He was offered a test drug from the center which he attributes to keeping him alive. When diagnosed in 2017, she was told that half of those with her prognosis would die within a year.
Farquharson of Heaton in Newcastle has been isolated for four months due to the risk from the coronavirus.
However, he managed to complete the 2,082-mile route while working from home alongside his wife Amber and his seven-year-old son Caspian.
Going about 30 miles a day, Farquharson chose the 2018 Tour because he watched it in its entirety after being diagnosed.
The ascent on the course is equivalent to five climbs of Mount Everest.
Speaking after he finished his feat, he said, “I’m upset and happy that it’s over, but it’s been so, so good.
“Strangely, the hardest part was halfway when I got out of the hills and it was flat. It was just less interesting to do, so it was quite difficult to stay motivated.
“Fundraising for the Sir Bobby Robson Foundation has really helped. I was always cycling when I had chemo.
“It helps you mentally, you can go out and think about something other than what’s going on and it makes a big difference.” ”
After his ride, which began on March 28, Mr. Farquharson was cheered by family and friends as he celebrated on a podium outside his home.
Among the crowd was Lady Elsie Robson, widow of former English football manager Sir Bobby, who founded the foundation in 2008. He died a year later from lung cancer.
Lady Elsie said, “What a wonderful achievement it is. I think Keith must be a very special man to finish this race and in such difficult circumstances. “
It is not the first time that Mr. Farquharson has taken on a physical challenge, after registering for the Great North Run two years after a triple diagnosis of cancer struck his family.
Within five months, he, his wife Amber, and his father were all diagnosed with cancer. His wife is now in remission but his father died in March of last year.