Sergii, normally, tissue that is consumed should be broken down in the digestive system and the body's immune system should also help block allograft transmission. However, I recall that Tasmanian devils (marsupial dogs) suffer from endemic oral cancer in which the cancerous cells appear to be the infectious agent and spread from animal to animal (devil facial tumour disease (DFTD)) when the devils rub their faces together. There is a variant that affects placental dogs which is normally blocked by the dog immune system.

Although not consumption there was a study recently published in Cell showing leukemia transferring between soft shell clams (see: http://www.cell.com/cell/abstract/S0092-8674%2815%2900243-3). Very interesting stuff.

Adding to what Pawel just mentioned:

http://www.the-scientist.com/?articles.view/articleNo/42633/title/Clam-Cancer-Rips-Along-Atlantic-Coast/

I also happened upon this medical report in NEJM that might be of interest.

"Genetic Analysis of a Sarcoma Accidentally Transplanted from a Patient to a Surgeon"

http://www.nejm.org/doi/full/10.1056/NEJM199611143352004

check this out as well. 

in an animal called "Tasmanian devils", there is a tumor that can be transferred by the cancer cells between animals. Devil facial tumour disease (DFTD) is an aggressive non-viral transmissible parasitic cancer among Tasmanian devils. The most plausible route of transmission is through biting, particularly when canine teeth come into direct contact with the diseased cells.[10] Other modes of transmission include, but are not limited to, the ingesting of an infected carcass or the sharing of food, both of which involve an allogeneic transfer of cells between unrelated individuals.

http://en.wikipedia.org/wiki/Devil_facial_tumour_disease

Dear Sergii,

This is an interesting question, one that I have asked myself; and I am seeing for the first time being asked by some one else! Probably, no one wants to ask this and either do they want the answer; for one thing cancer is considered as a non-infectious disease, and this is very difficult to experiment ethically.

Now, let me tell you of something that happened in our place a few years back. There was a family that had a milch cow; and they sold the milk to many neighbors. Then one family member and two or three neighbors developed cancer and soon the cow too developed it. Then the people started blaming the family saying that it was the milk that had spread the cows cancer to others. Of course Oncologist allayed the fears that cancer does not spread from person to person or cow to person. I used to tell this story to Senior medical students and ask their opinion; invariably they (having learnt it during pathology class) say the same. Then I asked them will you drink that cow's milk and 50% will now honestly back track, and say: No. To the 50% who still say Yes, I will drink it, I ask: Will you give to your (future) children. They too will now say No. Any rare individual who still says Yes, will say No if asked whether they will eat its meat.

So, even when we say No, cancer is not infectious, we are not sure and not ready to take any risk.

In a more scientific perspective, I have read (I am not sure of the references, but they should be available in the internet) that clustering of cancer of cervix and penis has been reported from same street; well it could be due to viral infection too. Horizontal transmission of Lymphomas is also noticed; again viruses can be blamed (As long as viruses are there, they can be blamed as causes, rather than the cancer cells). In the DFTD too, some one will soon come up with the finding that viruses are being transmitted and they cause the cancer. This is the easiest way out.

I also read somewhere (? in Israel) that a male boy with Leukemia was given bone marrow transplantation by his female twin. He recovered and later  relapsed. But the leukemic cells now showed Brr bodies suggesting that the donated cells had become malignant!.

My question is this: If human cancer cells can grow in mice and guinea pigs, why can't they grow in other humans?

Narayanan

More on the Tasmanian Devils. It seems that viral transmission has been thoroughly ruled out.

http://www.wired.com/2010/01/tasmanian-devil-cancer-mystery-solved/

http://www.livescience.com/27804-contagious-devil-tumor-disease.html