You can sleep in a room where a cancer patient has slept. The cause of cancer is not yet clear and may be related to factors such as heredity and diet. After suffering from this disease, the cells in the patient’s body will divide and spread indefinitely, and the impact on the body is relatively serious. However, it should be noted that cancer is not a contagious disease and does not cause transmission, so other people can sleep in the same room where a cancer patient has slept. In some cases, the immune system of a cancer patient is severely damaged in the later stages of the disease, and he or she is susceptible to bacterial or viral infections, which may lead to infectious diseases. Other people should disinfect the room before moving into the room where the cancer patient has slept to avoid the spread of infectious diseases. Cancer patients should go to the hospital in a timely manner and choose the appropriate method of treatment.