[Primary pulmonary meningioma; report of a case]

Primary pulmonary meningiomas are quite rare, and their occurrence has been reported only sporadically. A 49-year-old, asymptomatic female was hospitalized for the evaluation of a coin lesion in the left lung radiography. She has no history of previous neoplasm or symptom referable to the central nervous system. Chest computed tomography (CT) demonstrated a 9 x 14 mm, round, noncalcified, well-demarcated lesion in the left upper lobe of the lung (S(1+2)). For diagnostic purposes, enucleation of the tumor was performed. The resected specimen revealed histologically classical typical meningioma. Because postoperative magnetic resonance imaging (MRI) of the brain did not show any intracranial mass, this case was and diagnosed as a primary pulmonary meningioma. The patient was discharged with no complication, and alive without recurrence of disease 14 months after surgery.

Surgical Treatment for Lung Cancer with COPD Based on the Global Initiative for Chronic Obstructive Lung Disease (GOLD)

OBJECTIVE

The surgical indications for non-small cell carcinoma (NSCLC) with chronic obstructive pulmonary disease (COPD) are not well known. A classification of severity in COPD has been newly recommended by the US National Heart, Lung, and Blood Institute (NHLBI) and the World Health Organization (WHO). Therefore, based on this new system of classification, we review here a series of NSCLC patients with COPD who underwent lung resection at our hospital and attempt to identify the survival and morbidity of such patients.

METHODS

We retrospectively reviewed the patients with NSCLC treated at our hospital between January 1994 and December 2002. Among these 640 patients, a curative approach was attempted in 50 with COPD (31 lobectomies, 11 segmentectomies, 8 bilobectomies). The patients were consequently divided into two groups (moderate group and severe group) according to the Global Iinitiative for Chronic Obstructive Lung disease (GOLD). Lung function was evaluated by FEV1 and FVC, and the survival rates were analyzed at 5 years. Postoperative morbidity was also compared between the two groups.

RESULTS

FEV1 was 1.527 +/- 0.311 L in the moderate group compared with 1.025 +/- 0.224 L in the severe group ( p < 0.001). Postoperative decrease in FEV1 was lower compared to the predicted data of patients who underwent surgery for NSCLC with COPD. Postoperative pulmonary support such as mechanical ventilation or tracheotomy were necessary more frequently in the severe group. A significant difference was observed between the two groups in respiratory support ( p = 0.0102). Overall 5-year survival rate for NSCLC with COPD was 73.9 %, although there was no statistically significant difference between the moderate and severe groups in terms of survival. Lobectomy and segmentectomy show a remarkable advantage for the patients with bilobectomy, although this difference was not statistically significant. On the other hand, gender, degree of COPD, and histological type were shown to be not significant factors. Survival rate of these NSCLC patients with COPD were demonstrated to be comparable to those of the NSCLC patients without COPD in stages I and II.

CONCLUSION

Stringent selection of candidates among NSCLC patients with a severe grade of COPD based on GOLD could be an acceptable and valuable approach compared to conventional patients without COPD, although NSCLC with severe COPD patients more frequently needed respiratory support.

Micropapillary pattern: a distinct pathological marker to subclassify tumours with a significantly poor prognosis within small peripheral lung adenocarcinoma (<=20 mm) with mixed bronchioloalveolar and invasive subtypes (Noguchi's type C tumours)

AIMS

A micropapillary pattern (MPP) in lung adenocarcinoma, characterized by papillary structures with epithelial tufts lacking a central fibrovascular core, has been reported to be a new pathological marker of poor prognosis. However, its clinicopathological and prognostic significance in small lung adenocarcinomas (</=20 mm) remains undetermined. A new histological classification of small lung adenocarcinoma proposed by Noguchi et al. has been found to be useful since it has defined surgically curable bronchioloalveolar carcinoma (BAC)-type tumours (Noguchi's type A and B) based on the absence of active fibroblastic proliferation. However, BAC-type tumours with active fibroblastic proliferation (Noguchi's type C), which is adenocarcinoma with mixed subtypes including BAC and invasive carcinoma in the new World Health Organization (WHO) classification, account for most of the small adenocarcinomas and represent a heterogeneous group ranging from minimal to overtly invasive cancer with variable prognoses. Therefore, in this study the aim was to investigate whether MPP can be an additional histological marker(s) to subclassify this heterogeneous group in small lung adenocarcinoma.

METHODS AND RESULTS

One hundred and twenty-two cases of small lung adenocarcinomas (</=20 mm in maximum dimension) classified according to the new WHO classification and Noguchi's proposal were analysed with reference to the presence of MPP. Of the 122 cases, 67 (55%) were MPP-positive and 55 (45%) were MPP-negative. Lymph node metastasis and pleural invasion were significantly more frequent in the MPP-positive group: 74% and 66% in the positive group versus 26% and 34% in the negative group, respectively. The 5-year survival of the MPP-positive group was 54%, whereas that of the MPP-negative group was 81% (P=0.024). The 5-year survival rates of BAC (Noguchi's type A and B) (n=14), mixed BAC and invasive adenocarcinoma (Noguchi's type C) (n=85) and invasive adenocarcinoma (Noguchi's type D and F) (n=23) were 100%, 68% and 36%, respectively. In patients with mixed BAC and invasive adenocarcinoma (Noguchi's type C tumours), the 5-year survival of the MPP-positive group (n=51) was 54%, significantly lower than that of the MPP-negative group (n=23) of 100% (P=0.02).

CONCLUSIONS

MPP is a simple and distinct pathological marker to subclassify tumours with a significantly poor prognosis within small (</=20 mm) mixed BAC and invasive adenocarcinoma (Noguchi's type C tumours).

[Thoracoscopy and intraoperative upper gastrointestinal endoscopy was effective for Boerhaave syndrome; report of a case]

Boerhaave syndrome is a rare disease and needs an exact diagnosis and a proper treatment plan because of its terrible clinical course. We experienced a case of Boerhaave syndrome that thoracoscopy and intraoperative upper gastrointestinal (GI) endoscopy was very effective. Sixty-four-year-old man realized chest and back pain after vomitting. Esophageal perforation was suspected, but 64 hours had passed already when we started a surgical treatment. By the thoracoscopy and intraoperative endoscopy, lower esophageal perforation and infectious pleural effusion were found. Therefore, we selected a surgical treatment under the assistance of thoracoscopy. Secondly, a simple closure and intracostal muscle overlapping was performed with small incisional thoracotomy. Postoperative complication, such as mediastinal abscess, has not occurred. Thoracoscopy and intraoperative upper GI endoscopy was effective for an appropriate diagnosis and treatment of Boerhaave syndrome.

[Diaphragmatic eventration resulting from phrenicectomy treated with surgical method; report of a case]

The case was a 59-year-old man who has a history of left mediastinal tumor resection with left phrenicectomy. The elevated diaphragm revealed by chest X-ray 7 years after the operation led to diagnosis of diaphragmatic eventration. Since any symptom was seen in the early period, "wait and watch" strategy was done for management. Both the abdominal enlarged feeling and the dyspnea on effort were appeared 10 years after the operation. Under the speculation of these symptoms related to the elevated abdominal organs came up with diaphragmatic eventration, surgical method the plication of the diaphragm was performed. The diaphragm was plicated by interrupted suture as opening the diaphragm to avoid injury the abdominal organs, and reinforced with the Marlex mesh. We used artificial mesh to reinforce the thin diaphragm with exceptation of prevent the postoperative recurrence, because a result of the etiological process of the case was considered as disuse atrophy of diaphragm after phrenicectomy.

Biosorbable poly-L-lactide rib-connecting pins may reduce acute pain after thoracotomy

OBJECTIVE

Conventional thoracotomy is currently used as a standard procedure, and is often required to treat numerous diseases. Additionally, rib resections are occasionally required to maintain an adequate field of view for surgery. The benefits of using rib pins for chest closure following such procedures have not yet been established. This study sought to evaluate the usefulness of rib pins in reducing acute postoperative pain.

METHODS

Thirty-three consecutive patients with lung cancer underwent lobectomies using the posterolateral approach. The patients were rib-resected and reconstructed with two techniques: 21 patients with absorbable rib pins (ARP group) and 12 patients by ligation with absorbable sutures (LAS group). Intensity of pain was assessed during the 3 days immediately following surgery. The two groups were assessed using the visual analogue scale (VAS) as a pain scale, amounts consumed of patient-controlled analgesics (PCA), and additional chest x-rays.

RESULTS

On the first day following surgery, the mean VAS intensity of the ARP group for patient motion was 2.71 +/- 2.14, compared to 5.33 +/- 2.99 in the LAS group. After three days, the mean score for the ARP group was 1.98 +/- 1.89, compared to 4.60 +/- 1.97 in the LAS group. Scores in the ARP group were significantly lower than in the LAS group one day and three days following thoracotomy. The LAS group (55.0 +/- 15.9 times) made more frequent requests than the ARP group (16.1 +/- 10.3 times). The PCA requirement was also significantly lower in the ARP group. Excessive derangement of the rib (grade 2) was found in one case (4.7 %) in the ARP group compared to five cases (41.6 %) in the LAS group. Rib shifts were seen in numerous cases in the LAS group compared to the ARP group as measured by chest x-rays.

CONCLUSIONS

Use of absorbable rib pins reduced postoperative pain and may improve long-term prospects for the post-thoracotomy course.

[Pleuropneumonectomy for pulmonary tuberculosis and chronic tuberculous empyema]

Surgical intervention is often necessary to treat either the active pulmonary tuberculosis or its sequelae such as destroyed lung, tuberculous empyema, and bronchial stenosis. Pleuropneumonectomy, which has been reported to be associated with high mortality and morbidity, is performed when the pleural space is completely obliterated due to previous inflammation or when preoperative empyema is complicated. In this article we report 3 patients receiving pleuropneumonectomy for pulmonary tuberculosis or chronic tuberculous empyema in recent 3 years. The mean operation time is 5 hours and 56 minutes, and the mean volume of intraoperative bleeding amounted to 1,417 ml. Autologous blood transfusion was prepared for all 3 patients and transfused them during the operation. No mortality, but postoperative complications were seen in 2 patients (67%) with a history of diabetes mellitus. They were sternum infection and bronchopleural fistula, which were successfully treated conservatively. Diabetes mellitus is thought to be a major risk factor for not only tuberculous disease itself, but also postoperative morbidity. As for surgical techniques, wide skin incision with multiple thoracotomy is necessary to keep a good operative field, and special care must be taken for great vessels and nerves at extrapleural dissection. We conclude that pleuropneumonectomy is relatively risky but effective surgical procedure for adequately selected patients with destroyed lung and tuberculous empyema.

Results of Surgical Treatment for Non-Small Cell Lung Cancer of 20 mm or Less in Diameter

BACKGROUND

Surgical efficacy is still unsatisfactory for small lung cancer; accordingly, minimal resection has recently been the focus of increased study. The objective of the current study was to evaluate the factors associated with small lung cancer, and to determine whether such factors are reliable predictors of long-term survival.

METHODS

We retrospectively investigated 130 patients with histologically confirmed non-small cell carcinoma, whose treatments were primarily surgical, with no chemotherapy or radiotherapy prior to surgery. All tumors were located peripherally and were less than 20 mm in diameter. Follow-up was performed for five-year and eight-year survivors and multivariate analysis with Cox's proportional hazards regression model was performed.

RESULTS

Of all 130 patients, the 5-year survival rate among patients with tumors less than 15 mm was 82.5 %, vs. 57.4 % of patients with tumors with a diameter of 16 - 20 mm. The 5-year survival rate of patients who were node negative was 73.9 % while it was 28.5 % for node-positive patients. Status of nodal invasion was also significantly associated with survival in small-size tumors ( p < 0.0001). Furthermore, the 5-year survival rate among patients with pleural involvement was 55 % vs. 83.8 % for patients without pleural involvement. Using multivariate Cox analysis, lymph node involvement ( p = 0.0004), size ( p = 0.0475), and pleural invasion ( p = 0.0482) were found to be independent prognostic factors in cases of tumors 20 mm or less in diameter.

CONCLUSIONS

The results of this study at least demonstrate that the optimal therapy for patients with nodal involvement or patients with tumors of 16 - 20 mm must be carefully determined even in cases of small lung cancer.

[Extrapleural pneumonectomy for malignant pleural mesothelioma and primary lung cancer]

The extrapleural pneumonectomy for 6 patients with malignant pleural mesothelioma and 2 patients with primary lung cancer have been performed in our unit in those 10 years. Range of the age was 48-57 year-old. All of them were male and have been in occupational asbestos exposure. The mean survival time after extrapleural pneumonectomy was 620 days. In those, we experienced a case of malignant mesothelioma with excellent reduction by induction therapy of cisplatin+docetaxel hydrate, who underwent the extrapleural pneumonectomy continuously. We mentioned more over about the role of extrapleural pneumonectomy for primary lung cancer with pleural dissemination, and intrapleural perfusion hyperthermo-therapy for malignant mesothelioma.

Video-assisted thoracoscopic surgery (VATS) segmentectomy for small peripheral lung cancer tumors: intermediate results

BACKGROUND

We investigated the feasibility and suitability of video-assisted thoracoscopic surgery (VATS) segmentectomy for curing selected non-small cell lung cancer (NSCLC) with this less invasive technique.

METHODS

We performed VATS segmentectomy for small (< 20 mm) peripherally located tumors and pathologically confirmed lobar lymph node-negative disease by frozen-section examination during surgery. Of the 34 patients who underwent this limited resection, 22 were treated with complete hilar and mediastinal lymph node dissection (intentional group), whereas 12 patients who were deemed to be high risk in their toleration for lobectomy underwent VATS segmentectomy with incomplete hilar and mediastinal lymph node dissection (compromised group). The surgical and clinical parameters were evaluated and compared with those of segmentectomy under standard thoracotomy to evaluate the technical feasibility of VATS segmentectomy.

RESULTS

We found that VATS segmentectomy could be performed safely with a nil mortality rate and acceptably low morbidity. The mean period of observation was relatively short at 656.7 +/- 572.1 and 783.4 +/- 535.8 days in the intentional and compromised groups, respectively. At the time of writing, all intentional patients remain alive and free of recurrence. There were two cases of non-cancer-related death in the compromised group. Clinical data indicated that VATS segmentectomy caused the same number or fewer surgical insults compared with segmentectomy under standard thoracotomy.

CONCLUSIONS

The present results are intermediate only; the rate of long-term survival and the advantages of the less invasive procedure still need further investigation. Nevertheless, we believe that VATS segmentectomy with complete lymph node dissection is a reasonable treatment option for selected patients with small peripheral NSCLC.

Mediastinal Solitary Fibrous Tumor: Report of a Case with Direct Invasion to the Trachea

The solitary fibrous tumors in the pleura are a rare entity that is usually adhesive and sometimes invasive. Because of its benign feature, complete surgical resection is generally considered. We describe a very rare case of mediastinal solitary fibrous tumor arised or invaded into the tracheal wall, which was surgically resected with combined cylindrical resection of the trachea.

Evaluation of lung volume reduction surgery (LVRS) based on long-term survival rate analysis

OBJECTIVE

Lung volume reduction surgery (LVRS) is an effective therapy for some patients with end-stage emphysema. In most cases, functional improvement is maximized during the first 6 months after surgery and decreases steadily afterwards. This study was aimed at gaining further understanding of the optimal candidates for LVRS and survival rates.

METHODS

62 patients with LVRS were selected according to the inclusion criteria. Changes in lung function were evaluated by FEV1, VC, RV, TLC, DLCO, PaO2, and PaCO2, and survival rates were analyzed at 12, 24, 36, and 48 months. Patients with LVRS were divided into two groups--those surviving after 48 months and those not surviving after 48 months--and analyzed according to group.

RESULTS

The overall survival rate at 2 years and 4 years was 81.0 % and 67 %, respectively, with LVRS. VC, FEV1, TLC, DLCO, PaO2, and PaCO2 were potential factors leading to mortality according to univariate analysis. Multivariate analysis demonstrated that DLCO was the only independent factor that could predict the post-LVRS prognosis; the other factors failed as independent factors. Preoperatively, the FEV1 percentage predicted gave a good index for post-LVRS survival.

CONCLUSIONS

Patients with higher preoperative FEV1 values had higher survival rates. These favorable long-term survival rates might justify LVRS for treating selected patients with severe emphysema. Additionally, DLCO turned out to be the only predictive factor for high mortality risk 4 years after LVRS. DLCO may thus be a very important marker in surgical planning.

Clinicopathological analysis of 143 primary malignant lymphomas in the small and large intestines based on the new WHO classification

AIM

To study the clinicopathological and immunohistochemical features of 143 cases of primary small and large intestinal non-Hodgkin's lymphoma (NHL) in Japanese patients who presented between 1981 and 2000.

METHODS AND RESULTS

The new World Health Organization (WHO) classification was used to classify NHL. The patients included 109 males and 34 females, with an average age of 54.1 years. Tumour sites were as follows: ileocaecal (n = 51, 35.7%), ileum (n = 29, 20.3%), rectum (n = 13, 9.1%), and duodenum (n = 11, 7.7%). Macroscopically, 124 cases (86.7%) were classified as tumorous type, 12 (8.4%) as diffuse infiltration type (erosion, superficial ulceration), five (3.5%) as polyposis type, and only two cases (1.4%) as ulceration type. Immunohistochemically, 122 lesions (85.3%) were of B-cell phenotype and 21 lesions (14.7%) were of T-cell phenotype. According to the WHO classification, of the B-cell lymphomas, 84 cases (68.9%) were large cell, 16 (13.1%) were Burkitt, 10 (8.2%) were marginal zone B-cell lymphomas of mucosa-associated lymphoid tissue (MALT), and seven (5.7%) were mantle cell tumours. Among the T-cell lymphomas, 15 (71.4%) were of unspecified type, two (9.5%) were natural killer type, two were anaplastic large-cell lymphomas, one was lymphoblastic, and one was an adult T-cell leukaemia lymphoma. The survival rate for T-cell lymphomas was poorer than for B-cell lymphomas. Among the B-cell lymphomas, mantle cell lymphoma tended to have a poorer prognosis, whereas MALT lymphomas had a better prognosis than other B-cell tumour types.

CONCLUSIONS

Our retrospective study of patients with primary malignant lymphomas in the small and large intestines has illustrated the clinical features and outcomes of patients with this disease.

Video-assisted thoracic needle aspiration cytology for malignancy of the peripheral lung

BACKGROUND

The technique of video-assisted thoracic fine-needle aspiration cytology (VAT-FNA) to the lung has been described in very few publications, and its diagnostic role has not been evaluated so far. Thus current studies focus on whether the diagnostic role could be applied usefully to VAT-FNA of peripheral lung lesions.

METHODS

Between January 1995 and January 2000, a total of one hundred and twenty-eight cases of VAT-FNA on lung tumors were reviewed retrospectively. The superficial lung was visualized a part of directly or indirectly by scope and a 22-gauge needle inserted for FNA. Material was expressed onto glass slides, and smears were stained by our modified quick-stain method. The cytological diagnoses based on VAT-FNA were reviewed and compared with the final histopathological diagnoses.

RESULTS

The cytological diagnosis was true positive in 100 cases (93.5% sensitivity), whereas the true negative result in 20 cases was 95.2% specificity. The false-positive rate was 4.8%, and false-negative results were 6.5%. The accordance in all malignant cases between cytology and histology was 73.8%. VAT-FNA caused no difficulties in any of the cases.

CONCLUSION

The application of VAT-FNA to the peripheral lung lesion is not only useful, cost-beneficial, safe and minimally invasive but also accurate. Especially, this method may play an important role in cases of suspected malignancy in peripheral cases.

[Surgical treatment for esophageal cancer in elderly patients over 75 years of age]

We performed 127 esophageal resections for the esophageal cancer patient from December 1995 to September 2001. It was separated to under 70 years old patients group (group I), 71-74 years old patients group (group II), and over 75 years old patients group (group III).

RESULTS

Postoperative complication was occurred in 53 cases (41.7%) within all of 127 esophageal resected cases. It was 33.7% in group I, 53.6% in group II, 62.5% in group III. Four years survival rate of each group is 38.3% in group I, 44.6% in group II, 31.3% in group III. It is significantly better in group II rather than in group III. Operative death rate is 12.5% (2 cases) in group III, 7.1% (2 cases) in group II, 3.6% (3 cases) in group I, and it is gradually higher and higher by patient's age.

CONCLUSIONS

(1) In the esophageal cancer patient over 75 years old, postoperative complication rate is higher than under 74 years old patients, and prognosis is significantly poor rather than in 70-74 years old patients group. (2) In the esophageal cancer patient over 75 years old, we considered it is good indication of esophagectomy for stage I and stage II patient without preoperative complication, however, there are no operative indication for stage III and stage IV patient.

[Surgical therapy for patients with thymoma or thymic carcinoma; based on WHO classification]

The treatment strategy for patients with thymoma or thymic carcinoma still has not been confirmed, and the molecular biologic characteristics of these tumors have not been defined also. We have emphasized the clinical significance of this classification so far by the research cooperation with professor Müller-Hermelink, the institute of pathology, Würzburg University. This time, We introduced clinico-pathological findings based on the new WHO classification in 59 Case of thymic epithelial tumor and reffered the treatment strategy for patients with thymic cancer.

An immunohistochemical examination of basaloid squamous cell carcinoma of the esophagus: report of a case

We recently encountered a patient with basaloid carcinoma of the esophagus with extensive node involvement. The patient died of hematogenous metastasis 6 months after surgery. The tumor expressed cytokeratin but did not express either Type IV collagen or laminin. Both tumor cells and metastatic lesions in the regional lymph nodes expressed p53, Bcl-2, and Ki-67 proteins, but did not express cyclin D1 proteins.

[Result of surgical treatment to early stage peripheral non-small cell lung cancer]

In the lung cancer, the announcement of the definition, the clinical behavior and the treatment result of the central early stage lung cancer, especially in situ lung cancer, have been seen. However, the definition and a clinicopathological concept of the peripheral lung cancer are still uncertain. The so-called small lung cancer of the tumor diameter 20 mm or less are peripheral lung adenocarcinoma. These patients' prognosis is excellent better, in contradiction to the prognosis of the patients with positive for pleural involvement or vessels invasion is worse. We studied the clinicopathological features, the Noguchi's classification, and prognosis of the 101 patients with small lung adenocarcinoma which were performed the operation, and refere about the selection of the operation method including the VATS and the limited operation.

Glutathione S-transferase mu1 null genotype is associated with K-ras gene mutation in lung adenocarcinoma among smokers

Glutathione S-transferase mu1 (GSTM1) plays a role in the detoxification of benzo[a]pyrene (BP) diol epoxide in tobacco smoke. Individuals who genetically lack the GSTM1 gene are likely to have an increased risk of smoking-related lung cancers, however, the target oncogenes for mutation are unknown. To investigate the relation between GSTM1 genotype and K-ras gene mutation we examined 193 adenocarcinomas and 119 squamous cell carcinomas of lung. The GSTM1 genotype was determined by PCR and K-ras gene mutations at codons 12 and 13 were detected by dot-blot hybridization analysis using sequence-specific oligonucleotide probes. K-ras gene mutations were found in 29 of 312 (9.3%) tumors. All of them arose in patients who were habitual smokers. Mutations of the K-ras gene were detected in 6 of 100 (6%) and 15 of 93 (16.1%) adenocarcinoma cases with the GSTM1(+) and GSTM1(-) genotypes, respectively, and the difference was statistically significant. These findings suggest that the cause of K-ras gene mutation in smokers with lung adenocarcinoma may be in part an accumulation of BP diol epoxide which is not well detoxified in individuals with the GSTM1 null genotype.

New technique for the cystic mediastinal tumor by video-assisted thoracoscopy

Thoracoscopic operations for benign mediastinal tumors have been useful. However, it is difficult to remove cystic mediastinal tumors completely because of their cystic structure. We herein describe a useful technique of tumor cannulation that allows for the simple and safe removal of these tumors.

[Less invasive treatment for lung carcinoma]

Today, less invasive treatments for lung carcinoma are divided to two categories. One is the surgical option which includes 1. surgery by muscle sparing thoracotomy, 2. reduced operation represented by segmentectomy or partial resection, 3. so-called VATS (video-assisted thoracoscopic surgery), and 4. sentinel node navigation surgery. Other options such as photodynamic therapy or brachytherapy are also very useful for the treatment of superficial malignancies at the hilar zone, because of their lower level of invasiveness.

[Video-assisted thoracoscopic surgery lobectomy for lung carcinoma]

Video-assisted thoracoscopic surgery (VATS) has been utilized worldwide for the treatment of various types of thoracic disease, in particular for lung carcinoma. The following criteria are accepted as the operative indications for VATS lobectomy: i) clinical T1N1M0: ii) tumor located in the peripheral zone; and iii) non-small cell carcinoma. Videoscopic surgery has the merit of being less invasive, resulting in a low level of postoperative chest pain, short incisional scar, and short duration of hospital stay. Right-side upper mediastinal lymph node dissection is easy under the thoracoscope, although compared with standard thoracotomy it is not always possible to perform complete level II dissection on the left, because of the difficult approach to lymph nodess No. 3 and No. 4 under the aortic arch via the thoracoscope. The postoperative 5-year survival rate after VATS lobectomy is superior to that after standard thoracotomy. It is expected that the indications for VATS will be expanded to include T2 or N1 disease as thorascopic instruments and techniques improve.

K-ras gene mutations in non-small cell lung cancer in Japanese

To evaluate the association of mutations in the K-ras gene with the incidence of non-small cell lung cancer (NSCLC) in Japanese patients, 410 patients treated surgically were studied. DNA was extracted from frozen specimens, and polymerase chain reaction-sequence specific oligonucleotide probe (PCR-SSOP) hybridization assay was used to examine K-ras mutations in codons 12, 13 and 61. K-ras mutations were found in 33 patients (8.0%), and all were smokers or ex-smokers. There were no significant differences in clinical or pathological stage between wild-type cases and mutant cases. The most frequently identified mutation was a G-->T transversion (25/33, 75.8%) that resulted in the substitution of a glycine for a cysteine or a valine. Previous studies have shown that the majority of K-ras mutations among smokers are G-->T transversion. In our study, K-ras mutations were found only in smokers, and there was a high frequency of G-->T transversions. A clear correlation exists between smoking and K-ras gene mutations.