The retired Celtic player was diagnosed with the illness in July 2009 and was left in a critical condition after it spread to his brain and lungs.
Following chemotherapy and emergency surgery, the cancer was successfully removed from his body and he set up the John Hartson Foundation in 2010 to raise awareness of the illness.
The 38-year-old, who played 51 times for Wales during his career, has hosted a series of fundraising events for the foundation, including hikes up Ben Nevis.
He was speaking today as he launched his charity's first celebrity golf day in Scotland, which will be held at The Carrick on the banks of Loch Lomond in March.
He said: "I get amazing support in Scotland, hence why my charity office is based in East Kilbride, and three out of the four people that work for the foundation are Scottish, so that tells you one thing."
Stars taking part in the golf day include football veterans Neil Lennon, Ally McCoist, Robbie Savage and Alan Shearer, while former Westlife singer Brian McFadden and professional golfer Marc Warren will also take part.
Hartson said : "I've never asked for anything from anyone in my life, but I've been a little bit out of my comfort zone and had to call on a few favours from several people, but the response and support that I've had has been overwhelming.
"I'm sure it will be a great experience for everyone involved, but there's a serious side to it all too - we're raising awareness of testicular cancer in the hope that men will get the message about checking themselves and not leave it as long as I did if they have any worrying symptoms.
"I nearly died because I ignored lumps on my testicle and I don't want other families to go through the same heartache and worry that mine did."
Hartson was joined at the launch today by other former Celtic players Frank McAvennie and Murdo MacLeod.
McAvennie, who was sporting multicoloured golf trousers, said he expected some big competition from celebrities participating in the event.
"Oh it'll be very competitive, that's a certainty," he said.
"As you can see with the outfits we have on today, it'll be who can wear the brightest on the day.
"Savage and Shearer take their golf as serious as their football, so it'll definitely be competitive but good fun."
The foundation hopes to raise thousands of pounds to support cancer patients and their families.