Here is a my selection of candidates as well as the reason for eligibility. Some were already mentioned.
Christopher Hitchens (oesophigeal cancer)
Harper Lee (in need of 24-hour care, elderly)
Penny Marshall (lung cancer)
Robin Gibb (liver cancer)
Larry Hagman (Notable liver problems, cancer)
Etta James (leukemia, dementia)
Gene Wilder (lymphoma)
Muhammad Ali (Parkinson's disease)
Andy Williams (Bladder cancer)
Stephen Hawking (ALS)
Zsa Zsa Gabor (Everything)
Fergie Frederikson (Inoperable Cancer)