Kissing for breast cancer is not contagious. There are multiple causes of breast cancer, which may be related to long-term use of oral contraceptives, poor lifestyle, hereditary factors, obesity, environmental pollution, poor mood and other factors, there is no contagious, so breast cancer kissing will not appear contagious. Breast cancer is often manifested as breast lumps, breast skin changes, nipple overflow, axillary lymph node enlargement and so on. Breast cancer patients should pay attention to psychological adjustment and maintain a positive attitude towards life, which is conducive to the recovery of the disease. It is recommended to have low-fat diet, eat more protein-rich food, and eat more vegetables and fruits to supplement the vitamins and dietary fiber needed by human body. Breast cancer patients should go to the hospital in time, standardize the treatment under the guidance of doctors and have regular follow-up.