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.[1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19] 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.[16,20,21] Although reports of malignant tumors in sharks are rare, a variety of cancers have been detected in these animals.[20,21,22,23] Nonetheless, several substances that have antitumor activity have been identified in cartilage.[2,3,4,7,15,16,17,18,19,24,25,26,27,28,29,30,31,32,33,34,35,36,37,38,39,40,41,42,43,44,45,46,47,48,49] More than half a dozen clinical studies of cartilage as a treatment for people with cancer have already been conducted.[2,3,4,6,7,8,9,15,16,17,18,49,50] Additional clinical studies, MDA-ID-99303 and AETERNA-AE-MM-00-02 have been completed.[6,15,50]
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.[27,28,29,30,35,36,48] 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.[33,34,41,51,52,53,54] 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.
Cancer of the hypopharynx is uncommon; approximately 2,500 new cases are diagnosed in the United States each year. The peak incidence of this cancer occurs in males and females aged 50 to 60 years. Excessive alcohol and tobacco use are the primary risk factors for hypopharyngeal cancer.[3,4] In the United States, hypopharyngeal cancers are more common in men than in women. In Europe and Asia, high incidences of pharyngeal cancers, namely, oropharyngeal and hypopharyngeal,...