Women have hidden defence against cancer
For patients with breast cancer, it is vital that breast tumours are detected and treated, before the cancer cells manage to spread. Scientists from the Johns Hopkins University in the US have discovered that special breast cells in women probably prevent that.
Most breast cancer tumours originate in cells along the inside of the lactiferous ducts, i.e. the ducts that proceed from the milk glands towards the nipple. Around those, there is a layer of muscle cells that can stretch and contract to carry the milk through the lactiferous ducts. But myoepithelial cells can do more than that, the scientists discovered. The muscle cells also function as police officers that can catch loose cancer cells. They reach out to get hold of the cancer cells that escape through the muscle layer, subsequently pulling them back to the inside of the lactiferous duct.
The scientists watched the muscle cells capture cancer cells 105 times out of the 114 cases, in which they observed an escaped cancer cell. Later experiments also showed that the defence is most efficient, when there are many muscle cells in a dense layer, and that, moreover, they are rich in actin proteins which they use for contraction purposes.
The experiments were made using breast tissue from mice, and they can help predict the risk of metastases in individual breast cancer patients, so, doctors can plan the best individual treatment.