Prognosis of patients after pulmonary artery plasty for non-small cell lung cancer.

OBJECTIVE: We evaluated the clinical outcomes of patients after lung resection with pulmonary artery (PA) plasty for non-small cell lung cancer (NSCLC). METHODS: From 1995 to 2006, 36 patients (26 males and 10 females) with NSCLC underwent lobectomy or segmentectomy with PA plasty at our institution. The mean age of the patients was 65.9 years old (range 45-87 years old). There were 17 left upper lobectomies, 10 right upper lobectomies, five left lower lobectomies, two right upper-and-middle bilobectomies, one right lower lobectomy, and one left upper division segmentectomy. Both bronchoplasty and PA plasty were performed in 15 patients. Six patients received preoperative chemotherapy, and one had preoperative radiotherapy. RESULTS: The postoperative morbidity rate was 27.8 % (10/36), and the mortality rate (30 days) was 2.8 % (1/36). One patient underwent completion pneumonectomy on postoperative day 13. Macroscopic residual cancer was identified in two patients at the thoracic wall and aorta, respectively; microscopic residual cancers were identified in two patients at the stumps of the pulmonary artery and in one patient at the bronchial stump. Postoperative radiation therapy was additionally given to those four patients, except one. The 5-year survival rate for all patients was 51.8 %. There was no significant difference in the 5-year survival rate between clinical N (cN) 0-1 patients and cN2 patients. However, in pathological N (pN) 0-1 patients, the 5-year survival rate was significantly better than that of pN2 patients (71.9 % versus 0.0 %; P < 0.001). CONCLUSIONS: PA plasty for NSCLC is acceptable and highly recommended for pN0-1 patients. Strict patient selection should be considered so as to avoid surgical operations in patients with pN2 staging.

Thoracoscopic lobectomy with systemic lymph node dissection for lymph node positive non-small cell lung cancer--is thoracoscopic lymph node dissection feasible?

INTRODUCTION: The impact of thoracoscopic systemic lymph node dissection (LND) on loco-regional control of non-small cell lung cancer (NSCLC) with positive lymph node metastasis was investigated. PATIENTS AND METHODS: Thoracoscopic lobectomy with systemic LND was performed for clinical stage I NSCLC. 340 patients were admitted for either a thoracoscopic (n = 98) or a standard open (n = 242) lobectomy with systemic LND. Of those 340 cases, 75 cases (20 thoracoscopic and 55 open) were pathologically diagnosed with node-positive disease. A retrospective chart review of these 75 cases was performed. RESULTS: No significant difference in the overall or loco-regional recurrence-free survival was observed between the groups. The results of a multivariate analysis of the overall and the loco-regional recurrence-free survival demonstrated that the significant factors were tumor size for overall recurrence-free survival, and sex and surgical procedure (use of thoracoscopic surgery) for loco-regional recurrence-free survival, respectively. CONCLUSION: In general, thoracoscopic lobectomy for c-stage I disease may have no survival disadvantage over open procedures. It might, however, increase the risk of local recurrence when used to treat pathologically node-positive disease. Caution should be used when treating those cases with thoracoscopic surgery.

New trainer for video-assisted thoracic surgery lobectomy.

BACKGROUND: Only a few simulators are available which offer training in video-assisted thoracic surgery (VATS). We have developed a VATS training model for surgeons. METHODS: The simulator consists of a training module housing three disposable components: the lung (made of polyurethane), the bronchus, and the artificial circulatory pulmonary vessels (made of polyvinyl chloride), connected to a pump. VATS procedures were videotaped and evaluated using a checklist assessment method. RESULTS: This unique module has been tested at several VATS seminars in Japan. In the questionnaire, training participants strongly agreed that the trainer was helpful and prepared them well for VATS lobectomy prior to performing actual surgery. Evaluation of the dexterity score for thoracoscopic surgery with our simulator correlated with the surgeons' experience with actual surgery. Technical factors were well taught using this model. CONCLUSIONS: Our unique trainer may enhance the skill of VATS surgeons at a national level.

Is systemic node dissection for accuracy staging in clinical stage I non-small cell lung cancer worthwhile in the elderly?

OBJECTIVE: The therapeutic role of systematic node dissection (SND) for early lung cancer remains controversial. Elderly patients have a background of insufficient physiological function and comorbidity, and a shorter life expectancy than that of younger patients. Therefore, we have evaluated the impact on survival, local recurrence, and complications of not performing systematic lymph node dissection in the elderly. METHODS: A retrospective analysis of 126 patients, including the elderly (75 - 89 years), who underwent a lobectomy for clinical stage I was performed. The patients were grouped according to node dissection numbers after surgery, and finally separated into two groups (SG: sufficient group, dissections of more than 10 nodes and 3 or more mediastinal stations; IG: insufficient group, less than 10 nodes and one or two mediastinal stations). Postoperative morbidity and sites of recurrence were evaluated between the two groups, and the survival rates were analyzed at 5 years. RESULTS: Upstage was identified in 12.6% of patients: 7.3% in IG (n = 45), 15.2% in SG (n = 86). Postoperative mortality occurred in 2 cases (1.58%). The incidence of postoperative respiratory or cardiac complications was more frequent in the SG, while there were fewer complications in the IG. There was no significant difference in recurrence rates between the two groups. Both local and distant recurrence was observed in the two groups. The 5-year survival rates were 61.5% for the SG and 59.4% for the IG. There was no significant difference in the survival rate between the IG and SG patients. CONCLUSIONS: Proper staging and the avoidance of nontherapeutic lymph node dissection seems acceptable for clinical stage I lung cancer in the group of elderly patients.

Identification of Lck-derived peptides applicable to anti-cancer vaccine for patients with human leukocyte antigen-A3 supertype alleles.

The identification of peptide vaccine candidates to date has been focused on human leukocyte antigen (HLA)-A2 and -A24 alleles. In this study, we attempted to identify cytotoxic T lymphocyte (CTL)-directed Lck-derived peptides applicable to HLA-A11(+), -A31(+), or -A33(+) cancer patients, because these HLA-A alleles share binding motifs, designated HLA-A3 supertype alleles, and because the Lck is preferentially expressed in metastatic cancer. Twenty-one Lck-derived peptides were prepared based on the binding motif to the HLA-A3 supertype alleles. They were first screened for their recognisability by immunoglobulin G (IgG) in the plasma of prostate cancer patients, and the selected candidates were subsequently tested for their potential to induce peptide-specific CTLs from peripheral blood mononuclear cells of HLA-A3 supertype(+) cancer patients. As a result, four Lck peptides were frequently recognised by IgGs, and three of them - Lck(90-99), Lck(449-458), and Lck(450-458) - efficiently induced peptide-specific and cancer-reactive CTLs. Their cytotoxicity towards cancer cells was mainly ascribed to HLA class I-restricted and peptide-specific CD8(+) T cells. These results indicate that these three Lck peptides are applicable to HLA-A3 supertype(+) cancer patients, especially those with metastasis. This information could facilitate the development of peptide-based anti-cancer vaccine for patients with alleles other than HLA-A2 and -A24.

Comparison between a case-matched analysis of left upper lobe trisegmentectomy and left upper lobectomy for small size lung cancer located in the upper division.

BACKGROUND: Although an increasing number of approaches for pulmonary segmentectomy to treat early lung cancer are being used, there have been few reports on left upper lobe trisegmentectomy, which is midway between single segmentectomy and lobectomy, for lung cancer. METHODS: We retrospectively reviewed the medical charts of 86 clinical stage I case-matched patients with a tumor size of less than 2.0 cm in diameter located in the left upper division who underwent resection between June 1998 and December 2005. The patients were divided into two groups as follows: LTS (31), left upper lobe trisegmentectomy; LUL (55), left upper lobectomy. We evaluated these groups with respect to several factors. RESULTS: The characteristics of the two groups (LTS vs. LUL) demonstrated no significant differences with respect to gender, histological type, tumor size, or upstaging of pathological node, or the mode of video-assisted thoracic surgery (VATS). Patients with LTS had a significantly lower pulmonary function compared to the LUL group. There were no significant differences between the two groups with respect to factors such as blood loss and duration of chest tube drainage. Morbidity and recurrence rates did not differ between the two groups, and there was no mortality in our series. The overall survival rate at 5 years was 69.7 % in the LTS and 72.5 % in the LUL group. There was no significant difference in survival rates between the LTS and the LUL group after resection. CONCLUSION: LTS may be suitable as a standard treatment if the tumor is small and the suspected margins are well away from the lingula.

[Successful treatment for descending necrotizing mediastinitis; report of a case].

A case of a 55-year-old man with descending necrotizing mediastinitis (DNM) after a tooth removal was reported. Chest computed tomography (CT) showed a fluid collection in the right thorax, in the cervical region and in the mediastinum. The patient underwent cervical drainage and thoracoscopic pleural dissective drainage. The cervical and right anterior thoracic drain was removed on the 6th day and posterior drain was removed on the 8th day after the operation. The patient was discharged on the postoperative day 13, and showed no recurrence.

[Airway injuries due to blunt chest trauma].

Although the incidence of blunt chest trauma is very high, the mediastinal tracheobronchial injuries are quite rare. The airway injuries are thought to be one of the most urgent clinical conditions in thoracic surgery, and we are requested to make not only a rapid and sharp diagnosis but also an appropriate treatment plan considering combined injuries. We present 9 cases of tracheobronchial injuries due to blunt chest trauma in recent years. The average age of these patients is 26.1 years, and they are consisted of 6 male and 3 female. The cause of trauma is traffic accident in 7, and occupational crane accident in 2. Bronchoplasty were done in 5 cases (right main bronchus in 2, left main bronchus in 1, trunks intermediate bronchus in 1, and the spur between middle and lower lobe in 1), membranous-tracheoplasty with right pneumonectomy in 1, left pneumonectomy in 1, conservative treatment in 2. Postoperative mortality is occurred in 1 case who was suffering from multiple injuries including severe head injury and contralateral lung contusion. Tracheobronchial plasties should be chosen if possible to preserve lung function for the patient suffering from airway injuries.

[Clinical features of thoracic injury; special reference to diaphragmatic injury].

UNLABELLED: We investigated the clinical feature of thoracic injury patients, mainly with diaphragmatic injury. From 1993 to 2005, 739 patients with thoracic injury were treated at our life-saving emergency center. There were more blunt trauma patients than penetrating injury patients (693 cases vs 46 cases). Regarding the thoracic injury patients, the causes of trauma were traffic injury in 462 (62.5%), unexpected accident including work place accident in 153 (20.7%), suicide in 90 (12.2%), and assault in 34 (4.6%). As the numbers of injured organs increased, the mortality rate increased. Among 156 patients with cardiopulmonary arrest on admission, 155 patients died. This result suggested that saving the life of patients presenting with cardiopulmonary arrest on admission is extremely difficult. Thirty-eight cases (5.1%) required surgical treatment, and surgery to repair diaphragmatic injury was performed in 14 cases. In 6 cases of diaphragmatic injury, thoracoscopy was performed during the examination and/or surgery. CONCLUSION: Urgently transporting thoracic injury patients to hospital before the onset of cardiopulmonary arrest is therefore essential in order to reduce the mortality rate of these patients. In addition, thoracoscopy is very useful for both examining and treating traumatic diaphragmatic injury patients.

Less vigorous surgery for second primary lung cancer.

BACKGROUND: Patients with second primary lung cancer (SPLC) have a heterogeneous background. The optimum modality of treatment for SPLC patients has not yet been determined. The objective of this study was to attempt to identify the value of less vigorous therapies such as segmentectomy or video-assisted thoracic surgery (VATS) in SPLC. METHODS: We retrospectively reviewed the medical records of 46 patients who underwent resection for SPLC in Fukuoka University Hospital between January 1994 and April 2005. Patients were separated into two groups (LVT: less vigorous therapy including segmentectomy or VATS lobectomy; LCT: lobectomy with conventional thoracotomy). The characteristics of each group were evaluated and survival rates were analyzed at 5 years after surgery. RESULTS: The mean amount of blood loss was found to be significantly different ( P = 0.0062) with 59.44 +/- 14.00 ml for LVT cases and 254.48 +/- 63.62 ml for LCT. None of the LVT patients experienced postoperative complications. The 5-year survival rate was 62.7 % for LVT and 57.7 % for LCT. There was no significant difference in survival rates between these groups. CONCLUSIONS: Although differences were seen in the characteristics, less invasive surgery such as VATS or segmentectomy may be a feasible treatment for SPLC.

A completely thoracoscopic lobectomy/segmentectomy for primary lung cancer--technique, feasibility, and advantages.

INTRODUCTION: A completely thoracoscopic lobectomy/segmentectomy for primary lung cancer was designed to maximize the benefits of this type of minimally invasive surgery. The technique, feasibility, and advantages of this surgical modality over the conventional procedure were investigated. MATERIALS AND METHODS: Between January 2003 and December 2004, 38 patients underwent a lobectomy (n = 30) or segmentectomy (n = 8) for clinical stage IA primary lung cancer. A resection using a standard thoracotomy (Thoracotomy Group) was performed in 19 patients, and a completely thoracoscopic resection was performed in 10 cases (CTR Group). Conventional video-assisted thoracic surgery with a mini-thoracotomy was performed in 9 cases. RESULTS: All CTR lobectomies or segmentectomies were carried out safely without any major complications. The number of resected mediastinal lymph nodes was similar in both groups. There was a tendency for the hospital stay to be somewhat shorter in the CTR Group. With respect to postoperative pain as evaluated by a visual analogue scale (VAS), the CTR Group showed a significantly lower level of pain in comparison to the Thoracotomy Group ( P = 0.024 on day 2). CONCLUSIONS: We concluded that a complete thoracoscopic lung resection is a safe and technically feasible surgical procedure which enables us to make thoracoscopic lung resections less invasive.

The value of tumor volume in surgically resected non-small cell lung cancer.

BACKGROUND: The aim of this study was to evaluate whether or not tumor volume (TV) has an impact on survival in non-small cell lung cancer. METHODS: In a retrospective analysis of 385 cases with NSCLC who underwent curative surgery between 1994 and 2003, we calculated the tumor volume by using an ellipsoidal formula. The patients were grouped according to TV as determined by histograms. Gender, age, histology, nodal involvement, size, and TV were analyzed. Multivariate analysis by Cox's proportional hazards regression model was performed to identify the prognosis. RESULTS: Cases of N0 showed a significantly lower TV than cases with other N statuses (p < 0.05). A significant difference was also observed between TV and histology or gender. The 189 patients belonging to the small volume group (SVG) (range, 0.105 to 9.265 cm3) had a significantly better overall survival rate than the other 196 patients in the large volume group (LVG) (9.266-366.522 cm3). With univariate analysis, gender, age, nodal involvement, size, and TV were significantly associated with prognosis. Multivariate analysis showed that only gender (p = 0.0184) and nodal involvement (p = 0.0001) were significantly independent prognostic factors. The size factor was not significant (p = 0.5285). However, TV was not an independent factor, but trending toward significance (p = 0.0801). CONCLUSIONS: Although TV provides no independent prognostic information with multivariate analysis, TV in NSCLC should be considered using volumetric measurement with a three-dimensional CT approach prior to surgery or treatment planning.

Prognostic significance of subcarinal station in non-small cell lung cancer with T1-3 N2 disease.

BACKGROUND: Surgical resection may continue to offer the best chance of long-term survival for patients with non-small cell lung cancer (NSCLC). Generally, patients with N2 NSCLC have a poor prognosis. However, the surgical treatment of patients with N2 remains controversial as in these patients, some N2 subgroups have better prognoses than others. The objective of the current study was to evaluate the factors associated with N2, and to determine whether such factors are reliable predictors of survival. METHODS: We retrospectively reviewed 142 non-small cell lung cancer patients with T1-3 N2 in whom a curative approach had been attempted between January 1994 and December 2003. The patients were consequently divided into four groups (NS-1, no subcarinal involvement and without N1; NS-2, no subcarinal involvement and with N1; SI-1, subcarinal involvement and without upper mediastinal site; SI-2, subcarinal involvement and with upper mediastinal site). We also evaluated two groups for N2 stations (single-station N2 versus multiple-station N2). Multivariate analysis by Cox's proportional hazards regression model was performed to identify the prognosis. RESULTS: Lobectomy was carried out in 105 of the patients; bilobectomy in 10, and pneumonectomy in 27. The patients with T1-3 N2 disease showed survival rates of 34.1 % at 3 years and 24.1 % at 5 years. The overall survival rates at 3 years and 5 years were as follows: NS-1, 56.3 % and 43.2 %; NS-2, 35.4 % and 29.5 %; SI-1, 16.7 % and 0 %; SI-2, 15.4 % and 0 %, respectively. The NS-1 group had better prognoses than the other groups. There was a significant difference in survival rates within each group ( p = 0.0005). In univariate analysis, the type of surgery, type of subcarinal involvement, and multiple-station N2 were significantly associated with prognosis. Multivariate analysis showed that NS-1 was only found to be an independent prognostic factor in cases of T1-3 N2 disease ( p = 0.0018). NS-2 was not an independent factor but tended toward significance ( p = 0.0681). But multiple-station N2 was not an independent factor ( p = 0.1549). CONCLUSIONS: Surgery for patients with T1-3 N2 NSCLC might be acceptable if subcarinal lymph node metastasis is predicted to be absent.

[Surgical treatment for primary non-small cell lung cancer with synchronous brain metastases].

The brain is one of the most common sites of metastasis from lung cancer. The strategies of treatment for non-small cell lung cancer patient with synchronous brain metastases (stage IV) is controversial. We evaluate retrospectively the effectiveness of surgical treatment for these patients. Forty patients were divided into 3 groups on the basis of surgical treatment, group A of patients received both lung and brain resection, group B of patients received lung resection plus gamma knife therapy, group C of patients received brain resection. Median survival from the date of diagnosis of brain metastasis was as follows: group A 331 days, group B 151 days and group C 92 days. Univariate analysis revealed that adenocarcinoma histology and serum LDH significantly affected survival. Multivariate analysis found that only adeocarcinoma histology also affected the survival. It is concluded that surgical treatment may acceptable in selected group of non-small cell lung cancer patients with synchronous brain metastases.

[Review of the surgical treatment in superior sulcus tumor].

The rarity of the superior sulcus tumor has led to varying treatment techniques. Generally, radiation therapy followed by surgery has been used. En bloc resection combined with lobectomy and nodal dissection remains standard therapy. The unique location of this tumor, surgical approach thought to be important. Involvement of the anterior areas such as subclavian vessels can be resected by anterior transcervical approach, and vertebral body or brachial plexus through the classic Shaw Paulson approach. Preoperative computed tomography (CT) or magnetic resonance imaging (MRI) is beneficial to the evaluation of the vessels, nerves, and surgical planning. Recent studies showed that induction concurrent chemoradiation therapy improved the resectability and curability. This article reviews the treatment of superior sulcus tumor.

Characteristic differences between patients who have undergone surgical treatment for lung metastasis or hepatic metastasis from colorectal cancer.

OBJECTIVE: The characteristic differences between patients with lung or liver metastases from colorectal carcinoma (CRC) have not yet been clarified. A small group of these patients demonstrate a better prognosis, and the selection criteria for resection of liver and/or lung metastasis are not well defined. It is important to compare and analyze the most common metastatic sites, which include liver metastases and lung metastases. The objective of this study was to compare the characteristics of the two groups in order to identify patients who benefitted from surgical resection of CRC. METHODS: We retrospectively reviewed the medical charts of 80 patients who had undergone resection for liver or lung metastasis from CRC in Fukuoka University Hospital between June 1991 and December 2004. These patients were grouped according to surgical therapy received for the metastases, and separated into two groups, as follows: LUM, lung metastases resection; LIM, liver metastases resection. We evaluated these groups for a set of several factors. RESULTS: The characteristic factors between the two groups (LUM vs. LIM) demonstrated significant differences according to histological differentiation, venous invasion, and lymphatic permeation. There was a statistical difference in the disease-free interval (DFI) between the two groups (947.06 +/- 840.39 days in LUM vs. 246.03 +/- 229.26 days in LIM). Although serum CEA levels at resection of metastasis showed significant differences between the groups (LUM, 13.25 +/- 31.55 ng/ml; LIM, 55.21 +/- 99.52 ng/ml), the primary serum CEA levels were not significantly different. Overall survival rates at 5 years were 37.0 % for LUM and 42.8 % for LIM. There was no significant difference in the survival rate of the LUM vs. the LIM group after resection of metastasis. The Cox proportional hazards regression model was used to determine serum CEA status at the time of the metastases and showed a significant difference indicating poor prognosis for patients with LUM, but the results were not significant for LIM cases. CONCLUSIONS: Candidates for surgical treatment for lung or liver metastases from CRC may be an acceptable for the same valuable approach, even if characteristic differences were observed in each group.

Extended resection of T4 lung cancer with invasion of the aorta: is it justified?

BACKGROUND: We report our 10-year experience of performing surgical resection of T4 lung cancer invading the thoracic aorta. PATIENTS AND METHODS: From 1994 to 2004, sixteen patients with T4 primary lung cancer with local invasion of the thoracic aorta underwent tumor resection. Surgical resection included 8 pneumonectomies and 8 lobectomies. The histologic type was squamous cell carcinoma in 7 patients, adenocarcinoma in 7, large cell carcinoma in 1, and small cell carcinoma in 1. Complete resection of the tumor with mediastinal lymph node dissection was achieved in 8 patients (50 %), while the resection was incomplete in the other 8 cases. RESULTS: The overall cumulative survival of the 16 patients at 3 and 5 years was 34.7 % and 17.4 %, respectively. The survival of the patients in the complete resection group was found to be 36.5 % at 5 years, with 2 patients surviving more than 5 years without a recurrence, which was significantly better than that of the incomplete resection group ( p = 0.005). CONCLUSIONS: Extended aortic resection with primary lung cancer is complex and possibly high risk, but can achieve long-term survival in selected patients. Surgical resection should be considered as a treatment option for T4 lung cancer for this T4 subcategory.

Penetration to the aortic wall by a metallic airway stent. A successfully treated case with left pneumonectomy and aortic repair.

Metallic airway stents were used widely at the beginning of airway stent use, but an accumulation of cases has revealed complications due to their use. A patient who received a Gianturco Z stent for bronchial tuberculosis suffered massive haemoptysis due to stent migration into the aortic wall. Left pneumonectomy with aortic repair was successfully performed. We suggest that metallic stents should not be used for benign airway palliation, as they may later cause life-threatening complications.

Lymphomatous polyposis of the gastrointestinal tract, including mantle cell lymphoma, follicular lymphoma and mucosa-associated lymphoid tissue lymphoma.

AIMS: Lymphomatous polyposis (LP) is considered to represent mantle cell lymphoma (MCL) of the gastrointestinal (GI) tract. However, a few reports have suggested that some are follicular lymphoma (FL) or mucosa-associated lymphoid tissue (MALT) lymphomas. In this study, we analysed 35 patients and clarified the clinicopathological features of LP. METHODS AND RESULTS: Paraffin-embedded tissue samples were stained immunohistochemically and analysed by tissue-fluorescence in situ hybridization (T-FISH) for IGH/CCND1 (cyclin D1) and IGH/BCL2. The average age of the patients was 58.3 years. Over half of the cases showed gastric, duodenal, small intestinal, ileocaecal and sigmoid colonic lesions (15, 19, 15, 16 and 16 cases, respectively). Phenotypically, cases were classified into three types of MCL (cyclin D1+ CD5+ CD10-) (n=12), FL (cyclin D1- CD5- CD10+) (n=14) and MALT (cyclin D1- CD5- CD10-) (n=9). T-FISH identified 11 of the 11 examined cases with MCLs to have IGH/CCND1, while seven of 10 cases with FL had IGH/BCL2, and none of the MALT cases were positive for IGH/CCND1 or IGH/BCL2. At the study endpoint, five of 12 patients with MCL were dead, two of 14 with FL and one of nine with MALT were dead of other disease. Event-free survival analysis showed significantly poorest outcome in MCL, followed by FL, while MALT was associated with a favourable outcome (P=0.0040). CONCLUSIONS: Our study emphasizes the importance of differentiating MCL, FL and MALT of LP in evaluating prognosis and hence the most suitable therapeutic regimen.

[Treatment strategy for patients, with locally advanced non-small cell lung cancer].

A total of 89 patients with locally advanced lung cancer (pT3-4N0-1) underwent pulmonary resection from April 1994 to April 2003 at our institutions. The overall 5-year survival rate of the 89 patients was 35.5%. No significant difference in the 5-year survival rate was found according to the following variables: histologic type, type of operation, number of resected organs, performance of adjuvant therapy and pulmonary function. In patients with pN1 disease, when patients with nodal metastasis were divided into patients with hilar (# 10) or lobar (# 11 approximately 13) metastasis, the survival rate of lobar metastasis group was superior to those of hilar metastasis group, but not significantly. In patients with pN1 disease, 5 patients were survived for more than 1,000 days. The histology was squamous cell carcinoma in 4 cases. According to the characteristics of pN1 involvement, all cases was involved only a single station.