The intensity of the immune response to cancer is determined by the genes of each patient, according to researchers in the Department of Molecular and Cellular Biology at Roswell Park Cancer Institute. This finding will contribute to the early assessment of prognosis of patients and an individualized choice of optimal therapy. A paper describing this work is published in the current issue of Cancer Immunology Immunotherapy.

When cancer arises and begins to progress in the body, it encounters several types of cells that make up the immune system. This defense system recognizes the cancer cells as foreign elements and attacks them. In fact, it is likely that many early cancers are destroyed by immune cells before they can reach clinically detectable stage. However, the immune response varies among patients.

"Patients whose immune defense cells migrate massively into the cancer mass have a greater chance to escape invasive tumor growth and metastasis," according to Peter Demant, MD, PhD, lead author on the paper. "On the other hand, the patients whose cancers are not infiltrated by large numbers of immune cells have a greater chance of early recurrence of cancer after surgery, invasive growth and/or metastasis."

Attempts to enhance the immune system to destroy cancer have focused on the development of therapeutic vaccines that boost the capacity of the immune system to destroy the cancer cells and efforts to find out how immune cells leave the blood circulation and enter the tumors in hopes of increasing the presence of immune cells in tumors. Although both approaches have yielded important information, neither has provided a workable solution to the problem of failure of immune cells to invade the cancer.

Dr. Demant's research team applied a new strategy to attack this problem. "We wanted to know why the immune cells in some patients migrate into the tumors and why in others they do not," explains Dr. Demant. "Our hypothesis was that it is the genes of each individual that determine the intensity of each individual's immune response."

Laboratory studies led the investigators to a novel group of genes that have not, until now, been known to play a role in the defense against cancer. The present work aims to identify precisely the genes that regulate this process. "These novel genes will have a great potential in assessing the prognosis of each patient and the probability that immune cells will be able to invade cancer," notes Dr. Demant.

Until now, the ability of immune cells to infiltrate cancer could be assessed only after a surgery or biopsy, when cancer tissue can be examined for the presence of immune cells. With the new method, the probability of immune cells invading the cancer can be established before the surgery, actually even before any cancer has developed, and help physicians choose the optimal treatment for each patient.

Moreover, the researchers conclude, the understanding of the function of these genes will open the way toward the manipulation of the pathways they regulate, so that the body's defenses can be specifically augmented.

Roswell Park Cancer Institute, founded in 1898, is the nation's first cancer research, treatment and education center and is the only National Cancer Institute -designated comprehensive cancer center in Upstate New York. RPCI is a member of the prestigious National Comprehensive Cancer Network, an alliance of the nation's leading cancer centers. Roswell Park has affiliate sites and collaborative programs in New York, Pennsylvania and in China.

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