You might be laughing, but baking soda used to be injected to tumors to reduce lactic acidosis (cancer cells can't proliferate without being immersed in lactic acid). So the people you mentioned might have been running on older research and scientific beliefs. The new version is to use medication that actually decreases lactic acid to slow down/stop growth of tumors (DCA, mega-dose thiamine etc.)

Another funny fact - most cancer cells get energy the same way as fungus/yeast - by fermentation, and not like most human cells by perspiration. That might be why those people said "cancer is just fungus".

Some Spanish "magufo" (think of Alex Jones but without the far right ideology and being a fake practicioner) are like that, search for Pamies in Google/DDG. I'm worried about the reaction from these snake-oil scammers, too.

EDIT: I found an article in English:

https://english.elpais.com/elpais/2018/10/18/inenglish/15398...