Efficacy of low-dose chemotherapy with methotrexate and vinblastine for patients with extra-abdominal desmoid-type fibromatosis: a systematic review

Objective: The treatment modality for desmoid-type fibromatosis has shifted from surgery to conservative treatment. This systematic review aims to evaluate the efficacy of low-dose chemotherapy with methotrexate and vinblastine for patients with extra-abdominal desmoid-type fibromatosis. Methods: We searched the pertinent literature from January 1990 to August 2017. Two reviewers evaluated and screened the literature independently for eligibility and extracted data. We evaluated the quality of body of evidence and made a recommendation according to the Grading of Recommendations Development and Evaluation methodology. Results: The search yielded 40 studies, 9 of which were included after the first and second screenings. There were three prospective case series but no randomized controlled trials among the nine studies. There was no case-control report (vs. no treatment). According to Response Evaluation Criteria in Solid Tumors criteria, the mean response rate (complete remission or partial response) was 36% (11-57%). Including stable disease, namely, clinical benefit was consistently as high as 85% (69-100%). Mean adverse event rate of G3 or G4 according to CTCAE was 31%. One study reported improvement of pain (87.5%) because of this chemotherapy. Conclusion: The efficacy of this chemotherapy was convincing. However, the overall evidence was weak, and this chemotherapy is not covered by insurance in Japan; we only weakly recommend low-dose chemotherapy with methotrexate and vinblastine in patients with extra-abdominal desmoid-type fibromatosis.