Immunosurveillance is the process by which the cells of the immune system, especially lymphocytes, look for, recognize and eliminate pre-cancerous and cancerous cells in our body. This forms the first step of the general process of immunoediting, which involves the transformation of cancerous cells to escape immunosurveillance giving rise to malignancy. The study of these processes, initiated by Burnet and Thomas in 1957, and supported by advances in the understanding of both antibody-mediated and cell-mediated immunity and the intricate complexity of the immune system, have since aided in the development of various cancer immunotherapies. These therapies aim at activating the immune system to combat and eliminate cancerous cells in the body.
Immuno-oncological approaches are opening new avenues in curative cancer treatment currently. Development of these therapies require specific and sensitive bioanalytical methods and customized oncology assays.
When it comes to immuno-oncology assessments, a broad range of analytical methods across diverse matrices, including tumor, blood, cells, and DNA/RNA, is necessary to paint the best, most informative picture. Options include the measurement of circulating proteins in the blood using immunoassays; the examination of the cellular component of the blood, including the analysis of circulating tumor cells and/or circulating free DNA via Flow Cytometry; and tumor gene expression by PCR.
Patient samples are precious and are often subject to limited availability — either in terms of the biopsy material available or blood volume restriction. This necessitates highly sensitive and reproducible assays capable of running small sample volumes, such as the multiplex assays described above. Immunoassays and flow cytometry allow more data to be generated from the smallest amount of sample. The measurement of gene expression is generally performed by quantitative real-time PCR, and multiplex or single plex ELISpot analysis is applied for the measurement of specific T- or B-cell responses. Flow Cytometry is applied for further granular information from these cells.