Tuesday 27 March 2012

Towards An Ideal Anti-cancer Protocol

There was an interesting piece at the Anticancer.Org.Uk website commenting on some new research showing that blocking the mu-opiod receptor pathway (the one exploited by opiate-based medicines such as morphine, fentanyl etc), can slow cancer progression. The source of the article is a journal paper by a group of doctors treating late stage cancer patients with the drug methylnaltrexone (trade name Relistor) for opiate induced constipation. They noticed that patients treated with methylnaltrexone survived for longer than expected. They then followed up in the lab, doing experiments that showed that there is a direct effect of the mu-opiod receptor pathway on disease progression.

While this is plenty interesting, what's also worth pointing out that this is yet another example of an existing drug being shown to have anti-cancer activity. Crafting new drugs from scratch takes years and many millions of dollars, re-using existing drugs is much cheaper as a lot of the trials of toxicity and pharmacology have already been done. The combination of off-label drugs is an area that we are keen to see exapnd. Few of these drugs have direct cancer killing activity, but what they do is act gently to change the environment around the tumours. By attacking the tumour microenvironment you subvert the mechanisms that the tumour puts in place to survive.

A list of some of the most promising off-label drugs with anti-cancer activity include:

  • Metformin - targets tumour metabolism, (read up on the reverse warburg effect, for example)
  • Statins - targets the mevalonate pathway (starves the tumour of esential building blocks for cell proliferation)
  • Aspirin - targets the inflammatory environment
  • Beta-blockers - targets the beta-adrenergic pathway
  • Naltrexone and methylnatrexone - target the mu-opiod receptor pathway
What we would like to see is a clinical trial that uses combinations of these drugs to target the tumour microenvironment. These drugs have relatively low toxicity, they're cheap and together they attack multiple pathways giving less room for the tumours to evolve resistance. Throw in some omega 3s, some polyphenols and some exercise and you have the ideal anti-cancer protocol.