Eastshire Communications Health Report
Jsnuary 2012 Edition

Immunological biomarkers for diagnosing cancer

Limitations in current methods of diagnosing cancer

Conventional methods of cancer diagnosis involve obtaining a tissue biopsy from a primary tumor and evaluating its histopathological characteristics. These characteristics include abnormal morphology of the cells, size of tumor, depth of invasion through tissues, and extent of vascularization. This information is used to assign a stage or extent of the cancer. However, the stage of cancer can be of limited value in prognosis as cancer outcome can vary significantly among patients with the same stage. This lack of predictability is due to the assumption that tumor progression is largely a cell directed process without considering other factors, such as the host immune response.

Developing an immune score to diagnose cancer

The immune system protects the body from invading organisms through a process of inflammation. Since cancer cells are derived from normal body cells, the immune system may have difficulty in recognizing the cells as foreign, and may only mount a weak response. A chronic inflammation response is non-specific and is characteristic of wound healing. This type of response promotes cancer cell proliferation and angiogenesis (blood vessel growth). An adaptive or acute immune response results from detecting specific proteins called antigens on the organisms or cancer cells. This leads to the production of antibodies that attack and destroy these cells.

Many studies have shown that the presence of immune cells within tumors result in better prognosis for the patient, and may provide insight into an effective immune therapy. Based on these studies, Galon and co-workers proposed a simple immune score, which quantifies the density and location of specific immune cells within the tumor. The authors point out that the density of two types of lymphocytes, cytotoxic and memory T cells are associated with low risk of relapse and metastasis and high overall survival.

What is the promise of using an immune score?

References

Ascierto, Maria, et al. “An immunologic portrait of cancer
A href="http://www.biomedcentral.com/1755-8794/4/282011,4: 28-42.

Dsis, Mary. "Immune Regulation of Cancer"
Newsletter Archive 2011