You can use nude mice and implant human cancer, simple injection of cells in matrigel. But nudes doesn't have their own immunological system.

Otherwise you can use SCID or Rag2, gamma chain KO mice to perform tumor cell graft (in a matrix scaffold) or injection subcutaneously in mice back in order to promote tumorigenesis.

Good luck

You can also inject human cancer cells intraperitoneally into SCID mice and monitor their development using bioluminescence (IVIS) or CT.