[Examinations with DNA cytometry of mouth and oropharyngeal lavage fluid as a screening method in diagnosis of malignancies of the mouth cavity and oropharynx].

Background: Due to a high rate of false negative results, cytologic examinations of scrapings are currently not very common in diagnosing squamous cell carcinomas of the upper aerodigestive tract. The purpose of the present study was to determine whether cytometric and cytologic examinations are suitable in diagnosing squamous cell carcinomas of the oral cavity and oropharynx.

Methods: Cytologic and cytometric examinations of rinsing fluid from the mouth and throat were performed in 14 patients with histologically confirmed squamous cell carcinomas of the oral cavity and oropharynx. The patients were asked to rinse their mouth and throat with 10 ml of Ringer's solution. The rinsing fluid was centrifuged and fixed. The sediment was then smeared onto glass slides and stained according to the technique of Feulgen. Quantitative DNA measurements were then performed using a TV-based image analysis system. The DNA indices, 2 c DI, 5 c EE, and DNA entropy were determined from the single-cell measurements.

Results: The results of the carcinoma patient group were compared to those obtained in 19 patients without any evidence of cancer (control group). With this method, malignant and benign cells could be distinguished in all cases, i.e., all patients with a carcinoma could be identified as positive by this examination, whereas patients without evidence of cancer were identified as negative in all cases.

Conclusions: The results of this pilot study show that quantitative DNA measurements might be a suitable tool for non-invasive screening of patients who are at high risk for developing a carcinoma in the upper aerodigestive tract and for follow-up of patients in order to detect tumor recurrence after successful initial treatment.