Mixed response – pro
Mixed response is a situation where some tumors radiographically respond and others progress, or new ones appear. In general, it it thought to portend progression, but it is legitimate to continue present chemotherapy on the assumption that some effeectiveness has been retained and that continuing treatment will allow a more effective applicaiton of other tratments in the future. There is little literature on it. Naing et al found that patients who develop acquired resistance after durable SD/CR/PR or who have an initial mixed response may attain SD 6 months/PR/CR with a retreatment approach.
van Kessel CS et al, Radiological heterogeneity in response to chemotherapy is associated with poor survival in patients with colorectal liver metastases. Eur J Cancer. 2013 Jul;49(11):2486-93 Naing A et al, Retreatment after Secondary Resistance or Mixed Response: A Pilot . tudyOncology 2013;85:350-355