The paranormal investigator and star of the A&E series spoke about his battle with the disease on his Facebook page.
"You all also know that Ryan is the type of person that not only likes to keep things relatively private, but wants to make sure that others are taken care of first," a member of the Paranormal Research Society wrote on his fan page.
"Ryan has been honoured and humbled by the support, but also wants to make sure that we all remember the struggle is not his alone.
"There are those who have struggled with this disease for years, those who are diagnosed every day and those within the support network surrounding them. Ryan knows he is loved and supported, and would want for that love and support to stretch beyond this community."
Buell himself posted: "I know there are many of you suffering from illnesses, and not just cancer. I say to all of you: SOLDIER ON!
"I know the pain that you will feel. And the pain for treatment. I still say SOLDIER ON! Let's think of one another during those moments, even though we don't know each other."
The 30-year-old has appeared in the paranormal reality TV series since 2007, and founded the Paranormal Research Society when he was 19.
Paranormal State has so far run for five seasons on A&E.