Granting immunity.

We recently discouraged inferential leaps in treatment decisions based on tumor-infiltrating lymphocytes (TIL) alone. But, to be fair, it’s becoming more and more apparent that TILs are tumor witnesses we want on our side. As indications for effective immunotherapy expand, so too does our interest in understanding the influence of our bodies’ natural immune responses on malignancies. Last week’s JAMA onc pub measured degree of TIL in ovarian cancer specimens of >5500 women and prospectively observed overall survival times. Not surprisingly, longer survival was associated with the presence of TILs in a dose-dependent manner. Does this help us predict treatment response? Not exactly. But understanding tumor biology is a necessary precursor to the next wave of novel therapeutics, and this adds the immune system to a growing list of the body’s innate defenses (such as DNA damage repair and adhesion molecules) we can commandeer in the battle against ovarian cancer.