The clinical significance of cytology versus histology-based diagnosis in small cell lung cancer: a retrospective study

OBJECTIVES

The aim of this study was to investigate the clinical significance of cytology versus histology-based diagnosis among patients diagnosed with small cell lung cancer (SCLC).

MATERIALS AND METHODS

Retrospective analysis of medical records of 443 patients with histologically or cytologically confirmed small cell lung carcinoma (SCLC) was performed. All patients received platinum-based chemotherapy regimens. Survival data (overall survival) were compared between patients with histology or cytology-based diagnosis in the overall study population as well as after stratification of patients according to disease stage (limited or extensive) at the time of diagnosis.

RESULTS

Distribution of demographics and clinicopathological characteristics among the two groups ("histology" and "cytology") was similar. No statistically significant differences in the survival curves between the "histology" and "cytology" groups were found in the overall study population (log rank test, p=0.237), as well as in the subgroup of patients with limited disease (log rank test, p=0.474). In contrast, patients with histology-based diagnosis had a statistically significant longer survival as compared to those with cytology-based diagnosis in the extensive disease subgroup (log rank test, p=0.031), but this association was not retained after adjusting the analysis for demographics and clinical characteristics via a Cox regression model (HR=1.18, 95% CI: 0.96-1.44, p=0.110).

CONCLUSION

The results of our study suggest that the type of diagnostic modality employed (histology or cytology-based) for the establishment of a diagnosis of SCLC may not have a significant effect on the overall survival of patients. Further studies are warranted to further investigate this important, yet rather unexplored, issue.

Multitarget Fluorescence In Situ Hybridization Elucidates Equivocal Lung Cytology

The category of equivocal respiratory cytology is a common diagnostic dilemma to both cytopathologists and clinicians. Chromosomal alterations are a hallmark of cancer but are rare or absent in benign conditions. The goal of this study was to test the ability of multitarget fluorescence in situ hybridization (FISH) for dissecting equivocal respiratory cytology into reactive and malignant categories. A consecutive series of 54 Papanicolaou-stained cytologic specimens of the lung was analyzed. The Papanicolaou-stained atypical cell groups were photographed, and the exact locations on the specimens were saved using automated stage and relocation software. The specimens were hybridized with a multitarget FISH probe that contains a mixture of fluorescent probes to the centromeric region of chromosome 6 and to the 5p15, 8q24 (site of the MYC gene) and 7p12 (site of the EGFR gene) loci. The hybridized atypical cells were selectively scored after relocation. A final diagnosis was available in 45 patients, revealing lung carcinoma in 55.5% (n = 25), no evidence of malignancy in 37.8% (n = 17), and pulmonary metastasis of another primary carcinoma in 6.7% (n = 3). FISH results were negative in all 17 patients with benign pulmonary disease and positive in 20 of the 25 patients (80%) with lung carcinoma (p < 0.0001). The sensitivity, specificity, and positive and negative predictive values for detection of malignancy were 79%, 100%, 100%, and 74%, respectively. These data suggest that multitarget FISH in conjunction with automated relocation is a powerful approach for the elucidation of equivocal lung cytology.

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.

Estimation of performance and sequential selection of diagnostic tests in patients with lung lesions suspicious for cancer

CONTEXT

Measuring variation in clinician test ordering behavior for patients with similar indications is an important focus for quality management and cost containment.

OBJECTIVE

To obtain information from physicians and nonphysicians regarding their test-ordering behavior and their knowledge of test performance characteristics for diagnostic tests used to work up patients with lung lesions suspicious for cancer.

DESIGN

A self-administered, voluntary, anonymous questionnaire was distributed to 452 multiple-specialty physicians and 500 nonphysicians in academic and private practice in Pennsylvania, Iowa, and North Carolina. Respondents indicated their estimates of test sensitivities for multiple tests used in the diagnosis of lung lesions and provided their test selection strategy for case simulations of patients with solitary lung lesions. Data were analyzed using descriptive statistics and the chi(2) test.

RESULTS

The response rate was 11.2%. Both physicians and nonphysicians tended to underestimate the sensitivities of all minimally invasive tests, with the greatest underestimations reported for sputum cytology and transthoracic fine-needle aspiration biopsy. There was marked variation in sequential test selection for all the case simulations and no association between respondent perception of test sensitivity and their selection of first diagnostic test. Overall, the most frequently chosen first diagnostic test was bronchoscopy.

CONCLUSIONS

Physicians and nonphysicians tend to underestimate the performance of diagnostic tests used to evaluate solitary lung lesions. However, their misperceptions do not appear to explain the wide variation in test-ordering behavior for patients with lung lesions suspicious for cancer.

The utility of transbronchial (Wang) fine needle aspiration in lung cancer diagnosis

We evaluated our experience with transbronchial fine needle aspiration (TBNA) in cancer diagnosis over a period of 1 year. A total of 51 aspirates were performed by specialist chest physicians in the presence of a cytopathologist who made on spot evaluation of Diff-Quik smears for adequacy and guided the aspirator for additional sampling if necessary. Two clusters of at least 10 malignant cells were required on the Diff-Quik smears to render an on the spot positive diagnosis of malignancy. Aspirates showing atypical cells or few malignant cells not fulfilling the above criteria were placed in a suspicious category and additional material was requested. The TBNA results were correlated with the transbronchial biopsy when available.

Increasing use of bronchoscopic needle aspiration to diagnose small cell lung cancer

OBJECTIVE

To review pathology reports to determine whether a temporal change in diagnostic procedures that included bronchoscopic needle aspiration (BNA) in evaluation of small cell lung cancer (SCLC) had occurred.

METHODS

A retrospective review of the computerized pathology database of the Wake Forest University Baptist Medical Center from 1990 to 1998 was performed. All pathology reports of patients newly diagnosed with SCLC were reviewed and abstracted.

RESULTS

The number of patients newly diagnosed with SCLC during the 9-year study period totaled 277. Of these, 173 underwent bronchoscopy. From January 1990 to December 1991, 32% (8/25) of bronchoscopies done in patients with SCLC included BNA compared with 81% (120/148) (P < .001) from January 1992 to December 1998. In addition to the increased use of BNA in patients with SCLC undergoing bronchoscopy, the overall diagnostic yield for BNA in SCLC significantly increased over the 9-year study period from 50% (4/8) in 1990 and 1991 to 88% (106/120) thereafter (P = .001). Overall sensitivity of BNA during bronchoscopy was 86% for SCLC with only a small increase in sensitivity with use of all procedures (including BNA) to 91%. The use of forceps biopsy and bronchial brushings decreased over this period.

CONCLUSION

With progressive experience with BNA, the frequency of its performance and its diagnostic yield in patients with SCLC increased markedly. The SCLC yield may be a worthwhile marker of BNA program development.

The role of pRb2/p130 protein in diagnosing lung carcinoma on fine needle aspiration biopsies

The retinoblastoma gene family is composed of three members: the retinoblastoma gene, one of the most studied tumor suppressor genes, and two related genes: p107 and pRb2/p130. These proteins are also known as the pocket proteins due to a unique structural and functional domain composed of subdomains A and B separated by a spacer region that is highly conserved among each of the proteins. These proteins exhibit unique growth suppressive properties that are cell type specific, suggesting that although the pocket proteins may complement each other, they are not fully functionally redundant. With the development of antibodies recognizing these three proteins it is now possible to detect expression in formalin-embedded specimens. Recent studies on 235 lung cancers, using immunohistochemical techniques, suggested an independent role for Rb2/p130 in the development and/or progression of human lung carcinoma. We found a statistically significant inverse relationship between the histological grading (degree of malignant potential) and the expression of pRb/p105, p107 and pRb2/p130 in squamous cell carcinomas, meaning that an increase in grading resulted in a significant decrease in protein expression. This phenomenon was particularly evident for pRb2/p130 (p < .0001) which had the highest percentage of undetectable levels in all the specimens examined and the tightest inverse correlation (p value) with both the histological grading and PCNA expression in the most aggressive tumor types, suggesting an important role for pRb2/p130 in the pathogenesis and progression of certain lung cancers. We further explored the expression of pRb2/p130 protein in routine archival FNAB cytological material from 30 Patients with lung cancer using immunocytochemical techniques, comparing protein expression with tumor type. Two pathologists evaluated the staining pattern and scored the percentage of positive cells. Of the 30 neoplasms, 27 displayed a positive staining for pRb2/p130. In particular, we detected pRb2/p130 in 9 (100%) squamous carcinomas, 11 (84%) adenocarcinomas, 5 (100%) BAC, and 2 (66%) SCC. The percentage of positive nuclei varied in different tumors with the highest expression level in adenocarcinomas. Immunocytochemistry represents a sensitive method for detection of pRb2/p130 expression in cytological or archival specimens, and the level of detection seems to be comparable to paraffin sections. Therefore, this methodology could be used in the preoperative evaluation of routine cytological specimens in order to improve the diagnostic and prognostic evaluation of lung cancer patients.