Neoplasm, Residual

Residual neoplasm arises from incomplete eradication of the original cancer after therapy. The supplied grounding does not support more specific etiologic causes beyond persistence of tumor cells after treatment.

The biological basis is persistence of malignant cells after treatment, which can be detected or inferred through minimal residual disease approaches such as circulating tumor DNA. The grounding also links residual disease to tumor heterogeneity and acquired drug resistance, including resistant subclones and other mechanisms that allow tumor cells to survive therapy and later drive progression or relapse.

Factors associated with residual disease include detectable circulating tumor DNA after treatment, which is used as a marker of molecular residual disease. The grounding also supports treatment-related resistance mechanisms and tumor heterogeneity as contributors to persistence after therapy.

Management is described at the level of post-treatment surveillance, residual disease detection, and therapy adaptation using modalities such as ctDNA-based liquid biopsy and minimal residual disease assessment. In the reviewed literature, residual disease status can inform escalation, switching, or monitoring of systemic therapy, including targeted therapy and immunotherapy in relevant cancers, but no disease-specific regimen is supported here.