Seiki Hasegawa

Circulating Tumor Cell as a Diagnostic Marker in Primary Lung Cancer

Purpose: To investigate the diagnostic performance of circulating tumor cells (CTC) in discrimination between primary lung cancer and nonmalignant diseases as well as in prediction of distant metastasis. Patients and Methods: We prospectively evaluated CTCs in 7.5-mL samples of peripheral blood sampled from patients with a suspicion or a diagnosis of primary lung cancer. A semiautomated system was used to capture CTCs with an antibody against epithelial cell adhesion molecule. Results: Of 150 eligible patients, 25 were finally diagnosed as having nonmalignant disease, and 125 were diagnosed as having primary lung cancer with (n = 31) or without (n = 94) distant metastasis. CTCs were detected in 30.6 of lung cancer patients and in 12.0 of nonmalignant patients. CTC count was significantly higher in lung cancer patients than in nonmalignant patients, but a receiver operating characteristic (ROC) curve analysis showed an insufficient capability of the CTC test in discrimination between lung cancer and nonmalignant diseases with an area under ROC curve of 0.598 (95 confidence interval, 0.488-0.708; P = 0.122). Among lung cancer patients, CTC count significantly increased along with tumor progression, especially with development of distant metastasis. The area under ROC curve for CTC count in prediction of distant metastasis was 0.783 (95 confidence interval, 0.679-0.886; P < 0.001). When patients with one or more CTCs were judged as having metastatic disease, sensitivity and specificity of the CTC test were 71.0 and 83.0, respectively. Conclusions: CTC is a useful surrogate marker of distant metastasis in primary lung cancer. (Clin Cancer Res 2009;15(22):69806)

Frequent inactivation of the BAP1 gene in epithelioid-type malignant mesothelioma.

In the present study, we analyzed genomic alterations of BRCA1‐associated protein 1 (BAP1) in 23 malignant mesotheliomas (MMs), 16 epithelioid and seven non‐epithelioid, consisting of 18 clinical specimens and five established cell lines. In examining these samples for homozygous deletions and sequence‐level mutations, we found biallelic BAP1 gene alterations in 14 of 23 MMs (61%). Seven of these 14 MMs had homozygous deletions of the partial or entire BAP1 gene, another five had sequence‐level mutations, including small deletions, a nonsense mutation, and missense mutations with additional monoallelic deletions, and the remaining two had homozygous mutations without allelic loss. All but one of the 14 BAP1 gene mutations were found in the epithelioid‐type MMs; BAP1 mutations were found in 13 of 16 epithelioid‐type MMs, but in only one of seven non‐epithelioid‐type MMs (13/16 vs 1/7; P = 0.005). There was no BAP1 mRNA expression in MMs with biallelic deletion and repressed expression was confirmed in MM specimens with deletion/mutation as compared with Met5a, SV40‐transformed normal mesothelial cells. Western blot showed that seven of eight epithelioid MMs analyzed were BAP1 negative. Immunostaining with anti‐BAP1 antibody in normal lung tissues revealed clear nuclear staining of normal mesothelial cells. No nuclear staining was observed among BAP1 mutation‐positive MM tumors, whereas nuclear staining was observed among BAP1 mutation‐negative MM tumors. These results suggest that the lack of the tumor suppressor BAP1 may be more specifically involved in the pathogenesis of epithelioid MM rather than non‐epithelioid MM, and would be useful for diagnosis of epithelioid‐type MM. (Cancer Sci 2012; 103: 868–874)

Prognostic Impact of Circulating Tumor Cells in Patients with Small Cell Lung Cancer

Background: Enumeration of circulating tumor cells (CTCs) may be valuable for prognostic assessment in lung cancer patients. In this study, we report the clinical significance of CTCs in small cell lung cancer (SCLC). Methods: In total, 51 consecutive patients newly diagnosed as having SCLC and starting chemotherapy or chemoradiotherapy were prospectively enrolled. Blood samples were drawn at the baseline, after chemotherapy, and at relapse. CTCs were isolated using the CellSearch System (Veridex LLC). Thresholds of 1 to 100 cells at the baseline were systematically correlated with the overall survival. The optimal cutoff was determined by comparing the Cox proportional hazard ratios (HRs). Results: Two or more CTCs were detected at baseline in 35 patients (68.6%; 95% confidence interval, 55.0–79.7). The HR signifying the difference between the unfavorable (more than or equal to threshold) and favorable (less than threshold) groups was maximal at the threshold of 8 CTCs (HR, 3.50; 95% confidence interval, 1.45–8.60). Patients with ≥8 CTCs had worse survival than those with <8 CTCs at baseline (p = 0.0014). Patients with ≥8 CTCs posttreatment or at relapse also showed worse survival than those with <8 CTCs (p = 0.0096 and <0.0001). Patients whose baseline and posttreatment CTC levels remained <8 tended to show better survival than those whose CTC level converted from ≥8 to <8 cells (p = 0.0288) or whose posttreatment CTC level was ≥8 cells (p = 0.0047). Conclusions: CTCs were highly detectable in SCLC, and higher CTC levels were strongly associated with worse survival. Consistently favorable CTC levels were associated with favorable outcomes.

The IASLC Lung Cancer Staging Project: Proposals for Coding T Categories for Subsolid Nodules and Assessment of Tumor Size in Part-Solid Tumors in the Forthcoming Eighth Edition of the TNM Classification of Lung Cancer

ABSTRACT This article proposes codes for the primary tumor categories of adenocarcinoma in situ (AIS) and minimally invasive adenocarcinoma (MIA) and a uniform way to measure tumor size in part‐solid tumors for the eighth edition of the tumor, node, and metastasis classification of lung cancer. In 2011, new entities of AIS, MIA, and lepidic predominant adenocarcinoma were defined, and they were later incorporated into the 2015 World Health Organization classification of lung cancer. To fit these entities into the T component of the staging system, the Tis category is proposed for AIS, with Tis (AIS) specified if it is to be distinguished from squamous cell carcinoma in situ (SCIS), which is to be designated Tis (SCIS). We also propose that MIA be classified as T1mi. Furthermore, the use of the invasive size for T descriptor size follows a recommendation made in three editions of the Union for International Cancer Control tumor, node, and metastasis supplement since 2003. For tumor size, the greatest dimension should be reported both clinically and pathologically. In nonmucinous lung adenocarcinomas, the computed tomography (CT) findings of ground glass versus solid opacities tend to correspond respectively to lepidic versus invasive patterns seen pathologically. However, this correlation is not absolute; so when CT features suggest nonmucinous AIS, MIA, and lepidic predominant adenocarcinoma, the suspected diagnosis and clinical staging should be regarded as a preliminary assessment that is subject to revision after pathologic evaluation of resected specimens. The ability to predict invasive versus noninvasive size on the basis of solid versus ground glass components is not applicable to mucinous AIS, MIA, or invasive mucinous adenocarcinomas because they generally show solid nodules or consolidation on CT.

Matrix metalloproteinase-2 status in stromal fibroblasts, not in tumor cells, is a significant prognostic factor in non-small-cell lung cancer

Purpose: The purpose is to assess clinical significance of matrix metalloproteinase (MMP)-2 and MMP-9 status, especially MMP-2 status, in stromal cells in non–small-cell lung cancer (NSCLC) because experimental studies have revealed that stromal MMP-2 plays important roles in progression of malignant tumors, but most clinical studies focused on tumoral MMP-2 expression, not stromal MMP-2 expression. Experimental Design: We conducted a retrospective study on MMP-2 and MMP-9 expression as evaluated immunohistochemically in a total of 218 consecutive patients with completely resected pathological stage I–IIIA, NSCLC. Results: Strong MMP-2 expression in tumor cells and stromal fibroblasts were documented in 54 (24.8%) and 132 (60.6%) patients, respectively. Strong MMP-2 expression in stromal fibroblasts was more frequently seen in squamous cell carcinoma (72.7%) than in adenocarcinoma (54.9%; P = 0.016). Tumors showing strong MMP-2 expression in stromal fibroblasts showed a significantly higher intratumoral microvessel density (IMVD) than weak stromal MMP-2 tumors (mean intratumoral microvessel density, 50.9 versus 32.4, P = 0.003). In addition, postoperative prognosis of strong stromal MMP-2 patients was significantly poorer than that of weak stromal MMP-2 patients (5-year survival rate, 77.5 versus 60.2%, P = 0.032), and the prognostic significance was enhanced in squamous cell carcinoma patients but disappeared in adenocarcinoma patients. Multivariate analyses confirmed that strong stromal MMP-2 expression was a significant factor to predict a poor prognosis in squamous cell carcinoma patients, not in adenocarcinoma patients. In contrast, MMP-2 or MMP-9 status in tumor cells was not a significant prognostic factor. Conclusions: MMP-2 status in stromal fibroblasts, not in tumor cells, was a significant prognostic factor associated with angiogenesis in NSCLC.

The role of surgical cytoreduction in the treatment of malignant pleural mesothelioma: Meeting summary of the International Mesothelioma Interest Group Congress, September 11-14, 2012, Boston, Mass

The treatment of all solid tumors, including malignant pleural mesothelioma (MPM), is dependent on (1) macroscopic complete resection and (2) treatment of micrometastatic disease. The role of surgery in the treatment of MPM has been the subject of debate after the recent publication of the Mesothelioma and Radical Surgery (MARS) I trial. The International Mesothelioma Interest Group (IMIG) met from September 11 through 14, 2012, in Boston, Mass. During this meeting, more than 500 participants representing all the involved specialty groups met in multiple comprehensive sessions to review, critique, and extend the state of knowledge regarding the role of surgery, including both extended pleurectomy/decortication (P/D) and extrapleural pneumonectomy (EPP), in the treatment of MPM. Some of the deficiencies of the MARS I trial, which was published a year ago in Lancet Oncology, were discussed in multiple sessions of the IMIG meeting. The editorial that accompanied the publication articulated numerous shortcomings of the trial. TheMARS I trial was designed as a pilot feasibility trial, the result of which was negative in that it failed to demonstrate the feasibility of randomly allocating patients to surgery versus no surgery. Nevertheless, the

Circulating Tumor Cells in Pulmonary Venous Blood of Primary Lung Cancer Patients

BACKGROUND Circulating tumor cells in peripheral blood (CTC) is a potential surrogate of distant metastasis, which is the critical factor influencing decision making regarding therapy and prognosis of primary lung cancer patients. After our preliminary study showing that CTCs were detected in peripheral blood in 29.4% of resectable lung cancer patients, we conducted a prospective study on CTC in pulmonary vein (PV) blood because tumor cells apart from the primary tumor may circulate after passing through the drainage PV. METHODS A total of 30 consecutive lung cancer patients who underwent thoracotomy were included. The CTCs in peripheral blood and in PV blood from the primary tumor site were quantitatively examined with the CellSearch system, and the numbers of CTCs per 7.5 mL peripheral and PV blood in each patient were represented as periCTC count and pvCTC count, respectively. RESULTS Circulating tumor cell was detected in peripheral blood in 5 patients (16.7%; the periCTC count was 1 in 2 patients; and 2, 3, and 16 in 1 patient each), and the incidence of positive periCTC was higher in squamous carcinoma patients than in adenocarcinoma patients (p = 0.028). Circulating tumor cell was detected in PV blood in most patients (29 of 30, 96.7%), and the mean and median pvCTC counts were 1,195 and 81, respectively (range, 0 to 10,034). There was no significant correlation between pvCTC count and any other patient characteristic, including periCTC count. CONCLUSIONS In resectable lung cancer, CTC was positive in peripheral blood of some patients and in PV blood of most patients. A long-term follow-up study to clarify the clinical significance of pvCTC status is warranted.

Immunocytochemistry of CD146 is useful to discriminate between malignant pleural mesothelioma and reactive mesothelium

Malignant pleural mesothelioma is a refractory tumor with poor prognosis associated with asbestos exposure. Pleural effusion is frequently observed in patients with malignant pleural mesothelioma, and cytological analysis is effective to detect malignant pleural mesothelioma. However, cytological discrimination between malignant pleural mesothelioma and reactive mesothelium is often difficult. Increased expression of CD146, a cell adhesion molecule, has been reported to be closely associated with an advanced stage of malignant melanoma, prostate cancer, and ovarian cancer. In this study, to evaluate the diagnostic utility of CD146 for discrimination between malignant pleural mesothelioma and reactive mesothelium, we examined immunocytochemical expression of CD146 in malignant pleural mesothelioma and reactive mesothelium using two clones of CD146 antibody, OJ79 and EPR3208, on smear specimens of effusion fluids. Immunocytochemical stains were semiquantitatively scored on the basis of immunostaining intensity (0, negative; 1, weak positive; 2, moderate positive; and 3, strong positive). CD146 expression was detected in 15 of 16 malignant pleural mesothelioma with median immunostaining score of 3 by OJ79, and in 19 of 21 malignant pleural mesothelioma with median immunostaining score of 2 by EPR3208. Strong immunoreactivity of CD146 was observed at the apposing surfaces of cell–cell interactions on the plasma membrane of mesothelioma cells. In addition, one OJ79-negative case of malignant pleural mesothelioma was positive for CD146 by EPR3208 and two EPR3208-negative cases of malignant pleural mesothelioma were CD146 positive by OJ79, showing that all 23 malignant pleural mesothelioma cases were positive for CD146 by either OJ79 or EPR3208. On the other hand, CD146 expression was undetectable in all reactive mesothelium cases by OJ79 and EPR3208. The sensitivity of OJ79 and EPR3208 was 94 and 90%, respectively, and the specificity was 100% for both clones. We propose that CD146 is a sensitive and specific immunocytochemical marker enabling differential diagnosis of malignant pleural mesothelioma from reactive mesothelium.

A new method of segmental resection for primary lung cancer: intermediate results.

OBJECTIVE To improve the postoperative results of limited resection for small lung cancer, we have developed a new operative method, pulmonary artery-guided segmentectomy. This resection begins with identification of the pulmonary arterial branches involved in the tumor, then the pulmonary tissue is divided along the pulmonary arteries (i.e. guided by pulmonary arteries) from the hilum toward the periphery by electrocautery. The advantages of this method include the facilitation of securing adequate margin from the tumor, and the feasibility of intralobar lymph node dissection during operation. To examine the efficacy of the new method of segmental resection, we retrospectively reviewed 74 cases of T1N0M0 disease who underwent the pulmonary artery-guided segmentectomy. METHODS From 1993 to 2000, 74 patients with pathological T1N0M0 lung cancer were treated by the pulmonary artery-guided segmentectomy. Forty-one patients (55.4%) who underwent the segmentectomy had been considered suitable candidates for lobectomy (intentional resection group). The other 33 patients (44.6%) were considered poor candidates for lobectomy because of poor cardiopulmonary reserve (compromised resection group). RESULTS The overall survival rate at 5 years was 82.0%. The 5-year survivals in the intentional and the compromised resection groups were 81.6 and 77.6%, respectively, and no significant differences were detected between the groups. According to tumor size, the 5-year survival rate for patients with tumors of 20 mm or smaller (92.9%, n=53) was higher than that for the patients with tumors of 21-30 mm (63.0%, n=21), but the difference did not reach statistical significance. Median follow-up time of 27.0 months revealed eight locoregional recurrences and four deaths due to lung cancer. Sixty-three patients (85.1%) are alive with no evidence of disease, and six patients (8.1%) are alive with recurrent disease. Locoregional recurrences occurred in one of 53 patients (1.9%) with tumors 20 mm or smaller and in seven of 21 patients (33.3%) with tumors 21-30 mm, the difference being statistically significant (P<0.01). CONCLUSIONS Our intermediate results demonstrated that the new pulmonary artery-guided segmentectomy could be an alternative method for selected patients with small lung cancer, particularly with tumors 20 mm or smaller in diameter.

Attenuation of ischaemia reperfusion injury by human thioredoxin.

BACKGROUND--Active oxygen species are thought to play a part in ischaemia reperfusion injury. The ability of a novel agent, human thioredoxin (hTRX), to attenuate lung damage has been examined in a rat model of ischaemia reperfusion injury. METHODS--Twenty eight animals were studied. At thoracotomy the left main bronchus and the left main pulmonary artery were clamped for 75 minutes and the lung was then reperfused for 20 minutes. Phosphate buffered saline was administered intravenously to nine control animals and hTRX (30 micrograms/g body weight) was given intravenously to another group of nine animals. Two experiments were carried out. The first (Exp 1) was a time matched pair experiment (five treated, five controls), and the second (Exp 2) was performed under controlled conditions (four treated, four controls; temperature 25 degrees C, humidity 65%). In another 10 nonischaemic rats and those in Exp 1 biochemical measurements of lipid peroxide, superoxide dismutase, and glutathione peroxide levels were performed. RESULTS--In both experiments rats perfused with hTRX survived longer than controls. In Exp 1 the arterial oxygen tension (PaO2) on air in the hTRX group was higher at 20 minutes than at one minute after reperfusion. In Exp 2 PaO2 at 20 minutes was higher in the hTRX group than in the controls. Lipid peroxide, superoxide dismutase, and glutathione peroxide levels in the control group were higher than in the hTRX group and in the non-ischaemic groups. Histological examination showed less thickening and oedema of the alveolar walls in the hTRX group than in controls. CONCLUSIONS--These results suggest that hTRX is effective as a radical scavenger and can limit the extent of ischaemia reperfusion injury of the lungs of experimental animals.