The following is a transcript based on an earlier draft of this week's podcast. As a result, the written transcript and the podcast may differ.

Greetings from the National Library of Medicine and MedlinePlus.gov

Regards to all our listeners!

I’m Dr. Donald Lindberg, the Director of the U.S. National Library of Medicine.

To listen to Dr. Lindberg's comments, click here

So what’s new in MedlinePlus this week? Well some exciting and encouraging news! Researchers at the National Cancer Institute at NIH reported this week they reduced and even eradicated large, metastatic tumors in a few patients with melanoma using gene therapy.

Their report, which was published in the online edition of Science, is the first successful use of gene therapy for cancer treatment. It also provides initial clinical evidence that gene therapy could be a viable approach to treat cancer in general in the future.

A team of 16 researchers reported they safely destroyed large tumors that had metastasized, or spread, in the body of two patients who were terminally ill with melanoma, an advanced type of skin cancer. The treatment reversed the spread of cancer in the lung of a patient in Detroit and completely destroyed growth of axillary metastatic melanoma and 89% destroyed Metastatic Melanoma in the liver of a patient from Wisconsin such that they could subsequently excise it from the liver. Both patients have been cancer free for about 19 months since their pioneering treatment in the NIH Clinical Center.

Both patients candidly discussed their treatment and illness with the news media and have been interviewed extensively in recent days but I don’t feel entitled nonetheless to say their names.

Similar experiments with lymphocytes, a person’s own white blood cells, have previously been used in experiments to treat Metastatic Melanoma but the various limitations in this method led investigators to try this new method.

In this experiment NIH investigators led by Dr. Steven Rosenberg at the National Cancer Institute converted normal lymphocytes in patients by transferring into them genes that encourage specific anti-cancer proteins. The proteins are called T-Cell receptors. These reside on the surface of lymphocytes and recognize and bind to specific molecules on the cancer cells thus destroying the cancer cells. The method to transfer the anti-cancer genes was by using retroviruses in a laboratory, you might say, a more or less test tube procedure. Done in the laboratory not in the patient in other words. Patients with advanced melanoma seemed to no longer have enough cancer fighting T-Cells in their bloodstream to block the cancer spread. Researchers hypothesize that by injecting targeted reinfused T-Cells into a patient with the anti-cancer receptor proteins present on their cells the process would help kill cancer cells. And indeed it did.

The targeted, reinfused T-cells cells grew at low levels for a few months in all the patients who were treated by the NCI research team. The reinfused cells grew especially vigorously within the two patients I noted and eliminated their tumors.

The targeted therapy used in this study is promising because, theoretically, it destroys specific cancer cells without harming others. One of the challenges of current cancer treatments, such as chemotherapy, is the introduction of side effects, which can destroy healthy as well as the intended, harmful cancer cells. Of course this makes many patients feel ill during the usual treatments.

We emphasize that the study’s findings are preliminary and we repeat that the study’s patient population was limited to 17 persons. It is possible that the initial success within the current study might not be corroborated by researchers around the world and even if it is, it may be years before gene therapy is safely integrated into routine clinical care.

The findings are promising, however, because they represent an initial proof of concept that gene therapy could be a viable tool in future cancer treatment. The results also are important because a medical intervention mitigated, and in two cases apparently reversed, cancer in an advanced stage. This is pretty hard to do with any treatment.

Current cancer treatments are more successful in early stages, or well before cancer metastasizes. So, a new procedure that fosters a therapeutic alternative for advanced cancer patients is very very welcome. Besides continuing work on melanoma, the National Cancer Institute researches told CBS News recently they will attempt to use gene therapy to treat advanced breast and colon cancer in order to understand the viability and diverse use of the technique. Similar to the current study, the researchers will use targeted therapy and reinfused cells derived from the patient’s own white blood cells.

If you wish to learn more about gene therapy, you may type “Gene Therapy for Cancer” into Medline Pluses “Search” box and select Gene Therapy for Cancer Nation Cancer Institute from the list that is displayed. the National Cancer Institute has provided a very full discussion of this topic including a review of the theory and a description of the risks associated with the current gene therapy trials , a listing of the numerous steps in approving such studies and a discussion of some of the recognized social and ethical issues surrounding human gene therapy.

While gene therapy provides hope for future treatment, the experiments just described were against malignant melanoma which is certainly the most dangerous of skin cancers. It is not however the most common.

MedlinePlus has useful information for you about common skin cancers and their prevention and their treatment by customary methods. You can get this by typing ‘skin cancer’ in the search box on MedlinePlus’ home page. I think I’ll leave for another podcast a fuller description for the commonest skin cancers. For the moment then this reminder

…… MedlinePlus.gov is authoritative,….. free…. does not accept advertising …and is written to help you.

To find MedlinePlus.gov, just type in “MedlinePlus.gov’ in any web browser, such as Firefox, Safari, Netscape, or Explorer.

We encourage you to use MedlinePlus and please recommend it to your friends.

Your comments about this or any of our podcasts are always welcome. Please email me anytime at: NLMDirector@nlm.nih.gov

That’s NLMDirector (one word) @nlm.nih.gov

A written transcript of this podcast is always available. Just click on the ‘Director’s comments’ link on MedlinePlus’ home page.

The National Library of Medicine is one of 27 institutes and centers within the National Institutes of Health. The National Institutes of Health is part of the U.S. Department of Health and Human Services.

It was nice to be with you….

Please join me here next week.