Complex sentence: It is based in part around Nieper's belief that cancer is rarer among sharks than other fish and his theory that the lower blood-sodium level of sharks may be the reason; it places among its primary goals the reduction of that sodium in cancer patients.
Split into simpler sentences: It is based in part upon Nieper's belief that cancer is rarer among sharks than other fish, and upon his theory that the lower blood-sodium level of sharks may be the reason. "Nieper Therapy" places among its primary goals the reduction of that sodium in cancer patients.