Evaluation of a 6-Month Chemotherapy Protocol with No Maintenance Therapy for Dogs with Lymphoma

Abstract

The purpose of this study was to compare a maintenance-free chemotherapy protocol based on CHOP (H from hydroxydaunorubicin = doxorubicin, O from Oncovin = vincristine) to a similar protocol with a maintenance phase for the treatment of canine lymphoma. Fifty-three dogs with multicentric lymphoma were treated with a 6-month modified version of the University of Wisconsin (UW)-Madison chemotherapy protocol (UW-25). Disease-free interval (DFI) and survival were compared to a historical control group of 55 dogs treated with a similar protocol with a prolonged maintenance phase. Remission rate for the study dogs was 94.2% (complete remission = 92.3%, partial remission = 1.9%). DFI and survival between the 2 groups did not differ significantly, with median DFI and survival of the study dogs equal to 282 and 397 days compared to 220 and 303 days for the control dogs (P = .2835 and .3365, respectively). Univariate analysis identified substage b (P = .0087), German Shepherd breed (P = .0199), and body weight > 18 kg (P = .0016) as significant for worse survival. Longer survival was associated with thrombocytopenia (P = .0436). Multivariate analysis revealed that substage (P = .0388) and weight (P = .0125) retained significance for DFI, whereas substage (P = .0093), thrombocytopenia (P = .0150), and weight (P = 0 .0050) retained significance for survival. Overall, the protocol was well tolerated by the dogs, with 41.5% (22/53) requiring a treatment delay or dose modification, but only 9.4% (5/53) needing hospitalization. The 6-month chemotherapy protocol based on CHOP with no maintenance phase provides similar DFI and survival times when compared to a similar protocol with a prolonged maintenance phase.

Epidemiological, clinical and immunohistochemical aspects of canine lymphoma in the region of Porto Alegre, Brazil

“…In addition, 23.33% of the animals in this study were in stage V; in other studies, the percentages of animals in stage V were similar, ranging from 18 to 29% (MacEwen et al 1987, Cardoso et al 2003, though one study reported a percentage of only 4.3% (Dobson et al 2001). Studies performed in the USA evaluating the sub-stage of dogs with lymphoma showed a high percentage of dogs in sub-stage "a" (Valerius et al 1997, Chun et al 2000, Garret et al 2002. In Italy, Dobson et al (2001) reported an incidence of 49% of animals in sub-stage "a" and 51% in stage "b".…”

Impact of Chemotherapeutic Dose Intensity and Hematologic Toxicity on First Remission Duration in Dogs with Lymphoma Treated with a Chemoradiotherapy Protocol

“…Nonetheless, in numerous studies using intent-to-treat analyses, chemotherapy-related deaths are relatively rare despite frequent neutropenia. 5,6,22,23,37,41 Despite these findings, dose escalation clearly carries substantial risk and should not be used without additional research to confirm or refute the findings of this study.…”

“…[17][18][19][20][21] The exception to this rule is found in the treatment of lymphoma, for which doxorubicin-based multiagent protocols provide the longest reported survival times in both cats and dogs. 5,6,22,23 Not surprisingly, this is also the single example of an animal cancer for which 3 drug classes (ie, vinca alkaloids, alkylating agents, anthracyclines) are known to have substantial activity as single agents. [24][25][26] In addition to using multiple drugs, the maximization of dose intensity (drug dose/m 2 /wk) has proven to be of importance for improving the efficacy of chemotherapy for some human cancers.…”

Autologous Peripheral Blood Hematopoietic Cell Transplantation in Dogs with T‐Cell Lymphoma

“…Treatment of all LSA phenotypes historically has involved the administration of multiagent CHOP‐based (cyclophosphamide, doxorubicin, vincristine, prednisone) chemotherapy protocols of varying length 4, 5. In addition, the use of cranial and caudal half‐body irradiation in conjunction with chemotherapy has been described for the treatment of both B‐ and T‐cell LSA 6, 7.…”