Publications

The personalization of cancer care is rooted in the premise that there are subsets of patients with tumors harboring clinically relevant targets for patient-specific treatments. Colorectal cancer (CRC) is a disease that has historically been notable for its dearth of biomarkers that are predictive of response to targeted therapies. In recent years, -mutated CRC has emerged as a distinct biologic entity, typically refractory to standard chemotherapy regimens approved for the treatment of metastatic CRC and associated with a dismal prognosis. Multiple clinical trials sought to replicate the successes of targeted therapies seen in -mutated melanoma without success; metastatic -mutated CRC is clearly a distinct biologic entity. We review a number of recent studies demonstrating the evidence of modest responses to combinations of BRAF, EGFR, and/or MEK inhibition in patients with metastatic -mutated CRC; however, despite advances, overall survival remains far inferior for these patients compared to their -wild-type counterparts. Development of combination therapies to impede signaling through the pathway through alternate targets remains an area of active investigation. Reflecting the rapid evolution of efforts for this small subset of CRC patients, the first-ever Phase III study is now underway evaluating the combination of , , and inhibition. Immunotherapies are also an area of active research, particularly for the subset of patients with tumors that are also microsatellite instability (MSI) high. Here, we summarize the current landscape and emerging data on the molecular, clinical, and therapeutic aspects of -mutant CRC.

INTRODUCTION

Coronary physiology is recommended for guiding percutaneous coronary intervention (PCI). Previous cases have demonstrated changes in fractional flow reserve in a donor collateral vessel after PCI to a chronic total occlusion (CTO). The behaviour of instantaneous wave-free ratio (iFR) in the context of CTO has not been described.

CASE PRESENTATION

In this case, we share the first case of the effect of CTO recanalization on iFR in the donor artery, and show how iFR can reflect the amount of myocardium subtended by a stenosis.

DISCUSSION

Instantaneous wave-free ratio is able to incorporate the amount of subtended myocardium in its quantification of coronary stenosis severity.