Your truck seemed to be running just fine yesterday, but you got in today and you’re going nowhere. The diagnosis: cancer.
You’d isolate some major system where the trouble seemed to be located: engine, drivetrain, electrical. Based on that diagnosis, you’d take it in, and the mechanic would try to save the truck by removing that entire system and replacing it… not necessarily a Ford engine into a Ford, but maybe rigging a Honda motor in there. Whatever they could do to get it rolling again, at least for a while.
In cancer, the system may have been breast, by virtue of that being the tissue in which the cancer started. The goal was to physically remove cancer cells with surgery, and to poison any remaining cancer cells with chemotherapy and/or radiation. (And normal tissues in the way take the same hit.)
Your truck has an engine problem, but there are several categories with which to narrow it down: mechanics, ignition, intake/exhaust, charging. Narrowing it down can significantly improve estimates of how hard it is to fix and how well the repair may work. But if it is only narrowed down to “mechanical” there are still many potential problems to address (valves, fans, seals, belts) and without knowing more the solution may still be full replacement as in the past.
In breast cancer, there are currently ways to categorize that help to assign a prognosis and to choose more rationale therapy. Clinically, we see estrogen positive tumors that may respond to hormonal therapies, HER2 amplified tumors that may be responsive to HER2 targeting drugs, and triple negative tumors with only standard chemotherapy options.
In automotive repair, the future is here. An expert mechanic (and maybe a diagnostic computer) can point to exactly what is broken. And if you need a new timing belt, you get the timing belt that is manufactured specifically for your make and model. The fix may still be easy or complicated, but knowing precisely what’s broken leads to the best options for considering repair.
In cancer, a major initiative has been underway to do the same. It’s called the Cancer Genome Atlas Project and the goal is to fundamentally understand all of the parts that might break so that accurate diagnoses can be made and specific treatments can be designed.
This week, the Cancer Genome Atlas Network published results of their “comprehensive molecular portraits of human breast tumours” in the journal Nature. They analyzed material from breast cancers and compared it to normal tissues from 825 patients, and used multiple different molecular platforms for analysis (DNA copy number, DNA methylation, gene exome sequencing, messenger RNA arrays, microRNA sequencing, and protein arrays). This is on a scale never done before. For example, they identified 30,626 gene mutations. This is the equivalent of taking 825 cars apart, listing every component, and marking which ones were broken in each.
They also reported on novel patterns of molecular abnormalities that classify breast cancers into four major biological subtypes. This is like taking all of those broken pieces of car parts and assigning them to the correct system (electrical, drivetrain, engine).
They even found that some of the broken molecular parts in some breast cancer samples were the same as those found in other cancers (specifically a type of ovarian cancer). That’s like finding that there is in fact a Honda part that is the same as (and could correctly replace) a Ford part.
This kind of comprehensive work in the mechanics of cancer is the future of cancer medicine. We will only be able to truly understand what’s broken, and choose treatments that specifically fix it without ripping out the whole engine, by learning this detail.
It means that in the future, we won’t care so much about whether your cancer is breast or ovarian (Ford or Honda) as we care about what is broken.
And it means that every cancer will need to be diagnosed with specific tools, rather than just based on the broad categories.
Your 2010 Ford F150 truck didn’t run, and even you knew the problem was mechanical (not electrical or drivetrain). But after correct diagnostics, the mechanics installed a Mahle W0133-1835879 engine timing chain, and your problem was fixed.
Here’s to the future of cancer medicine!