Emerging evidence indicates that impaired cellular energy metabolism is the defining characteristic of nearly all cancers regardless of cellular or tissue origin. In contrast to normal cells, which derive most of their usable energy from oxidative phosphorylation, most cancer cells become heavily dependent on substrate level phosphorylation to meet energy demands. Evidence is reviewed supporting a general hypothesis that genomic instability and essentially all hallmarks of cancer, including aerobic glycolysis (Warburg effect), can be linked to impaired mitochondrial function and energy metabolism. A view of cancer as primarily a metabolic disease will impact approaches to cancer management and prevention.
Is cancer a body's failure to attain global metabolic fitness?
One of the features is that the mitochondria in cancerous cells is broken and can only process glucose (and possibly fructose), they cannot do beta oxidation - (the other, more critical, is that they no longer respond to apoptosis.) So in that sense, yes.
Note that there are some cancers where this isn't true, and they can do beta oxidation, so it won't work in every case. But as a general preventative rule, it's a good idea to do some fasting once in a while so as to kill off any cells with broken mitochondria and invoke apoptosis in marginal ones.
Latest evidences shows that cancer should also be considered as a metabolic disease. Cancer is associated with meatbolic changes. The metabolic profile of tumor cells has been suggested to reflect the rapid proliferative rate.