Mast cells in squamous cell esophageal carcinoma and clinical parameters

Esophageal carcinoma is a malignancy with a poor prognosis and new treatment modalities must be sought. One possibility that has been tested in patients with malignant melanoma is treatment which aims towards boosting the immune system. In the present study, we investigated the role of mast cells in patients with esophageal carcinoma. The intention was to determine whether a higher number of mast cells is associated with better survival and may thus be a marker for future immunotherapeutic studies.

A total of 61 archived tumor samples were retrieved of patients having received treatment due to esophageal carcinoma at the Department of Oncology, Uppsala University Hospital, Sweden. The tissue specimens were fixed in formalin, embedded in paraffin and sectioned in 3 microm-thick sections. The monoclonal antibody G3, recognizing the mast cell-specific protein tryptase was used, and the avidin-biotin-horseradish peroxidase complex (ABC/HRP) and diaminobenzidine (DAB) techniques were used to visualize tryptase-positive cells. The positive cells were counted in 10 randomly selected high power fields.

When the number of mast cells was investigated in conjunction with relapse, no correlation was found (p=0.38). The number of mast cells was also not associated with survival (p=0.96). Using a pre-defined cut-off value of 31, no significant changes in survival was found (p=0.79) between patients with mast cell numbers above this value compared to those with numbers below.

We conclude that mast cells do not seem to be related to prognosis in patients with esophageal carcinoma.