Tumor Markers

A tumor marker is defined to be a tumor-specific substance produced by a tumor, or antigen. However, a tumor marker is also defined as a tumor-associated substance or antigen even when microdose substances exist in the normal non-cancerous condition since a tumor markers existence is not usual in human beings. Therefore, most tumor markers belong in this category. In the lecture clinical applications of tumor markers are to be discussed by disease by in the gynecological field. (1) Among untreated cases of all ovarian carcinoma, the positive rates were 78.1% for CA 125, 42.2% for CA 19-9, 60.4% for TPA, 72.0% for IAP, 24.0% for CEA, 64.9% for Ferritin and 50.0% for PP5. In serous cystadenocarcinoma CA 125 indicated 86.0% and CA 19-9 indicated 59.4%, whereas with mucinous cystadenocarcinoma, CEA indicated 37.0%. Among 61 cases, the highest values was 45.9% as shown in the larger quantity of 1,000 U/ml. (2) Positive rates for all ovarian carcinoma in the recurrence were 83.3% for CA 125, 88.9% for IAP, 88.9% for Ferritin and 66.7% for TPA. (3) In order to improve the cancer detection rate, a combination assay of tumor markers was used. Using discriminant function values the resulting higher cancer detection rates of 85.7% sensitivity, 100% specificity, and 93.2% accuracy in all ovarian carcinomas were achieved. (4) No differentiation of sensitivity between tumor marker and CT diagnosis system was found in the relationship. (5) Localization of antigen on CA 125 in surface membrane, microvilli, intercellular membrane and secretory granules of cytoplasma inside cancer cells was proved by immunoelectron microscopy. (6) The following rates were demonstrated;22.6% for stage I, 56.0% for stage II, 80.0% for stage III, 100% for stage IV and 54.7% as a whole by TA-4(SCC antigen) in diagnosing cervical squamous cell carcinoma. Positivity in recurrences was 57.1%. Therefore TA-4 is less useful for detecting early cervical cancers. (7) It is sugges ted that positivity of each tumor marker was low and helpful for diagnosing endometrial carcinomas, as CA 125 and CA 19-9 showed positive rate of 50% respectively. It is necessary to develop new combination assay for the future, since tumor markers only alone are not sufficient treatment. Radioimmunomaging and missile therapy are expected to be developed in the future.