Retrospective comparison of first‐line adjuvant anthracycline vs metronomic‐based chemotherapy protocols in the treatment of stage I and II canine splenic haemangiosarcoma

Abstract

Splenectomy followed by adjuvant chemotherapy is commonly used to treat canine splenic haemangiosarcoma (HSA), although it is unclear if different treatment protocols may have a similar efficacy. The objective of this retrospective study was to assess outcome in dogs with stage I and II splenic HSA treated with either first‐line adjuvant anthracycline (AC) or metronomic (MC)‐based chemotherapy protocols, by comparing median time to progression (TTP) and median survival time (MST). Medical records of nine institutions were searched for dogs diagnosed with stage I and II splenic HSA that underwent adjuvant treatment with AC‐ or MC‐based protocols following splenectomy. Patients treated with MC following AC were included in an additional group (AMC). Ninety‐three dogs were included: 50 in the AC group, 23 in the AMC group and 20 in the MC group. The overall MST was 200 days (range 47‐3352) and the overall median TTP was 185 days (range 37‐1236). The median TTP of stage I dogs was significantly longer compared to stage II dogs (338 vs 151 days, respectively, P = .028). When adjusting for treatment type, the MST was 154 days for the AC group (range 47‐3352 days), 338 days for the AMC group (range 79‐1623 days) and 225 days for the MC group (range 57‐911 days). The difference in MST and median TTP was not found to be statistically significant between treatment groups. This study suggests that adjuvant MC in canine splenic HSA may result in a similar outcome when compared to other treatment protocols. Further studies are warranted to confirm these findings.

Omental hemangiosarcoma in five dogs

“…Complete excision was performed in four of the five dogs despite adhesions to adjacent anatomic structures, specifically the ureters and urinary bladder. Although post‐chemotherapy survival data was only available for one dog in the current case series, survival time in this dog is consistent with recent studies evaluating adjunct chemotherapy following surgery for HSA 27–30 . Marconato et al.…”

“…Treggiari et al. reported overall MST for stage I and II splenic HSA to be 338 days and 151 days, with surgical intervention and anthracycline chemotherapy yielding an MST of 154 days, surgical intervention and metronomic chemotherapy yielding an MST of 225 days, and surgical intervention and anthracycline with metronomic chemotherapy yielding an MST of 338 days 29 . Alexander et al.…”

Adjuvant carboplatin for treatment of splenic hemangiosarcoma in dogs: Retrospective evaluation of 18 cases (2011‐2016) and comparison with doxorubicin‐based chemotherapy

“…This was surprising considering differences have been shown with DOX-based studies between dogs with the different stages of splenic HSA. [33][34][35] Our interest in determining if peripheral blood monocyte counts could predict survival stemmed from 2 different studies. A study showed that an increased infiltration of CD18 + macrophages was found preferentially in HSA compared with other tumor-types.…”

Editorial

“…With regard to treatment for sarcomas, a general review highlights emerging therapeutic approaches for canine sarcomas, while the potential of combined targeted Type I interferon pathway inhibitors and oncolytic viruses to treat sarcomas are discussed in a second review . Original research publications within this issue also report treatment outcomes for canine patients treated with metronomic or anthracycline‐based adjuvant chemotherapy protocols, stereotactic radiation therapy for multilobular osteochondrosarcoma, limb sparing in dogs using three‐dimensional printed endoprosthesis and outcome of dogs undergoing secondary amputation for complications related to limb salvage surgery for osteosarcoma . This special issue also includes two original research manuscripts that aim to better understand potential contributions of the immune landscape in the biology or outcome of injection site sarcoma and canine osteosarcoma …”