Prognostication in advanced cancer is increasingly complex in the era of personalized medicine. Although clinician predictions of survival (CPS) and performance status assessment remain standard, molecular diagnostics and targeted therapies challenge traditional prognostic frameworks and may lead to unexpected outcomes. We present a 53-year-old man with cancer of unknown primary with severe bone marrow infiltration, who experienced rapid deterioration, prompting early palliative care. However, next-generation sequencing revealed a human epidermal growth factor receptor 2 mutation, and targeted treatment with trastuzumab and pertuzumab led to marked clinical recovery and six months of sustained benefit. This case illustrates the uncertainty of prognostication in patients with acute complications undergoing novel treatments. Traditional CPS may be inaccurate, underscoring the need for flexible, multidisciplinary collaboration between oncology and palliative care. In the context of precision medicine, prognostic discussions must be individualized, balancing therapeutic potential with patient values and the realities of evolving evidence.
Keywords: hospital; neoplasms; oncology service; personalized medicine; precision medicine; prognosis; prognostication; unknown primary.