Is cancer the result of uncontrolled cellular growth? a glance into the tumorigenic process

BACKGROUND: Cancer has been defined as a group of diseases that result from the uncontrolled growth of abnormal cells that form tumors, invade nearby tissues, and spread to other parts of the body. The notion of “uncontrolled” growth, however, would imply that cancer cells grow following no biological rules and without any regulation. Yet, evidence presented over the past three decades, based on genomic, epigenetic, molecular, cellular, immunologic, and physiological approaches, indicates that cancer is, for the most part, a controlled, although abnormal, process that results in the formation of solid tumors or hematologic neoplasms. Cancer seems to be a hybrid process in which stochastic events coexist with constraining and regulatory influences. The present article is an up-to-date comprehensive overview on the current evidence supporting the notion that, although cancer implies abnormal -malignant- cellular growth, it is not uncontrolled cellular growth. Herein, we summarize and discuss the evidence indicating that cancer originates and progresses under the action and influence of specific factors and mechanisms that regulate, in a finely way, tumor cell growth and dissemination. CONCLUSION: While cancer manifests as abnormal cell growth, it cannot and should not be reduced to a set of uncontrolled processes. On the contrary, multiple biological mechanisms interact in a precise and coordinated manner, akin to the pieces of a Rubik’s cube, which do not align by chance, but rather as the result of a synchronized sequence of events. To conceive cancer merely as unregulated cell proliferation is to underestimate and misrepresent the nature of such an assembled disease.