Cytology in diagnosis of cancer affecting the lung. Results in 1,000 consecutive patients

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.

Sputum cytology in suspected cases of carcinoma of lung (Sputum cytology a poor man's bronchoscopy!)

Aims:

To evaluate the role of sputum cytology in the diagnostic work-up of patients with suspected lung cancer

Settings and Design:

Spontaneously produced fresh sputum was analyzed in clinically suspected cases of lung cancer.

Materials and Methods:

Spontaneously produced fresh sputum was analyzed in 36 clinically suspected cases of lung cancer. It was carried out using the “fresh pick and smear” method, which employs examination of sputum for blood-tinged, discolored or solid particles and preparation of thin and even smears from these selected portions.

Statistical Analysis Used:

Average and means.

Results:

Sensitivity of sputum cytology was 60%, which increased with an increase in the number of samples examined.

Conclusions:

Sputum cytology in suspected cases of carcinoma of lung is a useful diagnostic tool. It may be called as a poor man's bronchoscopy.

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.

Cytologic approach to tumors of the tracheobronchial tree

Cytologic testing is an integral part of the workup of patients suspected of having lung cancer. These tests are less invasive than other tissue procurement methods, with minimal risk of complications. In experienced hands, the tests are highly accurate and reliable. To achieve good results and avoid diagnostic errors, clinicians must be educated in proper collection and fixation methods and the pathologist should be cognizant of clinical and radiologic data. Close communication between the clinician and pathologist should be encouraged.

Performance characteristics of different modalities for diagnosis of suspected lung cancer: summary of published evidence

STUDY OBJECTIVES

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

DESIGN, SETTING, AND PARTICIPANTS

A systematic search of MEDLINE, HealthStar, and Cochrane Library databases to July 2001 and print bibliographies was performed to identify studies comparing the results of sputum cytology, bronchoscopy, transthoracic needle aspirate (TTNA), or biopsy with histologic reference standard diagnoses among at least 50 patients with suspected lung cancer.

MEASUREMENT AND RESULTS

For sputum cytology, the pooled specificity was 0.99 and the pooled sensitivity was 0.66, but sensitivity was higher for central lesions than for peripheral lesions (0.71 vs 0.49, respectively). Studies on bronchoscopic procedures provided data only on diagnostic yield (sensitivity). The diagnosis of endobronchial disease by bronchoscopy in 30 studies showed the highest sensitivity for endobronchial biopsy (0.74), followed by cytobrushing (0.59) and washing (0.48). The sensitivity for all modalities combined was 0.88. Thirty studies reported on peripheral lesions. Cytobrushing demonstrated the highest sensitivity (0.52), followed by transbronchial biopsy (0.46) and BAL/washing (0.43). The overall sensitivity for all modalities was 0.69. Peripheral lesions < 2 cm or > 2 cm in diameter showed sensitivities of 0.33 and 0.62, respectively. Updating a previous meta-analysis with 19 studies revealed a pooled sensitivity of 0.90 for TTNA. A trend toward lower sensitivity was noted for lesions that were < 2 cm in diameter. The accuracy in differentiating between small cell and non-small cell cytology for the various diagnostic modalities was 0.98, with individual studies ranging from 0.94 to 1.0. The average false-positive and false-negative rates were 0.09 and 0.02, respectively.

CONCLUSIONS

The sensitivity of bronchoscopy is high for endobronchial disease and poor for peripheral lesions that are < 2 cm in diameter. The sensitivity of TTNA is excellent for malignant disease. The distinction between small cell lung cancer and non-small cell lung cancer by cytology appears to be accurate.

Prevention of lung cancer: summary of published evidence

STUDY OBJECTIVES

To describe empiric research related to lung cancer prevention strategies, including chemoprevention aimed at reducing lung cancer incidence and various smoking avoidance and cessation interventions aimed at reducing smoking rates.

DESIGN, SETTING, AND PARTICIPANTS

Systematic searches of MEDLINE, HealthStar, and Cochrane Library databases to July 2001 and print bibliographies. For chemoprevention studies, we considered only randomized controlled trials (RCTs) with lung cancer incidence as an end point. For studies of smoking avoidance or cessation, we selected systematic reviews and meta-analyses, and searched for individual RCTs only where high-quality and current reviews and meta-analyses were not available.

MEASUREMENT AND RESULTS

Chemoprevention of lung cancer has been studied in five RCTs of primary prevention, no RCTs of secondary prevention, and five RCTs of tertiary prevention. None of these trials has shown evidence for efficacy of any agents tested, including retinol (vitamin A), beta-carotene, N-acetylcysteine, and selenium. There is a great deal of evidence about a wide variety of clinician-based and community-based efforts at smoking avoidance or cessation. Certain approaches have been shown to be effective (eg, mass media public education campaigns, direct restrictions on smoking, clinician-based approaches ranging from brief clinician advice to more in-depth sessions, and "life-skills training" in schools). Some approaches have intermediate or short-term effectiveness (ie, youth access restrictions and school-based interventions), and others have been shown to be ineffective (ie, acupuncture and provider education) or have been insufficiently studied (ie, provider feedback).

CONCLUSIONS

There are no agents that have been proven to be effective for preventing lung cancer. Several clinician-based and community-based interventions show promise for reducing lung cancer incidence through smoking avoidance and prevention.

Innovative molecular and imaging approaches for the detection of lung cancer and its precursor lesions

Current approaches for the therapy of lung cancer, the majority of which being advanced cancers, have failed to impact on long term survival. The key to improvement lies in the combination of early diagnosis and the introduction of novel targeted therapies. In this article we review some of the innovative approaches, both imaging and molecular, that are currently under investigation for early detection. Because lung cancers may arise in the central or peripheral compartments of the lung, newer approaches must target tumours arising in both of these compartments. Specimens available for analysis include sputa and blood. Detection of genetic changes in peripheral blood is a promising avenue being explored by several groups. Molecular techniques discussed include gene mutations, detection of nuclear riboprotein, methylation related silencing of genes and malignancy associated changes. Newer imaging technologies include autofluorescence bronchoscopy, virtual bronchoscopy, optical coherent tomography and confocal microscopy. Although the impact of these new technologies on survival has not been determined, they offer a wide range of exciting new approaches. In time they may completely revamp the present highly conservative and unsuccessful approaches to early diagnosis.

Induced sputum in the diagnosis of peripheral lung cancer not visible endoscopically

The diagnosis of small peripheral lung cancer is difficult to achieve by non-invasive methods. We hypothesized that in these patients induced sputum might ncrease the diagnostic yield over spontaneous sputum, representing a good diagnostic alternative in selected patients. We prospectively evaluated 60 patients with peripheral lung lesions and normal bronchoscopic evaluation. Six samples of sputum (three spontaneous and three induced with nebulization of hypertonic saline) before bronchoscopy and six samples of sputum after bronchoscopy (three spontaneous and three induced) were obtained in each subject. Forty-two out of the 60 patients included were finally diagnosed with lung cancer. Eighteen patients were diagnosed with different benign conditions of the lung. Overall, malignant cells in sputum were observed in 21 patients and in all but one, the final diagnosis of lung cancer was achieved. Only one patient with a pseudoinflammatory tumour of the lung had a false-positive result in one spontaneous sputum sample. The diagnosis of lung cancer was obtained in 18 patients with the induced sputum (43%) and in 14 patients with spontaneous sputum (31%) (P=NS). Samples of induced sputum were more adequate for cytological analysis than samples of spontaneous sputum (P < 0.001). Of 13 patients with peripheral lung neoplasms of 2 cm or less in diameter, five were diagnosed using induced sputum (38%) and only one using spontaneous sputum (8%) (P<0.05). In conclusion, induced sputum is a valuable technique for the diagnosis of peripheral lung cancer. Induced sputum gives better quality specimens and better diagnostic yield in small lesions than the spontaneous sputum and may be indicated in selected patients with disseminated disease, inoperability or severe co-morbities.

Early diagnosis of lung cancer

Recent advances in computer-assisted image analysis, tumor biology, PCR-based assays, fluorescence bronchoscopy, spiral CT, endobronchial treatment modalities, and chemoprevention make it possible to re-examine the strategy of early detection in the comprehensive management of lung cancer.

Sputum cytology-positive, bronchoscopically negative adenocarcinoma of the lung

Among a total of 114 cases of resected lung adenocarcinoma that were examined by sputum cytologic study before bronchoscopy, 17 were sputum cytology-positive, but had no abnormal bronchoscopic findings. In most of these cases, the reason for detection was sputum and bloody sputum (58.8 percent). Pathologically, many cases were classified as stage III A or more (82.4 percent) due to mediastinal lymph node metastases. More than 70 percent of the cases showed vascular invasion. The proportion of well-differentiated cases was also high (52.9 percent). The prognosis of these cases was worse than sputum cytology-negative adenocarcinoma without abnormal bronchoscopic findings and better than sputum cytology-positive adenocarcinoma with abnormal bronchoscopic findings. There was no significant difference between these cases and sputum cytology-negative adenocarcinoma with abnormal bronchoscopic findings. Combined with the bronchoscopic findings, sputum cytologic study is useful for preoperative evaluation of lymph node metastasis and prognosis. This combined approach can provide information necessary to perform sufficient dissection of mediastinal lymph nodes and proper adjuvant therapy in sputum cytology-positive adenocarcinoma cases, even though there are no abnormal bronchoscopic findings.

The value of sputum cytology

OBJECTIVE

To assess the value of cytologic examination of expectorated sputum in the diagnosis and management of patients with suspected lung cancer.

DESIGN

Retrospective chart review.

SETTING

Inpatient wards, tertiary care university hospital.

MEASUREMENTS AND MAIN RESULTS

The charts of 357 patients were reviewed. Two hundred eighty-eight of the 357 patients had had initial sputum cytologic examination prior to other diagnostic procedures, of which 41 (15%) had positive cytologic results. Thirty-six of the 41 were confirmed histologically or shown to have metastatic spread by noninvasive tests. Of the 222 patients with negative or unsatisfactory sputum tests, 97 went on to bronchoscopy and 35 had needle-aspiration biopsies. In the population of patients whose chest x-rays were highly suggestive of primary or metastatic lung cancer, the positive rate for cytologic examination was 38/94 (40%). There was no false-positive test in this study. Of the 50 patients with positive cytologic results, five (10%) had diseases that were of a different cell type; two of these five (40%) had diseases that involved small-cell cancer. There was an unsatisfactory delay in obtaining these samples for analysis.

CONCLUSIONS

Sputum cytology was found to be too insensitive and insufficiently accurate to be included in the routine workup of a patient suspected of having lung cancer. The results of the test did not influence further diagnostic procedures. This test should, therefore, be reserved for patients considered on initial assessment to be too sick for further investigations and treatment.

Carcinoma of the lung. Who will benefit from surgery?

The present staging methods for non-small-cell lung cancer provide little more than epidemiologic assessment of prognosis for grossly defined groups of patients. Except in extreme instances, physicians can tell patients very little about their prognosis or the need for supplemental therapy. More effective and less toxic chemotherapeutic agents are needed to treat this disease. Although improved results have been attained with combination therapy in patients with good functional status and less advanced disease, little help is available for lung cancer patients with advanced disease. Treating this large group of patients remains a great challenge for the surgical and medical oncologist.

Sputum cytology for the detection of pulmonary metastases from colorectal carcinoma

Twenty-two patients with pulmonary metastases from adenocarcinoma of the colon and rectum had sputum samples examined for cytology. All patients had lesions demonstrated on chest roentgenography and eight patients also underwent bronchoscopy. Three or more sputum samples were examined for eight patients, two samples for seven patients, and seven patients had one sample only examined. In five of 22 patients, the sputum samples were reported to be unsatisfactory for cytodiagnosis. Of the remaining 17, nine patients had at least one positive result for metastatic adenocarcinoma and in two additional cases the sample showed atypical cells. The result was therefore positive or atypical in 11 of 17 patients (65 percent). The positive cytology rate reported (79 percent for multiple pulmonary metastases) represents an improvement compared with previously published work. In this study 14 patients had either one or two samples collected for cytology and it is likely that the positivity rate would have been higher if three samples had been collected.

Predictive value of sputum cytology

A 60 year old woman non-smoker with bronchial asthma of 6 years' duration, treated with aminophylline, salbutamol, and oral corticosteroids, was admitted because of increasing dyspnoea and productive cough. On examination she was in moderate respiratory distress with inspiratory and expiratory wheezes. Her chest radiograph was interpreted as normal. Two consecutive sputum examinations requested by a junior doctor reveal "malignant" cells.

Cytologic diagnosis of lung cancer. Principles and problems

This diagnostic seminar discusses the current status of the principles and problems of cytology as it is applied to the diagnosis of lung cancer. This discussion is divided into four major parts. Part I presents a discussion of cytopreparatory techniques and cytology of the lung in the absence of cancer. The cytology of benign proliferations which may mimic cancer is emphasized. The role of cytology in the diagnosis of pulmonary infectious organisms is noted. Part II discusses lung cancer as manifested in specimens of sputum, bronchial washings, and bronchial brushings. Part III presents some data on the validity of cytology with respect to role of specimen number and type in lung cancer diagnosis and cell typing in lung cancer. The continued usefulness and importance of multiple specimens of sputum for lung cancer diagnosis are documented. Part IV presents a brief synopsis of fine needle aspiration biopsy of lung cancer.

Sputum cytology by the Saccomanno method in diagnosing lung malignancy

From 1,488 patients, satisfactory sputum was available for cytologic diagnosis. Overall diagnoses were correct in 85.4% of patients, false negative in 193 patients (13.0%), and false positive in 24 patients (1.6%). In patients with a malignant lung process, cytologic diagnoses were correct in 228 patients (54.2%) and false negative in 193 patients (45.8%). In patients with primary lung cancer, the proportion of correct positive diagnoses increased from 0.47 to 0.87 with one to five sputum specimens examined. In patients with metastatic disease, the figures were 0.35 with one specimen examined and 0.38 with two and more sputum specimens. Cytologic typing accuracy was 67% for large-cell carcinomas, 73% for adenocarcinomas, 91% for small-cell lung cancers, and 98% for squamous-cell carcinomas. For the clinically most relevant groups of nonsmall-cell lung cancer and small-cell lung cancer, these figures were 99% and 91%, respectively.

Relative accuracy of diagnostic method in bronchogenic carcinoma

The definitive diagnosis confirming lung cancer by microscopic examination is indicated before the therapy whenever possible and particularly prior to undertaking thoracotomy in situations when tissue diagnosis is not achieved. In such situations the thoracotomy becomes diagnostic with the therapeutic procedure. In clinically suspected cancer of the lung, histological confirmation is usually available at times, and cytology confirmation must suffice. At Tata Memorial Hospital for cancer and allied diseases in Bombay, India, we analyzed retrospectively 298 cases, which were submitted for different diagnostic procedures in suspected lung cancer. The yield of positive tissue diagnosis of malignancy obtained by each method is described and discussed. We observed that transthoracic needle biopsy gives significant information on inflammatory diseases of the lung. The sputum examination makes the simplest revelation of malignant cells, to an extent of 53% at our institution for three successive samples.