This has been an amazing year with unexpected findings.
We were all convinced that when we added Erbitux and Avastin to our chemotherapy, it would work in the adjuvant setting, which means with FOLFOX for 6 months after the successful removal of colon cancer.
But it did not work. Neither Avastin nor Erbitux showed any benefit. How is that possible?
This forces us to go back to the drawing board and get smarter and learn from these experiences. What we must assume is that when you treat with these antibodies, it does not work when you only have microscopic disease.
The reason tumors recur is because some cancer cells are left behind. Some of these cells are stem cells and can’t get killed with chemotherapy.
We have demonstrated benefit in patients with metastatic disease. When you take Avastin, tumors that are visible and big and need to grow up regulate VEGF which is bound away with Avastin. But what can Avastin do when the cancer cells are very small and don’t need VEGF to survive?
One discussion asks whether we should give adjuvant Avastin for a longer time. However there are also side effects seen when treatment with Avastin was extended to one year.
Erbitux also did not work. Why not?
I don’t think we have the answers, but it forces us to think about the difference of cancer and its microenvironment between cancer which has spread and is active and cancer which only exists in the form of a few cells somewhere.
We need to develop smarter therapies and how to select the effective therapy like we have begun to do in metastatic patients. Interestingly, KRAS mutation did not help to select patients who benefitted from Erbitux in the adjuvant setting . Maybe EGFR is not the right target? These results, even through disappointing will force us and industry to rethink and use our molecular biology of cancer to come up with more effective strategies.
Also, I want to mention diet, exercise and supplements in this setting. We need to invest more resources and research to understand what else we can do to reduce cancer recurrence. There are interesting data on exercise, aspirin, vitamin D and diet rich in vegetables. We need to systematically test these possible interventions.
In addition we need to develop a complete new class of medications which attack the colon cancer stem cells, because if they are not removed, they will cause recurrence. Research is going on at USC which may be successfully address this ongoing problem.
September 21, 2010 at 12:10 pm, rob said:
I have metastatic colon cancer. Resection in 12/06, diagnosed with metastatic colon cancer in April 2009.
No chemo since, ever, DCA (sodium dichloroacetate), aspirin, lots of vitamin D3, artemisinin, Metformin, fish oil, and a few other things have kept me symptom free and feeling fine for 17 months.
Is any of this a cure, probably not but I have had a 50% reduction in tumor size and stable desease. I could live like this a long time.
OR I could just be an anamoly. Maybe my tumors, which were very aggressive and grew quickly to 4.8 cm (one) in just a few months, just happened to stop and regress when I started taking DCA. I was clean from 12/06 till 12/08 and had the large tumor plus two others found four months later in April 2009.
The one thing that I know worked was the DCA since I took nothing else initially and that is when I had the tumor shrinkage.
I also think that the DCA and Metformin may be killing my cancer stem cells keeping me stable.
I am being watched and CT scanned at a top New York City cancer center and at the moment they agree with not starting chemo. Also am looking into clinical trials such as that for G202, Thapsigagin, a sister drug to Artemisinin.
DCA also attacks angiogenisis I believe. Never understood why Avastin was used for adjuvant therapy since there is little such with cancer stem cells.
September 23, 2010 at 9:02 pm, John OCOnnor said:
ROB,
THANK YOU FOR THE POST. WHERE ARE YOU BEING TREATED?
JOHN