Sunitinib in endometriosis: from bench to bedside

Dear Editor,

We read with interest the manuscript entitled ‘The effects of sunitinib on endometriosis’ recently published in the Journal of Obstetrics and Gynaecology (Pala et al. 2014). In the rat model of endometriosis, the authors observed that the oral administration of sunitinib caused a significant decrease in the volume of endometriotic implants; in the histopathological score of the implants; and in the extent, severity and total score of adhesions. Although the authors should be congratulated for their laboratory findings, we would like to raise some concerns on the use of sunitinib in the clinical treatment of endometriosis. Sunitinib is a competitive inhibitor of the catalytic activity of a group of receptor tyrosine kinases (RTKs), which has been used for the treatment of renal cell carcinoma, imatinib-resistant gastrointestinal stromal tumours, pancreatic neuroendocrine tumours and is currently being evaluated in several solid tumours (including breast, lung, thyroid, colorectal and ovarian cancer) (Leone Roberti Maggiore et al. 2013). Sunitinib may cause various adverse effects such as hypertension, asthenia, gastrointestinal disorders (such as diarrhoea, nausea and constipation), mucositis/stomatitis, a yellow skin discolouration and hand/foot skin reaction. Although the incidence and severity these adverse effects are considered manageable in the setting of cancer treatment, it seems unlikely that they can be tolerated by young women of reproductive age affected by endometriosis even for a short period of time of treatment (such as a 6-month postoperative therapy). Furthermore, endometriosis is a chronic disease that requires a long-term therapy combining clinical efficacy with low incidence of adverse effects (Ferrero et al. 2010). Given this background, it seems unlikely that sunitinib may have a role in the future treatment of endometriosis.

Declaration of interest: The authors report no declarations of interest. The authors alone are responsible for the content and writing of the paper.