Cannibalism: The Church has always defended herself against the charge of cannibalism and has been horrified of the very idea. I doubt that the Church has ever actually formally anathamatized cannibalism. The thought is so very horrid that I cannot see how sane people can even wonder. In some sort of extreme case, I believe it would still be sinful, though I can't provide any evidence from the theologians.
Cremation: The Catholic Church has always condemned cremation. The Conciliar church has, of course, made cremation into a multi-million dollar business.
Organ transplantation: The Church has not formally condemned organ transplantation as long as the organ donor is truly dead. The question that is currently up in the air is whether "brain death" is real or if the organ transplant business has successfully redefined death in such a way that living people are murdered in order to harvest their organs. Personally, I believe that often, these days, people who are not actually dead are murdered for their organs. On the other hand, I do not believe this is always the case as some lay Catholic apologists believe. While I will not be an organ recipient, I would not absolutely reject organ donation for me or a family member as long as I was absolutely sure the potential donor was dead. The absolutely worst thing that goes on these days is for the organ donation vultures to descend upon a family and pressure them to allow organ donation, telling them how the "victim" will be able to give life to others, etc., and not allow them to see any real proof of death other than the doctor's word.