His team analysed the 2016-2017 National Health Survey data for more than 4,500 cancer survivors and found that almost 35% of them suffer from chronic pain, defined as pain on most days or every day for six months. Researchers found no significant relationship between the type of pain and the time elapsed since the diagnosis of cancer, according to the study. This is an estimated 2.5 million people who have survived cancer across the country. And 16 per cent experienced such severe pain that their daily activities were limited. WebMD does not provide medical advice, diagnosis or treatment. There are about 5.4 million people living in the country. It was published on June 20 in JAMA Oncology magazine.