Although post-traumatic stress disorder (PTSD) is more commonly associated with traumatic events, such as a natural disaster or with veterans returning from war zones, a recent study found that many cancer survivors experience PTSD several months after diagnosis.

The study, which was published in the American Cancer Society's journal CANCER, found that approximately one-fifth of cancer patients experienced PTSD several months after diagnosis and many were still living with PTSD years later.

Caryn Mei Hsien Chan, Ph.D., of the National University of Malaysia, studied 469 adults with various cancer types within one month of diagnosis. Patients underwent additional testing after six months and again after four years.

Chan's research found that the risk of PTSD was 21.7 percent at six months, but dropped to 6.1 percent at the four-year follow-up. Although overall rates of PTSD decreased with time, roughly one-third of patients initially diagnosed with PTSD were found to have persistent or worsening symptoms four years later.

"Many cancer patients believe they need to adopt a 'warrior mentality', and remain positive and optimistic from diagnosis through treatment to stand a better chance of beating their cancer. To these patients, seeking help for the emotional issues they face is akin to admitting weakness," said Dr. Chan.

"There needs to be greater awareness that there is nothing wrong with getting help to manage the emotional upheaval — particularly depression, anxiety, and PTSD — post-cancer," she said.

Chan also stressed that many patients live in fear that their cancer may come back, and they may think the cancer has returned with every lump or bump, pain or ache, fatigue or fever. In addition, survivors might skip visits to their oncologists or other physicians to avoid triggering memories of their past cancer experience. This can lead to delays in seeking help for new symptoms or even refusal of treatment for unrelated conditions.

"We need psychological evaluation and support services for patients with cancer at an initial stage and at continued follow-ups because psychological well-being and mental health — and by extension, quality of life — are just as important as physical health," said Dr. Chan.

According to the American Cancer Society, 1,688,780 new cases of cancer will be diagnosed this year — 4,630 new cases every day. The ACS projects that cancer will cause 600,920 deaths in 2017.