1/2
November 14, 2020
Curing Cancer, Part 1 – Reductionism versus Complexity
natpernickshealthblog.wordpress.com/2020/11/14/39/
In 1971, President Richard M. Nixon announced the beginning of the US “war on cancer”
(see President Nixon’s 1971 State of the Union at 15:03). Despite massive government
expenditures (Kolata: Grant System Leads Cancer Researchers to Play It Safe, New York
Times, 27Jun09) and testimonials that the war on cancer “did everything it was supposed to
do” (NCI: National Cancer Act of 1971, accessed 10Nov20), cancer is still a leading cause of
death (Centers for Disease Control and Prevention 2016, Cancer Statistics 2020), with high
mortality from cancer of the lung, colon, pancreas and breast (Cancer Facts & Figures 2020).
Our war on cancer has failed because our basic approach to biology is wrong. Biologic
thinking has traditionally relied on reductionism, the theory that the behavior of the whole is
equal to the sum of the behavior of the parts. Based on this theory, sophisticated systems
are presumed to be combinations of simpler systems that themselves can be reduced to
simpler parts (Mazzocchi 2008), disease is due to flawed parts and treatment needs to
merely identify and repair the damaged parts. Although logical and rational, reductionism
does not actually describe how complex systems function.
In complex systems, the properties of the entire system are greater than the sum of the
properties of each part due to interactions between the parts (Kane 2015). Novel properties
emerge from the parts and their interactions if one views the entire system as a whole. For
example, start with a large number of biological molecules (proteins and other organic
compounds), each relatively inert by itself, but capable of interacting in different ways with
each other. Then confine them to a small space to promote these interactions. The result
may be a living system, a self-sustaining web of reactions that can reproduce and evolve,
properties that could not be even imagined by studying each part (Kauffman 1993, Pernick
2017).
Other examples of complex systems include communities formed by individuals and electric
grids composed of individual power plants. In each complex system, the result is more
dynamic and intricate than could be predicted from studying each component.
Complex systems often exhibit self-organized criticality, the tendency of large systems with
many components to evolve to a critical state or “tipping point” (Bak, How Nature Works
1999). When dropping individual grains of sand onto a surface, each grain typically just adds
to a growing sandpile. Occasionally, it triggers a small avalanche of the sandpile. Less
frequently, it triggers a larger avalanche, and rarely, it causes the entire sandpile to collapse.
What is different about the grain of sand that triggers an avalanche from the grain of sand
that just sits there? Surprisingly, there is no difference. The grain that appears to do nothing
2/2
causes subtle structural changes in the sandpile, promoting an eventual collapse after
enough grains are dropped. Although we focus on each grain as being important to the
outcome, the functional unit is the sandpile itself.
Similarly, cellular networks composed of biologic molecules, cells, tissues and organs are
poised at a critical state in which small perturbations typically cause no change but
occasionally cause small network changes. Rarely, a trivial event sets in motion a large
systemic response, leading to a major reconfiguration of the system (Bak, How Nature Works
1999), such as initial steps towards malignancy. Although cancer scientists tend to focus on
initial or “driver” mutations, complexity theory suggests that we should focus on the cellular
networks as the functional units.
The human body is composed of a myriad of interacting networks positioned at critical
states, which is required for network flexibility to enable embryonic development, the
inflammatory response to trauma and infection and the capability for our species to evolve to
a changing environment. However, the tradeoff for maintaining these critical states is that
cancer, a type of catastrophic systemic failure, is inevitable. We can reduce its incidence, we
can detect it earlier and we can treat it more effectively but attaining a “world without cancer”
(American Cancer Society, accessed 13Nov20) is not possible.
End of Part 1
