Incorporating anti-VEGF pathway therapy as a continuum of care in metastatic colorectal cancer

Abstract

Metastatic cancer was previously treated with distinctive lines of chemotherapy regimens upon disease progression or toxicity, yet the choices of therapy are actually interrelated, with the selection of a first-line regimen in part determining the choices available for subsequent treatment. Lately the therapeutic approach based on separate lines of treatment, tends to be replaced from a perspective strategical approach, that of the "continuum of care". This strategy targets to an improved overall survival, improved of quality of life and minimization of toxicity through upfront design of treatment selection and sequencing, exposure to all available drugs and minimization of unnecessary treatment. Anti-VEGF treatment has a well-documented role in this approach. Bevacizumab should be included in upfront treatment regimens for all mCRC patients independently of RAS status, unless contraindicated. Upfront bevacizumab could be combined with all available regimens since the optimal choice of backbone chemotherapy is yet to be defined. In RAS wild-type population, when metastasectomy is the target, an anti-EGFR combination is also a valid approach. Maintenance with bevacizumab and fluoropyrimidines should be considered upon intolerance of induction treatment and/or disease stabilization; maintenance with bevacizumab monotherapy should be avoided. In highly selected patients, complete treatment cessation could be also an option. Continuation with bevacizumab upon first progression and switch of the "backbone" chemotherapy is a validated approach. Patients progressing after first-line oxaliplatin regimen including bevacizumab combinations could be treated with an aflibercept-irinotecan combination. When no more options are available, regorafenib monotherapy should be the following choice. Combinations of anti-VEGF and anti-EGFR treatment have no place in this approach and are not indicated.