For patients getting the common FOLFOX chemotherapy for colorectal cancer, many oncologists add intravenous calcium and magnesium, hoping to decrease the neuropathy (nerve damage) associated with oxaliplatin-based drugs.
But this week, experts at the 2013 ASCO meeting (American Society of Clinical Oncology), announced strong evidence that the calcium/magnesium does no good in either preventing or decreasing neuropathy—and it should no longer be part of routine treatment.
Neuropathy affects cancer treatment
Oxaliplatin-based chemotherapy (e.g. FOLFOX, with Eloxatin®) is one of the most commonly used drugs for people having high-risk stage II, or stages III or IV colorectal cancer. But far too often after patients have had many doses of FOLFOX over months, they have to stop this effective treatment because of increasing neuropathy—burning or numbness especially in hands and feet that becomes chronic, even permanent.
Based on two earlier preliminary studies (and biological reasoning), many oncologists began giving calcium and magnesium intravenously a half-hour before and/or after the chemotherapy, in an effort to prevent the nerve damage.
But in results from the first large, randomized trial announced at this week’s ASCO meeting, researchers found absolutely no effect from the calcium/magnesium.
Trial shows no benefit
A multisite trial randomly assigned 350 colon cancer patients receiving FOLFOX into three groups—one receiving the calcium/magnesium before and after chemo; a second receiving a look-alike placebo; and the third group getting calcium/magnesium before chemo and a placebo afterwards.
Also, there were no differences in the average number of days until symptoms became significant, or in the number of patients who had to stop the chemotherapy.
“This study did not demonstrate any activity of IV CaMg [calcium magnesium]…” said lead author Charles Loprinzi from the Mayo Clinic. He noted that when he has asked medical meeting audiences how many use intravenous Ca/Mg, more than half the clinicians present say they do.
“This practice should now be stopped,” he told Medscape Medical News in an interview.
Practice-changing results; lesson learned
The study was called “practice changing,” by Dr. Richard Wilson from Queen’s University Belfast in Northern Ireland, speaking at a “Highlights of the Day” ASCO session.
The lesson learned, Dr. Wilson said, was that the original 2004 French study was not randomized and too small for definitive proof, but raised doctors’ hopes. Another 2011 study by Mayo Clinic’s Dr. Axel Grothey (a Medical Advisory Board member for Fight Colorectal Cancer) also showed promising early results. But Grothey’s study had to be stopped early before it could get enough participants because of concerns (later disproven) from a different ongoing study. Studies have shown that the calcium/magnesium infusion does not cause harm, and does not interfere with other chemotherapy drugs’ effectiveness.
If you are currently getting chemotherapy based on oxaliplatin (e.g. FOLFOX, CapeOx), ask if you are also getting a calcium/magnesium intravenous infusion. If you are, take some time to discuss your particular case with your doctor—because another lesson we’ve learned is that every individual situation is different.
This is also an excellent example of why you see recommendations for treatment, tests, and diet change over time. Science—and our understanding of cancer—builds step by step, as evidence and lessons are learned from many tests done over time.
For more information: You can ask further questions by email in advance, or live by phone, in the upcoming webinar reviewing ASCO called “What’s New and What’s On the Horizon” on Wed., June 19, at 8-9:30 pm. ET. Click here for more information or to register.
- “Phase III randomized, placebo-controlled, double-blind study of intravenous calcium/magnesium…” 2013 ASCO meeting and Journal of Clinical Oncology 31, 2013 (suppl; abstract 3501)
- ‘Stop Using Calcium and Magnesium With Oxaliplatin,” June 3 2013 Medscape News
- Intravenous Calcium and Magnesium…”, Grothey, Feb. 1 2011 Journal of Clinical Oncology
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