The prognostic significance of preoperative assessment of mediastinal lymph nodes in patients with lung cancer

CT for Predicting the Resectability of Lung Cancer

In order to assess the accuracy of CT in predicting the resectability of lung cancer, a prospective study was performed on 96 patients undergoing thoracotomy. The tumors were classified preoperatively according to the TNM classification and the new international staging system for lung cancer, and scored as being resectable by lobectomy or pulmectomy, potentially resectable by lobectomy or pulmectomy, or nonresectable. Of the tumors predicted to be resectable or potentially resectable, 86.6% and 63% were radically resected, respectively, and the need for lobectomy versus pulmectomy was correctly estimated in 81.3% of them. The insufficiency of CT for defining lymph node metastases and infiltrative tumor growth was considered a marked disadvantage of the method.

Establishing the diagnosis of lung cancer: Diagnosis and management of lung cancer, 3rd ed: American College of Chest Physicians evidence-based clinical practice guidelines

BACKGROUND

Lung cancer is usually suspected in individuals who have an abnormal chest radiograph or have symptoms caused by either local or systemic effects of the tumor. The method of diagnosis of lung cancer depends on the type of lung cancer (small cell lung cancer or non-small cell lung cancer [NSCLC]), the size and location of the primary tumor, the presence of metastasis, and the overall clinical status of the patient. The objective of this study was to determine the test performance characteristics of various modalities for the diagnosis of suspected lung cancer.

METHODS

To update previous recommendations on techniques available for the initial diagnosis of lung cancer, a systematic search of the MEDLINE, Healthstar, and Cochrane Library databases covering material to July 2011 and print bibliographies was performed to identify studies comparing the results of sputum cytology, conventional bronchoscopy, flexible bronchoscopy (FB), electromagnetic navigation (EMN) bronchoscopy, radial endobronchial ultrasound (R-EBUS)-guided lung biopsy, transthoracic needle aspiration (TTNA) or biopsy, pleural fluid cytology, and pleural biopsy with histologic reference standard diagnoses among at least 50 patients with suspected lung cancer. Recommendations were developed by the writing committee, graded by a standardized method (see the article "Methodology for Development of Guidelines for Lung Cancer" in this guideline), and reviewed by all members of the Lung Cancer Guideline Panel prior to approval by the Thoracic Oncology NetWork, the Guidelines Oversight Committee, and the Board of Regents of the American College of Chest Physicians.

RESULTS

Sputum cytology is an acceptable method of establishing the diagnosis of lung cancer, with a pooled sensitivity rate of 66% and a specificity rate of 99%. However, the sensitivity of sputum cytology varies according to the location of the lung cancer. For central, endobronchial lesions, the overall sensitivity of FB for diagnosing lung cancer is 88%. The diagnostic yield of bronchoscopy decreases for peripheral lesions. Peripheral lesions < 2 or > 2 cm in diameter showed a sensitivity of 34% and 63%, respectively. R-EBUS and EMN are emerging technologies for the diagnosis of peripheral lung cancer, with diagnostic yields of 73% and 71%, respectively. The pooled sensitivity of TTNA for the diagnosis of lung cancer was 90%. A trend toward lower sensitivity was noted for lesions < 2 cm in diameter. TTNA is associated with a higher rate of pneumothorax compared with bronchoscopic procedures. In a patient with a malignant pleural effusion, pleural fluid cytology is reported to have a mean sensitivity of about 72%. A definitive diagnosis of metastatic disease to the pleural space can be estalished with a pleural biopsy. The diagnostic yield for closed pleural biopsy ranges from 38% to 47% and from 75% to 88% for image-guided closed biopsy. Thoracoscopic biopsy of the pleura carries the highest diagnostic yield, 95% to 97%. The accuracy in differentiating between small cell and non-small cell cytology for the various diagnostic modalities was 98%, with individual studies ranging from 94% to 100%. The average false-positive and false-negative rates were 9% and 2%, respectively. Although the distinction between small cell and NSCLC by cytology appears to be accurate, NSCLCs are clinically, pathologically, and molecularly heterogeneous tumors. In the past decade, clinical trials have shown us that NSCLCs respond to different therapeutic agents based on histologic phenotypes and molecular characteristics. The physician performing diagnostic procedures on a patient suspected of having lung cancer must ensure that adequate tissue is acquired to perform accurate histologic and molecular characterization of NSCLCs.

CONCLUSIONS

The sensitivity of bronchoscopy is high for endobronchial disease and poor for peripheral lesions < 2 cm in diameter. The sensitivity of TTNA is excellent for malignant disease, but TTNA has a higher rate of pneumothorax than do bronchoscopic modalities. R-EBUS and EMN bronchoscopy show potential for increasing the diagnostic yield of FB for peripheral lung cancers. Thoracoscopic biopsy of the pleura has the highest diagnostic yield for diagnosis of metastatic pleural effusion in a patient with lung cancer. Adequate tissue acquisition for histologic and molecular characterization of NSCLCs is paramount.

Methods for staging non-small cell lung cancer: Diagnosis and management of lung cancer, 3rd ed: American College of Chest Physicians evidence-based clinical practice guidelines

BACKGROUND

Correctly staging lung cancer is important because the treatment options and prognosis differ significantly by stage. Several noninvasive imaging studies and invasive tests are available. Understanding the accuracy, advantages, and disadvantages of the available methods for staging non-small cell lung cancer is critical to decision-making.

METHODS

Test accuracies for the available staging studies were updated from the second iteration of the American College of Chest Physicians Lung Cancer Guidelines. Systematic searches of the MEDLINE database were performed up to June 2012 with the inclusion of selected meta-analyses, practice guidelines, and reviews. Study designs and results are summarized in evidence tables.

RESULTS

The sensitivity and specificity of CT scanning for identifying mediastinal lymph node metastasis were approximately 55% and 81%, respectively, confirming that CT scanning has limited ability either to rule in or exclude mediastinal metastasis. For PET scanning, estimates of sensitivity and specificity for identifying mediastinal metastasis were approximately 77% and 86%, respectively. These findings demonstrate that PET scanning is more accurate than CT scanning, but tissue biopsy is still required to confirm PET scan findings. The needle techniques endobronchial ultrasound-needle aspiration, endoscopic ultrasound-needle aspiration, and combined endobronchial ultrasound/endoscopic ultrasound-needle aspiration have sensitivities of approximately 89%, 89%, and 91%, respectively. In direct comparison with surgical staging, needle techniques have emerged as the best first diagnostic tools to obtain tissue. Based on randomized controlled trials, PET or PET-CT scanning is recommended for staging and to detect unsuspected metastatic disease and avoid noncurative resections.

CONCLUSIONS

Since the last iteration of the staging guidelines, PET scanning has assumed a more prominent role both in its use prior to surgery and when evaluating for metastatic disease. Minimally invasive needle techniques to stage the mediastinum have become increasingly accepted and are the tests of first choice to confirm mediastinal disease in accessible lymph node stations. If negative, these needle techniques should be followed by surgical biopsy. All abnormal scans should be confirmed by tissue biopsy (by whatever method is available) to ensure accurate staging. Evidence suggests that more complete staging improves patient outcomes.

Diagnostic workup of lung cancer

Lung cancer is the most frequent cause of mortality worldwide. According to recent estimates, 222,520 new cases of lung cancer (non-small cell and small cell combined) were diagnosed and 157,300 lung cancer-related deaths occurred in 2010 in the United States alone. The two major histologic types of lung cancer are small cell lung cancer and non-small cell lung cancer. The diagnosis and management of lung cancer requires a multidisciplinary approach.

Impact of Lymphoid Follicles and Histiocytes on the False-Positive FDG Uptake of Lymph Nodes in Non-Small Cell Lung Cancer

PURPOSE

Although (18)F-fluorodeoxyglucose (FDG) PET/CT has improved the accuracy of evaluating lymph node (LN) staging in non-small cell lung cancer (NSCLC), false-positive results remain a problem. The reason why benign LNs show high FDG uptake is still unclear. The aim of this study was to identify molecular and pathological characteristics of benign LNs showing high FDG uptake.

MATERIALS AND METHODS

We studied 108 mediastinal LNs of pathologically benign nature obtained from 43 patients with NSCLC who underwent FDG PET/CT and surgery. We measured the following parameters in each LN: maximum standardized uptake value (maxSUV), short diameter, maximum Hounsfield unit (maxHU) value, occupied proportions of lymphoid follicles, histiocytes in extrafollicular space and the degree of glucose transporter 1 (Glut1) expression. We compared the parameters between two LN groups according to maxSUV.

RESULTS

There were 74 LNs showing maxSUV≥3.0 (group 1) and 34 LNs with maxSUV<3.0 (group 2). The size of LN (p < 0.001) and maxHU (p = 0.003) in group 1 was higher than that in group 2. Histologically, the occupied proportions of lymphoid follicles (p = 0.031) or histiocytes (p = 0.004) were higher in group 1. The Glut1 expression of lymphoid follicles (p = 0.035) or histiocytes (p = 0.005) was also higher in group 1.

CONCLUSION

Lymphoid follicular hyperplasia and histiocyte infiltration associated with Glut1 overexpression are important molecular and pathological mechanisms for false-positive FDG uptake in benign mediastinal LNs in patients with NSCLC.

A performance and theoretical cost analysis of endobronchial ultrasound-guided transbronchial needle aspiration in a UK tertiary respiratory centre

BACKGROUND

New innovative techniques can improve patient care but may not be appropriately funded. Endobronchial ultrasound-guided transbronchial needle aspiration (EBUS) offers a minimally invasive mediastinal staging and diagnostic method for suspected lung cancer.

AIM

We report the performance and cost analysis of a newly established EBUS service in a prospective real world cohort of patients to assess the impact of Payment by Results (PbR).

DESIGN

Prospective cohort study.

METHODS

Fifty-four patients between June 2008 and April 2009 underwent EBUS for evaluation of unexplained mediastinal lymphadenopathy on CT. Cost analysis was performed from local Trust financial data and 2008-09 tariffs.

RESULTS

EBUS had an 89% sensitivity, 75% negative predictive value and 92% accuracy for malignancy. EBUS coding was inaccurate in 15.6% of cases. The actual cost of an EBUS is 1252-1433 pounds but is coded as a standard bronchoscopy (561 pounds). EBUS reduces health community costs by 107824 pounds/year, as a result of a Primary Care Trust cost saving of 113968 pounds/year and a Trust cost deficit of 6144 pounds/year. Coding inaccuracies further alter the Primary Care Trust costs.

CONCLUSION

Medical innovation is fundamental to improved patient care. EBUS can potentially reduce morbidity for lung cancer patients and save health community costs. However, with PbR the service provider delivers this at a loss as the tariffs do not reflect innovation and because of coding inaccuracies. We suggest tariffs for innovative procedures need to reflect the true cost.

Mediastinal staging procedures in lung cancer: EBUS, TBNA and mediastinoscopy

PURPOSE OF REVIEW

There is increasing awareness of minimally invasive endoscopic techniques for mediastinal staging in lung cancer. Traditionally, cervical mediastinoscopy has been utilized. Endobronchial ultrasound-guided fine needle aspiration (EBUS) has recently emerged as a potential alternative.

RECENT FINDINGS

EBUS has sensitivity for lung cancer which is at least equivalent (if not superior) to cervical mediastinoscopy. However, cervical mediastinoscopy remains superior to EBUS and other techniques in its high negative predictive value. More recent data suggest EBUS may have a role in presurgical staging of radiologically normal subcentimetre nodes and its negative predictive value may be equivalent to surgical staging. Ongoing comparative studies between EBUS and cervical mediastinoscopy may well clarify relative performance and cost analyses.

SUMMARY

Currently, insufficient data are present to recommend replacing cervical mediastinoscopy with EBUS for lung cancer staging; the negative predictive value of EBUS requires validation. However, EBUS can be recommended for initial staging as a minimally invasive option provided negative results are followed by cervical mediastinoscopy. This would also allow cervical mediastinoscopy to be reserved for re-staging. Conventional transbronchial needle aspiration has a limited role only as a first-line staging procedure but may aid diagnosis. In the future, EBUS may have a role in presurgical staging of the radiologically normal mediastinum and re-staging if prior staging is done by cervical mediastinoscopy.

Is there a subset of patients with preoperatively diagnosed N2 non-small cell lung cancer who might benefit from surgical resection?

OBJECTIVE

The role of surgery in the treatment of preoperatively diagnosed N2 non-small cell lung cancer remains controversial. This study sought significant prognostic factors to select candidates for surgery and assess prognosis.

METHODS

The study population included 277 patients who underwent primary resection (192) or induction chemotherapy followed by surgery (85) for preoperatively diagnosed, potentially resectable N2 non-small cell lung cancer. N2 descriptors were prospectively recorded. Kaplan-Meier curves were used to evaluate survival, and statistical significance of differences between curves was assessed by log-rank test. Cox regression was used for multivariate analyses.

RESULTS

Preoperative significant prognostic factors were number of mediastinal node levels involved (P < .001), symptom severity (P = .013), clinical T (P = .041), and induction chemotherapy (P = .001). Three groups with different prognoses were based on individual prognostic score. The group that did best had a median survival of 29.6 months. Postoperative predictors of survival were pathologic T (P = .003), tumor residue (P = .034), and number of mediastinal nodes involved (P < .001). Of 3 groups with different prognoses, the most favorable had a median survival as long as 42 months.

CONCLUSION

This study provides a practical tool that uses significant prognostic factors to predict which patients with preoperatively diagnosed N2 non-small cell lung cancer have better prognoses. Because patients with the favorable prognostic factors showed good long-term survival and excellent local disease control, surgery should still play an important role in the multimodality treatment of these patients.

Invasive mediastinal staging of lung cancer: ACCP evidence-based clinical practice guidelines (2nd edition)

BACKGROUND

The treatment of non-small cell lung cancer (NSCLC) is determined by accurate definition of the stage. If there are no distant metastases, the status of the mediastinal lymph nodes is critical. Although imaging studies can provide some guidance, in many situations invasive staging is necessary. Many different complementary techniques are available.

METHODS

The current guidelines and medical literature that are applicable to this issue were identified by computerized search and were evaluated using standardized methods. Recommendations were framed using the approach described by the Health and Science Policy Committee of the American College of Chest Physicians.

RESULTS

Performance characteristics of invasive staging interventions are defined. However, a direct comparison of these results is not warranted because the patients selected for these procedures have been different. It is crucial to define patient groups, and to define the need for an invasive test and selection of the best test based on this.

CONCLUSIONS

In patients with extensive mediastinal infiltration, invasive staging is not needed. In patients with discrete node enlargement, staging by CT or positron emission tomography (PET) scanning is not sufficiently accurate. The sensitivity of various techniques is similar in this setting, although the false-negative (FN) rate of needle techniques is higher than that for mediastinoscopy. In patients with a stage II or a central tumor, invasive staging of the mediastinal nodes is necessary. Mediastinoscopy is generally preferable because of the higher FN rates of needle techniques in the setting of normal-sized lymph nodes. Patients with a peripheral clinical stage I NSCLC do not usually need invasive confirmation of mediastinal nodes unless a PET scan finding is positive in the nodes. The staging of patients with left upper lobe tumors should include an assessment of the aortopulmonary window lymph nodes.

Initial Diagnosis of Lung Cancer

BACKGROUND

Lung cancer is usually suspected in individuals who have an abnormal chest radiograph finding or have symptoms caused by either local or systemic effects of the tumor. The method of diagnosis of suspected lung cancer depends on the type of lung cancer (ie, small cell lung cancer [SCLC] or non-SCLC [NSCLC]), the size and location of the primary tumor, the presence of metastasis, and the overall clinical status of the patient.

OBJECTIVES

To determine the test performance characteristics of various modalities for the diagnosis of suspected lung cancer.

METHODS

To update previous recommendations on the initial diagnosis of lung cancer, a systematic search of MEDLINE, Healthstar, and Cochrane Library databases to July 2004, and print bibliographies was performed to identify studies comparing the results of sputum cytology, bronchoscopy, transthoracic needle aspiration (TTNA), or biopsy with histologic reference standard diagnoses among at least 50 patients with suspected lung cancer. Recommendations were developed by the writing committee, graded by a standardized method, and reviewed by all members of the lung cancer panel prior to approval by the Thoracic Oncology Network, Health and Science Policy Committee, and the Board of Regents of the American College of Chest Physician.

RESULTS

Sputum cytology is an acceptable method of establishing the diagnosis of lung cancer with a pooled sensitivity rate of 0.66 and specificity rate of 0.99. However, the sensitivity of sputum cytology varies by location of the lung cancer. For central, endobronchial lesions, the overall sensitivity of flexible bronchoscopy (FB) for diagnosing lung cancer is 0.88. The diagnostic yield of bronchoscopy decreases for peripheral lesions. Peripheral lesions smaller or larger than 2 cm in diameter showed a sensitivity of 0.34 and 0.63, respectively. In recent years, endobronchial ultrasound (EBUS) has shown potential in increasing the diagnostic yield of FB while dealing with peripheral lesions without adding to the risk of the procedure. In appropriate situations, its use can be considered before moving on to more invasive tests. The pooled sensitivity for TTNA for the diagnosis of lung cancer is 0.90. A trend toward lower sensitivity was noted for lesions < 2 cm in diameter. The accuracy in differentiating between SCLC and NSCLC cytology for the various diagnostic modalities was 0.98, with individual studies ranging from 0.94 to 1.0. The average false-positive rate and FN rate were 0.09 and 0.02, respectively.

CONCLUSIONS

The sensitivity of bronchoscopy is high for the detection of endobronchial disease and poor for peripheral lesions < 2 cm in diameter. Detection of the latter can be aided with the use of EBUS in the appropriate clinical setting. The sensitivity of TTNA is excellent for malignant disease. The distinction between SCLC and NSCLC by cytology appears to be accurate.

Analyses on prognostic factors following tri-modality therapy for stage IIIa non-small cell lung cancer

This study is to evaluate and report the prognostic factors of N2 positive stage IIIA non-small cell lung cancer (NSCLC) treated with concurrent radiochemotherapy (CRCT) and surgery. CRCT and surgery were planned in 66 patients with stage IIIA NSCLC, and 46 evaluable patients were analyzed. Thoracic radiation therapy (TRT) dose was 45 Gy over 5 weeks, chemotherapy consisted of two cycles of intravenous cisplatin (100mg/m(2), on days 1 and 29 of TRT) and oral etoposide (50mg/m(2)/day, on days 1-14 and 29-42 of TRT), and surgery was performed in 4 weeks following CRCT completion. With the median follow up duration of 23 (range 5-74) months, the overall survival, disease-free survival, and local control rates at 5 years in all patients were 27%, 24% and 90%, respectively. The overall survival and disease-free survival rates at 5 years in the patients who achieved ypN0 stage and ypN1/2 stages were 47% and 0% (p=0.008), and 42% and 7% (p=0.01), respectively. The corresponding figures in those with initial "bulky" N2 disease and "mediastinoscopic" N2 disease were 31% and 19% (p=0.98), and 23% and 26% (p=0.68), respectively. Following CRCT and surgery, achieving ypN0 stage turned out to be a significantly favorable indicator, while the initial mediastinal lymph node extent did not, with respect to overall survival and disease-free survival.

Accuracy of transbronchial needle aspiration for mediastinal staging of non-small cell lung cancer: a meta-analysis

BACKGROUND

The reported accuracy of transbronchial needle aspiration (TBNA) for mediastinal staging in non-small cell lung cancer (NSCLC) varies widely. We performed a meta-analysis to estimate the accuracy of TBNA for mediastinal staging in NSCLC.

METHODS

Medline, Embase, and the bibliographies of retrieved articles were searched for studies evaluating TBNA accuracy with no language restriction. Meta-analytical methods were used to construct summary receiver-operating characteristic curves and to pool sensitivity and specificity.

RESULTS

Thirteen studies met inclusion criteria, including six studies that surgically confirmed all TBNA results and enrolled at least 10 patients with and without mediastinal metastasis (tier 1). Methodological quality varied but did not affect diagnostic accuracy. In tier 1 studies the median prevalence of mediastinal metastasis was 34%. Using a random effects model, the pooled sensitivity and specificity were 39% (95% CI 17 to 61) and 99% (95% CI 96 to 100), respectively. Compared with tier 1 studies, the median prevalence of mediastinal metastasis (81%; p = 0.002) and pooled sensitivity (78%; 95% CI 71 to 84; p = 0.009) were higher in non-tier 1 studies. Sensitivity analysis confirmed that the sensitivity of TBNA depends critically on the prevalence of mediastinal metastasis. The pooled major complication rate was 0.3% (95% CI 0.01 to 4).

CONCLUSIONS

When properly performed, TBNA is highly specific for identifying mediastinal metastasis in patients with NSCLC, but sensitivity depends critically on the study methods and patient population. In populations with a lower prevalence of mediastinal metastasis, the sensitivity of TBNA is much lower than reported in recent lung cancer guidelines.

Lymph node size and metastatic infiltration in non-small cell lung cancer

BACKGROUND

Preoperative lymph node staging of lung cancer by CT relies on the premise that malignant lymph nodes are larger than benign ones. Lymph nodes > 1 cm in size are regarded as metastatic nodes. The surgical approach and potential application of neoadjuvant therapy regimens are dependent on this evaluation.

PATIENTS AND METHODS

In a morphometric study, hilar and mediastinal lymph nodes from 256 patients with non-small cell lung cancer (NSCLC) were analyzed. The lymph nodes were counted, the largest diameter of each lymph node was measured, and each lymph node was analyzed for metastatic involvement by histopathologic examination. The frequency of metastatic involvement was calculated and correlated with lymph node size. Preoperative CT scans of 80 patients were retrospectively analyzed by a staff radiologist. Lymph node size was measured, and lymph nodes were evaluated due to radiologic criteria. The radiologic evaluation was compared to the histopathologic diagnosis.

RESULTS

A total of 2,891 lymph nodes were present in the 256 specimens examined for this study. One hundred thirty-nine patients had a pN0 status, whereas 117 patients had lymph nodes that were positive for cancer. Two thousand four hundred eighty-six lymph nodes (86%) were tumor-free, while 405 (14%) showed metastatic involvement on histopathologic examination. The mean (+/- SD) diameter of the nonmetastatic lymph nodes was 7.05 +/- 3.75 mm, whereas infiltrated nodes had a diameter of 10.7 +/- 4.7 mm (p = 0.005). One thousand nine hundred fifty-three of the tumor-free lymph nodes (79%) and 170 of the metastatic lymph nodes (44%) were < 10 mm in diameter. Of 139 patients with no metastatic lymph node involvement, 101 (77%) had at least one lymph node that was > 10 mm in diameter. Of 127 patients with metastatic lymph node involvement, 12% had no lymph node that was < 10 mm. The independent radiologic evaluation of the CT scans of 80 patients yielded a sensitivity of 57.1% and a specificity of 80.6%.

CONCLUSION

Lymph node size is not a reliable parameter for the evaluation of metastatic involvement in patients with NSCLC.

Invasive staging of non-small cell lung cancer: a review of the current evidence

STUDY OBJECTIVES

To determine the test performance characteristics of transbronchial needle aspiration (TBNA), transthoracic needle aspiration (TTNA), endoscopic ultrasound-guided needle aspiration (EUS-NA), and mediastinoscopy in staging non-small cell lung cancer (NSCLC).

DESIGN, SETTING, AND PARTICIPANTS

Systematic search of MEDLINE, HealthStar, and Cochrane Library databases to July 2001 and print bibliographies. Included were studies comparing staging results of TBNA, TTNA, EUS-NA, or mediastinoscopy against either tissue histologic confirmation or long-term clinical follow-up (> or = 1 year). Patients included were those with NSCLC or small cell lung cancer.

MEASUREMENT AND RESULTS

For patients with lung cancer, the pooled sensitivity for TBNA was 0.76, the pooled specificity was 0.96, and the negative predictive value (NPV) was 0.71. For TTNA, the pooled sensitivity was 0.91, with an NPV of 0.78. EUS-NA had a pooled sensitivity of 0.88, a pooled specificity of 0.91, and an NPV of 0.77. For standard cervical mediastinoscopy, the pooled sensitivity was 0.81, with an NPV of 0.91. The addition of either extended cervical mediastinoscopy or anterior mediastinotomy to standard cervical mediastinoscopy appeared to improve the sensitivity of any of the procedures alone.

CONCLUSIONS

Invasive clinical staging of NSCLC can be performed effectively by TBNA, TTNA, EUS-NA, or mediastinoscopy. Selection of the appropriate study is dependent on the degree of suspicion for metastatic disease, the patient's comorbid illnesses, and the availability and performance characteristics of procedural options.

Diagnosis of lung cancer: the guidelines

Lung cancer is usually suspected in individuals who have abnormal chest radiograph findings or have symptoms caused by either local or systemic effects of the tumor. The method of diagnosis of suspected lung cancer depends on the type of lung cancer (ie, small cell lung cancer or non-small cell lung cancer), the size and location of the primary tumor, the presence of metastasis, and the overall clinical status of the patient. Achieving a diagnosis and staging are usually done in concert because the most efficient way to make a diagnosis often is dictated by the stage of the cancer. The best sequence of studies and interventions in a particular patient involves careful judgment of the probable reliability of a number of presumptive diagnostic issues, so as to maximize the sensitivity and to avoid performing multiple or unnecessary invasive procedures. In this article, we consider all manner of clinical presentations of lung cancer in light of currently available diagnostic procedures. Published data supporting a particular diagnostic approach is weighed based on the quality of the benefit as well as the estimated net benefit. Recommendations are graded in terms of strength to provide clinicians with guidance as to the most efficient and approach to the diagnosis of lung cancer in individual patients.

The impact of fluorodeoxyglucose F 18 positron-emission tomography on the surgical staging of non-small cell lung cancer

OBJECTIVES

Staging data on patients with non-small cell lung cancer were prospectively collected to evaluate the accuracy and anatomic information provided by fluorodeoxyglucose F 18 positron-emission tomography and its impact on improving the accuracy of surgical staging.

METHODS

A total of 142 patients with potentially resectable non-small cell lung cancer were imaged with positron-emission tomography (neck to pelvis). Positron-emission tomographic scans were read prospectively with thoracic computed tomographic comparison. Patients without distant metastases at positron-emission tomography underwent staging with bronchoscopy and mediastinoscopy, with or without mediastinotomy or thoracoscopy. Patients with metastases, pleural implants, or N2 or N3 disease did not undergo primary resection.

RESULTS

Positron-emission tomography revealed unsuspected distant metastases in 24 of 142 patients (16.9%) and unsuspected pleural implants in 6 others. Nodal stage was surgically established in 118 cases. Positron-emission tomography showed that 5 patients had nodal disease not accessible by mediastinoscopy. In 35 (24.6%) of these 142 cases, positron-emission tomography directed the evaluation away from routine bronchoscopy and mediastinoscopy staging that would have resulted in inappropriate treatment selection. Positron-emission tomography correctly differentiated resectable stages IA through IIIA (N1) from stages IIIA (N2) through IV in 88.7% of cases. In identifying N2 or N3 disease, positron-emission tomography had an accuracy of 90.7%, a sensitivity of 80.9%, a specificity of 96%, and positive and negative predictive values of 91.9% and 90.1%, respectively. Of the 8 cases in which positron-emission tomography missed N2 disease, 7 had the disease discovered by mediastinoscopy and 1 had it discovered at thoracotomy.

CONCLUSIONS

The diagnostic accuracy of positron-emission tomography-enhanced clinical staging is high. Positron-emission tomography has previously been used primarily to screen for lymph node spread and distant metastases, but it also provides localizing information that allows directed and more sensitive surgical staging and refinement of patient selection for curative resection. Positron-emission tomography and surgical staging play complementary roles in the journey toward more accurate overall staging.

The role of computed tomographic scanning in diagnosing mediastinal node involvement in non-small cell lung cancer

OBJECTIVES

The reliability of computed tomographic scanning in evaluating mediastinal node involvement is controversial because of the high false result rate. We attempted to identify significant factors responsible for false-positive and false-negative scans.

METHODS

From August 1992 through April 1997, 401 patients with lung cancer who underwent major lung resection and systematic lymph node dissection were enrolled in this study. We retrospectively examined mediastinal node size, tumor location, maximum tumor dimension, the presence or absence of obstructive pneumonia, atelectasis, pulmonary fibrosis, and lymph node calcification on contrast-enhanced computed tomographic scans. We identified clinical and radiologic factors responsible for the false results by using univariate and multivariable analysis.

RESULTS

Central tumor location proved to be a significant factor of false-positive scans. Elevated carcinoembryonic antigen level and larger tumor dimension were significant factors of false-negative scans. In patients with a peripheral tumor smaller than 40 mm and normal levels of serum carcinoembryonic antigen, sensitivity, specificity, positive predictive value, and negative predictive value were 6%, 93%, 8%, and 90%, respectively. The reliability of computed tomographic scanning in this low-risk subgroup was high in detecting N0-1 disease but low in diagnosing N2 disease.

CONCLUSION

It is not possible to accurately diagnose N2 disease by using lymph node size on computed tomographic scanning alone, especially in patients with a central tumor, an elevated serum carcinoembryonic antigen level, or a tumor of 40 mm or larger. A preoperative invasive staging procedure is indicated in these populations and may not be indicated in the population with normal computed tomographic scan results without any of these risk factors.

[Usefulness of transbronchial punction and mediastinoscopy in mediastinal nodal staging of non-microcytic bronchogenic carcinoma. Preliminary study]

Preliminary study to compare the sensitivity and specificity of transbronchial needle aspiration (TBNA) and mediastinoscopy/anterior mediastinotomy (MED/AMED) and/or thoracotomy for staging of mediastinal nodes in non-small cell carcinoma. To determine the sensitivity and specificity of computerized tomography (CT) as a screening technique. Thirty-three patients with non-small cell carcinoma but no remote metastasis and good lung function were evaluated. A chest CT scan was performed before bronchoscopy in 27 patients and before surgery in the others. Nodular areas considered diseased based on CT images were staged by TBNA. When CT images were not available before bronchoscopy. TBNA for staging was performed in the subcarinal region. Results by TBNA were compared with those obtained by MED/AMED and/or thoracotomy. The prevalence of metastatic nodular disease was 47%. CT detected enlarged mediastinal nodes in 24 patients; the images were considered normal in 9 patients. Sensitivity and specificity of CT was 93% and 54%, respectively, with a positive predictive value (PPV) of 68% and negative predictive value (NPV) of 87.5%. The sensitivity and specificity of MED/AMED were 73% and 100%, respectively; PPV was 100% and NPV was 75%. The sensitivity and specificity of TBNA were 36% and 92%, respectively; PPV was 83% and NPV was 57%. The pneumothorax with pleural empyema suffered by one patient after MED could have been avoided, given that the earlier TBNA was positive. TBNA is a safe, useful technique for staging nodes in non-small cell carcinoma. Although the sensitivity of TBNA is lower than that of MED, regions that are difficult to reach with the latter technique can be sampled by TBNA. Furthermore, MED can be rendered unnecessary by positive TBNA results. CT imaging of the chest is sensitive but its specificity is low for detecting ganglial metastasis.

Vindesine-ifosfamide-platinum (VIP) induction chemotherapy in surgically staged IIIA-N2 non-small-cell lung cancer: a prospective study. Leuven Lung Cancer Group

PURPOSE

In the pioneer data from the Memorial-Sloan-Kettering group, preoperative mitomycin-C-vindesine-platinum (MVP) induction chemotherapy in N2-NSCLC was accompanied with substantial pulmonary toxicity. In this study, the efficacy and toxicity of three-drug VIP induction chemotherapy, the pathologic response in resection specimens, the early survival and relapse patterns are examined.

PATIENTS AND METHODS

Between June 1995 and March 1997, 39 consecutive patients with pathology proven N2-NSCLC were treated with three cycles of VIP induction, followed by definitive locoregional treatment (resection and mediastinal dissection or radical radiotherapy). Several patients had unfavorable prognostic characteristics with respect to clinical and biological findings, tumor location and bulk of disease.

RESULTS

The response rate to chemotherapy was 59% (95% Confidence Interval 34-75). Twenty-three responding patients had radical locoregional treatment: radical radiotherapy in four, resection in 19. Downstaging was present in nine of the 19 resection specimens, with two pathologic complete responses. The median survival time (MST) of all patients is 19 months, with a projected two-year survival of 49%. In patients responsive to chemotherapy who received definitive local treatment, the MST is not yet reached, and the projected two-year survival is 57%. Relapses were mainly distant, with isolated brain relapse as a disturbing finding. The main toxicity's were leukopenia and vomiting, but they were manageable. In contrast with MVP, no severe pulmonary toxicity occurred.

CONCLUSIONS

VIP is a suitable induction regimen for N2-NSCLC, demonstrating a good activity and very acceptable toxicity.

Clinical prognostic factors in surgically treated stage IIIA-N2 non-small cell lung cancer: analysis of the literature

There remains controversy on the prognostic value of several common clinical factors in NSCLC patients with resected N2-disease. The aim of this paper is to give a comprehensive overview of the available data on this issue. Literature data on surgically treated N2-NSCLC-patients from 1980-1995, peer reviewed and listed in Index Medicus, were analysed. Reported and calculated or estimated survival data were indexed. Eighteen series were selected: in 12 of them, direct comparisons between survival curves of subgroups are reported; six contained sufficient data to make comparisons of survivors at 5 years; three of them also made a multivariate Cox model. The analysis of prognostic factors in a single study was often hampered by the limited number of patients. Nonetheless, it could be concluded that patients with a clinical N0- or N1-status (so-called unforeseen N2) do better. There was no clear difference between patients undergoing lobectomy or pneumonectomy. There was strong evidence that N2-patients with a less advanced primary tumour (T-stage) have a better prognosis, and this is the case for all operable T-stages (T1 versus T2, T1 versus T3, T2 versus T3). Squamous cell type was a favourable prognostic factor, as was the presence of only one metastatic mediastinal lymph node station or absence of metastases to the subcarinal nodes. There was some evidence that the presence of extracapsular spread in metastatic MLN is an unfavourable finding. Stratification for these prognostic factors could help in the planning of future trials on combined modality treatment in N2-NSCLC.

Is it possible to differentiate malignant mediastinal nodes from benign nodes by size? Reevaluation by CT, transesophageal echocardiography, and nodal specimen

STUDY OBJECTIVE

To reevaluate whether it is possible to reliably differentiate malignant mediastinal lymph nodes from benign nodes by size, and to determine the frequency of metastases to normal-sized mediastinal lymph nodes that directly affects the sensitivity for detecting malignant mediastinal lymph nodes (N2 nodes) on CT.

DESIGN

Prospective study of patients with non-small cell lung cancer.

SETTING

Department of Radiology and First Department of Surgery, Yamaguchi University School of Medicine.

PATIENTS

We examined 40 patients with non-small cell lung cancer, who underwent thoracotomy because of operable stage (stage I, II, IIIA) in preoperative staging, using CT and transesophageal echocardiography (TEE).

INTERVENTIONS

None.

MEASUREMENTS AND RESULTS

Lymph nodes 10 mm or greater in short-axis diameter on CT and TEE were considered abnormal. Furthermore, lymph node size was measured by TEE and nodal specimens in long- and short-axis diameter in each patient. Two hundred eight mediastinal lymph nodes were dissected and N2 nodes were present in 28% of patients (11/40); in 7 of these 11 patients (64%), mediastinal lymph node metastases were misdiagnosed on CT because of normal-sized N2 nodes. Furthermore, in 73% of N2 nodes, nodal size was normal on TEE. There were no significant difference in both diameters between malignant mediastinal lymph nodes and benign nodes on TEE and nodal specimens.

CONCLUSIONS

It is not possible to reliably differentiate malignant mediastinal nodes from benign nodes by size alone, and we should be aware of high frequency of normal-sized N2 nodes in patients with operable stage of lung cancer.

Bronchogenic carcinoma: incidence of metastases to normal sized lymph nodes

BACKGROUND

The incidence of metastases to mediastinal lymph nodes was evaluated in patients with normal sized mediastinal nodes on the computed tomographic (CT) scan who underwent thoracotomy. The use of hilar lymph nodes in predicting mediastinal lymph node metastases was also assessed.

METHODS

Ninety patients with non-small cell lung cancer who later underwent thoracotomy wer prospectively examined by CT scanning. Lymph nodes with a short axis diameter of 10 mm or more were considered abnormal.

RESULTS

Mediastinal lymph node metastases were present at thoracotomy in 19 patients (21%). In 14 these lymph node metastases were misdiagnosed because the nodes were normal in size on the CT scan. In only one of the 19 patients with N2 nodes was an N1 lymph node enlarged, and four of the 19 patients with N2 nodes had metastases to these mediastinal nodes without N1 disease ("skipping metastases").

CONCLUSIONS

Metastases in normal sized nodes seen on the CT scan are a major problem in staging. Hilar lymph nodes did not help to predict reliably the presence or absence of metastases to the mediastinal lymph nodes.

The role of transcarinal needle aspiration in the staging of bronchogenic carcinoma

Metastatic spread to subcarinal lymph nodes in patients with bronchogenic carcinoma generally indicates unresectability. Transcarinal needle aspiration of the main carina (TCNA) has been used to obviate the need for more invasive procedures, particularly thoracic surgery. Of 510 transbronchial needle aspirations performed at our institution from 1983 to 1991, 88 (17 percent) were from the main carina in patients with bronchogenic carcinoma. We reviewed these 88 TCNA procedures to assess our experience with TCNA in the staging of lung cancer. The TCNA results were positive in 32 of 88 (36 percent) patients (20 non-small-cell cancers, 12 small-cell lung cancers). Following bronchoscopy, TCNA was the only evidence of unresectability in all 20 patients with non-small-cell lung cancer and was the only mode of diagnosis in 5 of 12 (42 percent) patients with small-cell lung cancer. Thirteen patients with non-small-cell lung cancer and positive TCNA also had positive bronchial secretion cytologic studies. Five of these patients had further subcarinal sampling and in all cases metastatic involvement was confirmed. TCNA was positive in 29 of 67 (43 percent) patients with radiographic evidence of mediastinal adenopathy. Of the remaining 38 patients with radiographic evidence of mediastinal adenopathy and negative TCNA results, 23 patients had further mediastinal sampling with mediastinoscopy or thoracotomy and in all cases mediastinal spread of cancer was established. Nineteen of 58 (33 percent) patients with an endoscopically normal-appearing main carina had a positive TCNA, while 13 of 30 (43 percent) patients with broadening or widening of the main carina had positive TCNA results. There were no complications. We conclude that TCNA is often a safe and useful staging modality in patients with bronchogenic carcinoma.

Surgical treatment for higher stage non-small cell lung cancer

Locally advanced lung cancer (stage IIIa, IIIb) in which the primary tumor is proximal (T3) or has invaded adjacent structures (T3) or organs (T4) or in which mediastinal lymph nodes are involved (N2, N3) worsens the prognosis significantly. However, in stage IIIa (T3 or N2), when surgical treatment results in total removal of the primary tumor and involved lymph nodes, there still is a reasonable chance for ultimate cure. On the other hand, total excision can be very rarely performed in T4 or N3 tumors. Therefore, this group (stage IIIb) usually indicates unresectability. Disseminated lung cancer with distant metastasis (stage IV) is still considered to be incurable. Nevertheless, solitary metastatic sites (M1), especially brain, have been treated on occasion by resection of the primary tumor and removal of the solitary metastasis. This appears to improve median survival and does yield 5-year survival in selected patients. The results after surgical treatment in these patients with higher stage lung cancer reported over the last 10 years are reviewed.

Aggressive surgical intervention in N2 non-small cell cancer of the lung

An aggressive attitude toward surgical treatment was taken in patients with N2 non-small cell lung cancer in the past 10 years. Computed tomographic scanning was employed in the diagnosis of N2 disease, and had a true-positive rate of 57%. Among patients with N2 disease detected by computed tomographic scanning, surgical intervention was attempted except for those with unresectable disease. Of 190 patients with clinical N2 disease, 115 underwent surgical exploration: 9 patients had only an exploratory thoracotomy, 53 patients underwent a curative operation, and 53 had a noncurative operation. The overall 5-year survival rate of these patients was 16% and that of curatively resected patients was 20%. There were 47 patients whose N2 disease was not recognized before operation. The 5-year survival rate of this group was 20% overall and 33% in curatively resected cases. The overall 5-year survival rate of patients with N2 disease who underwent resection (106 with clinical N2 disease and 47 with clinically unrecognized N2 disease) was 17%, and that of the 84 patients undergoing curative operations was 24%. An aggressive attitude toward surgical intervention can be advocated for patients with N2 disease on the basis of our present results.

Computed tomography to stage lung cancer. Approaching a controversy using meta-analysis

The ability of computed tomography (CT) to detect mediastinal lymph node metastases from nonsmall cell bronchogenic lung cancer is highly controversial, as evidenced by reported accuracies ranging from 0.35 to 0.95 over the past eight years. We examined all studies on this matter published between January 1980 and April 1988, both to describe the overall experience and to identify characteristics (study design and methodology and CT scan techniques) that influenced reported accuracy. Of 79 relevant publications, 37 were excluded because they were review reports, assessed small cell lung cancer, or contained insufficient evidence to construct a contingency table (CT result versus node histology). The pooled, unweighted (weighted) results based on the remaining 42 studies were as follows: sensitivity, 0.79 (0.83); specificity, 0.78 (0.81); accuracy, 0.79 (0.81). Using a node size greater than 1.0 cm to define a "positive" CT result, as compared to a smaller diameter, was associated with significantly higher specificity, 0.89 versus 0.76, and accuracy, 0.86 versus 0.75 (p less than or equal to 0.005), but not sensitivity, 0.79 versus 0.75. The observed differences in accuracy between a fourth generation CT (0.83) and either a third or a second generation CT, (0.77 and 0.78, respectively) were not significant at p less than 0.05. No characteristics, either singly or in combination, resulted in accuracies exceeding 0.86. There exists random variation of individual study results around an overall mean accuracy of only 0.79, which is marginally improved by advances in CT technology and methods. Significant advances in the noninvasive detection of lymph node metastases must await an approach fundamentally different from CT-determined node size.