The presence of immune cells within tumors can predict how well cancer patients are likely to fare, according to a recent study. Researchers at New Zealand's University of Otagov found that colorectal cancer patients with a specific subtype of immune cells called effector regulatory T-cells, or effector Tregs, in their tumors were more likely to survive. The study, “Inclusion of BLIMP-1+ effector regulatory T cells improves the Immunoscore in a cohort of New Zealand colorectal cancer patients: a pilot study,” appeared in Cancer Immunology, Immunotherapy. The study included 32 patients with stage 2 colorectal cancer and followed them for more than five years. During this period, 13 patients saw their cancer come back, and 19 patients remained disease-free. Taking advantage of a new prognostic tool called immunoscore, the authors evaluated the patients and classified them in terms of presence of immune cells in both the center of the tumor and at the invasive margins, where tumor tissue and normal bowel tissue intersect. High immunoscore values, representing increased numbers of immune cells in the tumor, were found to be predictive of better colon cancer disease-free survival. Identification of the specific immune cells infiltrating the tumors showed that Tregs in the invasive margins was associated with better disease survival. Combining immunoscore with a measure of effector Tregs in colon cancer patients helped identify patients more likely to see their cancer return. "This information could be used to tailor existing therapies to be targeted to people who really need them, rather than taking a more blanket approach," lead author Kirsten Ward-Hartstonge said in a news release. "By measuring an individual patient's Immunoscore and 'effector Treg' immune cells, it may be possible to more accurately identify patients at high risk of getting their disease back and treating them more effectively." Current outcome risk evaluation methods fail in about a quarter of patients who are currently considered "low risk" and will eventually develop the disease again, Ward-Hartstonge said. These new findings can pinpoint high-risk patients so they may benefit from additional treatments.