On August 18, the Aussie celeb posted a cryptic message on the Facebook page for Love Your Sister:
"sorry for my silence
gotta get it through my head first
back soon i promise
Followers flooded the post with supportive comments that insinuated Sam was speechless at the news that Love Your Sister had finally raised $10 million.
"If it’s true and you’ve reached it..... then you are allowed to feel pride. You are amazing!" wrote one person.
"Have you done it Sam? My gut feeling says that’s it ... and the reality may be overwhelming ...Either way we are here ... waiting for you. Take your time. Sending you much love & strength xxxx" wrote another.
Sam - who won a Gold Logie in 2017 after playing Molly Meldrum in the miniseries Molly - famously quit acting in order to raise money for Love Your Sister.
The actor is pragmatic about the role his notoriety played in helping him raise $10 million to fight cancer.
"I’ve leveraged my profile within an inch of what’s possible," told WHO last month.
"I’ve used it to subsidise my philanthropic pursuits. Anyone who sees me as a showbiz guy has got the wrong idea about me. I’ve just never felt I belonged in showbiz, and I still don’t."
After Connie received her terminal diagnosis in 2010, the siblings devoted themselves to raising money for cancer research.
Sam's sister was also awarded a Medal of the Order of Australia for her service to those with breast cancer before she passed away in 2017.