The story you heard is at least second hand (friend of a friend) and so is likely to have at least been exaggerated and embellished along the way in the telling.
No, there's no evidence and certainly no proof that emotions and feelings, suppressed or otherwise, can trigger cancer.
Cancer happens when normal cells change so that they grow in an uncontrolled way. This uncontrolled growth causes a tumour to form. It's difficult to see how a person's emotions, suppressed or not, could cause this to happen.
Nor is there a scrap of evidence to support the idea that stress, emotional upset or depression causes or contributes to any cancer.
This link is to is an interesting Dutch study of 9700 women; it found that the development of breast cancer had no link with personality, and no link with anxiety, anger, depression, or optimism.
This research is a prospective study, which means that at the start of the study nobody had breast cancer; the women were followed for 13 years. Many studies of stress etc are retrospective - asking people after they have had cancer if they were stressed, depressed etc, which of course is far less reliable.
http://www.webmd.com/breast-cancer/news/…Stress, depression, emotional trauma and suppressed feelings are easy and popular explanations for cancer, but there's no scientific evidence that demonstrate a causal link, and no evidence that the contributes to or cause any cancer or affect the course of any cancer.
