The conventional model of cancer is that it begins as a local disease (tumour) that then spreads (metastasis). Therefore conventional treatments are based on targeting the tumour. Yet there is evidence to suggest that cancer may be based on a different model of the disease. For example some alternative cancer treatments were found to have higher survival statistics compared to conventional treatments in randomised controlled trials; and those treatments with the highest survival benefits are based on an alternative model of cancer. If cancer is based on an alternative paradigm, then the overdiagnosis and overtreatment of this disease is currently significant.
We reexamine the cancer paradigm and the evidence for this, based on alternative and conventional approaches. In the first stage of our work, our objective is to analyse the various theories of what causes cancer to identify those that have a real causative, rather than simply correlative, basis.
For various treatments of cancer that have been claimed to be effective, we identified the underlying theories of cancer causation. We analysed for the various theories the evidence for a causal relationship with cancer. For example, we analysed whether there was a plausible mechanistic pathway and the evidence for each step.
In addition to the conventional model of what causes cancer, we identified approximately eight categories of alternative theories. For many of the theories there appeared to be a gap in the literature with respect to causation versus correlation. Often the proponents of a theory did not elucidate fully a scientific basis for cancer causation, though in some cases we found supporting evidence.
The evidence for the efficacy of conventional and alternative treatments leads us to reexamine the cancer paradigm. In the first stage of our work, we have analysed the theoretical basis for various cancer treatments and found gaps in the evidence. This analysis will be paired in future with data from treatment trials to develop an evidence-based model of cancer and its treatment. A valid model of cancer will serve to prevent its overdiagnosis and overtreatment.