new model for cancer

Undoubtedly, one of the leading causes of death in North America is cancer [1]. However cancer is a very poorly understood disease [2]. One of the main reasons is that cancer has very heterogeneous origins. In the molecular level, cancer takes many different forms - the problem can be in wnt, Ras, p53, etc. They do have something in common - the normal balance of proliferation, differentiation, and apoptosis is gone. The cancer cell is programmed to grow. Cancer is a communication problem.

Normal cells (of a multicellular organism) communicate with each other. Based on this signal, they make decisions - they might proliferate (divide to increase the number cells), differentiate (become a specialized cell that handles specific tasks), undergo apoptosis (programmed cell death), or "do nothing" (status quo). Cancer cells have mutations that somehow inhibit their communications in a way that promotes growth.

As they grow in an uncontrolled manner, they accumulate mutations. Eventually, there is some critical mutation which triggers metastasis - spreading to other regions. Cancer spreads to other parts of the patient. Eventually, the cancer takes over the vital organ (s) and the patient dies. Conventionally, this has been the view. However, a recent new hypothesis [3] suggest that the underlying cause of cancer is weakening of normal cells. It’s like how when your grass is strong, the weeds don’t grow well. When your healthy cells are strong, even when some cancer cells arise (ex. due to mutations), the cancer cells are outcompeted by the healthy cells and cannot grow. As interesting and plausible as this hypothesis sounds, I’m not sure if it’s the first time this has been suggested. When I was in university, the cancer researcher professor talked about cells as being in some competitive ecosystem and how it faces its own set of hardships. He didn’t think about healthy cells as direct competition, but in an abstract sense, the model was somewhat similar (in my opinion). What they [3] did do is build out a more elaborate and purposeful model. They also built a simple mathematical model that goes along with the model to show how some data can be explained using this model.

I value high level understanding, but I also value the mathematical models that can be built to more precisely pin down that high level understanding. It gives us a higher predictive capability. Mix 5g of citric acid to 100ml of pure water. The high level understanding would tell you that the pH will decrease and that the resulting solution be more acidic. The mathematical model will tell you that the final pH is 1.87.

refs:

[1] http://www.cdc.gov/nchs/fastats/leading-causes-of-death.htm

[2] according to the professor that taught me about cancer in university

[3] Rozhok and DeGregori (2015). Toward an evolutionary model of cancer: Considering the mechanisms that govern the fate of somatic mutations. Proceedings of the National Academy of Sciences 112(29), 8914-8921.