Shunsuke Tauchi

Significance of microscopic invasion into hilar peribronchovascular soft tissue in resection specimens of primary non-small cell lung cancer

INTRODUCTION The significance and handling of microscopic invasion of non-small cell lung cancer (NSCLC) into hilar peribronchovascular soft tissue (SHEATH+) have not been defined in the TNM classification by AJCC/UICC; nevertheless, SHEATH+ may be equivalent to spread into the mediastinum. Also, assessment of the margin of peribronchial resection is challenging because of the technical difficulty of inking, and intraoperative and postoperative artifacts. METHODS Records of 592 consecutive Asian patients with primary NSCLC (excluding adenocarcinoma in situ) who had, without any preoperative therapy, undergone lobectomy, sleeve lobectomy and pneumonectomy were examined. SHEATH+, simply defined as invasion of hilar peribronchovascular soft tissue, without categorizing any invasive patterns, and its significance were statistically analyzed. RESULTS Forty-four SHEATH+ cases demonstrated significantly advanced TNM stages, and were statistically associated with central occurrence, pN1-3, and vascular invasion, as assessed by logistic regression analysis. No statistically significant differences were observed between TNM stage-adjusted frequency of recurrence and recurrence-free intervals. Kaplan-Meiers estimates of the rate of overall and recurrence-free survival after surgery showed no statistically significant differences between SHEATH+ and SHEATH-. Coxs multivariate analysis suggested SHEATH was not a statistically independent prognostic factor under the TNM classification by AJCC/UICC (7th edition). CONCLUSIONS SHEATH+ in NSCLC was simply associated with central occurrence and advanced TNM stages. To the best of our knowledge, this is the first report on the significance of SHEATH+ in NSCLC.

Efficacy of adjuvant chemotherapy for lung adenocarcinoma patients with positive pleural lavage cytology findings

OBJECTIVES Positive pleural lavage cytology (PLC) findings are considered to be predictive of a poor prognosis in patients with non-small-cell lung cancer (NSCLC). We investigated the clinical benefit of adjuvant chemotherapy for lung adenocarcinoma patients with positive PLC findings. METHODS We retrospectively reviewed the medical records of lung adenocarcinoma patients who underwent tumour resection and had positive PLC findings between January 2000 and December 2009. RESULTS Fifty-three patients (4.8%) of 1114 patients with lung adenocarcinoma had positive PLC findings. The median follow-up period was 33.6 months. Adjuvant chemotherapy was administered to 24 patients (adjuvant chemotherapy group); 7, 8 and 9 patients had pathological Stage I, II and III, respectively . The surgery-alone group comprised 29 patients; 12, 8 and 9 patients had pathological Stage I, II and III, respectively. The 5-year recurrence-free survival (RFS) rates were 34.6 and 15.7% (P < 0.01) in adjuvant chemotherapy and surgery-alone groups, respectively. The rate of distant recurrence was significantly reduced in the adjuvant chemotherapy group (25.0 and 58.6%; P = 0.01). Even for Stage I cases, adjuvant chemotherapy tended to improve the 5-year RFS rate compared with surgery alone (60.1 and 29%; P = 0.11). Multivariate analysis for RFS revealed that adjuvant chemotherapy [hazard ratio (HR), 0.45; P = 0.03], tumour size >30 mm (HR, 2.23; P = 0.02) and lymph node metastasis (HR, 2.67; P < 0.01) were significant independent prognostic factors for recurrence. CONCLUSIONS Adjuvant chemotherapy for lung adenocarcinoma patients with positive PLC findings significantly improved recurrence-free survival.

Outcomes of segmentectomy for cT1bN0M0 lung adenocarcinoma and squamous cell carcinoma: a possible association with pathological invasion

OBJECTIVES We evaluated the clinical benefit of segmentectomy for patients with cT1bN0M0 lung cancer. METHODS We retrospectively reviewed the medical records of 178 patients who underwent lobectomy or segmentectomy for cT1bN0M0 lung adenocarcinoma and squamous cell carcinoma from January 1995 to December 2005. We investigated the association of surgical outcomes with the presence of pathological invasion. RESULTS The median follow-up period was 93.4 months. Of 178 patients, 37 were scheduled for segmentectomy, but 6 of these patients were switched to receive lobectomy due to surgical N1 or N2 in 3 patients and insufficient surgical margins in 3 patients. In total, 31 patients underwent segmentectomy, and 147 underwent lobectomy. The 5-year overall survival (OS) was similar between the patients who underwent lobectomy (5-year OS, 81.6%) and segmentectomy (5-year OS, 77.4%, P = 0.73). Among pN0 patients without pathological invasion, there was no difference in OS between patients who underwent lobectomy (5-year OS, 89.9%) and segmentectomy (5-year OS, 88.9%, P = 0.80). In contrast, among pN0 patients with pathological invasion, OS was greater in patients who underwent lobectomy (5-year OS, 80.9%) than in those who underwent segmentectomy (5-year OS, 54.6%; P = 0.19). Moreover, a significantly higher rate of local and local + distant recurrence was observed in patients who underwent segmentectomy (45%) than in those who underwent lobectomy (15%) in this group (P = 0.02). CONCLUSIONS The results of our study suggest that segmentectomy may not be recommended for cT1b tumours if pathological invasion is suspected before surgery.

The efficacy of 320-detector row computed tomography for the assessment of preoperative pulmonary vasculature of candidates for pulmonary segmentectomy

OBJECTIVES The purpose of this study was to compare the efficacy of 320-detector row computed tomography (CT) with that of 64-detector row CT for three-dimensional assessment of pulmonary vasculature of candidates for pulmonary segmentectomy. METHODS We included 32 patients who underwent both 320- and 64-detector CT before pulmonary segmentectomy, which was performed by cutting the pulmonary artery and bronchi of the affected segment followed by dissection of the intersegmental plane along the intersegmental vein. Before the operation, three-dimensional pulmonary vasculature images were obtained for each patient, and the arteries and intersegmental veins of the affected segments were identified. Two thoracic surgeons independently assessed the vessels with visual scoring systems, and kappa analysis was used to determine interobserver agreement. The Wilcoxon signed-rank test was used to compare the visual scores for the assessment of the visualization capabilities of the two methods. In addition, the final determination of pulmonary vasculature at a given site was made by consensus from thoracic surgeons during operation, and receiver operating characteristic analysis was performed to compare their efficacy of pulmonary vasculature assessment. Sensitivity, specificity and accuracy of either method were also compared by means of McNemars test. RESULTS Of the 32 cases, there were no operative complications, but 1 patient died of postoperative idiopathic interstitial pneumonia. Visualization scores for the pulmonary vessels were significantly higher for 320- than those for 64-detector CT (P < 0.0001 for the affected arteries and P < 0.0001 for the intersegmental veins). As for pulmonary vasculature assessment, the areas under the curve showed no statistically significant differences in between the two methods, while the specificity and accuracy of intersegemental vein assessment were significantly better for 320- than those for 64-detector row CT (P < 0.05). Interobserver agreement for the assessment yielded by either method was almost perfect for all cases. CONCLUSIONS Three hundred and twenty-detector row CT is more useful than conventional 64-detector row CT for preoperative three-dimensional assessment of pulmonary vasculature, especially when we identify the intersegmental veins, in candidates for pulmonary segmentectomy.

Clinical significance of the 'not otherwise specified ' subtype in candidates for resectable non‑small cell lung cancer

The histological subtype of non-small-cell lung cancer (NSCLC) is a significant factor when selecting treatment strategies. However, cases are occasionally encountered that are diagnosed as ‘not otherwise specified’ (NOS) prior to surgery, due to an uncertain histological subtype. The present study investigated the prognostic significance of the NOS subtype for patients with resectable NSCLC. Between 2001 and 2011, 1,913 patients were diagnosed with NSCLC using transbronchial biopsy and underwent surgical resection at two facilities in Japan. Of these patients, 151 (7.9%) were pre-operatively diagnosed with NSCLC-NOS (NOS group) and the remainder had confirmed histological subtypes (confirmed group). The present study compared the clinicopathological features and prognoses of these groups. Analyses of resected specimens revealed that pleomorphic cell carcinoma, large cell neuroendocrine cell carcinoma, large cell carcinoma and adenosquamous carcinoma were significantly more common in the NOS group than in the confirmed group (P<0.001, P=0.002, P=0.019 and P=0.014, respectively). The five-year survival rate was significantly poorer in the NOS group (60.5 vs. 67.1%; P=0.010), particularly for stage I disease (70.8 vs. 80.7%; P=0.007). The results of a multivariate analysis of overall survival indicated that NOS was a significant independent prognostic factor (hazard ratio, 1.40; 95% confidence interval, 1.02–1.86; P=0.041). These results indicated that pre-operative NOS was significantly associated with poorer survival, including for stage I disease. In conjunction with other clinicopathological parameters, NOS can be a useful prognostic factor when deciding on a treatment strategy for NSCLC.

Pulmonary large cell neuroendocrine carcinoma exhibiting extensive pagetoid spread in the bronchial epithelium: A case report

Pulmonary large cell neuroendocrine carcinoma (LCNEC) is a rare and aggressive malignant tumor, which was proposed as a novel type of neuroendocrine tumor in 1991. Although it is categorized as a non-small cell lung carcinoma, the precise pathological condition is unknown due to its rare occurrence. The present study outlines the case of a patient presenting with an LCNEC that exhibited pagetoid spread from the region of the primary tumor to the bronchial epithelium (distance, >30 mm). The pagetoid spread was unconfirmed preoperatively, however, was identified by intraoperative rapid diagnosis. This caused us to suffer the perioperative decision of additional resection and resulted in an incomplete resection, as suture of the bronchus was not possible. Pagetoid spread, which is often apparent in the breast, presents as a rare pattern of infiltration of cancer cells when a massive carcinoma is identified beneath the intraepithelial spread. Although preoperative diagnosis of pagetoid spread is difficult due to its rarity and undefined clinical features, it is important for surgeons and pathologists treating lung cancer patients to be aware of potential pagetoid spread in the thoracic region.