The serine protease kazal-type inhibitor (SPINK) family is central to the regulation of proteolytic function, the establishment of physiological homeostasis, and the development of many disease states, including cancer. Emerging research has identified that members of the SPINK family are commonly overexpressed in most malignancies and are deeply implicated in pivotal oncogenic pathways like cell growth, epithelial-to-mesenchymal transition (EMT), metastasis, and drug resistance. This review provides an in-depth examination of structural and functional characteristics of SPINK proteins and their involvement in the onset and development of multiple cancers, which include prostrate, pancreatic, and colorectal carcinomas. Significantly, SPINK proteins regulate major signalling pathways, including EGFR, NF-κB, and MAPK, highlighting their role as prognostic biomarkers and therapeutic targets. The review underscores the most recent advancements in therapeutic strategies for SPINK-related pathways and outlines the bottlenecks that have restricted their use in the clinic. By integrating current evidence, this work signals the potential of SPINK proteins as good precision oncology candidates with novel options for cancer prognosis, treatment, and management.