Cancer as a loss of homeostasis

Medicine has made great progress in treating and preventing disease caused by infectious agents. The noncommunicatable diseases that cause most deaths and maladies among older people are tougher.  They can often be managed, but the approach is different from the one used to go after the flu or small pox.  One way of looking at these diseases is that they result from a breakdown in the body’s homeostatic processes.  Osteoporosis results from a breakdown in homeostasis in regulation of bone mineralization. Diabetes is a breakdown in homeostasis in regulation of blood sugar levels.

Cancer, in this paradigm, is a breakdown in the balance between cell growth and cell death. The genetic for overexpressing the anti-apoptotic genes and turning down the pro-apoptotic genes is not understood, and why the homeostatic balance is lost (another term for carcinogenesis perhaps) is often unknown.

Types of Cancer

How do doctors classify different types of cancer?  There are many ways. The way most people are familiar with refers to the organ the cancer started in.  The American Society of Clinical Oncology website lists over 120 types of cancer and related syndromes using this classification.;

Other observers say there are on the order of 200 types of cancer. Much matters in how things are classified. For instance, there are at least four types of lung cancer: small cell and three types of non-small-cell (adenocarcinoma, squamous cell carcinoma, and large cell carcinoma.)

A new method has sprung up in recent decades where genetic mutations are the distinguishing factor for cancers. The mutation itself is identified by its association with biochemical pathways that signal tumor growth.