I recently completed the reading of this almost 500 page book. Reading about cancer might not be your idea of a “good read” but Siddhartha Mukherjee is a natural story teller and a doctor, and he tells the story of cancer with depth, discernment and loving kindness. (My Goodreads review of the book is here.)
I was intrigued by the discoveries of what cancer is, particularly that its possibility exists within each and every one of us. I don’t want to forget the explanation of how cancer gets turned on, hence this post.
As best I understand the explanation of genetics, each human cell contains two prominent genes – oncogenes and tumor suppressor genes. Oncogenes help cells grow and replicate; tumor suppressor genes inhibit cell growth. Mukherjee likens these two types of genes to putting your foot on a gas pedal (cell growth) and putting your foot on the brake (tumor suppressor genes.) When both types of genes are properly doing their job, all is well.
It is when a mutation occurs to a gene that the balance is thrown out of whack. Imagine a mutated oncogene, the gene that helps cells to grow; it would be as if the gas pedal was stuck in the down position, allowing cells to replicate with abandon. Imagine a mutated tumor suppressor gene, the gene that inhibits cell growth; it would be as if the brake was unable to be depressed, thus removing the function in the gene that stops the replicating of genes. As Mukherjee further describes the history of the discovery of how cancer comes to life he discusses specific proteins.
Genes encode proteins, and proteins often work like minuscule molecular switches, activating yet other proteins and inactivating others, turning molecular switches “on” and “off” inside a cell. … Proto-Oncogenes and tumor suppressor genes, cancer biologists discovered, sit at the hub of such signaling pathways.
Cancer, in short, was not merely genetic in its origin; it was genetic in its entirety. Abnormal genes governed all aspects of cancer’s behavior. Cascades of aberrant signals, originating in mutant genes, fanned out within the cancer cell, promoting survival, accelerating growth, enabling mobility, recruiting blood vessels, enhancing nourishment, drawing oxygen–sustaining cancer’s life.
These gene cascades, notably, were perversions of signaling pathways used by the body under normal circumstances. … Down to their innate molecular core, cancer cells are hyperactive, survival-endowed, scrappy, fecund, inventive copies of ourselves. (p 387-88)
In case you are wondering why my interest in what cancer is, I do not have a morbid curiosity. Rather, in 1998 I was diagnosed (thanks to mammography) with Stage 1 breast cancer, and treated via lumpectomy, radiation and tamoxifen. Among other things, this has made me a big proponent of mammograms and a huge fan of proactive, preventive care. I had my annual gynecological visit just a week prior to getting the mammogram, and a physical breast exam did not uncover any malady, precisely because the tumor was incredibly small. While cancer can be slow growing, it can also be fast growing, and my next mammogram would not have been for another year.
I conclude with a final quote from the last page of the book.
…to keep pace with this malady, you needed to keep inventing and reinventing, learning and unlearning strategies. (p 470)
While some cancers can be prevented (remove carcinogens in the environment such as asbestos and cigarettes), and others can be mitigated via treatment (surgery, transplants, medications), there are still others that are elusive and obstinate. Coupling the therapeutics of caring for someone with cancer, with all the myriad and sometimes debilitating approaches, and the study of cancer is insured a future history. Perhaps technology will help pave the way for deeper understanding of how our very human selves function, in turn leading to more humane approaches to care and treatment.