Cancer patients are often prone to a variety of pathological changes that disrupt normal homeostatic processes in the body. Aside from medical interventions and therapies associated with treating the disease, the cancer itself is a major contributor to systemic disruption of physiological processes. Extracellular body fluid is tightly controlled and monitored by a variety of sensors, hormones, proteins, and organs. Palpable changes in fluid homeostasis can commonly be attributed to inflammation, where the changes in vasculature necessary to facilitate an immune response compromise the vascular endothelial barrier. Such changes, although transient, reveal the consequences of compromised vessel walls, leakage of plasma proteins, and collection of fluid in the interstitial space. Edema represents a pathological form of fluid extravasation into the interstitium and is a common clinical feature in many cases of malignancy. By examining common inflammatory factors secreted by the tumour, it becomes evident that the increased levels of such factors in patient sera could, indeed, influence a pro-edematous state. Therefore, it is the dynamics of the tumour itself in isolation of therapeutic side effects that can influence local and systemic vasculature by promoting a chronic inflammatory state characterized by leaky vasculature and dysregulated fluid homeostasis.