This is per his daughter, Angela, on Facebook minutes ago:
"I wanted to post an update on Dad, although not a happy one. He has been
diagnosed with an aggressive form of carcinoma. We do not know much,
but we will be seeking appointments with specialists and having more
tests during the coming days. I will let you know when there is an
update. Thank you again for all of your thoughts and prayers."
RIP David Cassidy
46 minutes ago