Effectiveness of sputum cytology using ThinPrep® method for evaluation of lung cancer

Abstract

Sputum cytology is a non-invasive test for evaluating lung cancer. But, its sensitivity is yet lower than other tests. ThinPrep (TP) is an automated cytopreparatory method that has mucolytic and hemolysing effects. We compared 955 sputum specimens that were prepared by both TP and conventional preparation (CP). The nuclear details were more preserved on the TP slides, while the obscuring materials were more eliminated on the TP slides as compared with the CP. The cytologic rates of TP were 2.7% unsatisfactory, 4.7% normal, 81.0% benign, 2.4% suspicious, and 9.1% malignancy. The rates of CP were 7.9% unsatisfactory, 1.6% normal, 84.8% benign, 1.8% suspicious, and 4.0% malignancy. The false negative rates, relative to the histologic data for 352 cases which the tissue diagnosis was available, were 49.6% (TP) and 69.4% (CP). Sputum cytology using the TP method improves the diagnostic accuracy for evaluating lung cancer by reducing the unsatisfactory and false-negative rates.

Clinical application of the SurePath liquid-based Pap test in cytological screening of bronchial brushing for the diagnosis of lung cancer

“…The number of cases positively diagnosed using the CPS method was 76, whereas with the LPT only 80 cases were positively diagnosed. This may have been due to the large number of squamous cells obtained with the CPS method (Choi et al 2008), and the fact that the number of monolayer slides prepared for each specimen may not have been sufficient. In the cases of the eight SCC and one AC specimen examined using the LPT, the first slide showed no cancer cells, although carcinoma cells were found on the second one.…”

“…The liquid-based cytological test (LPT) is a useful cytological technique and its clinical application was approved by Food and Drug Administration in 1999. It is successfully used in sputum cytology for the preparation of clear cell monolayers through the removal of mucus, necrotic material and inflammatory cells (Wu et al 2009;Choi et al 2008).…”

The Implementation of Liquid-Based Cytology for Lung and Pleural-Based Diseases

“…The majority of these studies reported increased sensitivity and specificity for carcinoma by LBC compared to CP. Of the 955 Sp samples evaluated by Choi et al [2], 15 cases diagnosed as suspicious by CP were definitively diagnosed as malignant by TP. …”

“…Their global unsatisfactory rate decreased from 17 to 1% (9/75 vs. 1/97). Choi et al [2] evaluated 955 sputum (Sp) samples for which the specimens were equally divided between 1 DS and 1 TP and reported an unsatisfactory rate of 7.9 versus 2.7%, respectively. Of the 75 unsatisfactory specimens by DS, 42 were obscured by inflammation, blood or mucus while their correlate TP had a clear background.…”

Early proximal lung cancer diagnosis and treatment

“…However, because of the low percentage of bronchial epithelial cells in sputum or inadequate preparatory techniques, the sensitivity is usually low [23]. Induced sputum has found to be better than spontaneous sputum [24] and the ThinPrep technique has been shown to improve diagnostic accuracy by reducing the unsatisfactory and false-negative rates by a total of 30% [25]. The other limiting factor is the skill required for identifying subtle morphological abnormalities in cells; this results in significant variation in intra-and interobserver agreement in determining cancer cells [26].…”