Avastin

This was part of a reply to a question on another cancer site. I found it extremely interesting and was wondering if anyone else knew anything about this:

There is no evidence that Avastin works alone. In fact, there is some evidence that it doesn't.

A clinical trial with three arms compared chemotherapy alone, chemotherapy with Avastin, and Avastin alone. When patients appeared to get no benefit from Avastin given alone, that arm was dropped. Tumors in that arm progressed as quickly as if no drugs were being given.

The other important issue to consider is that Avastin has some significant side effects. They are different from what we often think of chemo side effects like nausea or diarrhea, but they can be life-threatening. Heart attacks, strokes, gastrointestinal perforations (holes in the intestines), and bleeding do occur and sometimes are deadly.



I think we were surprised that Avastin didn't work alone. The original idea that Avastin worked by shutting down blood supply with its food and oxygen to tumors may have been too simple. High resolution scans of blood vessels around tumors finds that they are twisted and leaky. Instead of blocking new blood vessels, Avastin appears to strengthen the blood vessel system so that chemotherapy can be delivered to the tumor more effectively.

Avastin is sometimes prescribed alone when the standard treatments for colorectal cancer aren't working anymore. Doctors see it as "something to try." But doing something isn't always better than doing nothing at all, especially when there is some evidence that a treatment doesn't work and evidence that it might be harmful.