Prognostic significance of pleural lavage cytology in patients with lung cancer: A meta-analysis

[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。

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.

Diagnostic value of medical thoracoscopy in malignant pleural effusion

Background

Medical thoracoscopy has been shown to be an efficacious procedure in diagnosing unexplained exudative pleural effusions with excellent safety. This study aimed to assess the diagnostic significance of thoracoscopy in the management of patients with malignant pleural effusion (MPE).

Methods

Consecutive patients with malignant pleural effusion were retrospectively reviewed, and their demographic, radiographic, thoracoscopic and histological data were collected.

Results

Between July 2005 and June 2014, 342 of 833 patients undergoing thoracoscopy were finally confirmed to suffer from MPE. The top three frequent causes of MPE were metastatic carcinoma (79.5%), malignant mesothelioma (10.2%), and lymphoma (2.9%). Among metastatic malignancies, the most common cancer was lung cancer (85.2%), followed by breast cancer (4.4%), ovarian cancer (2.2%), pancreatic cancer (1.8%), etc. No serious adverse events associated with thoracoscopy were recorded.

Conclusions

Medical thoracoscopy is a valuable and safe tool in diagnosing malignant pleural effusion with minimal complication rates.

The role of surgical intervention in lung cancer with carcinomatous pleuritis

Patients with non-small cell lung cancer (NSCLC) associated with carcinomatous pleuritis are currently classified as having stage IV disease per the 7^th edition of the tumor-node-metastasis (TNM) system, which means that the disease is deemed incurable. In fact, the 5-year survival rate of these patients was only 2% in a large global cohort collected by the International Association for the Study of Lung Cancer. However, patients with carcinomatous pleuritis have heterogeneous conditions. Some have minimal pleural effusion, which is first detected at thoracotomy; some have numerous pleural nodules without any effusion; and others have massive effusion and nodules with symptoms. Several investigators have reported the contribution of surgical intervention to favorable outcomes of patients with carcinomatous pleuritis first detected at thoracotomy. These reports show a relatively higher 5-year survival rate of 15% to 37%. The extrapleural pneumonectomy (EPP) is a radical surgical procedure that is commonly employed in the treatment of malignant pleural mesothelioma. Two authors reported that they have successfully performed EPPs for the treatment of patients with carcinomatous pleuritis. Their 5-year survival rates were estimated to be 22% and 61%, a significantly improved outcome. Although the development of chemotherapeutic agents, including molecular targeted drugs, might have the potential to prolong the survival of patients with advanced lung cancer, surgical interventions including EPP might have a role in improving the survival of patients with carcinomatous pleuritis of minimal disease and those without massive effusion or numerous pleural nodules.

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.

Frequency of EGFR mutations in lung adenocarcinoma with malignant pleural effusion: Implication of cancer biological behaviour regulated by EGFR mutation

OBJECTIVE

A retrospective single-centre study to compare the clinical features of patients with lung adenocarcinoma with and without epidermal growth factor receptor (EGFR) mutations.

METHODS

Pretreatment medical records of patients with lung adenocarcinoma were reviewed. DNA was extracted from paraffin wax-embedded tumour tissue for analysis of EGFR mutations. Malignant pleural effusion (MPE) was diagnosed by cytopathological testing of pleural fluid.

RESULTS

EGFR mutations (19-Del and L858R) were recorded in 81/283 patients (28.6%). MPE was found in 42/283 patients (14.8%). In patients with stage IV disease, the frequency of EGFR mutations was higher in those with MPE than in those without MPE. EGFR mutations were independently associated with female sex, no history of smoking and presence of MPE.

CONCLUSIONS

There was a positive association between EGFR mutation and the presence of MPE. EGFR mutations may play an important role in the formation of MPE.

Lung toxicity assessment using bronchoalveolar lavage fluid and pleural lavage fluid cytology by intratracheal treatment in rats

Usefulness of bronchoalveolar lavage fluid (BALF) and pleural cavity lavage fluid (PLF) as an experimental material was evaluated for the assessment of pulmonary toxicity of chemicals in rats. From the viewpoint of safety, isoflurane can be used for euthanasia/anesthesia because there was no difference in biological properties of BALF between diethyl ether and isoflurane. Here, we also recognized phosphate buffered saline (PBS) and distilled water equally as a solvent/vehicle for negative control. PLF is also provided as a useful target material as well as BALF for assessing chemical lung toxicity. To evaluate the method, we used zinc chloride as a model chemical and obtained the expected and satisfied results. We may conclude that the intratracheal treatment and combination usage of BALF and PLF as a target material is a good method for assessment of chemical pulmonary (lung and plural cavity) toxicity in rats.

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.