Elsevier

Lung Cancer

Volume 70, Issue 2, November 2010, Pages 195-199
Lung Cancer

Tumor histology affects the accuracy of clinical evaluative staging in primary lung cancer

https://doi.org/10.1016/j.lungcan.2010.02.010Get rights and content

Abstract

Objective

Pathological examination of lung cancer often reveals a more advanced stage than clinical stage. The objective of this study was to evaluate whether the association between clinical and pathologic stages depends on tumor histology.

Methods

This retrospective study enrolled patients who had undergone major lung resections and systemic lymph node dissections (1990–2004). In total, 483 patients had adenocarcinoma and 225 had squamous cell carcinoma.

Results

Clinical and pathologic N-status were significantly different in patients with adenocarcinoma (p < 0.0001) but not in those with squamous cell carcinoma. Patients with adenocarcinoma were more likely to be upstaged from clinical N0 disease to pathologic N2 disease than those with squamous cell carcinoma (p = 0.04). Of those patients with adenocarcinoma, surgical procedure, clinical N-status, metastatic pathologic N2 stations and curability were significant prognostic factors. It is of interest, however, that a similar statistically significant difference could not be shown in patients with squamous cell carcinoma. Furthermore, multivariate analysis demonstrated that clinically detectable N2 disease and multiple pathologic N2 stations significantly affected the poorer prognosis in adenocarcinoma. Adenocarcinoma patients with clinically undetectable N2 disease had significantly better 5-year survival than those with clinically detectable N2 disease (p < 0.0001), although this was not the case for patients with squamous cell carcinoma (p = 0.81).

Conclusion

In adenocarcinoma patients with pathologic N2 disease, clinical N-status and metastatic pathologic N2 stations were significant prognostic factors. A similar difference was not found in patients with squamous cell carcinoma. Adenocarcinoma and squamous cell carcinoma appear to have different tendencies for lymph node metastasis.

Introduction

The optimal treatment of lung cancer relies on proper staging of the disease. The stage of lung cancer patients not only guides the decision-making process with regard to choosing the optimal treatment modality, but also provides important prognostic information with regard to survival. Clinical stage is based on information provided by any method before thoracotomy, while pathologic stage is based on information obtained during the surgical procedure and after pathologic analysis of the excised surgical specimen.

Nodal status is a strong predictor of the effectiveness of surgical intervention for non-small cell lung carcinoma (NSCLC). Accurate staging of N2 disease has become particularly important. Computed tomography (CT) scans are widely available and the most commonly used noninvasive imaging modality for the evaluation of the mediastinum in patients with NSCLC. Unfortunately, the accuracy of the chest CT scans in differentiating benign from malignant lymph nodes in the mediastinum is unacceptably poor and has not improved over the past decade, despite improvements in CT scan resolution [1]. In recent years, numerous clinical staging modalities have become increasingly available [1], [2]. In particular, positron emission tomography (PET) with fluorodeoxyglucose has emerged as an important imaging modality in the evaluation of distant metastases as well as the primary tumor [1], [3]. However, CT scans and bronchoscopy have been systematically used in clinical staging. Contrast enhanced CT scans remain the standard imaging modality to define the extent and location of the primary tumor and detect metastases, although size criteria of CT scans have been reported to yield lower accuracy in the diagnosis of mediastinal lymph node involvement [1], [2], [4].

Although there have been many reports comparing clinical and pathologic stages, little is known about the relationship between these two staging methods according to tumor histology [5]. The objectives of this study were to compare the two staging methods according to tumor histology to evaluate the reliability of CT analysis, and analyze whether the upstaging affects the prognosis in patients with pathologic N2 disease.

Section snippets

Patients selection

This retrospective analysis was based on data collected in a database of patients with primary lung cancer, who had been histologically diagnosed and had received thoracotomy at National Hospital Organization Toneyama Hospital in Japan. Between 1990 and 2004, 1046 consecutive patients underwent thoracotomy for primary lung cancer, 944 of whom had adenocarcinoma or squamous cell carcinoma. Excluding 95 patients with limited resections, 102 patients with preoperative treatments, and 39 patients

Patient characteristics

The clinical characteristics of patients enrolled in the study are presented in Table 1. Among a total of 708 patients, 483 had adenocarcinoma and 225 had squamous cell carcinoma. The mean ages of these two groups were 62.4 ± 10.1 years and 65.4 ± 9.3 years, respectively (p = 0.0001). The difference in the proportional incidence of gender between these two histological groups was significantly different (p < 0.0001); about 90% of patients with squamous cell carcinoma were male. The mean tumor size of

Discussion

In the present study, we demonstrated that patients with adenocarcinoma were more likely to have clinically undetectable N2 disease than those with squamous cell carcinoma, although the diagnostic accuracy in patients with adenocarcinoma was higher than that in patients with squamous cell carcinoma. Patients with clinically undetectable N2 (cN0-1) disease had a significantly better survival rate than those with clinically detectable N2 (cN2) disease in patients with adenocarcinoma, while there

Conflict of interest statement

None declared.

References (18)

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