Can Low-Dose Shark Cartilage Shrink Kaposi's Sarcoma (KS)?
Kaposi's sarcoma (KS) is a tumour that usually appears on the skin and most commonly affects HIV positive men who have sex with other men. Not surprisingly, therefore, KS is caused by a sexually transmitted virus -- HHV-8 (human herpes virus-8). Although there is no cure for KS, sometimes the use of highly active antiretroviral therapy (HAART), with or without chemotherapy, can help shrink and control KS lesions.
Doctors at the University Hospitals of Cleveland, Ohio, reported details about their unusual and successful treatment of a KS lesion. According to their report, a 45-year-old man who developed a KS lesion on his foot sought medical care. Repeated blood tests revealed that he was HIV negative but was infected with HHV-8, the cause of KS. His CD4+, CD8+ and other blood counts were within the normal range. Laboratory analysis confirmed that his tumour was indeed KS. Doctors then prescribed oral ganciclovir, 1 gram three times daily for three months (because of its possible anti-HHV-8 activity), but this had no effect on his lesion.
After this failure, other options were considered, including the following:
- injecting the lesion with chemotherapy
- cidofovir (Vistide)
- foscarnet (Foscavir)
- Panretin (alitretinoin)
- radiation therapy
None of these options were selected because the lesion was growing very slowly and the side effects of therapy were not "acceptable to the patient." Instead the patient and his doctors chose an unconventional approach -- low-dose oral shark cartilage.
Shark Cartilage in the Lab
In lab experiments with tumours and mice with cancer, shark cartilage and its extracts appear to block the growth of blood vessels that feed a tumour. KS tumours are often associated with a rich network of blood vessels, so perhaps its not surprising that the research team chose to study shark cartilage: therapies that have the potential to reduce blood vessel growth could help "starve" the KS tumour.
Researchers monitored the man as he took shark cartilage at a dose of 1,875 mg twice daily for the first three months. The dose was then changed to 1,500 mg three times daily for another 18 months.
After three months, the lesion began to shrink and its colour faded. By the sixth month it became thinner and it became almost impossible to notice. No side effects were reported during this time. The man continues to take shark cartilage (Dr. Scot Remick, personal communication).
Notes About the Dose
Although shark cartilage has been tested in people with cancer, those subjects had received chemotherapy and also had "advanced" cancers of the breast, colon and lungs. Moreover, shark cartilage was given at a higher dose for only three months. In experiments where chemotherapy is used to attack the blood vessel networks that nourish a tumour, the best results were obtained when researchers used low-dose chemo for longer periods of time.
It is possible that the KS tumour in this patient could have simply disappeared on its own -- spontaneous regression. Until a controlled clinical trial takes place, we cannot be certain about the effectiveness of shark cartilage. Future research needs to examine issues relevant to people with HIV/AIDS, such as drug interactions and the additional effect of chemotherapy. Shark cartilage used in this man's treatment was distributed by Swanson Health Products and General Nutrition Center and cost between $1.08 and $1.32 US per day.
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