Considering the Western diet, human evolutionary history of constant near starvation, and how chemotherapy works, isn't cellular stress a near universal weakness of most neoplasmic cells?
Cancer and genetic instability has been known for a very long time (hallmarks of cancer). Many energy/maintenance pathways are impaired or outright broken in cancer cells. Despite this knowledge, effectively targeting these “weaknesses” is far from trivial. Broken pathway does not a cancer cure make.