Prognostic value of visceral pleural invasion in resected non-small cell lung cancer diagnosed by using a jet stream of saline solution

[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。

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.

Aberrant DNA methylation of integrin α4 in human breast cancer

Integrins are cell surface receptors that mediate cell-cell/extracellular interactions and have shown an association with metastasis or transformation in several cancers. However, the correlation between the clinicopathological status of breast cancer and the altered integrin α4 status is not clear. In this study, we investigated DNA methylation of integrin α4 in breast cancer. We retrieved 351 cases of surgically resected breast cancer (290 invasive carcinoma and 61 intraductal carcinoma). Methylation-specific polymerase chain reaction was performed to determine integrin α4 methylation status. Integrin α4 methylation was frequently observed in breast cancer specimens (145/351 cases, 41.3 %). In addition, DNA methylation of integrin α4 showed statistical correlation with HER2 positivity and higher histologic grade (p = 0.001, 0.008 in ductal carcinoma in situ and 0.003 in invasive ductal carcinoma). However, other clinicopathological data such as estrogen receptor, progesterone receptor, metastasis, and TNM status showed no statistical correlation. Moreover, we found that the downregulated expression of integrin α4 in a heavily methylated breast cancer cell line (ZR-75) was restored by treatment with 5-aza-2'deoxycytidine, a DNA methyltransferase inhibitor, implying transcriptional silencing by DNA methylation. We observed that integrin α4 methylation is associated with the histologic grade of tumors and lymph node metastasis. Also, this data supports a previous study that suggested integrin α4 and HER2 are involved in the same signaling pathway. DNA methylation of integrin α4 may be a poor prognostic factor which affects undifferentiated histologic change of breast cancer.

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.

Aberrant DNA methylation of integrin alpha4: a potential novel role for metastasis of cholangiocarcinoma

PURPOSE

Although the altered expression of integrin alpha4 is known to be associated with transformation or metastasis in several human cancers, the information on cholangiocarcinoma (CC) is still poor. In this study, we investigated the promoter methylation status of integrin alpha4 gene in CC.

METHODS

A total of 29 CC, 19 adjacent non-tumor-containing tissue and 15 normal liver specimens were used for identification of gene methylation status by methylation-specific polymerase chain reaction.

RESULTS

The frequency of DNA methylation was 55.17% (16 of 29) in the CC specimens (P < 0.001). Also, transcripts of the integrin alpha4 gene were decreased in all CC tissues in which there was DNA methylation of the integrin alpha4 gene. In addition, the downregulated expression of integrin alpha4 in CC cells with hypermethylation of the integrin alpha4 gene was restored by treatment with 5-aza-2'-deoxycytidine, a DNA methyltransferase inhibitor. Moreover, we found that DNA methylation of integrin alpha4 was detected in all CC tissues obtained from patients with LN metastasis (7/7). Furthermore, phosphorylation of paxillin, cell migration-related molecule, was regulated by silencing of integrin alpha4.

CONCLUSIONS

Taken together, these results suggest that loss of the integrin alpha4 gene is caused by aberrant DNA methylation of the 5'-CpG island site of the gene, and methylation of the integrin alpha4 gene can be a useful marker of metastasis of CC.

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.

The Prospect of Biologic Staging of Non–Small-Cell Lung Cancer

The reductionistic approach to cancer research has led to an enormous amount of information and publications regarding the molecular biologic processes that take place in cancer tissue. However, the specific influence of this information on clinical practice has been limited. With the advent of new reductionistic tools like the transcriptomic and proteomic technologies, many would argue that further advances in the field of lung cancer research will be dominated by advances on the technical level. However, we anticipate that the most revolutionary advances will be those at a conceptual level. Medical science has always been reductionistic in essence, reducing and analyzing the composing elements of our complex biologic machinery, overlooking the fact that the interrelation among a set of simple determinants creates a new dimension of characteristics and functions. Problems emerging from a reductionistic approach are heterogeneity and variability. This review addresses the current conceptual problems in the field of lung cancer biology and provides a new conceptual model based on recent publications.