Step 1: Solid tumours frequently outgrow their blood supply, creating regions of poor oxygen delivery. A specific metabolic strategy allows malignant cells to keep generating energy and dividing in such an environment.
Step 2: Otto Warburg noted that tumour cells rely heavily on glycolysis and lactate production rather than oxidative phosphorylation, a feature retained even when oxygen is plentiful. This rewiring of energy metabolism is the hallmark adaptation.
Step 3: This metabolic reprogramming favours rapid biomass synthesis, supports survival under hypoxia, and drives invasion and spread, so it is labelled a growth-promoting effect.
Step 4: Eliminating the alternatives: Wormian denotes accessory skull bones, Wolffian is an embryological duct system, and Wanton has no oncological meaning.
\[\boxed{\text{Warburg phenomenon}}\]