds ratio (OR) 5.34, P < 0.001] was an independent predictive factor for PLC positivity. Epidermal growth factor receptor (EGFR) mutation positivity (OR 5.48, P = 0.042) and carcinoembryonic antigen (CEA) ≥5 ng/ml (OR 3.78, P = 0.042) were associated with a PLC-positive status in patients with pl2-3. We found that the PLC-positive rate in patients with pl2-3 was 35.6%; however, if the tumour was EGFR mutation positive and had CEA ≥5 ng/ml, the PLC-positive rate increased to 77%.

CONCLUSIONS

If a tumour was suspected of being pl2-3 and had EGFR mutation positivity and CEA ≥5 ng/ml, the PLC-positive rate was extremely high.

CLINICAL TRIAL REGISTRATION NUMBER

Hyogo Cancer Center, G-138.

The Evolving Concept of Complete Resection in Lung Cancer Surgery

Simple Summary

In the surgical treatment of lung cancer, the complete removal of the portion of the lung where the cancer is and of the involved adjacent structures is of paramount importance to achieve long-term survival. The International Association for the Study of Lung Cancer (IASLC) proposed a definition of complete resection that included a well-defined type of removal of the regional lymph nodes as a fundamental step. The lymph nodes may contain cancer cells and, if left behind, cancer will soon progress. The IASLC also defined incomplete resection when there is any evidence of persistent cancer after the operation. It also defined an intermediate condition, uncertain resection, when no evidence of residual disease can be proved, but all the conditions of complete resection are not fulfilled. Four validations of the definitions have proved their prognostic value and, therefore, the definitions should be followed when a surgical resection of lung cancer is planned.

Abstract

Different definitions of complete resection were formulated to complement the residual tumor (R) descriptor proposed by the American Joint Committee on Cancer in 1977. The definitions went beyond resection margins to include the status of the visceral pleura, the most distant nodes and the nodal capsule and the performance of a complete mediastinal lymphadenectomy. In 2005, the International Association for the Study of Lung Cancer (IASLC) proposed definitions for complete, incomplete and uncertain resections for international implementation. Central to the IASLC definition of complete resection is an adequate nodal evaluation either by systematic nodal dissection or lobe-specific systematic nodal dissection, as well as the integrity of the highest mediastinal node, the nodal capsule and the resection margins. When there is evidence of cancer remaining after treatment, the resection is incomplete, and when all margins are free of tumor, but the conditions for complete resection are not fulfilled, the resection is defined as uncertain. The prognostic relevance of the definitions has been validated by four studies. The definitions can be improved in the future by considering the cells spread through air spaces, the residual tumor cells, DNA or RNA in the blood, and the determination of the adequate margins and lymphadenectomy in sublobar resections.

Incorporating radiomic feature of pretreatment 18F-FDG PET improves survival stratification in patients with EGFR-mutated lung adenocarcinoma

BACKGROUND

To investigate the survival prognostic value of the radiomic features of 18F-FDG PET in patients who had EGFR (epidermal growth factor receptor) mutated lung adenocarcinoma and received targeted TKI (tyrosine kinase inhibitor) treatment.

METHODS

Fifty-one patients with stage III-IV lung adenocarcinoma and actionable EGFR mutation who received first-line TKI were retrospectively analyzed. All patients underwent pretreatment 18F-FDG PET/CT, and we calculated the PET-derived radiomic features. Cox proportional hazard model was used to examine the association between the radiomic features and the survival outcomes, including progression-free survival (PFS) and overall survival (OS). A score model was established according to the independent prognostic predictors and we compared this model to the TNM staging system using Harrell's concordance index (c-index).

RESULTS

Forty-eight patients (94.1%) experienced disease progression and 41 patients (80.4%) died. Primary tumor SUV entropy > 5.36, and presence of pleural effusion were independently associated with worse OS (both p < 0.001) and PFS (p = 0.001, and 0.003, respectively). We used these two survival predictors to devise a scoring system (score 0-2). Patients with a score of 1 or 2 had a worse survival than those with a score of 0 (HR for OS: 3.6, p = 0.006 for score 1, and HR: 21.8, p < 0.001 for score 2; HR for PFS: 2.2, p = 0.027 for score 1 and HR: 8.8, p < 0.001 for score 2). Our scoring system surpassed the TNM staging system (c-index = 0.691 versus 0.574, p = 0.013 for OS, and c-index = 0.649 versus 0.517, p = 0.004 for PFS).

CONCLUSIONS

In this preliminary study, combining PET radiomics with clinical risk factors may improve survival stratification in stage III-IV lung adenocarcinoma with actionable EFGR mutation. Our proposed scoring system may assist with optimization of individualized treatment strategies in these patients.

Status of pleural lavage cytology in cases of pulmonary metastasis: a single-institution retrospective study

OBJECTIVE

In primary lung cancer surgery, intraoperative pleural lavage cytology (PLC) has been identified as a prognostic marker. However, there have been no reports on PLC for pulmonary metastasectomies. Therefore, the impact of PLC status for patients undergoing pulmonary metastasectomy remains unknown. We aimed to know the incidence and prognostic impact of positive PLC findings in pulmonary metastasectomies.

METHODS

We retrospectively reviewed patients undergoing pulmonary metastasectomies between January 2013 and December 2018. One hundred and eighty-nine PLC procedures in 159 patients undergoing pulmonary metastasectomy were analyzed. Follow-up information was available in 107 patients who underwent 132 procedure, and they were investigated for pleural recurrence-free probability (PRFP) and overall survival (OS) after pulmonary metastasectomy.

RESULTS

The type of primary lesion was colorectal cancer (101/189, 53%), urothelial/kidney cancer (17/189, 9%), skeletal/soft tissue tumor (18/189, 10%), hepatobiliary/pancreatic cancer (19/189, 10%), uterine/ovarian cancer (14/189, 7%), otorhinolaryngological cancer (11/189, 6%), and other minor lesions (9/189, 5%). Nine PLC-positive metastasectomies were revealed (9/189, 4.8%). They consisted of six metastasectomies from pancreatic cancer, two from osteosarcoma, and one from tongue cancer. Significant predictors for PLC status was type of primary tumor (P < 0.001). PRFP and OS rate of PLC-positive group were significantly lower than PLC-negative (P < 0.001, respectively).

CONCLUSION

PLC-positive results were rarely seen in pulmonary metastasectomies. PLC status was associated with the incidence of ipsilateral pleural recurrence and survival after metastasectomy. Cytologic examination of PLC should be considered in patients undergoing pulmonary metastasectomy.

Impact of Positive Pleural Lavage Cytology for Each Stage of Non-Small Cell Lung Cancer Patients

BACKGROUND

Positive preresection pleural lavage cytology (PLC⁺) is a poor prognostic factor in non-small cell lung cancer (NSCLC). This study evaluated the prognostic value of PLC⁺ for the different pathologic stages (p-stages) of NSCLC.

METHODS

A retrospective analysis was conducted of all 1293 staged patients who underwent curative resection in the Shizuoka Cancer Center Hospital, Shizuoka, Japan, for NSCLC to evaluate the impact of PLC⁺ on survival, specifically in patients with p-stage I NSCLC. The survival rate between patients with and without PLC⁺ was compared using the Kaplan-Meier method with the log-rank test for comparison.

RESULTS

PLC⁺ was identified in 50 of the 1293 patients (3.9%) and was correlated with lymph node metastasis (P < .001), a pathologic tumor size larger than 3 cm (P = .033), the presence of pleural invasion (P < .001), and adenocarcinoma (P = .038). In patients with PLC⁺, the 5-year disease-free survival (DFS) was 31.1%, compared with 75.7% for patients with a negative PLC (PLC^-) (P < .001). On multivariate analysis, the PLC⁺ status was an independent prognostic factor of DFS (hazard ratio 1.70; P = .013). Among the 818 patients with p-stage I NSCLC, PLC⁺ was identified in 22, with a 5-year DFS of 40.4%. The prognosis in patients with p-stage I NSCLC with PLC⁺ was equal to that in patients with p-stage IIIA NSCLC with PLC^- (5-year DFS, 40.4% and 39.0%).

CONCLUSIONS

PLC is an independent prognostic factor in early-stage NSCLC. Therefore, it may be appropriate to up-stage an NSCLC diagnosis in the presence of PLC⁺, especially for patients with p stage I.

Clinicopathological features of intraoperative pleural lavage cytology for non-small cell lung cancer

OBJECTIVE

The significance of clinicopathological features of pre- and post-resection pleural lavage cytology (PLC) for non-small cell lung carcinoma (NSCLC) currently remains unknown.

METHODS

Between January 2010 and December 2012, pre- and post-resection PLC were performed for NSCLC in 565 patients at Tohoku University, Miyagi Cancer Center, or Sendai Medical Center. The relationship between the clinicopathological features and patient outcomes was analyzed.

RESULTS

Twenty-two patients (3.9%) had positive findings from pre- or post-resection PLC. Both PLC were correlated with pT and pl factors, while only post-resection PLC was correlated with pN factor (p < 0.005). The 5-year disease-free survival (DFS) rate of the positive pre-resection PLC was significantly poorer than that of negative (26.7% vs. 76.9%, p < 0.0001). In addition, the 5-year DFS of the positive post-resection PLC was also poorer than that of negative (14.3% vs. 76.0%, p < 0.0001). Multivariate analyses revealed that both PLC were not independent prognostic factors in our study.

CONCLUSIONS

A significant association of post-resection PLC with N factor is considered to be characteristics of post-resection PLC different from pre-resection PLC. A prognostic impact of post-resection PLC and its detailed difference from pre-resection PLC should be clarified by further investigations.

[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。

Lung cancer staging: a concise update

Diagnosis and clinical staging of lung cancer are fundamental to planning therapy. The techniques for clinical staging, i.e anatomic and metabolic imaging, endoscopies and minimally invasive surgical procedures, should be performed sequentially and with an increasing degree of invasiveness. Intraoperative staging, assessing the magnitude of the primary tumour, the involved structures, and the loco-regional lymphatic spread by means of systematic nodal dissection, is essential in order to achieve a complete resection. In resected tumours, pathological staging, with the systematic study of the resected specimens, is the strongest prognostic indicator and is essential to make further decisions on therapy. In the present decade, the guidelines on lung cancer staging of the American College of Chest Physicians and the European Society of Thoracic Surgeons are based on the best available evidence and are widely followed. Recent advances in the classification of the adenocarcinoma of the lung, with the definition of adenocarcinoma in situ, minimally invasive adenocarcinoma and lepidic predominant adenocarcinoma, and the publication of the eighth edition of the tumour, node and metastasis classification of lung cancer, have to be integrated into the staging process. The present review complements the latest guidelines on lung cancer staging by providing an update of all these issues.

Pleural lavage cytology after lung resection in patients with non-small cell lung cancer and the feasibility of 20 mL saline solution

BACKGROUND

There are two issues to be discussed in pleural lavage cytology (PLC) for resected non-small cell lung cancer (NSCLC) whether it should be performed before (pre-PLC) or after (post-PLC) the lung resection and the dose of saline varies widely among the institutions.

METHODS

We retrospectively reviewed the clinical records of 466 consecutive patients who underwent a curative resection for NSCLC and received both a pre- and post- PLC using 20 mL of saline from January 2001 to December 2011.

RESULTS

There were 24/28 of positive pre- and post-PLC and 442/438 negative pre- and post-PLCs, respectively. Patients with a positive pre- or post-PLCs had significantly worse 5-year survival rates than those with negative results (pre-PLC positive/negative; 32.6%/69.9%, p = 0.001, post-PLC positive/negative; 21.4%/71.1%, p < 0.001, respectively). The post-PLC (p = 0.01) was an independent prognostic factor for the overall survival by a multivariate analysis, whereas the pre-PLC was not (p = 0.79).

CONCLUSIONS

The post-PLC was a more significant prognostic factor than the pre-PLC. Further, 20 mL of saline seemed feasible because of the consistent results compared to the past reports using a greater dose of saline for regarding the positive rates of the PLC and its prognostic significance.

The prognosis after contraindicated surgery of NSCLC patients with malignant pleural effusion (M1a) may be better than expected

Although non-small cell lung cancer (NSCLC) with malignant pleural effusion (M1a) is generally contraindicated for surgery, several reports have demonstrated favorable prognosis. This study aimed to describe the results of surgical intervention in this disease. In this retrospective study, we evaluated NSCLC patients with ipsilateral malignant pleural effusion selected from Surveillance Epidemiology and End-Results database (SEER). Primary tumor resection was compared to no tumor resection in the overall survival (OS) and lung cancer-specific survival (LCSS). Multivariate analyses and propensity score matching were applied to compare the two groups. The study included 2,217 eligible patients. Primary tumor resection group was significantly associated with better OS and LCSS compared to no tumor resection group (the median survival time (MST), 20 vs 7 months; OS, p <0.001; LCSS, p <0.001). Multivariable analyses indicated that no primary tumor resection was associated with decreased OS (Hazard Ratio (HR), 2.136; p<0.001) and LCSS (HR, 2.053; p<0.001). In propensity score-matched pairs, better OS and LCSS were further validated in patients with ipsilateral malignant pleural effusion who underwent primary tumor resection compared to no tumor resection (MST, 20 vs 6 months; OS, p <0.001; LCSS, p <0.001). Similarly, multivariable analyses also indicated that no primary tumor resection was associated with decreased OS (HR, 2.309; p <0.001) and LCSS (HR, 2.301; p <0.001) for patients with ipsilateral malignant pleural effusion. In conclusion, the prognosis after contraindicated surgery of NSCLC patients with malignant pleural effusion (M1a) may be better than expected. Thus, subsequent studies should aim to identify patients who could benefit from surgery.

Prognostic significance of preoperative plasma D-dimer level in patients with surgically resected clinical stage I non-small cell lung cancer: a retrospective cohort study

BACKGROUND

Plasma D-dimer level, a marker of hypercoagulation, has been reported to be associated with survival in several types of cancers. The present study aimed to evaluate the prognostic significance of preoperative D-dimer levels in patients with surgically resected clinical stage I non-small cell lung cancer (NSCLC).

METHODS

Participants comprised 237 patients with surgically resected clinical stage I NSCLC. In addition to factors such as age, sex, and smoking status, the association between preoperative D-dimer level and survival was explored.

RESULTS

Patients were divided into two groups according to D-dimer level: Group A, ≤ 1.0 μg/ml (n = 170); and Group B, > 1.0 μg/ml (n = 67). The 5-year recurrence-free survival rate was 81.6% for Group A and 66.6% for Group B (p < 0.001). The 5-year overall survival rate was 93.6% for Group A and 84.7% for Group B (p = 0.002). Multivariate survival analysis identified D-dimer level as an independent prognostic factor, along with age, maximum standardized uptake value of the primary tumor, and pathological stage.

CONCLUSIONS

Preoperative D-dimer level is an independent prognostic factor in patients with surgically resected clinical stage I NSCLC.

Epidermal Growth Factor Receptor Gene Mutation in Pleural Lavage Cytology Findings of Primary Lung Adenocarcinoma Cases

PURPOSE

In the present study, we examined the relationship between intraoperative pleural lavage cytology findings and presence of epidermal growth factor receptor (EGFR) gene mutations.

METHODS

We investigated 160 patients who underwent surgical treatment for primary lung adenocarcinoma at our hospital from January 2011 to December 2013 to determine the presence of EGFR gene mutations and pleural lavage cytology.

RESULTS

In all, 52 subjects (31.5%) were positive EGFR gene mutations, of whom 38 were found to possess the Exon 21 L858R mutation. Intraoperative pleural lavage cytology examinations were performed in 160 subjects and 12 had positive results, of whom 6 were positive for EGFR gene mutations, which was the Exon 21 L858R mutation in all. In a comparison between subjects possessing the Exon 21 L858R mutation and those negative for EGFR gene mutations, lavage cytology-positive (p = 0.02) and vascular infiltration-negative (p = 0.01) were characteristics of the Exon 21 L868R mutation-positive group.

CONCLUSION

Subjects positive for the EGFR Exon 21 L858R mutation had a higher positive rate of intraoperative pleural lavage cytology than those not possessing EGFR mutations.

Malignant pleural effusions because of lung cancer

PURPOSE OF REVIEW

The discovery of a pleural effusion in the setting of lung cancer has diagnostic, prognostic, and therapeutic challenges, some of which are addressed in this review.

RECENT FINDINGS

Around 20% of patients with lung cancer have minimal pleural effusions, which are not amenable to a diagnostic thoracentesis. These patients have a poorer overall survival (∼7.5 months) than those without effusions (∼12-18 months), although slightly better than those with proven malignant fluids (∼5.5 months). Tumor genotype techniques are feasible on pleural fluid specimens and clinically helpful in identifying patients who may benefit from targeted therapies. If limited pleural involvement is detected during lung cancer surgery despite the presurgical imaging studies, macroscopic complete resection of the lung tumor is still a treatment option. Cytological examination for cancer cells in pleural cavity washings at the time of thoracotomy (pleural lavage cytology) is recommended to uncover pleural dissemination. Patients with non-small cell lung cancer with visceral pleural invasion might be considered candidates for postsurgical adjuvant therapy.

SUMMARY

Some predictors of adverse survival in patients with lung cancer include the presence of a minimal pleural effusion, positive pleural lavage cytology, visceral pleural invasion on pathologic examination, and unexpected pleural involvement during surgery.

[Current knowledge on perioperative treatments of non-small cell lung carcinomas]

Surgery is still the main treatment in early-stage of non-small cell lung cancer with 5-year survival of stage IA patients exceeding 80%, but 5-year survival of stage II patients rapidly decreasing with tumor size, N status, and visceral pleura invasion. The major metastatic risk in such patients has supported clinical research assessing systemic or loco-regional perioperative treatments. Modern phase 3 trials clearly validated adjuvant or neo-adjuvant platinum-based chemotherapy in resected stage I-III patients as a standard treatment of which value has been reassessed several independent meta-analyses, showing a 5% benefit in 5y-survival, and a decrease of the relative risk for death around from 12 to 25%. Conversely perioperative treatments were not validated for stage IA and IB patients. In more advanced stage patients, neo-adjuvant radio-chemotherapy has not been validated either. Adjuvant radiotherapy for N2 patients is currently tested in the large international phase 3 trial Lung-ART/IFCT-0503. The development of video-assisted thoracic surgery (VATS) has helped adjuvant chemotherapies for elderly patients. Perioperative targeted treatments in NSCLC with EGFR or ALK molecular alterations is currently assessed in the U.S. ALCHEMIST prospective trial. Finally, the role of immune check-points inhibitors is currently evaluated in a large international phase 3 trial testing adjuvant anti-PD-L1 monoclonal antibody, the BR31/IFCT-1401 trial, while a proof-of principle neo-adjuvant trial IONESCO/IFCT-1601, has just begun by the end of the 2016 year, with survival results of both trials expected in 5 to 7 years.

Photodynamic Therapy of Non-Small Cell Lung Cancer. Narrative Review and Future Directions

Photodynamic therapy (PDT) is an established treatment modality for non-small cell lung cancer. Phototoxicity, the primary adverse event, is expected to be minimized with the introduction of new photosensitizers that have shown promising results in phase I and II clinical studies. Early-stage and superficial endobronchial lesions less than 1 cm in thickness can be effectively treated with external light sources. Thicker lesions and peripheral lesions may be amenable to interstitial PDT, where the light is delivered intratumorally. The addition of PDT to standard-of-care surgery and chemotherapy can improve survival and outcomes in patients with pleural disease. Intraoperative PDT has shown promise in the treatment of non-small cell lung cancer with pleural spread. Recent preclinical and clinical data suggest that PDT can increase antitumor immunity. Crosslinking of signal transducer and activator of transcription-3 molecules is a reliable biomarker to quantify the photoreaction induced by PDT. Randomized studies are required to test the prognosis value of this biomarker, obtain approval for the new photosensitizers, and test the potential efficacy of interstitial and intraoperative PDT in the treatment of patients with non-small cell lung cancer.

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.

MHC class I chain-related molecule A and B expression is upregulated by cisplatin and associated with good prognosis in patients with non-small cell lung cancer

MHC class I chain-related molecule A and B (MICA/B) are NK group 2 member D (NKG2D) ligands, which are broadly expressed in transformed cells. Both DNA damage-induced ataxia-telangiectasia-mutated (ATM)- and ATM and Rad3-related protein kinases (ATM-ATR) signaling and oncogene-induced PI3K-AKT signaling regulate the expression of NKG2D ligands, which promote NK cell-mediated cytotoxicity via NKG2D-NKG2D ligand interactions. NKG2D ligand overexpression was recently reported to be correlated with good prognosis in several types of cancer. However, the prognostic significance of NKG2D ligands in non-small cell lung cancer (NSCLC) remains unclear. Here, MICA/B expression was evaluated based on immunohistochemistry of 91 NSCLC samples from patients following radical surgery. In addition, expression of MICA/B was assessed in NSCLC cell lines treated with cisplatin in order to evaluate the regulatory mechanisms of MICA/B expression. Overall, 28 out of 91 (30.8%) specimens showed high expression level of MICA/B, which was associated with low (18)F-fluorodeoxyglucose uptake and manifestation of adenocarcinoma. After a median follow-up of 48.2 months, high MICA/B expression was associated with good recurrence-free survival (p = 0.037). In vitro assays using cell lines revealed that MICA/B expression was upregulated by cisplatin via ATM-ATR signaling, resulting in enhanced NK cell-mediated cytotoxicity. Upregulated MICA/B expressions in patients with radically resected NSCLC are predictive of good disease prognosis. Cisplatin-induced MICA/B upregulation is possibly an indirect mechanism by which the innate immune system eliminates tumor cells. NKG2D-NKG2D ligand-targeting therapy is a promising avenue for future immune-chemotherapy development.

The seventh tumour-node-metastasis staging system for lung cancer: Sequel or prequel?

Anatomical cancer extent is an important predictor of prognosis and determines treatment choices. In non-small-cell lung cancer (NSCLC) the tumour–node–metastasis (TNM) classification developed by Pierre Denoix replaced in 1968 the Veterans Administration Lung cancer Group (VALG) classification, which was still in use for small-cell lung cancer (SCLC). Clifton Mountain suggested several improvements based on a database of mostly surgically treated United States (US) patients from a limited number of centres. This database was pivotal for a uniform reporting of lung cancer extent by the American Joint Committee of Cancer (AJCC) and the International Union against Cancer (IUCC), but it suffered increasingly from obsolete diagnostic and staging procedures and did not reflect new treatment modalities. Moreover, its findings were not externally validated in large Japanese and European databases, resulting in persisting controversies which could not be solved with the available database. The use of different mediastinal lymph-node maps in Japan, the (US) and Europe facilitated neither the exchange nor the comparison of treatment results.

Peter Goldstraw, a United Kingdom (UK) thoracic surgeon, started the process of updating the sixth version in 1996 and brought it to a good end 10 years later. His goals were to improve the TNM system in lung cancer by addressing the ongoing controversies, to validate the modifications and additional descriptors, to validate the TNM for use in staging SCLC and carcinoid tumours, to propose a new uniform lymph-node map and to investigate the prognostic value of non-anatomical factors. A staging committee was formed within the International Association for the Study of Lung Cancer (IASLC) – which supervised the collection of the retrospective data from >100,000 patients with lung cancer – treated throughout the world between 1990 and 2000, analyse them with the help of solid statistics and validate externally with the Surveillance, Epidemiology and End Results (SEER) database.

The ten modifications and the mediastinal lymph-node map – which were proposed in 2007 and adopted by the AJCC and IUCC in their respective seventh revision of the TNM system – were implemented as of 2010 and were rapidly adopted by the thoracic oncology community and cancer registries. As expected, not all controversies could be fully addressed, and the need for a prospective data set containing more granular information was felt early on. This data set of 25,000 consecutive incident cases will form the base for the eighth revision in 2017 and is currently being collected. Other threats are the role of stage migration and the increasing number of biological factors interfering with disease extent for prognostication. The latter issue will be addressed by the creation of a prognostic index, including several prognostic factors, of which stage will be one.

For the time being, the seventh TNM classification is considered the gold standard for the description of disease extent, initial treatment allocation and the reporting of treatment results. The uniform use of the TNM descriptors and the lymph-node map by all involved in lung cancer care is to be considered a process indicator of quality.

Preoperative concurrent chemoradiotherapy followed by extrapleural pneumonectomy for patients with non-small cell lung cancer with malignant pleural effusion and/or pleural nodules: Ten-year results of a prematurely terminated single institute phase II trial

BACKGROUND

Malignant pleural effusion and/or pleural nodules are a final stage of disease extension of non-small cell lung cancer (NSCLC), which is currently classified as M1a-Stage IV disease. The role of surgery, especially extrapleural pneumonectomy (EPP) for local disease control and its impact on the survival of patients remains uncertain.

PATIENTS AND METHODS

This single institute phase II trial was performed from March 1997 to March July 2004 to assess the effects of induction concurrent chemoradiotherapy (CRT) using a pro-drug of 5-FU, uracil-tegafur (UFT(®), Taiho Pharmaceutical Co., Ltd, Tokyo, Japan), plus cisplatin concurrently with 40 Gy hemithorax radiation followed by EPP. Intraoperative hypotonic cisplatin treatment in the pleural cavity before resection of the pericardium and diaphragm was performed. The primary endpoint of this study was the overall survival (OS), and the secondary endpoint was the disease-free survival (DFS), safety, response to the induction CRT, local disease control period in the affected thorax and the type of disease recurrence.

RESULTS

This trial was prematurely terminated because of the slow registration pace. During the study period, 11 patients were enrolled. There were five males and six females, with a median age of 55 (36-64) years. All patients had adenocarcinoma. All patients received the planned induction CRT. Five patients achieved a partial response and five achieved stable disease, and one patient could not be evaluated. One patient underwent exploratory thoracotomy due to unresectable chest wall invasion, and nine patients (81.8%) underwent EPP. No perioperative deaths were encountered. The median follow-up time was matured at 32.1 (range 15.0-100) months. The one-, three- and five-year DFS rates were 77.8% (95%CI: 50.6-100%), 11.1% and 11.1% (95%CI: 95%CI: 0-31.7%), respectively. The one-, three- and five-year OS rates were 100.0%, 33.3% (95%CI: 2.5-64.1%) and 22.2% (95%CI: 0.0-49.4%), respectively. Recurrence developed in eight of nine patients who underwent EPP (88.9%). All first recurrent sites were distant regions, and no ipsilateral local recurrence was identified.

CONCLUSION

The trimodality treatment used in this trial appears to be a choice of treatment for highly selected patients. However, the impact on the survival of NSCLC patients with malignant pleural effusion and/or pleural nodules still remains uncertain given the small number of patients enrolled in the study.

The ABO blood group is an independent prognostic factor in patients with resected non-small cell lung cancer

Background

The ABO blood group is reported to be associated with the incidence and patient survival for several types of malignancies. We conducted a retrospective study to evaluate the prognostic significance of the ABO blood group in patients with resected non-small cell lung cancer (NSCLC).

Methods

A total of 333 patients (218 men and 115 women) with resected NSCLC were included in this study. In addition to age, sex, smoking status, preoperative serum carcinoembryonic antigen (CEA) level, operative procedure, histology of tumors, pathological stage (p-stage), and adjuvant therapy, the association between the ABO blood group and survival was explored.

Results

The 5-year overall and disease-free survival rates were 83.0% and 71.6% for blood group O, 67.2% and 62.3% for blood group A, 68.8% and 68.8% for blood group B and 69.2% and 65.3% for blood group AB, respectively. A multivariate analysis for overall survival showed the ABO blood group (group A vs. group O: HR 2.47, group AB vs. group O: HR 3.62) to be an independent significant prognostic factor, in addition to age, sex, smoking status, p-stage, and serum CEA level. A multivariate analysis for disease-free survival also showed the ABO blood group to be an independent significant prognostic factor.

Conclusions

The ABO blood group is an independent prognostic factor in patients with resected NSCLC. Studies of other larger cohorts are therefore needed to confirm the relationship between the ABO blood group and the prognosis among patients with resected NSCLC.

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.

Current readings: the most influential and recent studies regarding resection of lung cancer in m1a disease

M1A disease is a recent concept appearing in the 7th TNM classification of lung cancer. M1A encompasses two different entities, malignant pleural or pericardial effusions and separate tumor nodules in the contralateral lung, who constitute very different diseases, with very different management and prognoses. On one hand, patients with pleural dissemination have extremely poor survival, with median and 5-year survivals of 4 months and 3.1%, respectively. Only selected patients whose limited pleural extension has been diagnosed at the time of thoracotomy and completely resected, may experience prolonged survival. On the other hand, recent progress in molecular biology still failed to establish whether a contralateral lesion is a second primary or a metastasis. These contralateral lesions are now gathered as multiple lung cancers in the surgical literature, and misleadingly classified as M1A disease in the TNM classification. Patients with contralateral nodules may experience prolonged survival after the surgical treatment of both localizations. Changing the staging by establishing the diagnosis of metastasis is probably an important issue warranting further biologic research, but according to current results this diagnosis must not in any case preclude surgery.

Obligate progression precedes lung adenocarcinoma dissemination

Despite its clinical importance, very little is known about the natural history and molecular underpinnings of lung cancer dissemination and metastasis. Here, we used a genetically engineered mouse model of metastatic lung adenocarcinoma in which cancer cells are fluorescently marked to determine whether dissemination is an inherent ability or a major acquired phenotype during lung adenocarcinoma metastasis. We find very little evidence for dissemination from oncogenic KRAS-driven hyperplasias or most adenocarcinomas. p53 loss is insufficient to drive dissemination but rather enables rare cancer cells in a small fraction of primary adenocarcinomas to gain alterations that drive dissemination. Molecular characterization of disseminated tumor cells indicates that downregulation of the transcription factor Nkx2-1 precedes dissemination. Finally, we show that metastatic primary tumors possess a highly proliferative subpopulation of cells with characteristics matching those of disseminating cells. We propose that dissemination is a major hurdle during the natural course of lung adenocarcinoma metastasis.

SIGNIFICANCE

Because of its aggressively metastatic nature, lung cancer is the top cancer killer of both men and women in the United States. We show that, unlike in other cancer types, lung cancer dissemination is a major initial barrier to metastasis. Our findings provide insight into the effect of p53 deficiency and downregulation of Nkx2-1 during lung adenocarcinoma progression.

Extraction bag lavage cytology during video-assisted thoracoscopic surgery for primary lung cancer

OBJECTIVES

Sample extraction from the thoracic cavity through an intercostal space during video-assisted thoracoscopic surgery can result in cancer cell contamination by tumour crushing and tumour cell extravasation, and may have adverse effects on the surgical outcome. Lavage cytology of the sample extraction bag was investigated to clarify the risk of cancer cell spillage and identify the clinicopathological features associated with susceptibility to cancer cell spillage during extraction.

METHODS

Lavage cytology of the sample extraction bag was investigated in 464 patients with negative pleural lavage cytology who underwent lung resection for primary lung cancer via video-assisted thoracoscopic surgery between January 2010 and December 2012. The surgical procedures, pathological findings and clinical course were evaluated by hospital record review.

RESULTS

The incidence of positive bag lavage cytology (BLC) was 13.6%. Statistically significant factors associated with susceptibility to BLC positivity were tumour size, standardized uptake value of positron emission tomography, pathological features such as pathological N score, pleural invasion, vascular invasion and papillary-predominant adenocarcinoma. Among patients with Stage I lung cancer, the survival rate was significantly lower in the BLC-positive group than in the BLC-negative group.

CONCLUSIONS

BLC positivity can be related to oncological characteristics such as tumour invasiveness and adhesiveness as opposed to tumour size and surgical margin, and may help to determine the prognosis of Stage I lung cancer. The sample extraction bag must be carefully manoeuvred through the intercostal space to prevent cancer cell dissemination to the chest wall or thoracic cavity.

Prognostic impact of minimal pleural effusion in non-small-cell lung cancer

PURPOSE

Minimal (< 10 mm thick) pleural effusion (PE) may represent an early phase of malignant PE, but its clinical relevance has rarely been studied. Therefore, we examined the proportion of minimal PE in patients with non-small-cell lung cancer (NSCLC) and its impact on survival. We also considered possible accumulation mechanisms in our data set.

PATIENTS AND METHODS

On the basis of PE status from chest computed tomography scans at diagnosis, 2,061 patients were classified into three groups: no PE, minimal PE, and malignant PE. Twenty-one variables associated with four factors-patient, stage migration, tumor, and treatment-were investigated for correlation with survival.

RESULTS

Minimal PE presented in 272 patients (13.2%). Of 2,061 patients, the proportion of each stage was the following: 5.2% stage I, 10.9% stage II, 13.2% stage IIIA, 23.8% stage IIIB, and 13.9% stage IV. Minimal PE correlated significantly with shorter survival time than did no PE (median survival time, 7.7 v 17.7 months; log-rank P < .001), even after full adjustment with all variables (adjusted hazard ratio, 1.40; 95% CI, 1.21 to 1.62). Prognostic impact of minimal PE was higher in early versus advanced stages (Pinteraction = .001). In 237 patients (87.8%) with minimal PE, pleural invasion or attachment as a direct mechanism was observed, and it was an independent factor predicting worse survival (P = .03).

CONCLUSION

Minimal PE is a commonly encountered clinical concern in staging NSCLCs. Its presence is an important prognostic factor of worse survival, especially in early-stage disease.

[The prognostic value of micrometastasis in non-small cell lung cancer]

肺癌是我国目前发病率和死亡率最高的恶性肿瘤。非小细胞肺癌（non-small cell lung cancer, NSCLC）占肺癌的80%-85%。诊断时的分期是NSCLC主要的预后因子，也是治疗模式选择的重要依据。然而，完全性切除术后的Ⅰ期的NSCLC仍有25%-30%的复发率。这部分复发的患者可能早期就存在局部和（或）远处的隐匿性转移。因此，很多研究开始对NSCLC患者进行微转移的检测，并评估其预后价值。本文总结了近年来的相关研究，并就NSCLC的淋巴结微转移、骨髓微转移、胸膜腔微转移及外周血微转移的预后作用进行综述。

Outcome of platinum-based chemotherapy for non-small-cell lung cancer patients with pleural dissemination detected during surgery

Pleural dissemination detected by computed tomography (CT) is considered to be unfavorable for patients with non-small-cell lung cancer (NSCLC). However, the prognosis of NSCLC patients who are diagnosed with pleural dissemination at the time of surgery has yet to be adequately elucidated. To assess the outcomes of platinum-based chemotherapy in NSCLC patients in whom pleural dissemination was detected during exploratory thoracotomy with or without a videoscope, the clinical records of NSCLC patients who were admitted to Shizuoka Cancer Center between September, 2002 and April, 2009 were reviewed. A total of 19 patients were included in this study, 12 males and 7 females, with a median age of 65 years. All patients were diagnosed with adenocarcinoma and 6 were epidermal growth factor receptor (EGFR) gene mutation-positive. The median number of treatment cycles of first-line platinum-based chemotherapy was 4 (range, 1-6 cycles) and the objective response rate was 21% [95% confidence interval (CI): 8.5-43]. The median progression-free and overall survival were 10.4 (95% CI: 6.3-18.4) and 50.5 months (95% CI: 32.5-98.0), respectively. Of the 18 patients with reported disease progression, 9 (50%) developed locoregional tumor progression. In conclusion, NSCLC patients in whom pleural dissemination is detected during surgery tend to have a favorable prognosis for survival. Systemic chemotherapy and additional local treatment may improve their clinical outcomes.

New staging system: how does it affect our practice?

The anatomic extent of disease, as described by the TNM classification, remains the most powerful prognostic indicator for lung cancer. It is used daily by specialists in all branches of lung cancer care and research. Any new edition of the TNM classification is therefore an important event in the thoracic oncology community and one greeted with mixed feelings. The changes introduced in the seventh edition were the first for 13 years and arguably the most profound since the first data-driven revision more than 40 years earlier. Inevitably there will be concerns that any change in the T, N, or M descriptors and resultant stage groupings will have implications for previous treatment pathways. In this article, the changes to the classification are described, and their possible impacts on clinical care and research are discussed.

Detection of human telomerase reverse transcriptase mRNA in cells obtained by lavage of the pleura is not associated with worse outcome in patients with stage I/II non-small cell lung cancer: results from Cancer and Leukemia Group B 159902

OBJECTIVE

Previous studies suggest that cytologic analysis of cells obtained by lavage of the pleural surfaces at the time of resection of non-small cell lung cancer can identify patients at risk for recurrence. Because telomerase gene expression has been associated with worse outcome in non-small cell lung cancer, we hypothesized that identification of cells obtained from pleural lavage that express telomerase would identify patients at risk for recurrent disease.

METHODS

Patients with presumed non-small cell lung cancer underwent thoracotomy with curative intent. Cells obtained by lavage of the pleural surfaces were analyzed for telomerase catalytic subunit human telomerase reverse transcriptase mRNA expression using reverse transcriptase polymerase chain reaction.

RESULTS

A total of 194 patients with stage I/II non-small cell lung cancer had adequate samples, and median follow-up was 60 months (17-91 months). By using Cox models, no statistical differences were found between human telomerase reverse transcriptase-negative and positive patients in disease-free survival (hazard ratio, 1.28; 95% confidence interval, 0.85-1.94; log-rank test, P = .2349) or overall survival (hazard ratio, 1.13; 95% confidence interval, 0.72-1.79; log-rank test, P = .5912) CONCLUSIONS: Detection of human telomerase reverse transcriptase in cells obtained from pleural lavage of patients with stage I/II non-small cell lung cancer does not identify patients at risk for recurrent disease.