We believe that Automated Cytometry of Quantitatively (AQC) stained cells from sputum and buccal mucosa provide information that can be used to guide the management of patients at risk for lung cancer. We have studied whether it is possible to construct a management regime for patients at risk of developing lung cancer based on sequential application of simple assays.
Induced sputum specimens and buccal scrapings were collected from 120 patients with confirmed lung cancer and 810 high risk negative patients. The specimens were prepared to slide and stained using the Feulgen-thionin process, which highlights DNA distribution in cell nuclei. They were scanned using a fully automated image cytometer which produces a single score for each specimen, indicating the likelihood of presence of malignancy. The buccal and sputum cytometry scores were compared to see if the assay results provide essentially the same information or if they complement each other. The answer to this question suggests how the two tests can be used for patient management.
The correlation of the tests’ outcomes was significant (correlation=0.37) and suggests the assays could be used in a sequential approach for managing patients. The buccal assay eliminated 262 negatives (32%) at the cost of 9 false negatives (7.5%). See the figure below. After the addition of the sputum assay results, 87 lung cancer cases were deemed “suspicious” (72.5%) at the cost of 125 (15.4%) false positives.
A simple buccal test can eliminate one third of patients from more comprehensive testing. The further application of the sputum assay provides high sensitivity and specificity for detecting lung cancer. The AQC testing approach has undergone a validation trial involving 1183 patients from clinical sites in six countries. Patients were accrued from March 2003 until October 2004. Results of the trial will be unblinded in June 2005 and presented at the conference.
Cytometry based assays may prove to be an important tool for management of high risk patients.
Bojana Turic, Employee Perceptronix Medical Inc.