Riken Kawachi

Which is the better prognostic factor for resected non-small cell lung cancer: the number of metastatic lymph nodes or the currently used nodal stage classification?

Introduction: This retrospective study was conducted to evaluate the prognostic significance of the number of metastatic lymph nodes (nN) in resected non-small cell lung cancer (NSCLC) in comparison with the currently used pathologic nodal (pN) category in the staging system. Methods: A total of 1659 patients who underwent potentially curative resection for NSCLC from 2000 to 2006 were included in this study. The association between the nN and survival was explored, and the results were compared with those using the location-based pN stage classification. Results: The patients were divided into four categories according to the number of metastatic nodes: nN0, absence of metastatic nodes; nN1, metastasis in one to two nodes; nN2, metastasis in three to six nodes; and nN3, metastasis in seven or more nodes. The 5-year overall survival for nN0, nN1, nN2, and nN3 was 89.2%, 65.1%, 42.1%, and 22.4%, respectively (p < 0.001). The nN category could be used to subdivide pN1 and pN2 patients into two (nN1 and nN2) and three (nN1, nN2, and nN3) prognostically distinct subgroups, respectively. Multivariate analysis showed the nN category was an independent prognostic factor for resected NSCLC. The difference in overall survival between pN1 and pN2 was not significant (55.4% versus 47.8%, p = 0.245). Patients in each nN category could not be subdivided into different prognostic subgroups according to the pN classification. Conclusions: The nN category in this study was shown to be a better prognostic determinant than the location-based pN stage classification.

Gender difference in survival of resected non–small cell lung cancer: Histology-related phenomenon?

OBJECTIVE It remains controversial whether there is a gender difference in survival of patients with resected non-small cell lung cancer. METHODS We retrospectively analyzed 2770 patients (1689 men and 1081 women) with non-small cell lung cancer who underwent pulmonary resection between 1995 and 2005 at the National Cancer Center Hospital, Tokyo. A gender difference in survival was studied in all patients, in those divided according to histology or pathologic stage, and in propensity-matched gender pairs. RESULTS There were no differences in background, such as preoperative pulmonary function, operation procedures, or operative mortality. The proportions of adenocarcinoma and pathologic stage I in women were greater than those in men (93.6% vs 61.7% and 71.4% vs 58.6%, respectively) (P < .001). Overall 5-year survival of women was better than that of men (81% vs 70%, P < .001). In adenocarcinoma, the overall 5-year survival for women was better than that for men in pathologic stage I (95% vs 87%, P < .001) and in pathologic stage II or higher (58% vs 51%, P = .017). In non-adenocarcinoma, there was no significant gender difference in survival in pathologic stage I (P = .313) or pathologic stage II or higher (P = .770). The variables such as age, smoking status, histology, and pathologic stage were used for propensity score matching, and survival analysis of propensity score-matched gender pairs did not show a significant difference (P = .69). CONCLUSION Women had better survival than men; however, there was no survival advantage in propensity-matched gender pairs. A gender difference in survival was observed only in the adenocarcinoma subset, suggesting pathobiology in adenocarcinoma in women might be different from that of men.

Clinical significance of pleural lavage cytology for non-small cell lung cancer: is surgical resection valid for patients with positive pleural lavage cytology?

The purpose of the present study was to retrospectively analyze the clinicopathological characteristics and clarify the validity of surgical resection for patients with positive pleural lavage cytology (PLC). Between 1993 and 2006, 563 patients who underwent complete surgical resection for primary non-small cell lung cancer and who were examined with regard to PLC were retrospectively analyzed. Forty-two patients (7.2%) showed positive PLC. The 5-year survival rates were 65.0% and 33.5% for patients with negative and positive PLC, respectively. The 5-year survival rates for patients with positive PLC were 57.1%, 50.8%, 40.0%, and 0% for pathological stage I, II, IIIA, and IIIB, respectively. Multivariate analysis revealed that preoperative carcinoembryonic antigen (CEA) level, PLC, vascular invasion, lymphatic permeation, and pathological stage were independent prognostic factors. The 5-year survival rate for the patients with a high CEA level and positive PLC was 0%. Intrathoracic recurrence was observed more frequently in patients with positive PLC. PLC was an independent prognostic factor. While positive PLC alone may not be a contraindication for surgical resection, patients who are complicated with a high CEA level preoperatively should receive special attention since no long-term survivors were observed.

Prognostic Impact of Pleural Invasion in 1488 Patients with Surgically Resected Non-small Cell Lung Carcinoma

OBJECTIVE This study aimed to verify the prognostic impact of pleural invasion according to the revised TNM classification, seventh edition. METHODS The study consisted of 1488 patients with surgically resected non-small cell carcinoma. The degree (pl0-3) and location of pleural invasion were examined using hematoxylin and eosin- and elastica van Gieson-stained slides, and outcome was compared with stratification by several clinicopathological factors. RESULTS The 5-year overall survival rates of 1008, 260, 85 and 135 patients with pl0, pl1, pl2 and pl3 tumours were 80, 60, 55 and 52%, respectively. Overall survival differed significantly between patients with pl0 tumours and those with pl1 tumours (P < 0.0001). The difference was significant for patients with 1<≤ 2 cm (P = 0.004), 2<≤ 3 cm (P = 0.003) and 3<≤ 5 cm (P = 0.02) tumours. The overall survival of pl0 patients was also significantly better in patients with adenocarcinoma (P < 0.0001) than squamous cell carcinoma (P = 0.043). The overall survival of pl0 patients was significantly better in patients without lymph node metastasis (P < 0.0001) than in those with lymph node metastasis. The 5-year overall survival rates of patients with interlobar, lateral, mediastinal and diaphragmatic pl3 tumours were 65, 51, 51 and 40%, respectively. Overall survival did not differ significantly among these four groups. CONCLUSIONS Outcome differs between patients with pl0 tumours and those with pl1-3 tumours, particularly among patients with 1<≤ 2 cm, 2 <≤ 3 cm and 3<≤ 5 cm tumours, adenocarcinoma histology and no lymph node metastasis. The location of pl3 pleural invasion did not affect outcome significantly.

Clinicopathological characteristics of screen-detected lung cancers

Background: The efficacy of screening for lung cancers remains controversial, and none of the guidelines for lung cancer detection recommend screening for lung cancers. The purpose of the present study was to retrospectively analyze and characterize the clinicopathological features of screen-detected (SCR) lung cancer in comparison with lung cancers detected by other means. Patients: The records of 2281 patients who underwent lung resection for primary lung cancer between 2000 and 2006 were analyzed retrospectively. Patients were classified into three groups according to the method of detection: SCR (n = 1290), symptom-detected (SYM, n = 481), and incidental (INC, n = 568). In the SCR group, clinicopathological factors were analyzed according to the detection modality: chest x-ray (n = 1136, 82.6%), computed tomography (CT, n = 196, 13.9%), positron emission tomography (n = 22, 1.6%), and sputum cytology (n = 17, 1.3%). Results: The percentages of smaller (≤2 cm) lung cancer (42.6%: SCR, 19.6%: SYM, 40.9%: INC), adenocarcinoma (85.8%: SCR, 58.6%: SYM, 73.1%: INC), and pathologic stage I (73.0%: SCR, 47.0%: SYM, 71.2%: INC) were higher in the SCR group than in the other two groups. The 5-year survival rates in SCR, SYM, and INC group were 79.6%, 74.6%, and 64.6%, respectively. The patients with CT-detected lung cancer had a higher incidence of smaller size (≤2 cm, 76.4%), adenocarcinoma (92.6%), and stage I (clinical: 97.2%, pathologic: 93.1%). The 5-year survival rates in the chest x-ray and CT groups were 77.8% and 91.2%, respectively. Conclusions: SCR lung cancers were characteristically less advanced, had a smaller diameter, and were more frequently adenocarcinoma histologically. CT-screening may be able to detect early stage lung cancers, and improve the prognosis of lung cancer patients.

The impact of residual tumor morphology on prognosis, recurrence, and fistula formation after lung cancer resection

Introduction: The prognosis and proper management of patients with microscopic residual tumor at the bronchial resection margins (bronchial R1) remain unclear. Methods: We performed a retrospective analysis of 74 patients who underwent pulmonary resection for lung cancer between 1976 and 2003 and had bronchial R1. The prognosis, pattern of the recurrence, and occurrence of the bronchopleural fistula (BPF) were analyzed according to the types of bronchial R1 morphology: direct extension (DIR, n = 11), peribronchial extension (PER, n = 54), and carcinoma in situ (CIS, n = 9). Results: Five-year survival rates of patients with DIR, PER, and CIS were 0, 10, and 63%, respectively. The patients with CIS showed significantly better prognosis than those with DIR and PER (p = 0.0006, p = 0.0009, respectively). No prognostic difference was observed between patients with DIR and PER (p = 0.1753). Recurrent disease developed in 43 patients (58%). Only one of nine patients with CIS (11%) had recurrence, whereas 6 of 11 patients with DIR (55%) and 36 of 54 patients with PER (67%) had disease relapse. The recurrence rate in the CIS group was significantly lower than those of the other two groups (CIS versus DIR, p = 0.036; CIS versus PER, p = 0.006, respectively). BPF formation was not detected in patients with CIS; however, BPF developed in 3 of 11 patients with DIR (27%) and 3 of 54 patients with PER (5.6%). Conclusions: Residual tumor morphology influenced the prognosis of patients with postresection bronchial R1 disease.

Clinical significance of preoperative carcinoembryonic antigen level for clinical stage I non-small cell lung cancer: can preoperative carcinoembryonic antigen level predict pathological stage?

The purpose of the present study was to retrospectively analyze the clinicopathological characteristics and clarify whether or not the preoperative carcinoembryonic antigen (CEA) level could be used as a decision-making factor as an adjunct to the TNM staging system in patients with clinical stage I non-small cell lung cancer (NSCLC). Between 1993 and 2006, 815 patients who had clinical stage I NSCLC were analyzed retrospectively. The CEA level was defined as being either normal (CEA<or=5 ng/ml), high (530 ng/ml) sub-groups. The rate of patients with an elevated CEA level was 33.6%. The five-year disease-free survival rates for patients with normal, high and very high CEA levels were 76.7, 60.0 and 31.3%, respectively. The survival curve for patients with a normal CEA level almost overlapped that for p-stage I, that for a high CEA level nearly overlapped that for p-stage II, and that for a very high CEA level nearly overlapped that for p-stage III. The present study demonstrated that the preoperative CEA level was a very good predictor of the pathological stage. These findings suggest that the preoperative CEA level may be useful as an adjunct to the TNM staging system.

Clinical application of costal coaptation pins made of hydroxyapatite and poly-l-lactide composite for posterolateral thoracotomy

BACKGROUND Costal coaptation pins made of hydroxyapatite and poly-l-lactide (HA/PLLA) composite are used to prevent slippage of the connected ribs in posterolateral thoracotomy. The objective of this study was to evaluate rib fixation achieved by HA/PLLA costal coaptation pins. METHODS Between September 2005 and January 2006, HA/PLLA costal coaptation pins were used in 106 consecutive patients who underwent posterolateral thoracotomy at the National Cancer Center Hospital, Tokyo, Japan. Among these, 96 patients who were followed for one year were analyzed. Fixation was assessed on chest X-ray at one week, two months, and one year after surgery, and classified into four types: no displacement, vertical displacement, lateral displacement, and combined vertical with lateral displacement. RESULTS The incidence of displacement at one week, two months, and one year after surgery was 22%, 19%, and 31%, respectively. No severe adverse events leading to the removal of HA/PLLA pins occurred. At one year, the most frequent type of displacement was vertical displacement (15%), which reflected a delay in bone formation. The use of analgesics among patients with different types of displacement was not significantly different (p=0.97). CONCLUSIONS Based on the results of this study, the fixation of cut ribs with HA/PLLA costal coaptation pins may be less advantageous in posterolateral thoracotomy, as displacement and delay of bone formation appear to occur frequently.

A Malignant Peripheral Nerve Sheath Tumor of the Mediastinum in a Patient with Neurofibromatosis Type 1 : Report of a Case

Malignant peripheral nerve sheath tumor (MPNST) is rare, but its association with neurofibromatosis type 1 (NF1) is well known. A 56-year-old man with NF1 was referred to our hospital for investigation of dyspnea. Computed tomography showed a huge mass occupying the right thorax and invading the inferior vena cava. A salvage resection was performed to alleviate the developing hypoxemia. Histological examination confirmed an MPNST. The tumor regrew rapidly and the patient died 6 weeks after the resection. This case report reinforces the importance of monitoring patients with NF1 carefully because of their increased risk of the development of malignant neoplasms.

Thoracoscopic modified pleural tent for spontaneous pneumothorax

OBJECTIVES We developed a modified pleural tent (m-tent) procedure and used it in our hospital in almost 30 consecutive patients with spontaneous pneumothorax. The objective of this study was to clarify the feasibility and effectiveness of a thoracoscopic m-tent for the treatment of spontaneous pneumothorax. METHODS From July 2013 to November 2014, 107 patients with spontaneous pneumothorax were treated in our institution. Eighty-nine of these patients were analysed retrospectively. The inclusion criteria for thoracoscopic m-tent for spontaneous pneumothorax were multiple and widespread bullae, postoperative relapse and secondary spontaneous pneumothorax. The surgical procedures were usually performed through three ports. After bullectomy, an m-tent is made to strip the parietal pleura off the chest wall from about the level of the fourth or fifth rib to the apex, and two or three ligations are then applied to fix the pleural tent and lung parenchyma. Patients in whom an m-tent was not indicated underwent bullectomy plus coverage using absorbable materials. RESULTS Twenty-seven patients underwent bullectomy plus m-tent (m-tent group) and 62 underwent bullectomy plus coverage over a staple line using an absorbable material such as a polyglycolic acid sheet or nitrocellulose sheet (coverage group). No severe postoperative complications were observed in either group. The m-tent and coverage groups showed significant differences in operation time (129 vs 86 min, mean), haemorrhage (12.8 vs 7.2 ml), postoperative hospital stay (3.7 vs 2.9 days) and postoperative painkiller intake (8.6 vs 6.8 days). Recurrence was observed in 1 (3.7%) and 2 patients (3.2%), respectively. CONCLUSIONS The thoracoscopic m-tent procedure requires a longer operation, a longer hospital stay and greater painkiller intake. However, these differences are acceptable, and an m-tent should be considered as an option for pleural reinforcement in spontaneous pneumothorax, especially in patients who are complicated with severe pulmonary emphysema, widespread bullae or recurrent pneumothorax.