Takashi Anayama

A prospective study of indications for mediastinoscopy in lung cancer with CT findings, tumor size, and tumor markers

BACKGROUND Biopsies by mediastinoscopy remain the most reliable preoperative staging method for N2 lung cancer. Because it is neither practical nor economical to recommend mediastinoscopy for all candidates for surgery, we developed indicational criteria for video-assisted mediastinoscopy (VAM) and carried out a prospective study to validate its usefulness. METHODS Patients with resectable primary lung cancer were chosen for VAM when at least one of three clinical indicators was present: (1) computed tomographic evidence of mediastinal adenopathy, (2) elevated levels of serologic tumor markers, and (3) diameters of primary cancers (> 2 to 3 cm). Patients without positive nodes (group 2) underwent thoracotomy, and patients with positive nodes (group 3) received induction therapy. When none of these criteria were met (group 1), thoracotomy with R2b lymph node dissection was performed without VAM. RESULTS One hundred twenty-one men and 82 women (total, 203) were eligible for the study. The mean age of the patients was 64.4 years (range, 39 to 75 years) with primary lung cancer. The patients were comprised of 135 adenocarcinomas, 46 squamous cell cancers, and 22 other carcinomas. There were 78 patients in group 1, 87 in group 2, and 38 in group 3. The stages of group 2 patients were more advanced (chi2 = 63.2668; p < 0.001) than those of group 1. As the incidence of positive indicators for VAM increased, the ratios of N2 patients increased from 2.5% (all negative) to 90.4% (triple positive: p < 0.001). The correlation of our criteria with the pathology findings revealed a diagnostic sensitivity of 95.8% and a negative predictive value of 97.4%. Using three indicators for N2 prediction, we selected 96% (46 of 48) pN2, N3 patients and avoided 37% (76 of 203) unnecessary VAMs. CONCLUSIONS We established and validated currently useful criteria for VAMs in the management of primary lung cancer.

Simultaneous Isolation of Total RNA, DNA, and Protein Using Samples Obtained by EBUS-TBNA.

Background:Samples obtained by endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) have been shown to be useful for molecular analysis. Methods:The purpose of this study was to evaluate the feasibility of simultaneous isolation of DNA, RNA, and protein using EBUS-TBNA samples. We extracted DNA, RNA, and protein from 59 archived samples obtained by EBUS-TBNA. All samples were mixed with DNA, RNA, and protein-protective solution immediately after taking the biopsy and stored in −80°C for at least 1 year (range, 12 to 30 mo). We used QIAzol Lysis Reagent for the sequential isolation of total RNA, DNA, and protein. The concentration of RNA and DNA was measured and the quality of RNA was evaluated. The concentration of protein was measured using the Bradford protein assay. Results:Total RNA was successfully isolated in all 59 samples. DNA was isolated in 58 of 59 (98.3%) samples and protein was isolated in 57 of 59 (96.6%) samples. On average, 7.18 &mgr;g of total RNA, 7.79 &mgr;g of DNA, and 3.96 mg of protein were isolated. RNA integrity number (RIN) was measured in 32 samples and the average RIN number was 6.2 (range, 2.7 to 7.3). Twenty of 32 total RNA samples (62.5%) showed a RIN of >6. Conclusions:DNA, RNA, and protein can simultaneously be isolated from archived samples obtained by EBUS-TBNA. This method facilitates direct comparisons of alterations in the genome, transcriptome, and proteome within metastatic lymph nodes through a minimally invasive approach.

Assessment of the new thin convex probe endobronchial ultrasound bronchoscope and the dedicated aspiration needle: a preliminary study in the porcine lung.

Background:Endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) allows for accurate minimally invasive mediastinal lymph node staging of lung cancer. The current convex probe EBUS (CP-EBUS) has limitations in the access to certain N1 lymph nodes (lobar and segmental) because of its size. The aim of this study was to assess the new thin CP-EBUS (TCP-EBUS) and an aspiration needle for sampling of N1 lymph nodes in a porcine model. Methods:The prototype TCP-EBUS (BF-Y0046, Olympus Medical Systems Corp.) with a thinner tip (5.9 mm) and larger bending angle (170 degrees upward) was used. Accessibility, operability, and TBNA capability of the TCP-EBUS were assessed and compared with the current CP-EBUS using porcine lungs. The endoscopic visibility range and the maximum reach were evaluated at the left upper lobe bronchus, tracheobronchus, and right lower lobe bronchus. The prototype aspiration needle (Olympus Medical Systems Corp.) was used for EBUS-TBNA. Results:In all of the evaluated bronchi (n=9), the TCP-EBUS had a greater reach (14.7 mm in the endoscopic visibility range, 16.0 mm in the maximum reach) than the current CP-EBUS. The TCP-EBUS was able to visualize 1 to 3 distal bifurcations farther compared with the current CP-EBUS. Adequate lymph node sampling from lobar and segmental lymph nodes was possible using the aspiration needle. Conclusions:The TCP-EBUS has improved accessibility to peripheral bronchi with excellent operability and is capable of sampling lobar and segmental lymph nodes using the dedicated aspiration needle.

A strategy of sequential therapy with a bronchoscopic excision and thoracotomy for intra- and extrabronchial wall schwannoma: report of a case.

A 69-year-old woman was admitted with dyspnea on effort and left lung atelectasis on chest X-ray. Fiberoptic bronchoscopy revealed a complete obstruction of the left main bronchus due to a polypoid lesion. This lesion was diagnosed to be a schwannoma arising from the left lower bronchus. Bronchoscopic treatments were performed with electrosurgical snaring and the intratumoral injection of 99.5% ethanol. These treatments were performed once per week for 4 weeks, then were followed with a one-time application of semiconductor laser cautery. These treatments opened the airway and restored the left lung expansion. However, a residual tumor remained at the bifurcation of the left basal bronchus and B6. A cautious follow-up was conducted because schwannoma is a potentially benign tumor. A follow-up bronchoscopic examination at 21 months revealed a regrowth of the residual tumor. A complete resection using a left S6 sleeve segmentectomy was thus performed. The pathologic diagnosis of the tumor was benign schwannoma. There were no complications and no evidence of disease recurrence has been observed after the surgery.

Photothermal ablation of human lung cancer by low-power near-infrared laser and topical injection of indocyanine green.

The present study was designed to evaluate the efficacy of photothermal ablation therapy for lung cancer by low-power near-infrared laser and topical injection of indocyanine green (ICG). In vitro study 1: an 808 nm laser with 250 mW was irradiated for 10 minutes using different dilutions of ICG and the temporal thermal effect was monitored. ICG (1 mL of 0.5 g/L) was heated to a temperature of >30°C from the base temperature by laser irradiation. In vitro study 2: the cytotoxic effect of hyperthermia on human lung cancer cells was examined in different temperature and time settings. Cell viability was quantified by both an MTS assay and reculturing. Fatal conditions evaluated by reculturing were as follows: thermal treatment at 55°C for 5 minutes, 53°C for 10 minutes, and 51°C for 15 minutes. The MTS assay study suggested that thermal treatment at 59°C for 5 minutes and 57°C for 20 minutes showed a severe cytotoxic effect. In vivo study: nude mouse subcutaneous NCI-H460 human lung cancer xenograft models were used for the study. Saline or 0.5 g/L of ICG was injected topically into the tumor (n=3/group). Tumors were irradiated with a laser at 500 mW for 10 minutes. Although the tumor diameter reached 1 cm within 24 days after treatment in all 3 mice using saline/laser, tumor sizes were gradually reduced in all 3 mice using the ICG/laser. In 2 of the 3 mice using ICG/laser, tumors had disappeared macroscopically. The efficacy of the photothermal ablation therapy by low-power near-infrared laser and a topical injection of ICG was clarified using a mouse subcutaneous a lung cancer xenograft model.

Extraction of RNA using fine-needle aspiration samples stored under different conditions: a pilot study.

Background:Diagnosis of lung cancer is achieved by fine-needle aspiration (FNA) techniques such as computed tomography-guided FNA and transbronchial needle aspiration. The purpose of this study was to establish an optimal storing method for molecular testing in FNA samples. Methods:We performed FNA using a 21-gauge needle in surgically resected lung cancer samples. The aspirates were stored according to the following protocol: in group 1, the aspirate was snap frozen with liquid nitrogen and in group 2, the aspirate was mixed with RNA later. After sample collection from both groups, these samples were stored at −80°C for 6 months. RNA was extracted from each sample using a commercially available RNA extraction kit, and the quality and quantity of RNA were measured. Quantitative real-time reverse transcriptase polymerase chain reaction (RT-PCR) was performed for human actin &bgr; (hACTB) and keratin 19 (KRT19). Results:FNA was performed from 7 lung cancers. RNA was extracted from all samples. The median total amount of extracted RNA was 33.9 &mgr;g for group 1 and 35.8 &mgr;g for group 2. The mean RNA integrity number was 3.5 for group 1 and 6.3 for group 2. RT-PCR for hACTB and KRT19 could be successfully performed in all samples; however, the relative gene expression value showed intrasample variation. Conclusions:Samples obtained from computed tomography-guided FNA or transbronchial needle aspiration may be used for genetic profiling of lung cancer. RNA can be extracted from FNA samples and can be used for RT-PCR. RNA quality may affect mRNA expression analysis; therefore, an optimal FNA sample storing protocol is essential.

Pleomorphic Carcinoma of the Lung with Mediastinal Extension Following Malignant Lymphoma: Report of a Case

In following up a patient with non-Hodgkins lymphoma, we encountered a case of pulmonary pleomorphic carcinoma with mediastinal direct invasion. A 65-year-old man with hemoptysis was found to have an abnormal shadow in the right upper lung field. A 6.4 × 4.8-cm tumor adjacent to the upper mediastinum occupied the right anterior segment of the upper lobe (S3) and invaded the superior vena cava (SVC). The serum level of neuron-specific enolase was elevated to 11.9 ng/ml. A specimen from a transbronchial lung biopsy of the right B3b bronchus revealed giant tumor cells. A right upper lobectomy with SVC reconstruction was performed. The resected tumor was diagnosed as a pulmonary pleomorphic carcinoma with a large component of giant and spindle cells, and it is considered to be a rare histologic type.

Indocyanine green fluorescence/thermography evaluation of intercostal muscle flap vascularization: Blood supply of intercostal muscle flap

During anatomical lung resection in high‐risk patients, the bronchial stump is covered with tissue flaps (e.g. pericardial fat tissue and intercostal muscle) to prevent bronchopleural fistula development. This is vital for reliable reinforcement of the bronchial stump. We evaluated the blood supply of the flap using indocyanine green fluorescence (ICG‐FL) and thermography intraoperatively in 27 patients at high risk for developing a bronchopleural fistula.