In this study we have analysed the impact of chemotherapy in the acquisition of the CAF-like, catabolic tumour stroma phenotype, which emerges in stromal fibroblasts in contact with cancer cells, and is characterised by increased glucose uptake, lactate production and extracellular acidification, increased expression of αSMA, augmented production of ROS, an activation of the JNK/AP1, HIF1, TGFβ/SMAD, STAT3 and NFkB stress-induced pathways, senescence and autophagy, and a greater secretion of inflammatory cytokines. This evidence concerns the gene STAT3 and cancer.