The notification of the name of disease is a premise for making the system of informed consent more complete in case of cancer treatment. In Japan, however, the notification of cancer can hardly be said to have an attained social consensus. Considering that the notification can ultimately improve patients quality of life (QOL), the breast cancer group of our department informs all breast cancer patients of their diseases in principle. This paper reports and discusses the results of a survey by questionnaire on the notification of cancer in 100 patients with breast cancer. The notification of cancer was received favorably in 83% of the patients. For those who answered, the explanation on the notification was convincing and it accounted for 81%. An examination of background factors of patients who had not been convinced revealed that many of them were suffered from advanced cancer. After the notification, a human relationship with the family and friends aggravated few of them and improved in 30% (family) and 18% (friends), respectively. The notification of cancer was thus suggested to contribute to the improvement of QOL. Although 83% well received the notification of their own diseases, only 21% were affirmative for the notification of cancer in case of a member of the family. We medical professionals should make a further effort not to make the notification of cancer the pronouncement death but to make it an aid for patients to live better.