Edit: Found one study, but this is likely to be a confirmation bias effect:
<a href="http:&#x2F;&#x2F;www.ncbi.nlm.nih.gov&#x2F;pubmed&#x2F;26094889" rel="nofollow">http:&#x2F;&#x2F;www.ncbi.nlm.nih.gov&#x2F;pubmed&#x2F;26094889</a><p>&quot;Bi-monthly FMD cycles started at middle age extended longevity, lowered visceral fat, reduced cancer incidence and skin lesions, rejuvenated the immune system, and retarded bone mineral density loss.&quot;<p>This study shows not so promising results:
<a href="http:&#x2F;&#x2F;www.ncbi.nlm.nih.gov&#x2F;pubmed&#x2F;20733612" rel="nofollow">http:&#x2F;&#x2F;www.ncbi.nlm.nih.gov&#x2F;pubmed&#x2F;20733612</a>
Points to &quot;Overall, there was no difference in mouse survival (P=0.37) or tumor volumes (P ≥ 0.10)&quot; (mice that already had prostate cancer)<p>tl;dr: There might be some potential benefits of fasting in the prevention of cancer, might not be the case for treatment of cancer...