To shrink tumors and detoxify the body are important approaches in TCM anticancer strategies, however, many ingredients are either too strong or toxic that they cannot be used internally. These include unprocessed herbs like:  

tian nan xing	Jackinthepulpit tuber	Rhizoma Arisaematis
ban xia	Pinellia tuber	Rhizoma Pinelliae
chuan wu	Common Monkshood mother root	Radix Aconiti
teng huang		Resina Garciniae
xiong huang	Realgar	Realgar

Or herbs for activating blood and removing stasis like:

san leng	Common Burreed tuber	Rhizoma Spargani
e shu	Zedoray rhizome	Rhizoma curcumae
shui zhi	Leech	Hirudo
su mu	Sappan wood	Lignum Sappan
meng chong		Tabanus Bivittatus

Common Burreed tuber

Zedoray rhizome

Leech

Or herbs in pungent and warming properties like:

gan jiang	Fried ginger	Rhizoma Zingiberis
fu zi	Monkshood	Radix Aconiti
rou gui	Cassia bark	Cortex Cinnamomi
xi xin	Chinese wild ginger	Herba Asari
bi bo	Long pepper	Fructus Piperis Longi

Monkshood

Sappan wood

Chinese wild ginger

Local applications of medicinal substances mean that the active ingredients of certain preparations are absorbed through the skin and then onto the cancer site. Through the slow absorption process, there is less risk to develop general poisoning reactions, it also enables drugs to bypass the interference from the kidney and liver as well as avoid adverse stimulation on the intestinal tract. During application, physicians will change the base constantly so as to avoid local reactions like itchiness and rashes appearing.