No residual cancer at surgery–the neoadjuvant endpoint that predicts long-term outcomes.
In neoadjuvantLoading... settings, pCR provides an early readout of treatment efficacy. Patients achieving pCR in breast cancer have dramatically better event-free survival than those with residual disease. This correlation is strong enough that FDA has granted accelerated approval based on pCR rates.
In melanomaLoading..., neoadjuvant checkpoint immunotherapyLoading... is under investigation. pCR rates with combination anti-PD-1/anti-CTLA-4 can exceed 50% in selected patients.
What pCR Means: Pathologic complete response means no cancer cells are found in the surgical specimen after neoadjuvant therapy. The treatment eliminated all visible disease.
Why It Matters: pCR strongly predicts long-term survival in many cancers. It's also faster to measure than waiting years for survival data.
Currently, pCR is only known after surgery. But if pretreatment biopsies could predict who will achieve pCR, therapy could be optimized upfront. Patients unlikely to achieve pCR might receive alternative approaches; likely responders could proceed confidently.
iFRETLoading... measurement of checkpoint engagement in pretreatment biopsies offers this potential–identifying tumors actively using checkpoint suppression and therefore likely to respond to blockade.
Early Response Indicator: Biomarkers that predict or track pCR could identify patients likely to benefit from neoadjuvant therapy.
TVEC Study: In melanoma, patients achieving complete response showed different iFRET patterns than non-responders. Functional biomarker changes correlated with pathologic response.
