title: Importance of continuing therapy and maintaining one-month relative dose intensity in sunitinib therapy for metastatic renal cell carcinoma.
abstract: Sunitinib is a multikinase inhibitor used as first- and second-line treatment of metastatic renal cell carcinoma. However, there are few reports on the necessary doses of sunitinib to get better clinical outcome in general practice with Japanese patients. We examined the relationship between the efficacy and the necessary doses of sunitinib therapy in a multi-institutional retrospective study. A study population of 94 metastatic renal cell carcinoma patients was eligible for this investigation. The most frequent grade 3/4 laboratory adverse events were decreased platelet (31.9 %) and white blood cell (21.3 %) counts. Treatment was discontinued in 18 patients (31.0 %) initially receiving a 50-mg/day dose within only one course, and median 1-month relative dose intensity was 74.3 %. Median progression-free survival time was 2.3 months in patients treated for only one course and 10.8 months in patients treated for more than one course (P < 0.001). Multivariate analysis showed that only one course of treatment and 60 % and less of 1-month relative dose intensity were significantly associated with inferior progression-free survival (P < 0.001 and P = 0.027, respectively). Moreover, modified Memorial Sloan-Kettering Cancer Center poor risk was significantly associated with progression-free survival time. It is difficult for Japanese patients to continue an initial dose of sunitinib therapy without drug withdrawal. Continuing therapy for more than one course and maintaining more than 60 % of 1-month relative dose intensity were very important in the prolongation of progression-free survival time regardless of the initial treatment doses.
authors.affiliation: Department of Urology, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, Suita City, Osaka, 565-0871, Japan.
authors.forename: Atsunari
authors.initials: A
authors.lastname: Kawashima
authors.forename: Akira
authors.initials: A
authors.lastname: Tsujimura
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Takayama
authors.forename: Yasuyuki
authors.initials: Y
authors.lastname: Arai
authors.forename: Mikio
authors.initials: M
authors.lastname: Nin
authors.forename: Go
authors.initials: G
authors.lastname: Tanigawa
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Yasunaga
authors.forename: Masatoshi
authors.initials: M
authors.lastname: Mukai
authors.forename: Motohide
authors.initials: M
authors.lastname: Uemura
authors.forename: Yasutomo
authors.initials: Y
authors.lastname: Nakai
authors.forename: Kazuo
authors.initials: K
authors.lastname: Nishimura
authors.forename: Norio
authors.initials: N
authors.lastname: Nonomura
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000970:Antineoplastic Agents / Q000008:administration & dosage*; D002292:Carcinoma, Renal Cell / Q000188:drug therapy* / Q000401:mortality; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D007211:Indoles / Q000008:administration & dosage*; D007680:Kidney Neoplasms / Q000188:drug therapy* / Q000401:mortality; D008297:Male; D008875:Middle Aged; D016016:Proportional Hazards Models; D011758:Pyrroles / Q000008:administration & dosage*; D012189:Retrospective Studies; D000077210:Sunitinib
chemical_list: D000970:Antineoplastic Agents; D007211:Indoles; D011758:Pyrroles; D000077210:Sunitinib