Vitamin K Boosts Cancer Drug Effects

Every year, at the American Association for Cancer Research annual meeting, thousands of scientists gather to share their own research and learn about the latest findings from others who study cancer. At the recent 2009 Annual Meeting, Dr. Brian Carr presented work that he and his colleagues at Thomas Jefferson University in Philadelphia conducted to show that a simple, non-toxic nutrient, vitamin K, may increase the effectiveness of a cancer treatment medication called sorafenib (Nexavar). This type of medication, known as a kinase inhibitor, has been used to treat kidney and liver cancer, and now is being studied as a possible treatment for other cancer types, including colon cancer.

The study was conducted in the lab, using liver cancer cells, and demonstrated that at different dose levels of sorafenib and vitamin K, the combination of the drug and the vitamin together was more effective at killing cancer cells than either substance alone. The researchers concluded that vitamin K, which is a non-toxic nutrient, can decrease the amount of the drug sorafenib that is needed to cause cancer cell death.

Why Does This Matter?

This research is exciting for a number of reasons, but one of the most important is that it points the way to the possibility of treating cancer more effectively, with fewer toxic side effects. One of the major problems with many current cancer treatment medications, including sorafenib, is that they can have serious, toxic side effects. In some people, the side effects can become severe enough that the dose of the drug being given must be reduced, to a potentially less-effective level, or the treatment must be discontinued altogether.

For someone coping with cancer and it's treatment, this can be devastating. Just when you think you may have a way to better manage your disease, you find out that your body cannot tolerate that medication. But the research presented by Dr. Carr offers hope. By combining this particular medication, sorafenib, with vitamin K, doctors may be able to more effectively treat cancer with a lower, less toxic dose of the drug.

Is Vitamin K for Me?

Before you add vitamin K to your pillbox, it's important to keep a few things in mind.

• This study was conducted in cancer cells in a laboratory. We don't yet know if adding vitamin K to the sorafenib treatment plan of a person with cancer will have the same effect.
• The study was conducted using liver cancer cells. The medication in question, sorafenib, is being studied as a possible treatment for colon cancer, but more research is needed to determine that this is a good approach for cancers other than liver.
• Vitamin K is very safe, and considered non-toxic, but it can interact negatively with some medications that are used during cancer treatment. In particular, if you are taking medications to manage risk of blood clots, including blood thinners (anti-coagulants) such as warfarin (Coumadin) or heparin, do not take vitamin K without first talking to your doctor. This nutrient can interfere with the actions of blood thinners, making them less effective and increasing the risk that you end up with a serious blood clot.

It may be fine for you to use vitamin K in an effort to improve the effectiveness of your colon cancer treatment plan, even though we don't yet have all the answers. However, talk to your doctor first, before you take vitamin K or any other dietary supplements. For some people, vitamin K may be worth a try. For others, however, the risks may far outweigh any possible benefit, and if this is the case, it is better to err on the side of caution and skip the vitamin K. With the help of your doctor, you can make an informed choice, while being sure to avoid harmful interactions with other medications you are taking. Only you and your doctor, working together, can decide what's right for you.