Protocol 1
**Please note : Protocols are not listed in order of preference or efficacy.
Protocol 1: Vinblastine/prednisone protocol
- Week 1 : Vinblastine
2-2.5 mg/m2 IV. Prednisone
1 mg/kg PO SID. - Week 2 : Vinblastine 2-2.5 mg/m2 IV. Prednisone 1 mg/kg PO SID.
- Week 3 : Vinblastine 2-2.5 mg/m2 IV. Prednisone 1 mg/kg PO SID.
- Week 4 : Vinblastine 2-2.5 mg/m2 IV. Prednisone 1 mg/kg PO SID.
- Week 5 : No chemotherapy. Prednisone 1 mg/kg PO SID.
- Week 6 : Vinblastine 2-2.5 mg/m2 IV. Prednisone 1 mg/kg PO SID.
- Week 7 : No chemotherapy. Prednisone 1 mg/kg PO SID.
- Week 8 : Vinblastine 2-2.5 mg/m2 IV.
- Week 9 : No chemotherapy. Prednisone 1 mg/kg PO SID.
- Week 10 : Vinblastine 2-2.5 mg/m2 IV.
- Week 11 : No chemotherapy. Prednisone 1 mg/kg PO SID.
- Week 12 : Vinblastine 2-2.5 mg/m2 IV. Prednisone 1 mg/kg PO SID.
Important considerations
- In dogs, use of this protocol is indicated in patients with non-resectable MCT , metastatic grade II MCT, grade II MCT in high grade locations (eg pinnae, muzzle, perineum, prepuce, vulva, digits, etc), and all grade III MCT.
For gross/measurable disease likely response rates are in the order of 40% and rarely are they sustained. - For dogs weighing <15 kg, use lower end of vinblastine dose (2.0 mg/m2).
- Myelosuppression and gastrointestinal toxicity (eg inappetence, vomiting, and/or diarrhea) are possible toxicities of vinblastine.
- Extravasation injury is also an important toxicity. Vinblastine should be administered through a clean stick catheter and given as a bolus.
Careful monitoring of the patient is advised during administration to ensure the catheter remains in place. - A complete blood count (CBC ) with platelet count must be performed within 48 hours prior to chemotherapy administration. Ideally this should be done the day of chemotherapy administration. Delay chemotherapy by 3-7 days and then recheck CBC if:
- Neutrophil count < 2000 cells/µl.
- Platelet count < 75,000 cells/µl.
- Patient is exhibiting GI signs secondary to previous chemotherapy.
- Reduce vinblastine dose by 25% in patients experiencing significant myelosuppression, GI toxicity and/or those requiring treatment delays during weekly administration.
- Taper and discontinue prednisone after the final vinblastine treatment.
- Restage patients prior to final vinblastine treatment.
Protocol 1 is probably all that is required for the veterinarian in practice; this is the most widely published and used protocol. The other protocols have not really been proven to offer superior efficacy and run the risk of increased toxicity especially myelosuppression as more myelosuppressive drugs are combined.
Sources
Publications
Refereed papers
- Recent references from PubMed.
- Taylor F, Gear R, Hoather T, Dobson J (2009) Chlorambucil and prednisolone chemotherapy for dogs with inoperable mast cell tumors: 21 cases. JSAP 50 (6), 284-289 PubMed.
- Thamm D H, Turek M M, Vail D M (2006) Outcome and prognostic factors following adjuvant prednisone/vinblastine chemotherapy for high-risk canine mast cell tumour: 61 cases. J Vet Med Sci 68 , 581-587 PubMed.
- Camps-Palau M A, Leibman N F, Elmslie R et al(2007) Treatment of canine mast cell tumours with vinblastine, cyclophosphamide and prednisone: 35 cases (19972004). Vet Comp Oncol 5 , 156-167.
- Kristal O, Rassnick K M, Gliatto J M et al(2004) Hepatotoxicity associated with CCNU (lomustine) chemotherapy in dogs. J Vet Intern Med 18 , 75-80 PubMed.
- Charney S C, Bergman P J, Hohenhaus A E et al(2003) Risk factors for sterile hemorrhagic cystitis in dogs with lymphoma receiving cyclophosphamide with or without concurrent administration of furosemide: 216 cases (1990-1996). J Am Vet Med Assoc 222 , 1388-1393 PubMed.
- Rassnick K M, Moore A S, Williams L E et al(1999) Treatment of mast cell tumors with CCNU (lomustine). J Vet Intern Med 13 , 601-605.
- Thamm D H, Mauldin E A, Vail D M (1999) Prednisone and vinblastine chemotherapy for canine mast cell tumor - 41 cases (1992-1997). J Vet Intern Med 13 , 491-497.
