As one of the most prevalent and burdensome symptoms across the cancer continuum, cancer pain affects patients with active disease, those approaching the end of life, and a growing population of long-term survivors. Despite advances in supportive oncology, clinically meaningful gaps in pain control persist. These gaps increasingly reflect limitations in implementation, inequitable access to care, delayed recognition of structural pain generators, and inconsistent integration of interdisciplinary services rather than a simple lack of therapeutic options. This narrative review provides a clinically oriented synthesis of contemporary guidelines and selected high-impact evidence on adult cancer pain management. We review the pathophysiology of cancer pain, multidimensional assessment, phenotype-informed pharmacologic strategies, disease-directed interventions, and nonpharmacologic supportive approaches. We also examine the tension between rational opioid stewardship and the risk of undertreatment in the context of the opioid crisis. Contemporary cancer pain management requires individualized, mechanism-informed care that extends beyond linear analgesic escalation. Three practical themes emerge from current evidence and guideline synthesis: first, routine multidimensional assessment is needed to distinguish nociceptive, neuropathic, mixed, and temporal pain phenotypes; second, disease-directed interventions such as palliative radiotherapy should be considered early when they address the underlying pain generator; and third, proactive multidisciplinary collaboration is essential to address functional impairment, psychosocial distress, and barriers to equitable care delivery.