The main objective of this doctoral research was to expand the scientific knowledge on the complex interface between cancer and biological aging. In the first part, we started by studying stromal characteristics of breast cancers arising in young respectively old patients. Differences in stroma, could lead to a different behaviour of the tumour cells according to age. By laser capturing the stromal compartments of breast cancers from young and old patients, and comparing the gene expression profiles, we confirmed for the first time in humans, the presence of a Senescence Associated Secretory Profile and of Autophagy to Senescence Transition in older breast cancer stromal samples as well as differences in gene expression mainly in genes responsible for proliferation, dedifferentiation and migration into the extracellular matrix.

In the second part of the thesis, we investigated biological aging in the rest of the organism, and the impact from cancer treatment (by chemotherapy) on this process. In a retrospective study investigating several biological and clinical parameters of aging in young and old breast cancer patients, IL-6 showed to be a robust frailty marker. Next, we performed a prospective study in early breast cancer patients either or not treated with adjuvant chemotherapy, and tested if the natural evolution of clinical and/or biological aging markers was influenced by chemotherapy. We did not find convincing evidence that chemotherapy would accelerate biological aging in breast cancer patients.

(BELG J MED ONCOL 2018;12(1):29–32)