A4.2 Systemic response to surgery

Topic

Major surgery is not limited to the removal of the tumor; beyond the extraction itself, it triggers a systemic host response affecting multiple physiological systems throughout the patient's body, extending far beyond the surgical site.

This systemic host response encompasses several distinct changes occurring simultaneously: an acute inflammatory response characterized by rising levels of circulating inflammatory substances; activation of the hypothalamic-pituitary-adrenal axis, leading to a sharp spike in cortisol levels; transient immunosuppression that temporarily weakens the patient's immune system; alterations in blood coagulation that leave the patient in a procoagulant state post-surgery; and additional hemodynamic and metabolic disturbances.

The significance of this systemic host response in the context of cancer extends well beyond the typical complications of surgical recovery: the transient immunosuppression induced by major surgery creates a window of vulnerability—a period during which pre-existing micrometastases, previously dormant and non-growing, can break out of dormancy and establish new foci of disease.

This same window of vulnerability for dormant micrometastases can also be opened through a pathway distinct from transient immunosuppression: during surgical wound healing, the patient's body releases growth factors that stimulate postsurgical angiogenesis—the formation of new blood vessels—and these same growth factors can activate dormant micrometastases, even in the absence of immunosuppression. Thus, transient immunosuppression and postsurgical angiogenesis are two distinct pathways triggered by major surgery itself, and both converge on the same outcome: dormant micrometastases—which the surgery could neither detect nor remove—cease to be dormant. Consequently, the host's systemic response to major surgery is not merely a phenomenon of postoperative recovery but an active component of the patient's oncological course, with consequences extending far beyond the surgical site.

ID:2311