Williams GH et al. (2004) Diagnosis of oesophageal cancer by detection of minichromosome maintenance 5 protein in gastric aspirates. Br J Cancer 91: 714–719

Esophageal cancer is usually advanced by the time symptoms appear, and at this stage the prognosis is generally poor. Since combined surgery and chemotherapy are effective in early disease, there is a pressing need for a reliable screening test. A pilot study conducted at Addenbrooke’s Hospital in the UK offers a promising new approach.

Williams et al. have previously demonstrated that dysregulation of minichromosome maintenance (MCM) proteins is characteristic of early epithelial carcinogenesis, and they have used these biomarkers in diagnostic screening applications for cervical and genitourinary tract cancer. On the basis of this work, the authors have now devised an immunofluorometric assay to measure levels of minichromosome maintenance protein 5 (Mcm5) in gastric aspirates. Samples were analyzed from 40 patients with suspected or known esophageal carcinoma or symptoms of dyspepsia. Results were then compared to endoscopy and biopsy histology results.

Mcm5 levels in the samples from patients with esophageal cancer were shown to be significantly elevated. The test differentiated between patients with and without cancer with a high degree of sensitivity (85%, 95% confidence interval (CI) 62–97%) and specificity (85%, 95% CI 66–96%). Inflammatory conditions (including esophagitis and Barrett’s metaplastic esophagus) did not yield false-positive results. Ulcerative lesions did generate higher signals than seen in other patients without malignancy, but these were significantly lower than for cancer patients.

The authors conclude that the level of Mcm5 is an important marker of esophageal cancer, and they suggest that their method could be applied widely in diagnosis and screening.