Dr. Royal Raymond Rife ran Clinical trials on terminal Cancer patients in the 1930's using a technology he'd spent years developing.
Today his technology is considered highly controversial and most physicians either haven't heard of it or don't acknowledge it because it lacks both FDA and AMA approval. It is also stigmatized as a consequence of the very factors discussed in the video the OP posted. The technology was mastered by 1934, however the profit margin apparently wasn't very large in contrast to the new therapies appearing at that time period. These machines had wide spectrum use and only needed to be purchased once. Multiple people could access a single machine, thus making it even more profitable than vaccination treatment.
For those with Cancer who have actually used it -- regardless of which type of Cancer, many report success. Unfortunately it is highly experimental since it has not been thoroughly tested under large spectrum double blind placebo controlled trials. Frequency therapies and Electromedicine have been studied heavily around the world and are accepted as therapies for pain and tissue regeneration -- much like Hyperbaric Oxygen Therapy, but the technology has far greater implications for other ailments and this is where it hasn't been studied much -- especially for Cancer.
Without financial funding, it will remain an "alternative" therapy which remains stigmatized. Anything considered alternative -- even if it works better than conventional medication therapies -- is considered quackery or less effective (Alternative).
Cliff Notes: Rife Machine technology is an experimental therapy using electromedical frequency equipment (and amplifier) that has wide spread ancedotal support of "curing" Cancer. It is highly controversial and not FDA approved for the very reasons in the video.