Researchers have found one possible explanation for the link between obesity and poor cancer prognosis: cells from fat tissue are recruited to the blood vessels that feed tumours, actively supporting tumour growth.

Mikhail Kolonin and his colleagues at the University of Texas Health Science Center at Houston grafted tumour cells into obese and lean mice that were fed the same diet. Tumours grew faster in the obese mice than in the lean ones. The researchers found that fat-progenitor cells were mobilized into the bloodstream in the obese mice and were more abundant in the tumours of these animals than in those of their lean counterparts. In the tumours, the progenitors developed into fat cells and cells that support blood vessels. Tumours with a greater contribution from fat cells had a more extensive and functional vasculature, and grew faster.

Cancer Res. 72, 5198–5208 (2012) http://dx.doi.org/10.1158/0008-5472.CAN-12-0294