Bovine (cow) cartilage and shark cartilage have been investigated as treatments for people with cancer, psoriasis, arthritis, and a number of other medical conditions for more than 30 years.[1,2,3,4,5,6,7,8,9,10,11,12,13] Reviewed in [14,15,16,17,18,19,20] At least some of the interest in cartilage as a treatment for people with cancer arose from the mistaken belief that sharks, whose skeletons are made primarily of cartilage, are not affected by this disease. Reviewed in [16,21,22] Although reports of malignant tumors in sharks are rare, a variety of cancers have been detected in these animals. Reviewed in [21,22,23,24] Nonetheless, several substances that have antitumor activity have been identified in cartilage.[25,26,27,28,29,30,31,32,33,34,35,36,37,38,39,40,41,42,43,44,45,46,47] Reviewed in [2,3,4,7,15,16,17,18,19,20,46,48,49,50] More than half a dozen clinical studies of cartilage as a treatment for people with cancer have already been conducted.[2,3,4,7,8,9,50,51] Reviewed in [6,15,16,17,18,19] Additional clinical studies, MDA-ID-99303 and AETERNA-AE-MM-00-02 have been completed. Reviewed in [6,15,51]
The absence of blood vessels in cartilage led to the hypothesis that cartilage cells (also known as chondrocytes) produce one or more substances that inhibit blood vessel formation. Reviewed in [28,29,30,31,36,37,49] The formation of new blood vessels or angiogenesis is necessary for tumors to grow larger than a few millimeters in diameter (i.e., larger than approximately 100,000 to 1,000,000 cells) because tumors, like normal tissues, must obtain most of their oxygen and nutrients from blood. Reviewed in [34,35,42,52,53,54,55] A developing tumor, therefore, cannot continue to grow unless it establishes connections to the circulatory system of its host. It has been reported that tumors can initiate the process of angiogenesis when they contain as few as 100 cells. Inhibition of angiogenesis at this early stage may, in some instances, lead to complete tumor regression. The possibility that cartilage could be a source of one or more types of angiogenesis inhibitors for the treatment of cancer has prompted much research.
Hydrazine sulfate is a chemical compound that has been studied as a treatment for cancer and certain side effects caused by cancer (see Question 1).
Hydrazine sulfate may block the tumor from taking in glucose, which is a type of sugar that tumor cells need to grow (see Question 3).
In randomized clinical trials (a type of research study), hydrazine sulfate did not make tumors shrink or go away. In some randomized trials, however, hydrazine sulfate was reported to be helpful in treating...