Previous studies show that the interior of a cancer tumour is a hostile environment with oxygen deficiency, low pH levels and lack of nutrients. The cells that survive in this environment are called ‘stressed cells’ and are considered to be more aggressive.  Earlier studies from the lab show a possible way of delivering chemotherapy drugs into these cells, with similarities between stressed cells and fat cells being noted.  They observed that in order to survive inside the tumour, the stressed cells go into a resting phase to become inaccessible to radiation and chemotherapy.  The current study shows that these resting cancer cells can still accumulate fat droplets which serves as fuel for them, when they later leave their resting phase to grow and spread.

The current study utilised patient samples to show that cancer cells similar to fat cells are located precisely in those parts of a tumour where there is oxygen deficiency, i.e. where the cells are stressed. Results show that it is the cancer cells that are similar to fat cells that are most capable of forming metastases. The group explain that only a very small percentage of the cancer cells that enter the blood stream are capable of forming metastases.  Data findings show that they can either use fat deposits for energy, to build their cell membranes, or to manufacture signal substances, or do all of this at the same time.

The researchers state that the connection between fat and cancer is also consistent with the well-known fact that obesity involves an increased risk of developing certain types of cancer. They hypothesize that obese persons have more fat particles in their blood, which could become accessible to the stressed cancer cells; it is also known that tumours in obese patients can be more aggressive.

The team surmise that this new knowledge can be used to fight the spread of cancer cells, which is the cause of most cancer-related deaths.  For the future, the researchers state that the more that is known about how the stressed cells accumulate fat reserves, the more that can be done to prevent them from acquiring this additional energy.