Cancer Goggles

June 6, 2014

By Medical Discovery News

Cutting people open and sewing them back up for a living is a pretty stressful occupation to begin with, but some surgeons have tougher jobs than others. Cancer surgeons are charged with removing all tumor cells on the first try. But tumor growth can be irregular and it can be hard to distinguish cancer cells from normal cells during an operation. Imaging techniques like MRIs and CT scans can give surgeons a road map to the tumor, but they offer only limited help once an incision has been made.

This is because these images are merely snapshots – a single frame and dimension. Even three-dimensional images can only be viewed one frame at a time. In addition, the inside of the body is dynamic and it takes a skilled surgeon to understand the orientation of tissues and the precise margins where tumor tissue ends and regular tissue begins. 

Because of this challenge, surgeons often have to remove healthy tissue to be sure all tumor cells are gone. This requires a special step: staining the removed tissue then looking at it under a microscope to identify the cells. The surgeon wants to be sure a margin of healthy tissue is removed so no tumor cells remain.

If tumor cells remain, they will grow and second operation may be necessary to remove more cancerous tissue. Again, the removal of additional healthy tissue will be necessary. But what if a surgeon could distinguish cancer cells from normal cells during surgery? It seems impossible. Each cell is microscopic, thousandths of a millimeter. Just observing cells takes special staining and high-powered optics.

But scientists at the University of Missouri and Washington University in St. Louis are working on the impossible. They are developing cancer goggles that will allow surgeons see tumor cells right in the operating room. This new technology uses LS301, a fluorescent dye combined with a short chain of amino acids called peptide, that is only absorbed by cancer cells and glows under infrared light. This dye specifically stains cells from prostrate, colon, breast, and liver cancers among others. Patients can be injected with the dye beforehand and it will last through a procedure.

These special goggles will illuminate cancer cells with LS301 using an infrared light source. A surgeon can distinguish glowing cancer cells from normal cells and observe when they are completely removed. As a result, the surgeon would not need to remove a margin of healthy tissue to be sure all cancerous tissue is gone. This may greatly improve success rates from surgeries to remove cancerous growths. 

Currently, this technique is being perfected in veterinary surgeries to guide the removal of tumors in pets and is not yet ready for use with humans. If effective, it will be a great resource for patients undergoing tumor removal surgery in the future.

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Knocking Out Hepatitis C

March 7, 2014

By Medical Discovery News

Hepatitis C

Good news awaits Hepatitis C patients. In the next few years, new drugs that specifically target the Hepatitis C virus, curing a person more quickly without the severe side effects, will become available. Some physicians and patients are even opting to wait for these new drugs rather than endure the current therapy.

Today, this viral infection is most often acquired by drug users sharing needles. The Hepatitis C virus can cause a mild illness lasting a few weeks but in some people it can cause a serious lifelong illness. One major problem is that many people are unaware that they are infected until they have symptoms of liver damage. It is the leading cause of cirrhosis and liver cancer and the most common reason for liver transplantation in the United States.

An estimated three to four million Americans are infected, and deaths from Hepatitis C are expected to rise in the future as those unaware of their infections begin to have symptoms. There is no vaccine and the current drug regimens can cure about 70 percent of infected people but the serious side effects include anemia, insomnia, depression, fever, and severe rashes.

Hepatitis C is most commonly treated with a combination of interferon and ribavirin for 24 to 48 weeks. However, because of their side effects and the fact that the drugs do not work for everyone, drug companies have been working hard to develop new treatments.

These new drugs are predicted to wipe out Hepatitis C infections with one pill per day for as little as eight weeks, without severe side effects. The only downside is their predicted costs range from $60,000 to more than $100,000 for a course of treatment. The new drugs, much like those that are used to treat HIV infection, target enzymes the Hepatitis C virus requires to reproduce.  However, the Hepatitis C virus does not make its genetic information a permanent part of a cell’s genome like HIV does, so it can be eliminated, therefore curing the person. If the virus is eliminated the liver can heal itself to some extent, but people cured of Hepatitis C may still be at higher risk for liver cancer.

One of these new drugs, called sofosbuvir by Gilead Sciences, inhibits the enzyme that copies the virus’s genetic information, therefore blocking virus reproduction. The effectiveness of the drug depends on the type of Hepatitis virus. The majority of Hepatitis C patients in the U.S. would require the addition of interferon for 12 weeks. Gilead has a second drug nearly ready called ledipasvir, which in combination with ribavirin could eliminate the need for interferon, the source of the worst of the side effects of current treatments.

Several other companies are racing to introduce additional medications to treat Hepatitis C. Having tolerable therapies available will encourage people to get tested and treated earlier for Hepatitis C, before liver damage begins. This is a huge benefit to public health that will substantially reduce the need for liver transplants and the number of deaths from liver failure and liver cancer.

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