Doctors are telling me they can't give me a prognosis because the cancer i have is so rare. is that true?

Yes and No: It is true that doctors may not be able to give prognostic information if there is little prior experience with that kind of tumor. However, as a general principle, tumors with distant spread are worse than localized tumors. Tumors that are resectable are better than unresectable tumors invading important structures. More information is needed to give you any "prognostic" advice.

What is the name of: If you can give us the name of the cancer, we can give you fairly good idea about the prognosis. It will depend on the stage of your cancer.

Possible: It is possible. Some rare cancers may have very little data on them historically or with enrollment to clinical trials. One example are rare sarcomas. In those cases the best "evidence based medicine" (ebm) may be anecdotes from experts. Rare diseases might be less rare from disease experts at specific centers.