A miniscule “smart bomb” could become the latest weapon in the fight against cancer. Researchers in the US have developed a molecular-sized device that penetrates deep inside tumours where it explodes, destroying the cancerous cells but leaving the healthy ones intact. This means that debilitating side-effects from anti-cancer drugs such as hair loss and sickness could be eliminated.Doctor Ram Sasisekharan said: “Once these balloons are trapped inside the tumour micro-environment, they act like a smart bomb releasing the chemotherapeutic agent so you can have a very high dose of focal chemotherapeutic agent that could kill the tumour cells.” In another development, French scientists have identified a set of genes which enable breast cancer to spread to the lungs. The genes also reveal how virulent the cancer could be. The lungs, with the bones, liver and brain are the main organs to which breast cancer spreads. Caught early, there is a reasonable chance breast cancer can be treated successfully but once it has spread medical treatment is less effective.