In their continual search for answers, cancer patients often question every aspect of their lives. What caused them to become sick? Environmental factors, genetic disposition or maybe even stress? The strange comfort that comes from knowing something, anything, may be less secure than originally thought.

In the third installment of its Preventing Cancer series, today's NY Times examines the link between stress and cancer. As more and more cancer patients connect the disease to personal stress, researchers are looking deeper into the validity of the connection. One hypothesis suggests that that stress may suppress the immune system cells that fight cancer cells, but as of today there is no definitive proof that stress actually causes cancer.

According to Dr. Barrie Cassileth, chief of the integrative medicine service at Memorial Sloan-Kettering Cancer Center, even people who have experienced extreme stress like being a prisoner of war or losing a child had no higher incidence of cancer.

The link between stress and cancer may have come from patients' desperate need to understand why the disease happens. “People need answers,” Cassileth told the Times. “They are at a loss to understand why that happened to them.”