Results of resection in non-oat cell carcinoma of the lung with mediastinal lymph node metastases

Differentiation of metastatic versus non-metastatic mediastinal lymph nodes in patients with non-small cell lung cancer using respiratory-triggered short inversion time inversion recovery (STIR) turbo spin-echo MR imaging

OBJECTIVES

To differentiate between metastatic and non-metastatic lymph nodes in patients with non-small cell lung cancer using respiratory-triggered short inversion time inversion recovery (STIR) turbo spin-echo (SE) MR imaging.

METHODS AND PATIENTS

One hundred and forty mediastinal lymph nodes were detected in 25 patients with non-small cell lung cancer who underwent respiratory-triggered STIR turbo SE imaging. Ratios of signal intensity of lymph nodes to 0.9% saline phantoms (lymph node-saline ratio) were compared by Student's t-test using the pathological diagnosis as the gold standard. The threshold value of the lymph node-saline ratio was determined for a positive test, and tested for its capability to provide a differential diagnosis.

RESULTS

One hundred and forty lymph nodes were diagnosed and classified into two groups: metastatic lymph node (n=21) and non-metastatic lymph node (n=119). The mean lymph node-saline ratio in the non-metastatic lymph node group (0.42+/-0.01; mean+/-standard error) was significantly lower than that of the metastatic lymph node group (0.77+/-0.02, P<0.0001). When 0.6 was adapted as the threshold for a positive test, sensitivity, specificity, and accuracy for differentiating metastatic lymph node from non-metastatic lymph node per lymph nodes were 100, 96, and 96%, and sensitivity, specificity, and accuracy for differentiating metastatic lymph node from non-metastatic lymph node per patients were 100, 75, and 88%, respectively.

CONCLUSIONS

Both metastatic and non-metastatic lymph nodes in patients with non-small cell lung cancer were well differentiated using respiratory-triggered STIR turbo SE imaging.

Sentinel nodal assessment in patients with carcinoma of the lung

BACKGROUND

Assessment of sentinel nodes to predict metastases in a regional nodal basin is valuable for staging patients with melanoma and breast carcinoma. This study tested whether injection of isosulfan blue and technetium-99 could identify mediastinal sentinel nodes in patients with lung carcinoma and determine whether sentinel node histology predicts distal nodal metastases.

METHODS

Isosulfan blue and technetium-99 were injected into the tumor and pulmonary resection performed. The hilum and mediastinum were assessed visually and with the gamma probe, and a mediastinal nodal dissection was performed.

RESULTS

Thirty-one patients were evaluated. Three patients had positive sentinel nodes and positive distal mediastinal nodes. Twenty-two patients had negative sentinel nodes and negative distal nodes. No sentinel node was identified in 6 patients and 2 patients had two sentinel nodes.

CONCLUSIONS

These data demonstrate that this rapid, simple technique can identify sentinel nodes in the mediastinum and that the sentinel node is an accurate predictor of distal nodal metastases in patients with lung cancer.

A randomized trial of systematic nodal dissection in resectable non-small cell lung cancer

PURPOSE

We conducted a randomized trial to investigate whether systematic nodal dissection (SND) is superior to mediastinal lymph nodal sampling (MLS) in surgical treatment of non-small cell lung cancer (NSCLC).

METHODS

The patients resectable clinical Stage I-IIIA NSCLC were randomly assigned to lung resection combined with SND or lung resection combined with MLS. After postoperative pathological re-staging, eligible cases were followed up until 30 November 2000. The Kaplan-Meier method was used for survival analysis. COX proportional hazards model was used for prognostic analysis.

RESULTS

Of the 532 patients who were enrolled in the study, 268 patients were assigned to lung resection combined with SND and 264 were assigned to lung resection combined with MLS. After surgical restaging only 471 cases were eligible for follow-up. The median survival was 59 months in the group given SND and 34 months in the group given MLS (P=0.0000 by the log rank test). There was significant difference in survival in Stage I (5-year survival 82.16 vs. 57.49%) and Stage IIIA (26.98 vs. 6.18%) by the log rank test and Breslow test. There was no significant yet marginal difference in survival by log rank test (10-year survival 32.04 vs. 26.92%, P=0.0523) but significant difference in survival by Breslow test (5-year survival 50.42 vs. 34.05%, P=0.0284) in Stage II. Types of mediastinal lymph node dissection, pTNM stage, tumor size and number of lymph node metastasis were four factors that influenced long-term survival rate by multivariate analysis.

CONCLUSIONS

As compared with MLS, lobectomy (pneumonectomy) combined with SND can improve survival in resectable NSCLC.

Molecular assessment of lymph nodes in patients with resected stage I non-small cell lung cancer: preliminary results of a prospective study

OBJECTIVES

Routine histologic examination of resected lymph nodes in patients with stage I non-small cell lung cancer may underestimate the incidence of advanced disease. The presence of occult lymph node metastases may predict a higher risk of recurrence after intended curative resection. The purpose of this study was to determine the prognostic significance of TP53 and K-ras mutations in histologically determined negative lymph nodes from patients with stage I non-small cell lung cancer who underwent intended curative surgical resection.

METHODS

Between July 1995 and March 1998, clinical data and tissue samples of primary tumors and lymph nodes were collected in a prospective fashion from 102 patients undergoing resection for non-small cell lung cancer (stage I, n = 55; stage II, n = 32; stage IIIA, n = 15). TP53 and K-ras mutations were detected by direct sequencing. If molecular alterations were found in the primary tumor, the corresponding lymph nodes were examined for these same TP53 (by oligonucleotide hybridization) and K-ras (by allele-specific ligation) mutations.

RESULTS

TP53 mutations were found in 47 of 94 primary tumors (50%), and K-ras mutations were present in 26 of 55 adenocarcinomas (47%). A total of 134 lymph nodes from 32 patients with stage I disease were analyzed. In 9 cases (28%) the same TP53 or K-ras mutations were found in tumor and lymph node specimens, suggesting occult metastasis. On the basis of nodal location, 7 patients had their disease upstaged by a single stage and 2 patients by two stages. All 28 patients with stage II or III disease had pathologically determined positive nodes that were confirmed as positive by molecular analysis. Standard histopathologic assessment of regional lymph nodes failed to detect metastases at levels below 0.9% tumor-specific mutant TP53 clones per node. No statistically significant difference in disease-specific or overall survival was observed between patients with stage I disease with and without molecular lymph node metastases.

CONCLUSIONS

Occult lymph node metastases are present in a significant percentage of patients with stage I non-small cell lung cancer. These data suggest that molecular analysis allows a more accurate assessment of staging. However, larger studies are needed to determine the clinical role of molecular staging.

A prospective trial of systematic nodal dissection for lung cancer by video-assisted thoracic surgery: can it be perfect?

BACKGROUND

There have been no reports evaluating the completeness of systematic nodal dissection with video-assisted thoracic surgery (VATS). In order to elucidate the completeness of the dissection, we have conducted a prospective trial with patients having primary lung cancer.

METHODS

Patients with clinical stage I lung cancer were the candidates for this study. Thoracotomy was performed with a small skin incision of 7 cm to 8 cm in length. Through these small wounds and two trocars, pulmonary resection was performed and then hilar and mediastinal lymph nodes were dissected. After that, a standard thoracotomy was carried out by another surgeon to complete systematic nodal dissection.

RESULTS

Video-assisted thoracic surgery lobectomy with lymph node dissection was accomplished in 17 right lung cancer patients and 12 left lung cancer patients. On the right side, the average numbers of resected lymph nodes by VATS and remnant lymph nodes were 40.3 and 1.2, respectively. The average weights of dissected tissues by VATS and remnant tissues were 10.0 g and 0.2 g, respectively. On the left side, there were 37.1 and 1.2 lymph nodes and 8.3 g and 0.2 g of weight of dissected tissues. No nodal involvement was observed in the remnant lymph nodes.

CONCLUSIONS

The lymph node dissection with VATS was technically feasible and the remnant ("missed" by VATS) lymph nodes and tissues were 2% to 3%, which seems acceptable for clinical stage I lung cancer.

Building a better therapy for stage IIIA non-small cell lung cancer

What do clinicians know about stage IIIA lung cancer? They know accurate staging is critical and requires wide application of mediastinoscopy. They know that surgery and radiation alone each can cure a small subset of patients, and complete resection is of the utmost importance in surgically treated patients. They know that chemotherapy can increase the number of patients cured when combined with definitive radiation, and concurrent chemoradiotherapy seems superior to sequential. Neoadjuvant chemotherapy also seems to cure more patients than surgery alone, but more data are necessary. Trimodality therapy remains a promising but unproved approach in patients with stage IIIA disease. With the exciting new molecularly targeted agents, trials examining quad-modality therapy are just around the corner.

Outcomes and cost-effectiveness of alternative staging strategies for non-small-cell lung cancer

PURPOSE

To identify the optimal strategy for staging the mediastinum of patients with known non-small-cell lung cancer (NSCLC), stratified by tumor (T) classification.

METHODS

We used a decision-analytic model to compare the health outcomes and cost-effectiveness of three staging strategies: (1) chest computed tomography alone, (2) selective mediastinoscopy, and (3) routine mediastinoscopy. The overall effectiveness and cost of each strategy was a function of the proportion of patients accurately staged and the risks, benefits, and costs of the diagnostic tests and treatments used. Probability estimates and costs were derived from primary data and the literature. We adopted a societal perspective and calculated incremental cost-effectiveness ratios (ICERs) as cost per quality-adjusted life year (QALY) gained.

RESULTS

Both mediastinoscopy strategies correctly identified more patients with mediastinal involvement (N2/N3 disease) and assigned them to multimodal regimens. Routine mediastinoscopy maximized quality-adjusted life expectancy in all patients, irrespective of T classification, and this result was robust to varying the model estimates over their reported ranges. In T1 patients, selective mediastinoscopy cost $24,500 per QALY gained, compared with $78,800 per QALY gained for routine mediastinoscopy. In T2 and T3 patients, the ICER of routine mediastinoscopy was more favorable ($42,800 and $53,400 per QALY gained, respectively).

CONCLUSION

Routine mediastinoscopy maximizes quality-adjusted life expectancy in patients with known NSCLC, and its ICER compares favorably with other currently accepted medical technologies. The survival benefit and cost-effectiveness of this strategy are greater in patients with T2 and T3 tumors and are likely to improve with advances in multimodal therapy.

Can tumor size be a guide for limited surgical intervention in patients with peripheral non-small cell lung cancer? Assessment from the point of view of nodal micrometastasis

OBJECTIVE

We sought to determine the critical diameter of a peripheral non-small cell lung cancer tumor less than which no evidence of nodal micrometastasis is present.

METHODS

Samples of 3081 lymph nodes from 181 patients with stage I peripheral lung cancer (155 with adenocarcinoma and 26 with squamous cell carcinoma) who had undergone complete resection with systematic lymphadenectomy were used in the study. In the samples immunohistochemical staining for cytokeratin was performed. The expression of vascular endothelial growth factor (VEGF) at primary sites was also immunohistochemically assessed.

RESULTS

Nodal micrometastasis was detected in 44 patients. The mean tumor sizes were 2.2 +/- 1.3 cm (range, 1.0-7.0 cm) in nodal micrometastasis-positive adenocarcinoma, 2.1 +/- 0.9 cm (range, 0.5-6.0 cm) in nodal micrometastasis-negative adenocarcinoma, 4.8 +/- 2.3 cm (range, 2.2-10.0 cm) in nodal micrometastasis-positive squamous cell carcinoma, and 3.2 +/- 2.1 cm (range, 0-9.0 cm) in nodal micrometastasis-negative squamous cell carcinoma. The tumor size in the nodal micrometastasis-positive group tended to be greater than that in the nodal micrometastasis-negative group in squamous cell carcinomas, but there was no significant difference in adenocarcinomas. Nodal micrometastasis was not found in patients with squamous cell carcinoma of 2.0 cm or less in diameter. However, nodal micrometastasis was found in 20% (19/95) of the patients with adenocarcinoma of 1.1 to 2.0 cm in diameter and even in 4 of 11 patients with adenocarcinoma of 1.0 cm or less. Among the patients with nodal micrometastasis, survival of patients with vascular endothelial growth factor overexpression was worse than that of patients without it. The survival of patients with nodal micrometastasis without vascular endothelial growth factor overexpression was comparable with that of patients without nodal micrometastasis.

CONCLUSION

A limited surgical intervention without lymphadenectomy is validated for squamous cell carcinoma of 2.0 cm or less without pleural involvement. In adenocarcinoma the tumor size itself is not a reliable guide for nodal micrometastasis status. In patients with nodal micrometastasis with vascular endothelial growth factor overexpression, the risk of systemic disease should be considered.

Value of systematic mediastinal lymph node dissection during pulmonary metastasectomy

BACKGROUND

Systematic mediastinal lymph node dissection is the accepted standard when curative resection of bronchial carcinoma is performed. However, mediastinal lymph node dissection is not routinely performed with pulmonary metastasectomy, in which only enlarged or suspicious lymph nodes are removed. The incidence of malignant infiltration of mediastinal lymph nodes in patients with pulmonary metastases is not known.

METHODS

Sixty-three patients who underwent 71 resections through a thoracotomy for pulmonary metastases of different primary tumors were studied prospectively. Selected patients showed no evidence of tumor progression or extrathoracic metastases and pulmonary metastasectomy was planned with curative intent. All patients underwent preoperative helical computed tomography (CT) scanning. Only patients with no evidence of suspicious mediastinal lymph nodes on the CT scan (less than 1 cm in the short axis) were included in this study. A mediastinal lymph node dissection was performed routinely with metastasectomy.

RESULTS

In 9 patients (14.3%) at least one mediastinal lymph node revealed malignant cells in accordance with the resected metastases. When compared with the preoperative CT scan, additional pulmonary metastases were detected in 16.9% of performed operations. There was a trend toward an improved survival rate in patients without involvement of the mediastinal lymph nodes. The number of pulmonary metastases had no influence on survival.

CONCLUSIONS

On a patient-by-patient basis, the frequency of misdiagnosed mediastinal lymph node metastases is about the same as compared with non-small cell bronchial carcinomas. Systematic mediastinal lymph node dissection reveals a significant number of patients, who otherwise are assumed free of residual tumor. The knowledge of metastases to mediastinal lymph nodes after complete resection of pulmonary metastases could influence the decision for adjuvant therapy in selected cases.

Esophageal cancer: the mode of lymphatic tumor cell spread and its prognostic significance

PURPOSE

Data on skip metastases and their significance are lacking for esophageal cancer. This issue is important to determine the extent of lymphadenectomy for esophageal resection. In this study we examined the lymphatic spread in esophageal cancer by routine histopathology and by immunohistochemistry.

PATIENTS AND METHODS

A total of 1,584 resected lymph nodes were obtained from 86 patients with resected esophageal carcinoma and evaluated by routine histopathology. Additionally, frozen tissue sections of 540 lymph nodes classified as tumor-free by routine histopathology were screened for micrometastases by immunohistochemistry with the monoclonal antibody Ber-EP4. The lymph nodes were mapped according to the mapping scheme of the American Thoracic Society modified by Casson et al.

RESULTS

Forty-four patients (51%) had pN1 disease, and 61 patients (71%) harbored lymphatic micrometastases detected by immunohistochemistry. Skip metastases detected by routine histopathology were present in 34% of pN1 patients. Skipping of micrometastases detected by immunohistochemistry was found in 66%. The presence of micrometastases was associated with a significantly decreased relapse-free and overall survival (56.0 v 10.0 months and > 64 v 15 months, P <.0001 and P =.004, respectively). Cox regression analysis revealed the independent prognostic influence of micrometastases in lymph nodes. Lymph node skipping had no significant independent prognostic influence on survival.

CONCLUSION

Histopathologically and immunohistochemically detectable skip metastases are a frequent event in esophageal cancer. Only extensive lymph node sampling, in conjunction with immunohistochemical evaluation, will lead to accurate staging. An improved staging system is essential for more individualized adjuvant therapy.

Prognostic impact of bulky mediastinal lymph nodes (N2>2.5 cm) in patients with locally advanced non-small-cell lung cancer (LA-NSCLC) treated with platinum-based induction chemotherapy

A group of 70 patients with locally advanced non-small-cell lung cancer (LA-NSCLC), treated in different phase II-III trials with platinum-based chemotherapy in two institutions, have been evaluated to identify potential baseline prognostic factors predicting their survival. The eligibility criteria were patients with stage IIIA (N2)-IIIB, Eastern Cooperative Oncology Group performance status 0.1 and less than 5% weight loss. All 37 patients with stage IIIA(N2) were treated with platinum-based induction chemotherapy followed by surgery plus radiotherapy if no progression was observed. The other 33 patients with stage IIIB were treated with platinum-based induction chemotherapy followed by conventional fractionation radiotherapy if no progression was observed. The overall response rate to induction chemotherapy was 40%. Median survival of the 70 patients was 13 months, with a 4-year survival of 15%. At univariate analysis, two prognostic factors correlated with survival: partial or complete response to induction chemotherapy (P<0.00001) and bulky mediastinal lymph nodes (N2>2.5 cm) (P=0.03). At multivariate analysis, only the response to induction chemotherapy retained statistical significance (P=0.00001). Randomized well-balanced prospective trials considering initially mediastinal N2 node size are needed to clearly establish the role of chemotherapy, surgery and radiotherapy in LA-NSCLC.

Neoadjuvant therapy and surgical resection for locally advanced non-small cell lung cancer

During the past 15 years, treatment of stage IIIA (N2) non-small cell lung cancer has evolved considerably because of improvements in patients selection, staging, and combined modality therapy. Results of several clinical trials suggest that induction chemotherapy or chemoradiation and surgical resection is superior to surgery alone. However, the optimal induction regimen has not been defined. An intergroup trial is also underway to determine whether chemoradiation and surgical resection leads to better survival than chemotherapy and radiation alone. Future studies will assess ways to combine radiation and novel chemotherapeutic agents, and will identify molecular abnormalities that predict response to induction therapy.

Survival of patients with resected N2 non-small-cell lung cancer: evidence for a subclassification and implications

PURPOSE

Patients who suffer from non-small-cell lung cancer (NSCLC) with ipsilateral mediastinal lymph node involvement (N2) belong to a heterogeneous subgroup of patients. We analyzed the prognosis of patients with resected N2 NSCLC to propose homogeneous patient subgroups.

PATIENTS AND METHODS

The present study comprised 702 consecutive patients from six French centers who underwent surgical resection of N2 NSCLC. Initially, two groups of patients were defined: patients with clinical N2 (cN2) and those with minimal N2 (mN2) disease were patients in whom N2 disease was and was not detected preoperatively at computed tomographic scan, respectively.

RESULTS

The median duration of follow-up was 52 months (range, 18 to 120 months). A multivariate analysis using Cox regression identified four negative prognostic factors, namely, cN2 status (P <. 0001), involvement of multiple lymph node levels (L2+; P <.0001), pT3 to T4 stage (P <.0001), and no preoperative chemotherapy (P <. 01). For patients treated with primary surgery, 5-year survival rates were as follows: mN2, one level involved (mN2L1, n = 244): 34%; mN2, multiple level involvement (mN2L2+, n = 78): 11%; cN2L1 (n = 118): 8%; and cN2L2+ (n = 122): 3%. When only patients with mN2L1 disease were considered, the site of lymph node involvement according to the American Thoracic Society numbering system had no prognostic significance (P =.14). Preoperative chemotherapy was associated with a better prognosis for those with cN2 (P <.0001). Five-year survival rates were 18% and 5% for cN2 patients treated with and without preoperative chemotherapy, respectively.

CONCLUSION

This study has identified homogeneous N2 NSCLC prognostic subgroups and suggests different therapeutic approaches according to the subgroup profile.

Intraoperative radioisotope sentinel lymph node mapping in non-small cell lung cancer

BACKGROUND

Lymph node metastases are the most significant prognostic factor in localized non-small cell lung cancer (NSCLC). Nodal micrometastases may not be detected. Identification of the first nodal drainage site (sentinel node) may improve detection of metastatic nodes. We performed intraoperative Technetium 99m sentinel lymph node (SN) mapping in patients with resectable NSCLC.

METHODS

Fifty-two patients (31 men, 21 women) with resectable suspected NSCLC were enrolled. At thoracotomy, the primary tumor was injected with 2 mCi Tc-99. After dissection, scintographic readings of both the primary tumor and lymph nodes were obtained with a handheld gamma counter. Resection with mediastinal node dissection was performed and findings were correlated with histologic examination.

RESULTS

Seven of the 52 patients did not have NSCLC (5 benign lesions, and 2 metastatic tumors) and were excluded. Forty-five patients had NSCLC completely resected. Mean time from injection of the radionucleide to identification of sentinel nodes was 63 minutes (range 23 to 170). Thirty-seven patients (82%) had a SN identified; 12 (32%) had metastatic disease. 35 of the 37 SNs (94%) were classified as true positive with no metastases found in other intrathoracic lymph nodes without concurrent SN involvement. Two inaccurately identified SNs were encountered (5%). SNs were mediastinal (N2) in 8 patients (22%).

CONCLUSIONS

Intraoperative SN mapping with Tc-99 is an accurate way to identify the first site of potential nodal metastases of NSCLC. This method may improve the precision of pathologic staging and limit the need for mediastinal node dissection in selected patients.

[Surgical treatment of lung cancer: comparative assessment of the staging systems of 1986 and 1997. Results in 500 consecutive patients]

OBJECTIVE

To evaluate the influence of different variables on survival in relation to the staging guidelines of 1986 and 1997.

PATIENTS AND METHODS

Five hundred patients (473 men and 27 women) with non-small cell lung cancer were treated surgically from 1980 to 1997. Resections performed: 184 lobectomies, 16 bi-lobectomies, 244 pneumonectomies, 2 bronchoplastic lobectomies, and 54 segmentectomies.

HISTOLOGY

338 epidermoid, 86 adenocarcinoma, 40 giant cell, 36 mixed tumor. Differentiation: 216 N1, 91 N2, 193 N3. Stages according to 1986 guidelines were I: 246 (49.2%) (T1: 32, T2: 214); II: 27 (5.4%); IIIa: 197 (39.4%) (N0: 84; N1: 2; N2: 111); IIIb: 23 (4.6%) (N0: 12; N2: 11); and IV: 7 (1.4%) (N0: 4; N2: 3). Stages according to the 1997 guidelines were used for comparison of survival between patients with Ia and Ib tumors and with IIb and IIIa tumors.

RESULTS

With follow-up periods ranging from 2 to 17 years, 141 patients (28%) were alive, 26 (5%) were lost to follow-up and 333 had died. Two patients (0.4%) died during surgery and 36 (7.2%) died during the postoperative period. Among the remaining 462 patients, 295 deaths were related to the following causes: metastasis in 130 cases (44%), recurrence in 81 cases (27%), functional causes in 17 (6%), independent causes in 54 (18%) and unknown causes in 13 (4%). Overall survival rates at 5 and 10 years were 36 and 26%, respectively; survival rates by histological type: epidermoid 36 and 26%, adenocarcinoma 35 and 26%; stage I, 51 and 41% (Ia, 81 and 75%; Ib, 44 and 33%); IIIa 24 and 15% (IIb of 1997: 27 and 17%; IIIa of 1997: 20 and 13%). Survival by N factor: N0, 44 and 34%; N2, 17 and 8% (1986) and 17 and 11% (1997).

CONCLUSIONS

Survival agrees with other studies. The 1997 staging guidelines are useful for differentiating survival between stages Ia and Ib and between IIb and IIIa. N and T factors, histology and stage influence the appearance of metastasis; T factor influences recurrence.

The utility of transbronchial needle aspiration in the staging of bronchogenic carcinoma

We conducted a prospective multi-institutional clinical study involving community hospitals and academic medical centers to more carefully define the value of computerized tomography (CT) of the chest with transbronchial needle aspiration (TBNA) in the staging of bronchogenic carcinoma (CA), and to assess the predictors of a positive aspirate. Of 360 individuals determined to have bronchogenic carcinoma, 50 of 81 (62%) with small cell carcinoma (SCC) and 135 of 279 (48%) with non-small cell carcinoma (NSCC) had positive aspirates (p = 0.034). TBNA precluded additional thoracic surgery in a total of 104 of 360 (29%) patients and was exclusively diagnostic of carcinoma in 65 of 360 (18%) cases. Right-sided tumors were more likely to have a positive mediastinal TBNA (p = 0.002 to 0. 01) as were histologic (67 of 118 [57%]) rather than cytology aspirates (228 of 532 [41%]) (p < 0.001). Sensitivity was > 57% in lymph nodes (LN) >/= 10 mm, and among LN of equivalent size, right paratracheal and subcarinal sites were most likely to establish malignancy. Preoperative CT is a valuable adjunct in the staging of CA by TBNA. Increasing LN size, right-sided tumors, right paratracheal and subcarinal locations, use of a histology needle, and the presence of SCC are the best predictors of a positive aspirate.

The role of surgery in integrated therapies for non-small-cell lung cancer

Surgery represents the best treatment for early-stage non-small-cell lung cancer (NSCLC). In selected cases, even locally-advanced cancers may be suitable for surgical treatment. The combination of chemotherapy (with or without radiotherapy) and surgery has proved potentially useful in improving survival, but pre-operative treatment may represent a risk factor for the onset of post-operative complications. Studies performed to date indicate the need for further multidisciplinary research with a view to identifying more advantageous treatment modalities, particularly for locally-advanced NSCLC.

Non-small cell lung cancer: prognostic factors in patients treated with surgery and postoperative radiation therapy

PURPOSE

To determine survival outcomes, to identify adverse prognostic factors for relapse, and to compare American Joint Commission on Cancer (AJCC) staging systems in patients with non-small cell lung cancer (NSCLC) treated with surgery and postoperative radiation therapy.

MATERIALS AND METHODS

Between 1980 and 1995, 211 patients with NSCLC underwent surgery and postoperative radiation therapy. Surgery consisted of wedge resection (12.5%), lobectomy (67.8%), or pneumonectomy (19.7%). Pathologic stages (1992 AJCC) included I (n = 22), II (n = 70), IIIA (n = 104), and IIIB (n = 12). Indications for radiation therapy included compromised margins (n = 81) and/or positive mediastinal nodes (n = 55). Prognostic factors were identified by using univariate and multivariate models.

RESULTS

Overall 3-year survival for patients with stage I, II, and IIIA cancer was 58.9%, 44.1%, and 43.2%, respectively. Older age (P = .008), male sex (P = .021), large primary tumor (P = .004), and multiple positive mediastinal nodes (P = .046) were associated with worse rates of survival. Actuarial risk of local-regional relapse (36 patients) was 21.4% at 3 years. In a multivariate model, use of wedge resection (P = .001), positive margins (P = .010), and larger pathologic tumor (P = .059) were risk factors for local-regional recurrence. Actuarial rate of distant failure was 55.2% at 3 years.

CONCLUSION

Local-regional control can be achieved with surgery and radiation therapy in approximately 80% of patients; however, the rate of distant metastasis remains unacceptably high. Other variables, such as multiple positive nodes, may serve to identify patients at higher risk for relapse and poorer survival. Methods for improving treatment outcomes in these patients should be pursued.

A controlled study of postoperative radiotherapy for patients with completely resected nonsmall cell lung carcinoma. Groupe d'Etude et de Traitement des Cancers Bronchiques

BACKGROUND

Postoperative radiotherapy is commonly used to treat patients with completely resected nonsmall cell lung carcinoma, but its effect on overall survival has not been established.

METHODS

After undergoing complete surgical resection, 728 patients with non-small cell lung carcinoma (221 Stage I, 180 Stage II, and 327 Stage III) were randomized to receive either postoperative radiotherapy at a total dose of 60 gray or observation only . The main end point was overall survival.

RESULTS

At the reference date, 218 of 355 patients in the control group had died and 262 of 373 in the radiotherapy group had died. Five-year overall survival was 43% for the control group and 30% for the radiotherapy group (P = 0.002, log rank test; relative risk [RR]: 1.33; 95% confidence interval [CI]: 1.11-1.59). This result was not modified by adjustment for potential prognostic factors. The excess mortality rate for the radiotherapy group was due to an excess of intercurrent deaths (P = 0.0001; RR: 3.47; the 5-year intercurrent death rate was 8% for the control group and 31% for the radiotherapy group). Radiotherapy had no significant effect on local recurrence (RR: 0.85; 95% CI: 0.64-1.14) and no effect on metastasis (RR: 1.06; 95% CI: 0.85-1.31). The rate of non-cancer-related death increased with the dose per fraction delivered.

Lobe-specific extent of systematic lymph node dissection for non-small cell lung carcinomas according to a retrospective study of metastasis and prognosis

BACKGROUND

Complete lymphadenectomy of the mediastinum is advised for patients with lung cancer to provide prognostic information and possible survival benefit. The proper extent of dissection should be further defined.

METHOD

The lymphatic metastatic patterns according to the primary site and prognoses were retrospectively analyzed in 166 patients with non-small cell carcinoma who underwent at least lobectomy with hilar and mediastinal lymphadenectomy. All patients had histologically proven mediastinal metastasis (pN2).

RESULTS

Among 54 right upper lobe tumors the most common site of metastasis was the lower pretracheal station (74%), whereas metastases to the subcarinal station were seen only in 13%. Among 8 patients with right middle lobe tumors and 41 patients with right lower lobe tumors, both superior mediastinal and subcarinal stations were involved. The 34 left upper segment tumors metastasized to the aorticopulmonary window most commonly (71%) and to the subcarina only in 12% of cases. Inversely, the 10 left lingular tumors metastasized to the subcarina most commonly (50%) and to the aorticopulmonary window only in 20% of cases. Among 44 left lower lobe tumors the subcarinal station was most common for metastasis (58%), with infrequent metastases to the aorticopulmonary window. The 5-year survival for all 166 patients was 35%. Patients with single-station and single-node metastases had a significantly better prognosis than those with more extensive metastases. Right lower lobe tumors with superior mediastinal metastasis carried a particularly poor 5-year survival of only 4.1%.

COMMENT

Subcarinal lymphadenectomy is not always necessary for tumors of the right upper lobe and left upper segment. For tumors of other lobes both superior mediastinal dissection and subcarinal dissection are advised. However, superior mediastinal metastasis should be recognized as an indicator of poor prognosis in tumors of both lower lobes.

Predictors of subclinical nodal involvement in clinical stages I and II non-small cell lung cancer: implications in the inoperable and three-dimensional dose-escalation settings

PURPOSE

When mediastinal lymph nodes are clinically uninvolved in the setting of inoperable non-small cell lung cancer, whether conventional radiation techniques or three-dimensional dose-escalation techniques are used, the benefit of elective nodal irradiation is unclear. Inclusion of the clinically negative mediastinum in the radiation portals increases the risk of lung toxicity and limits the ability to escalate dose. This analysis represents an attempt to use clinical characteristics to estimate the risk of subclinical nodal involvement, which may help determine which patients are most likely to benefit from elective nodal irradiation.

METHODS

From 1987 to 1990, 346 patients undergoing complete resection of non-small cell lung cancer underwent a preoperative computed tomographic scan revealing no clinical evidence of N2/N3 involvement. Multivariate regression and regression tree analyses attempted to define which patients were at highest risk for subclinical mediastinal involvement (N2) and which patients were at highest risk for subclinical N1 and/or N2 involvement (N1/N2). Immunohistochemical data suggest that the conventional histopathologic techniques used during this study somewhat underestimate the true degree of lymph node involvement; therefore, a third end point was also evaluated: N1 involvement and/or N2 involvement and/or local-regional recurrence (N1/N2/LRR).

RESULTS

Regression analyses revealed that the following factors were independently associated with a high risk of more advanced disease: positive preoperative bronchoscopy (N2, p = 0.02; N1/N2, p < 0.0001; N1/N2/LRR, p < 0.001) and tumor grade 3/4 (N1/N2/LRR, p < 0.01). A regression tree analysis was then used to separate patients into risk groups with respect to N1/N2/LRR.

CONCLUSION

In inoperable non-small cell lung cancer, the patients for whom mediastinal radiation therapy may most likely be indicated are those with a positive preoperative bronchoscopy, especially with large (> 3 cm) primary tumors.

Proposal for reasonable mediastinal lymphadenectomy in bronchogenic carcinomas: role of subcarinal nodes in selective dissection

OBJECTIVE

The aims of this study were to reveal the characteristics of skipping N2 lung cancer and to develop a more reasonable approach for dissecting mediastinal lymph nodes.

METHODS

Of consecutive 956 patients who were operated on for primary lung cancer from 1986 through 1996, 760 (79.5%) had a diagnosis of non-small cell carcinoma and were subjected to complete resection of the tumor together with hilar and mediastinal lymphadenectomy.

RESULTS

Of 141 patients with N2 disease, 53 (37.6%) had skipping metastases. Among 78 patients with N2 cancer of the upper lobe, 37 (47.4%) had skipping metastases affecting upper or aortic mediastinal nodes whereas none of them had skipping metastases affecting lower mediastinal nodes. Among 47 patients with N2 cancer of the lower lobe, 13 (27.7%) had skipping metastases affecting mediastinal nodes. Of these 13 patients, 11 (84.6%) had skipping metastases affecting the subcarinal node. The remaining 2 patients had a huge primary tumor.

CONCLUSIONS

Dissection of the upper part of the mediastinum including the aortic regions should be performed regardless of the operative appearance when cancer is located in the upper lobe, but it is not required for lower lobe tumors with negative hilar and subcarinal nodes. Dissection of the subcarinal node in patients with an upper lobe tumor is not routinely needed when the nodes in both the hilum and upper mediastinum are intact. We consider that the subcarinal node is of significance and skipping metastases should be defined as metastases that skip the subcarinal node in addition to N1 nodes.

Long-term survivors with pN2 non-small cell lung cancer after a complete resection with a systematic mediastinal node dissection

OBJECTIVE

A substantial number of surgical patients with pN2 disease have survived longer than 5 years without any evidence of recurrence, although the surgical indications for those patients remain controversial. The present study was performed in order to clarify the clinical characteristics of the long-term survivors with pN2 disease.

METHODS

We retrospectively reviewed the cases of 111 patients with pN2 disease who had undergone a complete resection with a systematic mediastinal lymph node dissection from 1974 through 1991.

RESULTS

Of the 111 patients with pN2 disease, 20 survived longer than 5 years after a surgical resection. When both the pre- and post-operative conditions were compared between the long-term survivors and the others, the long-term survivors were characterized by significantly higher proportions of cN0 disease (P = 0.031), pT1 disease (P = 0.004), skip metastasis without hilar node metastasis (P = 0.028), and metastasis of a single mediastinal station (0.044). Of those characteristics, only the likelihood of having cN0 disease could be pre-operatively determined. The survival rate of such a population with cN0-pN2 disease was 34.5% at 5 years and 29.6% at 10 years after a complete resection, respectively.

CONCLUSIONS

Pathologic N2 patients with some favorable prognostic factors can survive long-term after a complete resection combined with a systematic mediastinal lymph node dissection. At present, due to the lack of any effective adjuvant therapy, a systematic mediastinal node dissection should be routinely performed even in patients with cN0 disease.

Effectiveness of radical systematic mediastinal lymphadenectomy in patients with resectable non-small cell lung cancer: results of a prospective randomized trial

OBJECTIVE

To evaluate the effectiveness of lymphadenectomy in the treatment of non-small cell lung cancer (NSCLC).

SUMMARY BACKGROUND DATA

The extent of lymphadenectomy in the treatment of NSCLC is still a matter of controversy. Although some centers perform mediastinal lymph node sampling (LS) with resection of only suspicious lymph nodes, others recommend a radical, systematic mediastinal lymphadenectomy (LA) to improve survival and to achieve a better staging.

METHODS

In a controlled, prospective, randomized clinical trial, the effects of LA on recurrence rates and survival were analyzed, comparing LS and LA in 169 patients with operable NSCLC.

RESULTS

After a median follow-up of 47 months, LA did not improve survival in the overall group of patients (hazard ratio: 0.78; 95% confidence interval: 0.47-1.24). Although recurrences rates tended to be reduced among patients who underwent LA, these decreases were not statistically significant (hazard ratio: 0.82; 95% confidence interval: 0.54-1.27). However, analysis of subgroups of patients according to histopathologic lymph node staging revealed that LA appears to prolong relapse-free survival (p = 0.037) with a borderline effect on overall survival (p = 0.058) in patients with limited lymph node involvement (pN1 disease or pN2 disease with involvement of only one lymph node level); in patients with pN0 disease, no survival benefit was observed.

CONCLUSIONS

Radical systematic mediastinal lymphadenectomy does not influence disease-free or overall survival in patients with NSCLC and without overt lymph node involvement. However, a small subgroup of patients with limited mediastinal lymph node metastases might benefit from a systematic lymphadenectomy.

Effectiveness of postoperative irradiation in stage IIIA non-small cell lung cancer according to regression tree analyses of recurrence risks

BACKGROUND

In the setting of grossly resected stage IIIA (N2 involvement) non-small cell lung carcinoma, the role of adjuvant postoperative thoracic radiation therapy (TRT) remains controversial. This study was initiated to subcategorize these patients into high-, intermediate-, and low-risk groups with respect to local recurrence and survival rates, and to determine whether there were certain subgroups of patients who were particularly likely or unlikely to benefit from postoperative TRT.

METHODS

Two hundred twenty-four patients were studied. A regression tree analysis was used to separate patients who had undergone operation alone into groups that had a high, intermediate, or low risk of local recurrence and death. The effect of adjuvant postoperative TRT then was examined in each of these groups.

RESULTS

The use of adjuvant postoperative TRT (compared with operation alone) was associated with an improvement in freedom from local recurrence and survival for patients who had an intermediate or high risk of local recurrence and death. However, the greatest level of improvement in freedom from local recurrence (p < 0.0001) and survival (p = 0.0002) associated with the use of adjuvant postoperative TRT was in the high-risk group. Similarly, but of lesser magnitude, the intermediate-risk group had improved freedom from local recurrence and survival rates with the use of adjuvant post-operative TRT (p = 0.002 and p = 0.01, respectively). For the low-risk group, the freedom from local recurrence and survival rates were not statistically different between the patients who received adjuvant postoperative TRT and those who underwent observation.

CONCLUSIONS

Patients with non-small cell lung carcinoma involving ipsilateral mediastinal lymph nodes (stage IIIA) who undergo gross resection and who are at either high or intermediate risk for local recurrence and death are likely to benefit from adjuvant postoperative irradiation. The role of radiation therapy in low-risk patients is unclear. Prospective confirmation of these observations is warranted.

Prognostic value of immunohistochemically identifiable tumor cells in lymph nodes of patients with completely resected esophageal cancer

BACKGROUND

Current methods of disease staging often fail to detect small numbers of tumor cells in lymph nodes. Metastatic relapse may arise from these few cells.

METHODS

We studied 1308 lymph nodes from 68 patients with esophageal cancer without overt metastases who had undergone radical en bloc esophagectomy. A total of 399 lymph nodes obtained from 68 patients were found to be free of tumor by routine histopathological analysis and were studied further for isolated tumor cells by immunohistochemical analysis with the monoclonal anti-epithelial-cell antibody Ber-EP4. This antibody did not stain lymph nodes from 24 control patients without carcinoma.

RESULTS

Of the 399 "tumor free" lymph nodes, 67 (17 percent), obtained from 42 of the 68 patients, contained Ber-EP4-positive tumor cells. Fifteen of 30 patients who were considered free of lymph-node metastases by histopathological analysis had such cells in their lymph nodes, and 5 of the 15 had small primary tumors. Ber-EP4-positive cells found in "tumor free" nodes were independently predictive of significantly reduced relapse-free survival (P=0.008) and overall survival (P=0.03). They predicted relapse both in patients without nodal metastases (P=0.01) and in those with regional lymph-node involvement (P=0.007). All 12 patients whose lymph nodes were negative on both histopathological and immunohistochemical analysis and who were available for follow-up survived without recurrence. The presence of micrometastatic tumor cells in bone marrow had no additional prognostic value.

CONCLUSIONS

Immunohistochemical examination of lymph nodes may improve the pathological staging of esophageal cancer.

The impact of surgical adjuvant thoracic radiation therapy for patients with nonsmall cell lung carcinoma with ipsilateral mediastinal lymph node involvement

BACKGROUND

Previous nonsmall cell lung carcinoma studies have shown that patients with ipsilateral mediastinal (N2) lymph node involvement who underwent surgical resection have a greater local recurrence rate than those with less lymph node involvement (N0, N1). Therefore, it was hypothesized that complete surgical clearance of subclinical lymph node disease is difficult in N2 patients and that adjuvant postoperative thoracic radiotherapy (TRT) may be beneficial.

METHODS

A retrospective review was performed to determine the local recurrence and survival rates for patients with N2 disease undergoing complete surgical resection with or without adjuvant TRT. Between 1987 and 1993 at the Mayo Clinic, 224 patients underwent complete resection of N2 nonsmall cell lung carcinoma. More than one mediastinal lymph node station was sampled in 98% of patients; 39% then received adjuvant TRT (median dose, 50.4 grays).

RESULTS

The median follow-up time was 3.5 years for the patients who were alive at the time of the analysis. The surgery alone versus surgery plus TRT groups were well balanced with respect to gender, age, histology, tumor grade, number of mediastinal lymph node stations dissected or involved, and involved N1 lymph node number. There were slightly more patients with right lower lobe lesions (compared with other lobes), patients with multiple lobe involvement, and patients with only one N2 lymph node involved in the surgery alone group. After treatment with surgery alone, the actuarial 4-year local recurrence rate was 60%, compared with 17% for treatment with adjuvant TRT (P < 0.0001). The actuarial 4-year survival rate was 22% for treatment with surgery alone, compared with 43% for treatment with adjuvant TRT (P = 0.005). On multivariate analysis, the addition of TRT (P = 0.0001), absence of superior mediastinal lymph node involvement (P = 0.005), and fewer N1 lymph nodes involved (P = 0.02) were independently associated with improved survival rate.

CONCLUSIONS

This study, which to the authors' knowledge is the largest evaluating adjuvant TRT in N2 nonsmall cell lung carcinoma, suggests that adjuvant TRT may improve local control and survival.

Implications of staging in lung cancer

Lung cancer staging, based on anatomic extent of disease and described by the TNM staging system (T, primary tumor; N, regional lymph nodes; M, distant metastasis), is an important parameter for determining the clinical course of this disease. To evaluate the prognostic importance of TNM staging for lung cancer, we conducted a retrospective study analyzing survival rates according to TNM staging in 2,382 patients who had pulmonary resection for non-small cell lung cancer. Postoperatively, 3 patients were classified in stage 0, 796 in stage I, 304 in stage II, 719 in stage IIIA, 233 in stage IIIB, and 327 in stage IV. The 5-year survival rates for these patients were as follows: stage I, 68.5%; stage II, 46.9%; stage IIIA, 26.1%; stage IIIB, 9.0%; and stage IV, 11.2% (including ipsilateral, intrapulmonary metastases); 5-year survival rates for 140 patients with stage IV disease with intrapulmonary metastases in either the same lobe or another ipsilateral lobe were 17.8% and 8.3%, respectively. There was prognostic significance between stage I and stage II disease, stage II and stage IIIA disease, and stage IIIA and stage IIIB disease, but not between stage IIIB and stage IV disease. Only a few modifications will be required for the TNM staging system, which at present accurately reflects the prognosis of patients with lung cancer and is helpful in determining treatment.

Time trends and survival after surgery for p-stage IIIa, pN2 non-small cell lung cancer (NSCLC)

OBJECTIVE

To evaluate the role of surgery for p-stage IIIa, pN2 non-small cell lung cancer (NSCLC), time trends and survival after surgery and the prognostic factors were investigated retrospectively.

METHODS

Consecutive patients, 155, with p-stage IIIa, pN2 NSCLC who underwent thoracotomy at the Department of Thoracic Surgery, Chest Disease Research Institute, Kyoto University between January 1976 and December 1990 were divided into three groups by the period of operation (the earlier period: 1976-1980, n = 49; the middle period: 1981-1985, n = 55; and the later period: 1986-1990, n = 51), and were reviewed. Of the 155 patients, 84 (54.2%) were preoperatively evaluated to have mediastinal lymph nodes metastases (cN2 disease).

RESULTS

The 5 year survival rates in the earlier, middle and later periods were 12.1, 18.6, and 43.8%, respectively, showing significant improvement in the later period (P < 0.001, for the later period versus the earlier period or the middle period). The improvement was caused by decrease in the rate of operation-related death (4.1, 1.8, and 0.0%, in the earlier, the middle, and the later period, respectively), increase in the rate of complete tumor resection (59.1, 76.4, and 96.1%, respectively), and decrease in the ratio of pT3N2M0 patients (44.9, 34.5, and 17.6%, respectively) having poor prognosis compared with pT1-2N2M0 patients. Decrease in the ratio of cT3N2M0 patients and for increase in the rate of complete resection could be realized by accurate preoperative diagnosis with introduction of chest computed tomography (CT). Based on the preoperative evaluation, the 5 year survival rates of cT1N2M0, cT2N2M0, and cT3N2M0 patients were 39.4, 30.5, and 10.2%, respectively, showing significant poor prognosis in cT3N2M0 patients.

CONCLUSION

In cT1-2N2M0 or pT1-2N2M0 patients, a good prognosis can be realized by complete tumor resection with mediastinal lymph nodes dissection. In contrast, surgical treatment should not be justified in cT3N2M0 or pT3N2M0 patients.

Treatment strategy for patients with surgically discovered N2 stage IIIA non-small cell lung cancer

BACKGROUND

The treatment strategy for patients with non-small cell lung cancer and clinically negative, but surgically detected mediastinal lymph node metastasis (surgically discovered N2 disease) is controversial.

METHODS

From August 1979 through December 1994, 53 patients with non-small cell lung cancer were found to have surgically discovered N2 disease. We retrospectively studied the clinical characteristics and the factors that influenced the prognosis in these patients.

RESULTS

The 3-year and 5-year survival rates and the median survival for the 53 patients with surgically discovered N2 disease were 44%, 21%, and 26 months. Two thirds of the patients had adenocarcinoma. Only complete resection affected long-term survival; adjuvant therapy had no effect on survival. In regard to lymph node status, a single metastatic focus in the aortic area was associated with long-term survival.

CONCLUSIONS

Patients with adenocarcinoma may require histologic determination of N2 disease. Complete resection, including extensive and complete mediastinal lymph node dissection, is warranted in patients with surgically discovered N2 disease. In particular, when the aortic lymph node (including stations 5 and 6) alone is involved, the patients should undergo as complete a resection as possible.

IIB or not IIB: the current question in staging non-small cell lung cancer

It has been suggested that T3/N0-1/M0 non-small cell lung cancer should be classified as stage IIB rather than IIIA. This is the result of a widespread perception that the survival of patients with T3/N0-1 lung cancers greatly exceeds that of patients with stage IIIA (N2) lung cancers. This perception is based primarily on the survival of T3/N0-1 patients who have chest wall involvement. However, the T3 classification also includes tumors that involve mediastinal structures, the main stem bronchus <2 cm from the carina, and the brachial plexus as seen in Pancoast tumors. Survival for each of these T3 categories is examined in this articles and found to be somewhat different. The available data show that patients with T3/N0-1 tumors involving the chest wall have a good prognosis after resection, whereas patients with central T3/N0-1 tumors (mediastinal or main stem bronchial involvement) have a prognosis similar to that of patients with resected IIIA (N2) tumors. If a new classification of T3/N0-1 tumors as stage IIB is to be adopted, it will be important for future studies to document which type of T3 tumor is being discussed.

The limits of surgical resection alone for non-small cell lung cancer

Surgical resection remains the best treatment for Stages I and II non-small cell lung cancer. In Stage IIIA disease the use of induction therapy has become widespread, although evidence supporting this approach is still preliminary. However, in subsets of patients with T3 tumours without mediastinal nodal involvement and those with certain single station, non-bulky N2 disease, surgery alone is still the preferred therapy. Studies show survival rates with surgery alone the same or higher than those achieved by most induction therapy regimens.

Mediastinoscopy, thoracoscopy, and video-assisted thoracic surgery in the diagnosis and staging of lung cancer

The surgical approach to the diagnosis and staging of lung cancer requires the assessment of the lung parenchyma, hilum, pleura, chest wall, and intrathoracic lymph nodes. Chest computerized tomography is sensitive in defining the location of the primary tumor, but is relatively insensitive to invasion. Similarly, radiographic imaging can identify lymph node enlargement, but lymph node enlargement alone is insufficient for accurate staging. To facilitate the tissue biopsies of both the primary tumor and potential sites of metastatic disease, video thoracoscopy has provided a useful complement to traditional bronchoscopy and mediastinoscopy. These instruments provide minimally invasive access to the lung, pleura, and ipsilateral lymph nodes. The combined application of thoracoscopy, bronchoscopy, and mediastinoscopy can provide intrathoracic staging information while minimizing surgical morbidity.

The multimodality treatment of stage III A/B non-small cell lung cancer. The role of surgery, radiation, and chemotherapy

The optimal management of stage III a/b non-small cell lung cancer is rapidly evolving. Depending on the stage of the disease, the modalities of surgical resection, chemotherapy, and radiation therapy may be used alone or in combination. This article reviews current management recommendations.

Mediastinal lymph node metastasis in patients with clinical stage I peripheral non-small-cell lung cancer

Our aim in this study was to determine the mediastinal areas where lymphadenectomy should be done at the time of surgical resection of clinical stage I lung cancer. Between 1984 and 1994, 575 patients with clinical stage I non-small-cell lung cancer underwent lobectomy and systematic mediastinal lymphadenectomy. Mediastinal lymph nodes were pathologically positive for disease in 79 patients (14%), and positive nodes appeared normal intraoperatively in 54 patients (68%). Thirty-three percent of those patients with positive N2 (mediastinal) nodes had negative lobar (N1) nodes. In cancer of the right upper lobe, all N2 cases had the lymph node metastases in the superior mediastinal compartment. In cancer of the right middle lobe, all N2 cases but one had the metastases in subcarinal or anterior mediastinal nodes. In cancer of the right lower lobe, all N2 cases but one the metastases in subcarinal nodes. In cancer of the left upper lobe, all N2 cases had the lymph node metastases in the subaortic compartment. In cancer of the left lower lobe, all N2 cases but one had the lymph node metastases in the subcarinal area or subaortic compartment. In conclusion, systematic staging of mediastinal lymph nodes is necessary for all patients with resectable clinical stage I lung cancer. The location of the primary tumor determines the mediastinal areas where lymphadenectomy should be done to examine all lymph nodes.

Skip metastasis to the mediastinal lymph nodes in non-small cell lung cancer

BACKGROUND

Whether any difference exists in clinical characteristics between resected non-small cell lung cancer with either skip or ordinary mediastinal lymph node metastases (N2 disease) needs to be clarified.

METHODS

There were 110 patients with stage IIIA N2 disease. Thirty-three patients demonstrating no metastasis at the hilar nodes [skip (+) group] were compared with the other 77 patients [skip (-) group]. To investigate the extent of nodal involvement, we classified the mediastinal lymph nodes into three regions (superior, inferior, or aortic).

RESULTS

There were no significant differences regarding histologic type, T status, or the site of the primary tumors between the skip (+) and the skip (-) N2 groups. In the skip (+) group, mediastinal node metastasis was found in only one region (level 1) in 30 patients (90.9%) and in two regions (level 2) in 3 (9.1%), whereas 28 patients (36.4%) from the skip (-) group revealed mediastinal metastasis at two or three regions (level 2 or 3). The overall survival rate at 5 years after operation was 35% in the skip (+) group and 12.7% in the skip (-) group (p = 0.054). This favorable clinical outcome in the skip (+) group could be explained partially by the higher proportion of patients with level 1 metastases. Furthermore, regarding patients with level 1 disease, the skip (+) group tended to have a better prognosis than the skip (-) group (p = 0.096).

CONCLUSIONS

These results suggest that patients with skip mediastinal lymph node metastases represent a unique subgroup of N2 disease.

Mode of spread in the early phase of lymphatic metastasis in non-small-cell lung cancer: significance of nodal micrometastasis

The impact of lymphatic micrometastases on prognosis of non-small-cell lung cancer has not been clearly established. We therefore prospectively assessed the frequency, mode of mediastinal spread, and prognostic significance of lymphatic micrometastases in lymph nodes of 93 patients with completely resected non-small-cell lung cancer staged as pT1 to pT4 pN0 and pN1 by conventional histopathologic techniques. Frozen tissue sections from 471 lymph nodes that were staged as free of metastases by routine histopathologic examination were screened for micrometastases by the alkaline phosphatase-antialkaline phosphatase immunostaining technique with the monoclonal antibody Ber-Ep-4. Twenty of 73 patients (27.4%) with disease staged as pN0 and nine of 20 patients (45.0%) with disease staged as pN1 had nodal micrometastases. Eight of 17 patients with upper lobe primary tumors and five of 12 patients with lower lobe primary tumors exhibited skip micrometastases. Mean relapse-free survival was significantly increased in patients with pN0 disease without micrometastases (41.1 vs 29 months, p = 0.0081). In patients with pN1 disease, mean relapse-free and cancer-related survivals were also significantly increased if no micrometastases were found (34.8 and 38.2 months vs 18 and 23.5 months, p = 0.0157 and p = 0.0094). Patients with disease staged as pN0 and pN1 with micrometastases revealed no difference in cancer-related survival compared with a control population of patients with disease staged as pN2. The mode of spread was erratic. The prognosis of patients after upstaging of pN0 and pN1 disease according to results of immunohistochemical staining correlated strongly with the prognosis of patients whose disease was staged at the higher stages by conventional histopathologic examination. These findings could represent a new indication for adjuvant therapy, supporting extensive lymph node sampling for staging purposes.

Lymph node involvement, recurrence, and prognosis in resected small, peripheral, non-small-cell lung carcinomas: are these carcinomas candidates for video-assisted lobectomy?

To determine the clinicopathologic characteristics of peripheral non-small-cell carcinomas, the cases of 337 patients undergoing major pulmonary resection with complete lymphadenectomy were retrospectively reviewed with regard to lymph node involvement, recurrence, and prognosis. All of the tumors were 3.0 cm or less in diameter and were categorized as T1 (318 patients) or T2 (19). Eighty-eight patients (26.1%) had lymph node involvement: 32 (9.5%) at N1 nodes, 55 (16.3%) at N2 nodes, and 1 (0.3%) at N3 nodes. Although the prevalence of lymph node involvement did not differ significantly with tumor histologic type, it was quite low in squamous cell carcinomas 2.0 cm or less in diameter. Of the 56 N2/3 metastases, 14 (25%) occurred in a "skipping" manner, and all but one had a nonsquamous histologic makeup. Of the 213 patients with a follow-up period of 5 years or more, 59 patients (27.7%) showed cancer recurrence. This occurred at a distant site in 67.8% of the cases. Five-year survival rates based on nodal status were 91.9% (NO), 61.8% (N1), 44.5% (N2), and 0% (N3). Because of the relatively high prevalence of lymph node involvement, complete hilar/mediastinal lymphadenectomy should be routinely done regardless of tumor histologic type and size, as long as patients are at good risk. However, in squamous cell histologic types, mediastinal lymphadenectomy might be dispensable if the tumor is less than 2.0 cm in diameter, or if the hilar node is proved to be tumor-free on pathologic examination of the frozen section during operation. Although video-assisted major pulmonary resection currently has limited application, this new technique may represent a surgical option in resection without complete lymphadenectomy.