Which Came First, the Mutation or the Cancer?
The current paradigm, some 40 or 50 years old now, would say it was the mutation. As the first plaintiff's expert witness I ever cross examined at the courthouse said of the chemical in question "it messes with your DNA and if your DNA is messed up anything, especially cancer, can happen". By the way, for the younger set, before Daubert and Robinson/Havner that's what all too often passed for "science" in the courtroom.
Yet in the new Million Women Study of breast cancer, mutations associated with higher risk and environmental insults associated with higher risk seem to have no relation with one another such that hormone replacement therapy doesn't increase the risk of breast cancer even in women with genes predisposing them to estrogen-receptor positive disease. How can that be?
Well, here's some food for thought. Where do we come from? Bacteria, way back when. How do bacteria talk to each other? Quorum sensing (by the way, don't you wish all your teachers had been like Bonnie Bassler?) So if our stem cells want to monitor how many undifferentiated cells they need to be making and if those cells want to monitor their path to differentiation might they not do it via the same signaling pathways that their ancestors employed? If that's the case then could it be that a disruption in signaling causes runaway production of immature cells (cancer) and that the mutations only occur later? There's more than a scintilla of evidence for it.
What recruits bone marrow cells to the gut where their signaling is disrupted? Is it significant that many of the benzene workers thought to have developed leukemia as a result of exposure lived not only in the same building but were roommates? Is the parallel between the fall in cancer mortality and the rise of antibiotic use suggestive? It's something to think about anyway.
