<s>[INST] My brother has colo rectal CA, I have read articles saying IV vitamin C can shrink the tumor. He is not into alternate medicine. They have given him 6 months to 1 1/2 years to live. But to take chemo is so devastating to most peoples quality of life, and to go though all that trauma when maybe this will shrink the tumor and give him some quality of life. it has also spread. Thanks [/INST] Hi, I had gone through your question and understand your concerns.I am afraid that the answer is no. There is no any scientific evidence that Vitamin C in any form can cause postitive effect on tumor spreading or shrinkage. So this is not good option as a replacement for chemotherapy. Vitamin c may improve immune system but there is no direct relation with tumor. So you should reconsider chmeotherapy with some less agressive protocols such as folfirinox. Vitamins in general can be taken and cant be harmful at least...Hope this answers your question. If you have additional questions or follow up questions then please do not hesitate in writing to us. I will be happy to answer your questions. Wishing you good health. </s>