Page 10 - Helicobacter pylori and Gastric Cancer: From Tumor microenvironment to Immunotherapy

Chapter 1
General introduction
Cancer
In 400 BC, Hippocrates, the Greek physician generally regarded as the “father of Medicine” was perhaps the first to recognize cancer as a separate disease entity which he denominated as “carcinos”. In Greek, the word refers to a crab. This invertebrate was probably associated with the disease because the finger-like spreading projections emanating from a growing cancer provoke associations with the morphological aspect of a crab. Referring to this concept of ‘carcinos,' as a disease entity in 28-50 BC, a Roman physician by the name of Celsus was probably the first to translate the Greek crab term to the Latin “Cancer” and this has been the name of this group of diseases ever since. Despite millennia of effort, however, the clinical problems associated with preventing and curing cancer have not been solved.
In our time, a group of over a thousand diseases share the generic name cancer. We recognize different types of cancer but all arise from unusual properties acquired by the cells involved. Once established, cancers often affect a different part of the body as from whence they originate and involve the loss of the intrinsic mechanisms that inhibit cell proliferation. Multiplication of cells is an intricate process requiring elaborate biochemical coordination. In physiology compartment size is well- controlled and limited by various forms of cell death, control from which cancer cells escape. In addition, tumor cells escape from the immune system surveillance, and thus instead of being killed, they proliferate rapidly at a geometric rate forming a mass of cells; a tumor. Also, cancer cells survive and multiply outside their normal tissue boundaries, invading neighboring tissues. Furthermore, cancer cells are highly mobile within the body and can affect different parts of the body. Following seeding they can initiate growth of a new cancer that can affect healthy tissue. Upon entrance of cancer cells into the lymph and bloodstream, migration to a different part of the body is even further enhanced. The process of cancer spreading, i.e., metastasis, is the primary cause of mortality due to cancer. In this thesis I want to contribute to the battle against this disease.
The urgency of such efforts is illustrated by that oncological disease accounts for annually 8.2 million cancer-associated deaths (2012 numbers) and 14 million newly diagnosed patients. Victories against other types of mortality now also make cancer an emerging global public health problem(1), a development also occurring in Nigeria, my home country. Most prevalent cancer types include the gastrointestinal,
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