Leukocyte migration inhibition assay of tumor immunity in patients with cervical squamous cell carcinoma

The leukocyte migration inhibition test was used to study specific tumor immunity in carcinoma of the cervix. The test was done by the capillary tube method using Sykes Moore chambers. Test antigen was extracted from the ME‐180 cervical squamous cell carcinoma cell line (either uninfected or infected with herpes simplex virus type II) by the hypotonic lysis, low frequency sonication method. Control antigen preparations from nonsquamous cell carcinoma tissues were also used. Thirty patients with invasive cervical carcinoma, sixteen patients with cervical dysplasia or in situ carcinoma, nineteen normal controls, and forty patients with other malignancies were studied. There was a significantly greater degree of leukocyte migration inhibition by the cervical cancer antigen among the leukocytes of the patients with invasive cervical carcinoma than in the other four groups. Mean migration indices were .55, .89, .93 and .91 in the four groups, respectively. Significant migration inhibition (defined as a migration index under 0.70) was not frequently seen among the leukocytes of the patients with in situ carcinoma or cervical dysplasia. Significant migration inhibition was not seen in any group with the control antigens. The antigen from herpes infected cells inhibited migration to a slightly greater degree than the antigen from noninfected cells. More vigorous reactions were seen in patients under the age of 50 than in patients over the age of 50. In patients with invasive carcinoma there was no relationship of the degree of migration inhibition to the stage of disease (Stage I‐IV). These data indicate that 1) there is specific tumor immunity in cervical carcinoma, 2) that there may be a common antigen expressed on the ME‐180 cell line and 3) that the tumor burden may have to reach either a critical size or level of invasiveness before it can elicit a host reaction detectable by these methods.