People under the age of 40 often think they have no chance of getting cancer and delay seeing their doctor if they have a worrisome symptom. Some cancers, like testicular cancer or Hodgkin's disease, are examples of cancers more likely to occur in younger people. Some researchers have been interested in the question of the relationship of an individual's personality and the development of cancer. For instance, several studies have concluded that people who have difficulty expressing anger are more likely to develop cancer. These studies have serious flaws in the way they were conducted, and most cancer specialists do not believe any link exists between personality and cancer.
Cancer is too complex a disease to be explained by a single cause.
There is no scientific evidence that a person's personality could cause the development of cancer. The same may be said about the idea that people under severe stress are more likely to develop cancer because they were emotionally upset for a long period of time. This area of research, however, deserves further study. There does seem to be some association between severe stress, combined with other physical and genetic factors , which may contribute to heart disease, ulcers, and other ailments. Scientists continue to study the relationship between the onset of these diseases and high levels of stress.