Immunosuppressive Acidic Protein (Iap) and Ca 125 Assays in Detection of Human Ovarian Cancer: Preliminary Results

Comparative Analysis of CEA and SCC Serum Markers with IAP in Human Lung Cancer

Serum levels of carcinoembryonic antigen (CEA), squamous cell carcinoma antigen (SCC) and immunosuppressive acidic protein (IAP) were measured in 37patients with lung cancers, in 24 with non-cancer pulmonary diseases and in 24 normal controls. We evaluated the sensitivity, specificity and accuracy of these three markers alone and combined. The highest specificity was observed for SCC (83.3%) and the highest sensitivity for IAP (94.6%). The best accuracy was obtained with the combined determination of CEA and SCC. In cancer and non-cancer pulmonary diseases the best correlation was observed between CEA and SCC (r=0.30 in cancer and r=0.45 in non-cancer pulmonary diseases). Although the IAP test is not specific in the detection of lung cancer, its use may be helpful in monitoring the acute phase reactions that occur very frequently in this malignancy.

Immunosuppressive Factors: Role in Cancer Development and Progression

The concept of the immunological surveillance against neoplastic cells was initially proposed by Erlich in 1909 and later elaborated by Burnet. This hypothesis states that the normal function of the immune system, in particular the cell-mediated immunity, is to recognize and destroy the transformed and proliferating tumor cells. The role of cell-mediated immunity during the first steps of tumorigenesis remains controversial. However, there is certain evidence about its importance in the progression and dissemination of cancer. The frequent immunosuppressed condition of cancer patients at tumor relapse or recurrence of secondary tumors is a clinical sign supporting this hypothesis, and many studies have demonstrated a defective immune response in patients diagnosed with advanced cancer. Several mechanisms of escape from the immune surveillance have been described, including the immunoselection of tumor antigen-negative variants, the downregulation of MHC class I expression, suppressive T cells, and the elaboration of immunosuppressive cytokines and other factors. Because of the technical difficulty of isolating the very small amounts from culture supernatants or body fluids, only a few of these substances have been characterized and studied with respect to their biological activity: transforming growth factor-β (TGF-β), the protein p15E, interleukin 10 (IL-10), prostaglandin E2 (PGE2), mucins, suppressive E-receptor (SER), immunosuppressive acidic protein (IAP), and adhesion molecules. The possibility of monitoring cancer patients by testing biochemical factors related to cancer growth led to a proposal to measure a number of these factors as tumor markers. Some of them, e.g mucins, enjoy the consensus of the oncologic community, as for some indications they can help the clinician in the management of cancer patients. Except for the class of mucins, the other above-mentioned immunosuppressive factors have not found any clinical application in the laboratory routine because the information deriving from their measurement, although of speculative and scientific interest, has limited clinical value at present. Nevertheless, even if they have no impact on patient management, these substances do have a potential role to play in the study of cancer patients, and should be taken into account when developing new therapeutic strategies.

Serum biomarkers for early detection of gynecologic cancers

Ovarian, endometrial, and cervical cancers are three of the most common malignancies of the female reproductive organs. CA 125, historically the most reliable serum marker for ovarian cancer, is elevated in 50% of early-stage ovarian tumors. For endometrial cancers, there are no established serum markers. SCC, which is the best studied serum marker for squamous cell carcinomas, has been unreliable; SCC is elevated in cervical squamous cell carcinomas ranging from 28–85% of the time. Recent proteomics-based analyses show great promise for the discovery of new and more useful biomarkers. In this review, we will discuss the currently utilized serum tumor markers for gynecologic cancers and the novel biomarkers that are now under investigation.

Serum immunosuppressive acid protein predicts lymph node metastases in patients with renal cell carcinoma

OBJECTIVE

To evaluate the usefulness of serum immunosuppressive acid protein (IAP) as a marker for lymph node metastases in patients with renal cell carcinoma.

PATIENTS AND METHODS

Serum IAP levels were studied in 73 patients with renal cell carcinoma, prior to therapy. Serum IAP levels were correlated with the clinical and the post-operative histopathological stage. A threshold value of 800 micrograms/ml was applied.

RESULTS

Statistical analysis revealed a better correlation between IAP concentration and disease than with any other variable. Sensitivity and specificity were 94% and 84%, respectively, thus providing good positive (65%) and negative (98%) predictive values regarding lymph node involvement.

CONCLUSION

Measuring serum IAP levels can be a valuable contribution to lymph node staging in patients with renal cell cancer. The choice of cut-off value of 800 micrograms/ml has yet to be supported by a larger series.

Immunosuppressive acidic protein serum levels in breast cancer patients in a reference to CA 15-3 levels

Immunosuppressive acidic protein (IAP) has been described as a tumor marker in a number of malignant diseases. To evaluate the clinical importance of IAP in breast cancer patients, IAP serum level was determined in 75 breast cancer patients, using single radial immunodiffusion. Serum samples were also tested for CA 15-3. Cut off value for IAP was determined according to IAP serum level in 50 patients with benign, non inflammatory, diseases, and was set as 725 microgram/ml. Mean IAP serum level (623 mcg/ml) and positivity rate (20%) in 24 breast cancer patients with active disease were similar to those in 51 breast cancer patients with no evidence of disease (590 mcg/ml and 18%). The mean CA 15-3 serum level and positivity rate were significantly higher in patients with active disease (200 units/ml, 67%), compared to patients with no evidence of disease (18.3 units/ml, 6%). In our experience IAP was not found to be an effective tumor marker in breast cancer.