The data also showed that, over the last decade, more than 1.2 million people under the age of 65 have been diagnosed with cancer.
This includes 343,000 people in the UK who were diagnosed with cancer in their 20s, 30s or 40s between 2006 and 2015.
Lynda Thomas, chief executive of Macmillan Cancer Support, said: "Being told you have cancer changes your life, and it can leave people feeling as if they've been thrust into the unknown, bewildered and unprepared.
"But as more and more people are being diagnosed with cancer, it's important that we are all better informed about what to expect if we do one day receive this shocking news.
"Cancer is almost always life-changing, but it isn't always life-ending. Life with cancer is still life - you're still a dad, a sister, a grandparent, a friend."
Research among more than 2000 people for the charity also showed that cancer is the disease people feared the most (37 per cent), ahead of Alzheimer's disease (27 per cent), stroke (7 per cent), depression (4 per cent), heart disease (4 per cent) or multiple sclerosis (2 per cent).
And for one in 10 people in the UK (10 per cent), cancer is their biggest fear of all, ahead of losing a loved one, their own death or terrorism.
Projections suggest that around half of people will develop cancer at some point in their lives.
However, 90 per cent of people living with cancer surveyed by Macmillan said they were still living their lives as normally as they could.
Jane Ives, 49, a mum of two from Hampshire who was diagnosed with breast cancer in 2014, says: "Getting a diagnosis of cancer was probably the single most terrifying thing that has happened to me.
"My biggest fear by far was not seeing my children fully grow up. Not being there for those milestones in their lives - their graduations, their weddings maybe.
"While the fear never quite leaves you - you realise life goes on after cancer and you appreciate the here and now."
