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

An accurate prediction of negative lymph node metastasis with consideration of glucose metabolism in early-stage non-small cell lung cancer

OBJECTIVE

We aimed to identify risk factors in lymph node metastasis in early-stage non-small cell lung cancer (NSCLC) and predict lymph node metastasis.

METHODS

A total of 416 patients with clinical stage IA2-3 NSCLC who underwent lobectomy and lymph node dissection between July 2016 and December 2020 at National Cancer Center Hospital East were included. Multivariable logistic regression was performed to develop a model for predicting lymph node metastasis. Leave-one-out cross-validation was performed to evaluate the developing prediction model, and sensitivity, specificity, and concordance statistics were calculated to evaluate its diagnostic performance.

RESULTS

The formula for calculating the probability of pathological lymph node metastasis included SUVmax of the primary tumor and serum CEA level. The concordance statistics was 0.7452. When the cutoff value associated with the risk of incorrectly predicting pathological lymph node metastasis was 7.2%, the diagnostic sensitivity and specificity for predicting metastasis were 96.4% and 38.6%, respectively.

CONCLUSIONS

We created a prediction model for lymph node metastasis in NSCLC by combining the SUVmax of the primary tumor and serum CEA levels, which showed a particularly strong association. This model is clinically useful as it successfully predicts negative lymph node metastasis in patients with clinical stage IA2-3 NSCLC.

Location of stage I-III non-small cell lung cancer and survival rate: Systematic review and meta-analysis

BACKGROUND

The association between the location of non-small cell lung cancer (NSCLC) and prognosis is a debated issue. Some studies have provided evidence of better prognosis of upper lobe tumors than lower to middle lobe tumors, while other studies have reported contrasting conclusions. The aim of this study was to further assess this association through a systematic review and meta-analysis.

METHODS

Medline, Embase, and the Cochrane Central Register of Controlled Trials were searched up to 27 January 2017. Patients pathologically diagnosed with stage I-III NSCLC with three or five-year survival data were included. The main meta-analysis compared differences in survival rates according to the primary tumor location using the Mantel-Haenszel method with a random effect model. Sensitivity analysis was conducted according to lymph node metastasis, tumor node metastasis stage, staging method, and treatment modality.

RESULTS

Ten clinical studies and 35 570 patients were recruited. Patients with tumors in the upper lobes had a higher rate of five-year survival compared to those with tumors in non-upper lobes (odds ratio [OR] 1.31, 95% confidence interval [CI] 1.15-1.49). Similarly, the three-year survival rate was high in patients with tumors in the upper lobes (OR 1.99, 95% CI 1.02-3.86) and low in those with lower lobe tumors (OR 0.31, 95% CI 0.12-0.77).

CONCLUSIONS

Stage I-III NSCLC located in the upper lobes showed higher five-year survival rates compared to other tumor locations.

Intraoperative fluorescence imaging in thoracic surgery

Intraoperative fluorescence imaging (IFI) can improve real-time identification of cancer cells during an operation. Phase I clinical trials in thoracic surgery have demonstrated that IFI with second window indocyanine green (TumorGlow^® ) can identify subcentimeter pulmonary nodules, anterior mediastinal masses, and mesothelioma, while the use of a folate receptor-targeted near-infrared agent, OTL38, can improve the specificity for diagnosing tumors with folate receptor expression. Here, we review the existing preclinical and clinical data on IFI in thoracic surgery.

Value of Wedge Resection for Lung Cancer in Poor Cardiopulmonary Status Patients

The strategic management of primary lung cancer in patients with poor cardiopulmonary status is still controversial. The aim of this study was to ascertain the early and late results of wide-margin wedge resection with curative intent in this group of patients. Between January 1995 and January 2002, 24 patients (13 males; mean age, 69.96 years) with baseline poor cardiopulmonary status underwent wide-margin wedge resection of preoperatively diagnosed primary lung cancer. All patients suffered from chronic obstructive pulmonary disease and 9 (37.5%) also had symptomatic ischemic heart disease. Eight patients were in New York Heart Association class III and 12 were in class IV. There were no post-operative deaths. Complications included chest infection in 3, surgical emphysema with prolonged air leak in 1, and atrial fibrillation in 6. Overall 7-year survival was 23.3%. Three patients with ischemic heart disease suffered late non-cancer-related death due to myocardial infarction at 48, 60, and 60 months postoperatively. Cancer-free 5-year survival was 54.3%, with 7/24 (29%) late recurrences. Our study suggests that wide-margin wedge resection is a valuable surgical option for primary lung cancer in patients with poor cardiopulmonary status.

F-18-FDG-avid lymph node metastasis along preferential lymphatic drainage pathways from the tumor-bearing lung lobe on F-18-FDG PET/CT in patients with non-small-cell lung cancer

OBJECTIVE

F-18-FDG-avid lymph node (LN) metastasis may preferentially occur along the lymphatic drainage pathway (LDP) from the tumor-bearing lobe in patients with non-small cell lung cancer (NSCLC) on FDG PET/CT. This study evaluated whether the identification of metastatic LNs according to LDP-based visual image interpretation can improve LN staging on FDG PET/CT in these patients.

METHODS

FDG PET/CT study was performed in 265 patients with NSCLC. The presence and LN station of metastatic LNs were determined by surgery or the clinical course. In the LDP-based interpretation, FDG-avid LNs, which were located along the preferential LDP from each tumor-bearing lobe and visually more intense in FDG uptake compared with the remaining LNs straying away from the preferential LDP, were diagnosed as metastatic. The result was compared with the quantitative method using a cutoff value of 2.5 for the maximum standardized uptake value.

RESULTS

Of the total 1031 mediastinal and hilar LN stations with FDG-avid LNs in 265 patients, 179 stations in 66 patients were metastatic and the remaining 852 were benign. All the metastatic LN stations except for 2 stations showing skip metastasis were located along the main preferential LDP or another preferential LDP via a direct anatomic pathway from each tumor-bearing lung lobe. The specificity, accuracy, and PPV for identifying metastatic LN stations by LDP-based interpretation were 97.9, 95.7 and 89.5 %, respectively, which were significantly greater compared with those of 92.7, 90.8 and 70.3 % by the SUV-based method (P < 0.001).

CONCLUSIONS

The present study shows that FDG-avid LN metastasis preferentially occurs along the LDP from the tumor-bearing lobe in NSCLC patients. LDP-based visual image interpretation on FDG PET/CT can improve LN staging in these patients.

Resectable left lower lobe non-small cell lung cancer with lymph node metastasis is related to unfavorable outcomes

Background

Despite numerous previous studies, the consideration of tumor location as a prognostic factor in resectable non–small cell lung cancer (NSCLC) remains controversial. The present study analyzed the association between tumor location and clinical outcome in patients with resectable NSCLC who had undergone lobectomy with systematic lymphadenectomy and who had presented with varying nodal statuses.

Methods

The data from a cohort of 627 eligible patients treated in Sun Yat-sen University Cancer Center between January 2000 and December 2008 were retrospectively collected, and the nodal statuses of patients with different tumor locations were compared. Cox proportional hazards regression model was used to determine the independent factors related to cancer-specific survival (CSS).

Results

Multivariate analysis demonstrated that left lower lobe (LLL) tumors [hazard ratio (HR): 1.465, 95% confidence interval (CI) 1.090–1.969, P = 0.011], lymph node metastasis (HR: 2.742, 95% CI 2.145–3.507, P < 0.001), and a tumor size of >4 cm (HR: 1.474, 95% CI 1.151–1.888, P = 0.002) were three independent prognosticators in patients with resectable NSCLC. However, LLL tumors were associated only with CSS in node-positive patients (HR: 1.528, 95% CI 1.015–2.301, P = 0.042), and a tumor size of >4 cm was the only independent risk predictor in the node-negative subgroup (HR: 1.889, 95% CI 1.324–2.696, P < 0.001).

Conclusions

Tumor location is related to the long-term CSS of NSCLC patients with lymph node metastasis. LLL tumors may be upstaged in node-positive patients to facilitate an optimal treatment strategy.

Long-term outcomes after lobectomy for non-small cell lung cancer when unsuspected pN2 disease is found: A National Cancer Data Base analysis

OBJECTIVE

There are few studies evaluating whether to proceed with planned resection when a patient with non-small cell lung cancer (NSCLC) unexpectedly is found to have N2 disease at the time of thoracoscopy or thoracotomy. To help guide management of this clinical scenario, we evaluated outcomes for patients who were upstaged to pN2 after lobectomy without induction therapy using the National Cancer Data Base (NCDB).

METHODS

Survival of NSCLC patients treated with lobectomy for clinically unsuspected mediastinal nodal disease (cT1-cT3 cN0-cN1, pN2 disease) from 1998-2006 in the NCDB was compared with "suspected" N2 disease patients (cT1-cT3 cN2) who were treated with chemotherapy with or without radiation followed by lobectomy, using matched analysis based on propensity scores.

RESULTS

Unsuspected pN2 disease was found in 4.4% of patients (2047 out of 46,691) who underwent lobectomy as primary therapy for cT1-cT3 cN0-cN1 NSCLC. The 5-year survival was 42%, 36%, 21%, and 28% for patients who underwent adjuvant chemotherapy (n = 385), chemoradiation (n = 504), radiation (n = 300), and no adjuvant therapy (n = 858), respectively. Five-year survival of the entire unsuspected pN2 cohort was worse than survival of 2302 patients who were treated with lobectomy after induction therapy for clinical N2 disease (30% vs 40%; P < .001), although no significant difference in 5-year survival was found in a matched-analysis of 655 patients from each group (37% vs 37%; P = .95).

CONCLUSIONS

This population-based analysis suggests that, in the setting of unsuspected pN2 NSCLC, proceeding with lobectomy does not appear to compromise outcomes if adjuvant chemotherapy with or without radiation therapy can be administered following surgery.

State of the art in surgery for early stage NSCLC-does the number of resected lymph nodes matter?

Surgery is the treatment of choice in patients with early stage NSCLC. However, the results remain poor in these patients. Lymph node involvement is the main prognostic factor in patients with NSCLC, but there is still no clear definition of the number of nodes required to consider a lymphadenectomy as complete. Although there is no defined minimum number of lymph nodes required for a complete lymphadenectomy, there are some recommendations to perform this procedure, published by different scientific societies. Current practice in thoracic surgery regarding lymphadenectomy, differs on some points from the guidelines recommendations, with data regarding patients with no mediastinal assessment between 30-45% according to some of the published data. Different studies have probed the fact that the probability of finding a positive node increases with the number of lymph nodes analyzed. Therefore, a complete lymphadenectomy provides proper staging, which helps to identify the patient's real prognosis. Several nonrandomized studies and retrospective series have shown that survival increases in the group of patients with a higher number of lymph nodes removed. There is no contraindication to performing a complete lymphadenectomy. The increase in survival in patients with a complete lymphadenectomy may be due to more accurate staging. Therefore, complete lymphadenectomy should be mandatory even in early stage patients.

Risk factors for recurrence after complete resection of pathological stage N2 non-small cell lung cancer

Background

Tumor recurrence is the most common cause of treatment failure, especially after complete resection of pathological stage N2 non-small cell lung cancer (NSCLC). In this study, we investigated the clinicopathological characteristics in order to identify independent risk factors for postoperative recurrence.

Methods

Between January 2001 and December 2013, 96 patients who underwent surgical resection for pathological N2 NSCLC were retrospectively reviewed. Recurrence-free survival (RFS) was calculated by the Kaplan-Meier method to explore risk factors, while the Cox proportional hazard model was used to assess independent predictors.

Results

The median and five-year RFS rates were 15 months and 27.4%, respectively. Univariate analysis showed a significantly poorer prognosis for non-regional N2 metastasis, more than three metastatic N2 lymph nodes, multiple N2 station, and multiple N2 zone involvement. Multivariate analysis demonstrated that non-regional N2 metastasis (hazard ratio [HR] 1.857, 95% confidence interval [CI] 1.061–3.249, P = 0.030) and more than three metastatic N2 lymph nodes (HR 2.555, 95% CI 1.164–5.606, P = 0.019) were independent risk factors for RFS. Additionally, the incidence of non-regional N2 metastasis was higher in patients with a primary tumor in the left lower (57.1%) or right lower lobe (48.1%), followed by left upper (31.8%), right middle (14.3%) and right upper lobe (7.7%).

Conclusion

The combination of the distribution and number of metastatic N2 lymph nodes provides a more accurate prediction for N2 NSCLC regarding recurrence. Non-regional N2 metastasis could occur with a primary tumor in any lobe, but occurs more frequently in the lower lobe.

The clinicopathological features associated with skip N2 metastases in patients with clinical stage IA non-small-cell lung cancer

OBJECTIVES

Understanding the clinicopathological features of patients with skip N2 metastases (SN2) in clinical early stage lung cancer is important for surgical planning and other treatment considerations; however, the factors associated with SN2 are unclear. This study aimed to investigate the clinicopathological features associated with SN2 in patients with clinical stage IA (cIA) non-small-cell lung cancer (NSCLC).

METHODS

We retrospectively studied patients with cIA NSCLC who underwent pulmonary resection (at least lobectomy) and extensive lymphadenectomy (more than ND2a-1) at our institution between January 2004 and December 2010. We investigated the following factors for their association with SN2: age; sex; tumour marker (carcinoembryonic antigen); tumour size on computed tomography (CT), evaluated with a lung-window (LW) and a mediastinal-window (MW) setting; pathology, with or without adenocarcinoma; differentiation; visceral pleural invasion (VPI) and vascular/lymphatic invasion.

RESULTS

In total, 422 patients were enrolled, with the following pathological node (pN) statuses: 331 pN0 (78.4%), 39 pN1 (9.3%) and 52 pN2 (12.3%). There were 21 (23.1%) SN2 cases among the patients with nodal metastases. When the cut-off level was defined as a receiver operating characteristic curve with MW (11.5 mm), the sensitivity and specificity of SN2 was 95.2% and 42.9%, respectively. VPI was a statistically independent relevant factor for SN2 in both the patients with cIA and in those with nodal involvement. The VPI classification comprised 59 PL-0 (64.8%), 12 PL-1 (13.2%) and 20 PL-2 (22.0%) with nodal metastases, and there was a significant difference between the three groups (P = 0.03) according to SN2 frequency. There was no difference between VPI 1 and 2 (P = 0.27).

CONCLUSIONS

In conclusion, our study suggests that the incidence of SN2 is significantly associated with VPI in patients with cIA NSCLC. Although MW (>11.5 mm) had a low specificity in the assessment of SN2, it had a high sensitivity, suggesting the possibility of a superior benefit compared with LW. Standard hilar and mediastinal lymph node dissection should be required in patients with suspicious VPI and MW (>11.5 mm) on preoperative CT.

Lymph node distribution in the central compartment of the neck: an anatomic study

BACKGROUND

Dissection of the central compartment of the neck (CCN) is performed for proven or suspected lymph node metastases of thyroid carcinoma. During this procedure, the recurrent laryngeal nerves and the parathyroid glands are at risk. The purpose of this study was to determine the anatomic distribution of the lymph nodes in the CCN.

METHODS

The anatomic distribution of the lymph nodes in the CCN was studied by dissection of 30 fresh cadavers. The soft tissue between the cricoid cartilage and the innominate vein, carotid arteries, and prevertebral fascia was removed and divided according to CCN sublevels. Nodules were identified by palpation in the specimen and sent for pathological examination.

RESULTS

Three to 44 (18.5 ± 10.29) nodules were identified macroscopically. Two to 42 nodules were confirmed as lymph nodes after microscopic examination. The lymph node distribution was as follows: precricoid: 0 to 2 (0.9 ± 0.72); pretracheal: 1 of 35 (12.4 ± 8.19); lateral to the right recurrent laryngeal nerve (RLN): 0 to 11 (3.4 ± 2.34); and lateral to the left: 0 to 4 (1.7 ± 1.30). Twenty-six parathyroid glands were removed by 14 dissections. The innominate vein was found at 15 mm above the superior border of the clavicles to 35 mm below on the left side of the neck and 5 to 45 mm on the right side.

CONCLUSION

The number of confirmed lymph nodes in the central neck varied from 2 to 42. Sixty-seven percent of the lymph nodes were in the pretracheal sublevel. There was no division between level VI and VII lymph nodes. Additionally, the innominate vein was found to be from 15 mm above the superior border of the clavicles to 35 mm below on the left side of the neck and 5 to 45 mm on the right side. Parathyroid glands were identified to be far away from the thyroid gland.

Lobe-specific mediastinal nodal dissection is sufficient during lobectomy by video-assisted thoracic surgery or thoracotomy for early-stage lung cancer

BACKGROUND

Lobectomy with complete mediastinal lymphadenectomy is considered standard for patients with early-stage non-small cell lung cancer (NSCLC). However, the benefits of complete lymphadenectomy are unproven. There is evidence suggesting a predictable pattern of mediastinal nodal drainage. This study analyzed the frequency and pattern of mediastinal nodal disease and its impact on outcome in patients with early-stage NSCLC.

METHODS

Patients with clinical N0/N1 NSCLC staged with CT scans and PET scans were identified. Disease involvement of resected nodal stations was recorded. Patterns of recurrence in patients who underwent lobectomy with complete mediastinal systematic lymph node sampling (SLNS) were compared with those who underwent lobe-specific mediastinal SLNS.

RESULTS

From July 2004 to April 2011, 370 patients were identified. Complete SLNS was performed in 282 patients. Fifteen patients (5.3%) in the group with complete SLNS were found to have N2 disease after pathologic evaluation. Patients with left-sided tumors were more likely to have pathologic N2 disease than were patients with right-sided tumors (P = .03). Only one patient (0.36%) had positive N2 disease in the distal mediastinum while skipping lobe-specific mediastinal nodes. In addition, patients with complete SLNS had a rate of recurrence similar to that of the group that had lobe-specific mediastinal evaluation (20.6% vs 18.2%, P = .68).

CONCLUSIONS

Mediastinal N2 metastases follow predictable lobe-specific patterns in patients with negative preoperative CT scans and PET scans. Lobe-specific N2 nodal evaluation results in a recurrence rate similar to that of complete mediastinal evaluation. Lobe-specific mediastinal nodal evaluation appears acceptable in patients with early-stage NSCLC.

Recurrence of mediastinal node cancer after lobe-specific systematic nodal dissection for non-small-cell lung cancer

OBJECTIVES

The standard surgical treatment for patients with non-small-cell lung cancer (NSCLC) is lobectomy with systematic nodal dissection (SND). Lobe-specific patterns of nodal metastases have been recognized, and lobe-specific SND (L-SND) has been reported. We performed L-SND depending on patient-related factors, such as age or the presence of diabetes or respiratory dysfunction, or in the context of specific tumour-related factors, such as the presence of a tumour with a wide area of ground-glass opacity.

METHODS

Between September 2002 and December 2008, 335 consecutive patients with clinical and intraoperative N0 NSCLC underwent curative lobectomies at Shizuoka Cancer Center Hospital. Among these 335 patients, 206 underwent SND (Group A) and 129 underwent L-SND. Of the 129 patients undergoing L-SND, 98 underwent L-SND due to patient-related factors (Group B) and 31 underwent L-SND due to tumour-related factors (Group C).

RESULTS

There were no significant differences in morbidity or blood loss between patients undergoing SND or L-SND, but there was a significant difference in the mean operative times. The 5-year disease-free survival (5-DFS) and 5-year overall survival (5-OS) of patients in Group C were 100%. Although the patients in Group B showed no significant difference in 5-DFS and 5-OS compared with Group A, patients in Group B had significantly more initial recurrence of mediastinal node cancer than did the Group A patients (P = 0.0050).

CONCLUSIONS

The recurrence of mediastinal node cancer in patients undergoing L-SND was significantly greater than that in those undergoing SND.

Mediastinal lymph nodes: ignore? sample? dissect? The role of mediastinal node dissection in the surgical management of primary lung cancer

The role of mediastinal lymph node dissection (MLND) during the resection of non-small-cell lung cancer is still unclear although most surgeons agree that a minimum of hilar and mediastinal nodes must be examined for appropriate pathological staging. Current surgical practices vary from visual inspection of the mediastinum with biopsy of only abnormal looking nodes to systematic mediastinal node sampling which is to the biopsy of lymph nodes from multiple levels whether they appear abnormal or not to MLND which involves the systematic removal of all lymph node bearing tissue from multiple sites unilaterally or bilaterally within the mediastinum. This review article looks at the evidence and arguments in favour of lymphadenectomy, including improved pathological staging, better locoregional control, and ultimately longer disease-free survival and those against which are longer operating time, increased operative morbidity, and lack of evidence for survival benefit.

Nodal involvement pattern in resectable lung cancer according to tumor location

The aim in this study was to define the pattern of lymph node metastasis according to the primary tumor location. In this retrospective cohort study, each of the operable patients diagnosed with lung cancer was grouped by tumor mass location. The International Association for the Study of Lung Cancer nodal chart with stations and zones, established in 2009, was used to define lymph node levels. From 2006 to 2010, 197 patients underwent a lobectomy with systematic nodal resection for primary lung cancer at Chiang Mai University Hospital. There were 123 male and 74 female patients, with ages ranging from 16– 85 years old and an average age of 61.31. Analyses of tumor location, histology type, and nodal metastasis were performed. The locations were the right upper lobe in 63 patients (31.98%), the right middle lobe in 18 patients (9.14%), the right lower lobe in 30 patients (15.23%), the left upper lobe in 55 patients (27.92%), the left lower lobe in 16 patients (8.12%), and mixed lobes (more than one lobe) in 15 patients (7.61%). The mean tumor size was 4.45 cm in diameter (range 1.2–16.5 cm). Adenocarcinoma was the most common histological type, which occurred in 132 cases (67.01%), followed by squamous cell carcinoma in 41 cases (20.81%), bronchiolo alveolar cell carcinoma in nine cases (4.57%), and large cell carcinoma in seven cases (3.55%). Eighteen cases (9.6%) had skip metastasis (mediastinal lymph node metastasis without hilar node metastasis). Adenocarcinoma and intratumoral lymphatic invasion were the predictors of mediastinal lymph node metastases. There were statistically significant differences between a tumor in the right upper lobe and the right lower lobe. However, there were no statistically significant differences between tumors in the other lobes. In conclusion, tumor location is not a precise predictor of the pattern of nodal metastasis. Systematic lymph node dissection is the only way to accurately determine lymph node status. Further studies are required for evaluation and conclusions.

Lung metastases from various malignancies combined with primary lung cancer

Various tumors metastasize to the lung, and they are often detected as multiple nodules. We report on two cases of such multiple lung metastases combined with primary lung cancer: a myxoid liposarcoma in the right thigh and a colon cancer. In each case, a pulmonary metastasectomy revealed that one of the tumors was primary lung cancer. Regardless of recent advances in computed tomography for detecting small pulmonary nodules and ground-glass opacity components, which indicate possible primary lung cancer, the preoperative differential diagnosis for either metastatic or primary lung cancers is usually difficult because they are too small to obtain enough tissue for diagnosis, except by surgery. When nodules are removed and diagnosed as lung metastasis combined with primary lung cancer, additional treatment should be considered depending on the prognosis of each disease.

18F-FDG PET/CT in mediastinal lymph node staging of non-small-cell lung cancer in a tuberculosis-endemic country: consideration of lymph node calcification and distribution pattern to improve specificity

PURPOSE

The aim of the study was to assess the accuracy of (18)F-fluorodeoxyglucose (FDG) PET/CT in mediastinal lymph node staging of patients with non-small-cell lung cancer (NSCLC) in a region with a high prevalence of granulomatous disease.

METHODS

Between March 2004 and February 2006, all patients with NSCLC underwent FDG PET/CT and contrast-enhanced thoracic CT, and subsequent surgical resection. PET/CT and contrast-enhanced CT images of 182 patients (126 men and 56 women; mean age 60.7 years) with NSCLC were acquired. Mediastinal node staging was determined using the American Joint Committee on Cancer (AJCC) staging system. Surgical and histological findings served as the reference standard.

RESULTS

A total of 182 patients with 778 mediastinal node stations were evaluated. Sensitivity and specificity of contrast-enhanced CT were 36% and 80% on a per-patient basis and 23% and 92% on a per-node station basis. Sensitivity and specificity of PET/CT were 81% and 73% on a per-patient basis and 75% and 85% on a per-node station basis. After lymph nodes with calcification and bilateral hilar distribution were considered benign, sensitivity and specificity of PET/CT were 75% and 89% on a per-patient basis and 66% and 96% on a per-node station basis.

CONCLUSION

This prospective study suggests that FDG PET/CT can more accurately stage mediastinal lymph nodes than CT. Considering lymph node calcification and distribution pattern could improve specificity at the cost of a decrease in sensitivity.

The significance of one-station N2 disease in the prognosis of patients with nonsmall-cell lung cancer

BACKGROUND

A retrospective study was conducted to define the characteristics and the prognosis of N2 disease subgroups according to their patterns of spread.

METHODS

From January 1993 to December 2004, 1,329 patients underwent lung resection for bronchogenic carcinoma The records of all patients with positive mediastinal lymph nodes at the surgical specimen (pIIIA/N2) after radical resection were analyzed, and the pattern of mediastinal lymphatic spread was classified according to regional spread, to skip metastasis, and to one or two or more lymph node stations, in relation to primary tumor location. Age, sex, type of resection, right or left lesion, T status, primary tumor location, tumor size, tumor central or peripheral location, histology, and survival were recorded and analyzed. Survival was analyzed according to regional spread or not, number of mediastinal lymph node stations involved, and skip metastasis status.

RESULTS

Among 302 cases (22.7%) with positive mediastinal lymph nodes pIIIA/N2, 66 (22%) were skip metastases, 72 (24%) had a nonregional mode of spread, and 199 (66%) included two or more stations of mediastinal lymph node invasion. Cox regression analysis of all cases disclosed malignant invasion in only one mediastinal lymph node station as the only favorable factor of survival (p < 0.001, odds ratio 0.57, 95% confidence interval: 0.42 to 0.78).

CONCLUSIONS

The presence of one-station mediastinal lymph node metastasis in patients with nonsmall-cell lung cancer who underwent major lung resection with complete mediastinal lymph node dissection proved to be a good prognostic factor that should be taken into account in the future.

Identifying patients with peripheral-type early non-small cell lung cancer (T1N0M0) for whom irradiation of the primary focus alone could lead to successful treatment

We investigated the indication of radiotherapy in operable patients with peripheral-type early non-small cell lung cancer (T1N0M0 (TNM staging in 1997)). The subjects comprised 396 patients with non-small cell lung cancer in whom the clinical stage was evaluated as IA. We examined age, gender, Brinkmann's index, histopathological type, the grade of histopathological differentiation, tumour diameter and the level of carcinoembryonic antigen as factors involved in lymph node metastasis. Lymph node metastasis was detected in 79 patients (20%). Factors such as the grade of histopathological differentiation and tumour diameter were involved in lymph node metastasis. In well-differentiated lesions, the probability of metastasis was <10% even when the tumour diameter exceeded 2 cm. However, the probability rapidly increased with tumour size in moderately and poorly differentiated lesions. Among the patients with peripheral-type early non-small cell lung cancer (T1N0M0), the risk of lymph node metastasis was low in those with well-differentiated carcinoma and those with moderately differentiated lesions measuring </=1.5 cm in diameter. The proportion of our patients fitting these criteria was approximately 30%. For these patients, stereotactic body radiotherapy and particle therapy may be indicated.

Mediastinal lymphatic drainage from pulmonary lobe based on CT observations of histoplasmosis: implications for minimal N2 disease of non-small-cell lung cancer

PURPOSE

The aim of this study was to assess mediastinal lymphatic drainage patterns from each pulmonary lobe using computed tomographic (CT) observations of calcified primary complex pulmonary histoplasmosis.

MATERIALS AND METHODS

We assessed 400 CT studies of patients with primary complex histoplasmosis consisting of a single lobe pulmonary lesion and mediastinal nodal disease. We assessed the distribution of mediastinal nodal involvement depending on pulmonary lobes for the total number of involved nodes, the number with single-station involvement (which suggests the initial site of involvement), and the number with skip involvement which suggests direct drainage to the mediastinum.

RESULTS

The most commonly involved mediastinal nodal stations from the right upper lobe, left upper lobe, and left lower lobe were the right lower paratracheal node (97%, 74/76), the subaortic node (72%, 49/68), and the left pulmonary ligament node (61%, 66/108), respectively. These nodes were the most common site of skip involvement in each lobe. In the right lower lobe and middle lobe, the subcarinal node was most commonly involved: 62% (65/105) and 81% (35/43), respectively. By contrast, skip involvement was uncommon in the drainage to this node.

CONCLUSION

Our data show a predictable pattern of lobar lymphatic drainage to the mediastinum. This may have implications on the minimal N2 disease of non-small-cell lung cancer.

Factors involved in lymph node metastasis in clinical stage I non-small cell lung cancer—From studies of 604 surgical cases

PURPOSE

To identify the factors involved in lymph node metastasis, 604 clinical stage I non-small cell lung cancer cases were studied.

MATERIALS AND METHODS

Age, sex, Brinkmann Index (BI), histopathological type, histopathological differentiation degree, tumor size and CEA value were studied as factors involved in lymph node metastasis for 604 cases that were diagnosed to be clinical stage I (T1-T2N0M0; 1997 TNM categorization) non-small cell lung cancer.

RESULTS

Lymph node metastasis was observed in 161 cases (27%). The factors involved in lymph node metastasis included the degree of histopathological differentiation and the tumor size. While the metastasis rate was less than 10% in well-differentiated cancers (even when the tumor size exceeded 4cm), in moderately differentiated and poorly differentiated cancers, the lymph node metastasis rate increased in proportion to tumor size.

CONCLUSION

In stage I non-small cell lung cancer cases, cases with a low probability of lymph node metastasis are well-differentiated cancers. In these cases, lymph node dissection may be omitted in surgery (reduction surgery), and such cases may thus be good subjects for undergoing either stereotactic body radiotherapy (SBRT) or particle therapy.

The IASLC Lung Cancer Staging Project: Proposals for the Revision of the N Descriptors in the Forthcoming Seventh Edition of the TNM Classification for Lung Cancer

INTRODUCTION

Accurate staging of lymph node involvement is a critical aspect of the initial management of nonmetastatic non-small cell lung cancer (NSCLC). We sought to determine whether the current N descriptors should be maintained or revised for the next edition of the international lung cancer staging system.

METHODS

A retrospective international lung cancer database was developed and analyzed. Anatomical location of lymph node involvement was defined by the Naruke (for Japanese data) and American Thoracic Society (for non-Japanese data) nodal maps. Survival was calculated by the Kaplan-Meier method, and prognostic groups were assessed by Cox regression analysis.

RESULTS

Current N0 to N3 descriptors defined distinct prognostic groups for both clinical and pathologic staging. Exploratory analyses indicated that lymph node stations could be grouped together into six "zones": peripheral or hilar for N1, and upper or lower mediastinal, aortopulmonary, and subcarinal for N2 nodes. Among patients undergoing resection without induction therapy, there were three distinct prognostic groups: single-zone N1, multiple-zone N1 or single N2, and multiple-zone N2 disease. Nevertheless, there were insufficient data to determine whether the N descriptors should be subdivided (e.g., N1a, N1b, N2a, N2b).

CONCLUSIONS

Current N descriptors should be maintained in the NSCLC staging system. Prospective studies are needed to validate amalgamating lymph node stations into zones and subdividing N descriptors.

Three-dimensional conformal radiation may deliver considerable dose of incidental nodal irradiation in patients with early stage node-negative non-small cell lung cancer when the tumor is large and centrally located

BACKGROUND AND PURPOSE

To determine the dose to regional nodal stations in patients with T1-3N0M0 non-small cell lung cancer (NSCLC) treated with three-dimensional conformal radiation therapy (3DCRT) without intentional elective nodal irradiation (ENI).

MATERIALS AND METHODS

Twenty-three patients with medically inoperable T1-3N0M0 NSCLC were treated with 3DCRT without ENI. Hilar and mediastinal nodal regions were contoured on planning CT. The prescription dose was normalized to 70 Gy. Equivalent uniform dose (EUD) and other dosimetric parameters (e.g., V40) were calculated for each nodal station.

RESULTS

The median EUD for the whole group ranged from 0.4 to 4.4 Gy for all elective nodal regions. Gross tumor volume (GTV) and the relationship between GTV and hilum were significantly correlated with irradiation dose to ipsilateral hilar nodal regions (P<.05). For patients with GTV>or=30.2 cm3 (diameter approximately 4 cm) and or having any overlap with hilum, the median EUDs were 9.6, 22.6, and 62.9 Gy for ipsilateral lower paratracheal, subcarinal, and ipsilateral hilar regions, respectively. The corresponding median V40 were 32.5%, 39.3%, and 97.6%, respectively.

CONCLUSIONS

Although incidental nodal irradiation dose is low in the whole group, the dose to high-risk nodal regions is considerable in patients with T1-3N0 NSCLC when the primary is large and/or centrally located.

Complete resection via medial sternotomy for non-small cell lung cancer in the right upper lobe

BACKGROUND

Right upper lobectomy with right cervical and bilateral mediastinal lymph node dissection via a median approach was performed for non-small cell lung cancer.

METHODS

From 1995 to 2003, 48 patients aged < or = 70 years underwent resection of cancer in the right upper lobe, including 26 with N0, four with N1 and 18 with N2 disease.

RESULTS

Metastases to the right cervical, highest mediastinal, pretracheal and bilateral tracheobronchial lymph nodes were frequent. There were no operative or hospital deaths. Preoperative accuracy of N-factor diagnosis was only 35.4%. The overall 5-year survival rate was 58.8%. The rate for C-N2 disease (n = 18) was 42.6%, and the rate for p-N2 disease (n = 7) and p-N3 disease (n = 13) was 57.1% and 0%, respectively, using the Kaplan-Meier method.

CONCLUSIONS

Patients without N3 disease have a good prognosis, and extended and systematic radical lymphadenectomy via median sternotomy improves the staging, and possibly the prognosis of pure N2 disease.

[Non-small cell bronchogenic cancer in stage IA: mortality patterns after surgery]

OBJECTIVE

To determine the causes of death in patients treated surgically for nonsmall cell lung cancer (NSCLC) in stage IA and to evaluate the impact on survival of not performing systematic lymph node dissection and of the number of nodes resected.

PATIENTS AND METHODS

The study sample consisted of 156 patients operated on for NSCLC and classified in stage IA according to TNM staging. Only palpable or visible lymph nodes were dissected. Kaplan-Meier survival curves were compared using a log-rank test.

RESULTS

At the end of the study, 85 (54.5%) patients had died, 67 (42.9%) were alive, and 4 (2.5%) were lost to follow up. Twenty-three (14.7%) died from a recurrence of NSCLC: 2 with local tumors (1.2%), 2 with mediastinal node involvement (1.2%), and 19 (12.1%) with distant metastasis. The cause of death was unrelated to NSCLC in 62 (39.7%) cases: 33 (21.1%) had a new tumor, 18 of which were bronchogenic, and 29 (18.5%) had nonmalignant disease. The 5-year survival rate was 81.4%. The rate was 88.9% among patients from whom no lymph nodes were excised and 79.9% among those with node excision, although the difference was not statistically significant (P=.4073).

CONCLUSIONS

Our experience suggests that neither the fact of not performing systematic lymph node dissection nor the number of nodes resected has an impact on survival. A substantial number of patients died of causes unrelated to the NSCLC for which they had been treated.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Patterns of lymphadenopathy in thoracic malignancies

There are different lymphatic drainage pathways in the thorax that are relevant in the staging of lung cancer, breast cancer, lymphoma, esophageal cancer, and malignant mesothelioma. To properly search for metastatic spread, it is important to carefully evaluate the specific nodal stations that drain the thoracic structures from which a primary tumor originates. Because size criteria have limitations in the prediction of nodal status, pathologic confirmation is essential for accurate staging. Computed tomography (CT) is useful in helping the surgeon or interventional radiologist determine the most appropriate approach for nodal sampling. Fluorine-18 fluorodeoxyglucose (FDG) positron emission tomography (PET) has an increasing role in detection of diseased lymph nodes that appear normal at CT alone, particularly when FDG PET images are fused with CT images. However, the role of radiologic imaging extends beyond initial staging and the guidance of interventions to include posttreatment assessment and the detection of recurrent disease. Therefore, at all levels of cancer imaging, it is essential to identify the relevant lymph node regions and their relations to the primary tumor.

Skip metastasis in nonsmall cell lung carcinoma

BACKGROUND

Skip metastasis to mediastinal lymph nodes is a prognostic factor for patients with nonsmall cell lung carcinoma (NSCLC). Little is known about the biologic behavior of tumors with noncontinuous spread to the mediastinal lymph nodes. In patients with pN2 skip metastases, micrometastases to N1 lymph nodes, which only mimic skip metastases, have not been investigated.

METHODS

In a retrospective study, the authors analyzed the primary tumor specimens from 45 patients with pN2 NSCLC (18 patients had squamous cell carcinomas, 23 had adenocarcinomas, and 4 had large cell carcinomas). They immunohistochemically evaluated the expression of p21, p53, MUC-1, Bcl-2, c-ErbB-2, and E-cadherin. Survival rates and biomarker expression levels were compared between patients with pN2 disease and infiltration of N1 lymph nodes (without skip metastasis [n = 28]) and patients with pN2 disease without N1 infiltration (with skip metastasis [n = 17]). To evaluate micrometastasis in the pN1 lymph nodes of 17 patients with skip metastases, lymph nodes were stained using the anticytokeratin antibody, AE1/AE3.

RESULTS

The 5-year survival rate of patients with skip metastases was 41%, compared with 14% for patients without skip metastases (P = 0.019). In a multivariate analysis, the incidence of skip metastases did not vary significantly according to gender, age, histology, pT status, or cM status. Three skip-positive patients (17.6%) had micrometastatic tumor involvement of pN1 lymph nodes. After adding these patients to the group of patients without skip metastases, there was still a significant difference in survival between the two groups. p53, MUC-1, c-ErbB-2, and E-cadherin expression levels in primary tumor specimens were not significantly different in patients with continuous metastasis and patients with skip metastases. Patients with skip metastases expressed lower levels of p21 (P = 0.026), whereas Bcl-2 expression levels were considerably higher (P = 0.019) compared with the corresponding levels in patients without skip metastases.

CONCLUSIONS

Patients with NSCLC and pN2 skip metastases have a more favorable prognosis than do patients with pN2 disease without skip metastases. Tumor specimens from these patients exhibit elevated expression of the antiapoptosis gene BCL2 and lower expression levels of p21 relative to patients with pN2 disease without skip metastases. Micrometastases occurred in 3 of 17 (17.6%) patients with pN2 disease and skip metastases diagnosed by routine histopathology.

Optimal management when unsuspected N2 nodal disease is identified during thoracotomy for lung cancer: cost-effectiveness analysis

OBJECTIVES

Whether to proceed with lung resection when N2 nodal disease is identified at the time of thoracotomy for lung cancer is controversial. A decision analysis model was developed to address this question.

METHODS

A meta-analysis was performed on data from reports published between 1990 and 2002 evaluating survival for (1) patients who were treated by initial resection for clinically unsuspected N2 nodal disease (initial resection) and (2) survival for patients undergoing resection after neoadjuvant therapy for N2 nodal disease (no initial resection). Hospital cost data for surgery were derived from our institution, and cost data for chemotherapy and radiation therapy were obtained from current literature. A decision model was developed to compare initial resection to no initial resection from the perspective of the medical center using survival, quality-adjusted life years survival, and cost-effectiveness as outcomes.

RESULTS

The no initial resection option provided better median survival (2.1 versus 1.7 years), quality-adjusted life years (1.8 versus 1.3), and cost-effectiveness, with an incremental cost-effectiveness ratio of 17,119 dollars/quality-adjusted life year. Outcomes were influenced by survival estimates for each treatment option.

CONCLUSIONS

When N2 nodal disease is discovered during thoracotomy, the approach of delaying resection until after neoadjuvant therapy provides the best survival and is more cost-effective. This is likely due to the beneficial effects of neoadjuvant therapy and the exclusion of patients with more aggressive disease from the surgical candidate pool.

Large coalescent parenchymal nodules in pulmonary sarcoidosis: "sarcoid galaxy" sign

OBJECTIVE

The purpose of this study was to evaluate the large parenchymal nodules in pulmonary sarcoidosis and to describe a new CT sign termed the "sarcoid galaxy."

CONCLUSION

The CT appearance of pulmonary sarcoidosis suggests that the large nodules arise from a coalescence of small nodules. The large nodules are surrounded by many tiny satellite nodules. These findings were considered to simulate the appearance of a galaxy. This observation was supported by radiologic-pathologic correlation. The sarcoid galaxy sign may be a useful adjunct in the diagnosis of pulmonary sarcoidosis.

Interlobar lymph node metastases according to primary tumor location in lung cancer

Interlobar lymph node metastases were analyzed in consecutive 284 lung cancer patients with lobar-hilar and mediastinal lymph node dissection. Interlobar lymph node metastases were observed in 46 (16.2%) patients with no difference between right and left cases. On the right side, there was a significant difference in the frequency of inferior interlobar lymph node metastases between upper lobe and middle/lower lobe tumors (P=0.0004), but no difference in the frequencies of superior ones according to primary site. On the left, there was a significant difference in the frequency of interlobar lymph node metastases between upper lobe and lower lobe tumors (P=0.0021). In per-segment analyses, the frequency of inferior interlobar lymph node metastases in segments 1-3 and 6 was significantly lower than in the other total segments (P<0.0001) on the right, and that of interlobar lymph node metastases in the upper division segments (S1-3) was significantly lower than in the other total segments (P=0.0008) on the left. Even limited to one lobe, the patterns of interlobar lymph node metastases were different among the segments in the right lower lobe and the left upper lobe.

Analysis of lobar lymph node metastases around the bronchi of primary and nonprimary lobes in lung cancer: risk of remnant tumor at the root of the nonprimary lobes

STUDY OBJECTIVE

The details of lobar lymph node metastases at the root of nonprimary lobes (NPLs) in patients with lung cancer are still unclear.

DESIGN

A prospective study from February 1989 to November 2000. Lobar lymph nodes in primary lobes (PLs) and NPLs were evaluated regardless of the location of the primary tumor.

PATIENTS

Two hundred forty-eight patients who underwent surgery and had no involvement of the adjacent lobe by primary tumor were enrolled in this study.

MEASUREMENTS AND RESULTS

Lobar lymph node metastases were observed in 53 patients (21.4%), with frequencies not different among the primary sites. Thirty-seven patients had lobar lymph node metastases limited to the PL, and 16 patients had metastases in the NPLs. The frequencies of lobar lymph node metastases in NPLs were not affected by histologic type or T classification, but they were dependent on laterality and proximal lymph node metastases. On the right side, lobar lymph node metastases in NPLs were observed in 9.0% of all 155 patients, in 45.2% of 31 patients with lobar lymph node metastases, and in 34.3% of 35 patients with mediastinal lymph node metastases. They were significantly higher in the patients with interlobar/hilar lymph node metastases (12 of 28 patients) or with mediastinal metastases (12 of 35 patients) than in those without metastases on the right (p < 0.0001, respectively).

CONCLUSIONS

Lobar lymph node metastases in NPLs were frequent on the right side and became more frequent according to the prevalence of the proximal lymph node metastases, rather than the clinicopathologic properties of the primary tumor itself.

Completely resected stage IIIA non-small cell lung cancer: the significance of primary tumor location and N2 station

BACKGROUND

The number of N2 stations (single vs multiple N2 stations) is an important prognostic factor in patients with completely resected stage IIIA-N2 non-small cell lung cancer. However, the significance of both the N2 station(s) actually involved and the primary tumor location remains unclear.

METHODS

The database was built with the use of a questionnaire survey on the survival of patients with pathologic stage IIIA-N2 non-small cell lung cancer completely resected between January 1992 and December 1993. The survey was performed by the Japan Clinical Oncology Group as of July 1999. The data include information on the survival and N2 stations of 402 patients.

RESULTS

A frequently metastasized single N2 station was the lower pretracheal station in primary tumors in the right upper lobe, the subaortic station in the left upper lobe, and the subcarinal station in the right middle or lower lobe and the left lower lobe. In multiple N2 stations, the frequency of metastasis of the N2 station observed in a single N2 station was as high as 72% to 89%, and one or two other frequently metastasized stations were added to each group. Regarding the survival of patients with a primary tumor in each lobe except for the left lower lobe, a single N2 station resulted in a significantly better survival than did multiple N2 stations. Furthermore, the overall survivals classified according to each primary site showed a significant difference among the four primary sites (P =.04).

CONCLUSIONS

The primary tumors in each lobe showed a prevalence of N2 station(s). The number of N2 stations is a good prognosticator except in patients with a primary tumor in the left lower lobe. In addition, the site of a primary tumor itself is also considered to influence the survival of the patients.

Analyses of segmental lymph node metastases and intrapulmonary metastases of small lung cancer

BACKGROUND

Curativity and indications for limited resection of small peripheral lung cancer remain controversial.

METHODS

Pathologic investigations of segmental lymph node metastases and intrapulmonary metastases in the resected lobe were performed for 94 small peripheral lung cancers (3.0 cm or less in diameter).

RESULTS

Nine patients had segmental lymph node metastases, 1 had intrapulmonary metastases, and 1 had both. Of these 11 patients, 5 had metastases limited to the primary tumor-bearing segments, 2 had metastases in nonprimary tumor-bearing segments, and 4 had metastases in both. Of the 10 patients with segmental lymph node metastases, 7 had metastases in both lobar-hilar and mediastinal lymph nodes, and 3 of 8 with adenocarcinoma had a tumor 2.0 cm or less.

CONCLUSIONS

Segmentectomy seems more favorable than wedge resection, but the risk of remnant tumor remains as compared with lobectomy. Evaluation of lobar-hilar or mediastinal lymph nodes is helpful to determine the presence or absence of segmental lymph node metastases. Limited resection can be undertaken with smaller tumors to allow preservation of more lung function while accepting a somewhat enhanced risk of recurrence.

Lymph node metastasis and prognosis in small peripheral non-small-cell lung cancers

OBJECTIVE

The lymph node dissection and curative resection for small peripheral non-small-cell lung cancers, it is essential to know the incidence and distribution of lymph node metastasis to confirm the pathological stage.

METHODS

Between January 1984 and August 1996, lobectomy with systemic mediastinal dissection (standard lobectomy) was conducted in 49 patients with small peripheral non-small-cell lung cancers (2.0 cm or less in diameter), and limited resection was conducted in 15 with cardiopulmonary insufficiency.

RESULTS

Lymph node metastasis was confirmed histologically in 14 patients undergoing standard lobectomy (28.6%). The incidence of lymph node metastasis was high in tumors with pleural (p2) or subpleural (p1) involvement (63.6%) (7/14). The 5-year survival between standard lobectomy and limited resection patients (83% vs. 71%) was not statistically significant. In patients undergoing standard lobectomy, survival in those with node-negative disease was better than in those with node-positive disease (94% vs. 44%, p < 0.01).

CONCLUSIONS

Lymph node involvement, especially in tumors with pleural involvement, is not uncommon, even when tumors are 2.0 cm or less in diameter. Systemic hilar and mediastinal dissection is therefore required for disease staging and treatment.

Prognostic significance of proliferative activity in pN2 non-small-cell lung carcinomas and their mediastinal lymph node metastases

OBJECTIVE

To investigate the expression of proliferating cell nuclear antigen (PCNA) in both primary tumor and lymph node metastases of pathologic stage IIIA N2 non-small-cell lung carcinoma (NSCLC) and the relation to prognosis.

SUMMARY BACKGROUND DATA

Although the prognosis of pN2 NSCLC is poor in general, long-term survivors have been reported among patients with completely resected or clinical N0 disease and those with skip metastasis. However, few reports are available on preoperative prognostic predictors. Expression of PCNA is known to be associated with tumor proliferation and is correlated with the prognosis of several carcinomas.

METHODS

Clinicopathologic factors were investigated in relation to prognosis in 76 patients with pathologic stage IIIA pN2 NSCLC from whom resected surgical specimens were available from both the primary tumor and lymph node metastases for evaluation of PCNA expression.

RESULTS

A significant correlation was observed between PCNA labeling index in the primary tumor and that in lymph node metastases. The prognosis in patients with PCNA-negative primary tumor (5-year survival rate, 66.0%) was significantly more favorable than that of patients with PCNA-positive primary tumor (5-year survival rate, 21.5%). The prognosis in patients with PCNA-negative metastases was significantly more favorable than that of patients with PCNA-positive metastases. For clinical N2 disease also, the prognosis of patients with PCNA-negative primary tumor was favorable (5-year survival rate, 66.1%). Multivariate analyses showed that PCNA expression and complete resection were significant prognostic factors.

CONCLUSIONS

Preoperatively diagnosed N2 NSCLC exhibiting negative PCNA expression in primary tumor or lymph node metastases is expected to result in a favorable postoperative prognosis and may be an indication for primary resection.

Non-small cell lung cancer: FDG PET for nodal staging in patients with stage I disease

PURPOSE

To determine the accuracy of 2-[fluorine-18]fluoro-2-deoxy-D-glucose (FDG) positron emission tomography (PET) in the evaluation of regional lymph nodes in patients with stage I non-small cell lung cancer (NSCLC).

MATERIALS AND METHODS

Imaging and clinical findings obtained during 5 years in 84 patients (mean age, 66 years) were reviewed. Patients had thoracic computed tomographic findings of stage I NSCLC, an FDG PET study, and histopathologic proof of lung cancer. At the time of diagnosis, disease stage was assigned on the basis of FDG PET results and was compared with the histopathologic stage to determine the accuracy of PET.

RESULTS

When PET stage was compared with histopathologic stage, the disease in 72 (86%) patients was accurately staged with PET, understaged in two (2%), and overstaged in 10 (12%). The overall sensitivity, specificity, and positive and negative predictive values for PET of regional lymph nodal metastases were 82%, 86%, 47%, and 97%, respectively.

CONCLUSION

FDG PET enables accurate staging of regional lymph node disease in patients with stage I NSCLC. A negative PET scan in these patients suggests that mediastinoscopy is unnecessary and that these patients can proceed directly to thoracotomy.