It’s a little reminiscent of the ‘60’s when many theorized that most cancers had viral etiologies...and vaccines to prevent cancer were just around the corner!
But some microbes have been linked to particular cancers, e.g. human pappilloma virus and cervical cancer in women, Epstein-Barr virus and Burkitt's lymphoma, helicobacter pylori and MALT stomach cancer, IIRC, MALT means mucosa associated lyphoid tissue, etc.