its depends upon a cancer type. so which cancer are you working now..

i am planning to induce mammary tumour in wistar rats using DMBA

Its better to chose anticancer drug based on the reported properties of plant..

say for example, vinca rosea has antitubulin property so Vincristine is standard, podophyllotoxin has topoisomerase inhibition property so doxorubicin may work out. 

for breast cancer studies , Tamoxifen is best std drug 

It depends on type of cancer study and also what type of compound under screening and one specific standard has limited effect on specific cancer and but on other cancers so that firstly decide the cancer type and it is better to do in-vitro study for screening and finally do in animals for better search specific cancer activity....