Conversation so far:
when did Eric Carr become ill?
Eric Carr began feeling ill in February 1991, .
what was Eric Carr diagnosed with?
Eric Carr's medical tests initially revealed what appeared to be manageable health issues.
what was Eric Carr prognosis?
Eric Carr's further tests determined that he had heart cancer

Question: What did his band mates think of his diagnosis?
Self-contained rewrite: What did Eric Carr's band mates think of his diagnosis?