Effector Memory T Cells, Early Metastasis, and Survival in Colorectal Cancer

In this study of patients with colorectal cancer, pathological signs of early metastatic invasion augured a poor prognosis, whereas the absence of these signs was associated with a good prognosis. Patients whose tumors had no signs of early metastatic invasion had evidence of a T-cell–driven immune response. Patients with colorectal cancer whose tumors had no signs of early metastatic invasion had evidence of a T-cell–driven immune response. Accumulating evidence suggests that tumor progression is governed not only by genetic changes intrinsic to cancer cells 1 but also by epigenetic and environmental factors. Inflammation is also a factor, and there is experimental evidence to support the idea that the innate immune system can promote tumor development through inflammation-dependent mechanisms. 2 , 3 Recently, increased production of inflammatory mediators, including tumor necrosis factor α (TNF-α), by stromal cells was found during cancer progression in mouse models of colorectal cancer. 4 – 6 These results are consistent with the association between an increased number of inflammatory cells in tumors and tumor progression. 7 – 10 By contrast, . . .