Amid unprecedented scientific progress in oncology, a growing body of evidence reveals a parallel and profound crisis in the human experience of cancer care. Despite overall survival outcomes improving, the systems designed to deliver care increasingly fall short in addressing the emotional, relational, and existential dimensions of cancer. Although examples of compassionate and attentive care can be found in every setting, patients and families across global contexts continue to report being unheard, unsupported, and, at times, actively harmed by care structures that prioritise technical precision over human presence. This Lancet Oncology Commission proposes that the human crisis of cancer is not defined by pathology, mortality, or cause, but by the erosion of meaning, connection, and compassion in the experience of cancer. This crisis is shaped by what is present and what is absent: the presence of fragmented, costly, and impersonal systems and the absence of human connection, psychological safety, and relational care. It is a crisis that spans delivery, mental health, palliative care, research, and education-one that is not peripheral to oncology's progress but central to its failures. The impacts of this crisis are felt most acutely by those already made vulnerable by inequity, discrimination, and economic precarity, but it is a system-level failure that ripples across every context, from the most resource-rich to the most resource-constrained settings. Addressing this crisis will require more than good intentions; it will demand confronting the structural incentives and ideologies that have devalued the relational foundations of cancer care. This Commission identifies a growing imbalance between technological innovation and the human dimensions of cancer care. As the field has increasingly prioritised biopharmaceutical development, genomic precision, and market-driven efficiencies, it has often neglected core practices that uphold dignity, alleviate suffering, and build trust.