Regorafenib is an oral multi-kinase inhibitor that was approved for treatment of colorectal cancer in Japan in 2013. It has characteristic side effects of skin damage, especially on palmoplantar surfaces of pressure areas, which can lead to suspension of treatment. We had one patient who suffered from severe foot damage and we managed to relieve her symptoms using personalized insoles. These insoles allowed us to continue her Regorafenib treatment for one year without foot damage. As a matter of fact, insole does not act as a cushion. It corrects the malalignment of foot arches which causes locally-concentrated undue stress on the feet. Therefore it appeases foot skin reaction. However, the type of malalignment of foot arches differs with each person, ready made insole cannot correct it appropriately, and may even cause more detrimental effects. Based on this case, we started a study to evaluate the benefits of prophylactic use of personalized insoles. Aim: To evaluate the benefits of prophylactic use of personalized insoles for patients treated with Regorafenib.
We prepared personalized insoles before the start of the treatment. The quality of fit of the insoles was evaluated and adjusted by baropodometry; a system for measurement of plantar pressure. The insoles were to be worn all the time, outside as well as at home. Foot damage in all patients, who could complete more than 1 course of Regorafenib treatment, was evaluated using the CTCAE v4.0 scale.
Since Nov. 2013 to Feb. 2015, 22 patients with metastatic colorectal cancer participated in this study. 4 patients stopped Regorafenib during the 1st course due to intolerable toxicities other than foot damage. Foot damage was evaluated in the 18 remaining patients. Hand foot skin reaction was observed 50.0% (G1 4 pts, G2 3 pts, G3 2 pts) on hands, and 27.8% (G1 3 pts, G2 2 pts) on feet. 1 case of G2 foot damage was due to the atrophy of plantar muscles that caused the decrease of ground contact area and change in the insole fit.
Personalized insoles could prevent foot damage by Regorafenib and could increase its compliance and so also the efficacy of treatment.
Clinical trial identification
All authors have declared no conflicts of interest.