Investigation of a Traditional Chinese Medicine herbal therapy protocol for treatment of dogs with stage II splenic hemangiosarcoma after splenectomy.
Funding and donations for this clinical trial are provided by an American Holistic Veterinary Medical Foundation (AHVMF) research grant, Natural Path and Rx Vitamins.
Canine splenic hemangiosarcoma (HSA) is a uniformly aggressive disease with a high metastatic rate and grave prognosis, despite aggressive treatment with surgery and chemotherapy. Reported median survival time (MST) for stage II disease treated with splenectomy alone is two months (range is 1.6 to 3.4 months). With the addition of chemotherapy, the reported MST for stage II disease ranges from 3.1 to 5.9 months. The published overall one-year survival rates for stage II are 6% to 13% with surgery alone, and 12% to 20% with the addition of chemotherapy. Given the minimal overall survival benefit seen with the addition of chemotherapy, and the high rate of early mortality, novel and affordable treatment options are needed for this aggressive disease.
Many herbal medicines have demonstrated mechanisms of action relevant to tumor progression pathways known to be important in the development, progression and metastasis of canine HSA. To assess the potential impact of palliative treatment with Chinese herbal medicine in managing dogs with stage II splenic HSA, a retrospective evaluation was done of dogs matching this diagnosis and treated with surgery and personalized Traditional Chinese Herbal Medicine (TCHM) at Oakland Veterinary Referral Services (OVRS) between 2007 and 2015, and at the Edmonton Holistic Veterinary Clinic (EHVC) between 2011 and 2016, for whom standard chemotherapy was declined. A total of ten patients from OVRS and four from EHVC met the inclusion criteria. The median survival time was 8.7 months with a 64% six-month survival rate, a 43% one-year survival rate, and a 21% two-year survival rate. No toxicities were reported.
Median survival time along with one- and two-year survival rates in this small patient population show improvement compared to published statistics for splenectomy and chemotherapy. Based on the results of this patient population, a funded multi-institutional prospective clinical trial is currently underway. To date, 17 dogs have been enrolled; we aim to enroll a total of 50. Funding was not sufficient for a chemotherapy arm, and for compassionate care reasons there is no placebo control, so all patients enrolled will receive the study protocol.
One main limitation to retrospectively evaluating the efficacy of TCHM treatments is that prescribing according to patient-specific TCHM principles results in a non-homogenous treatment regimen. Not only does this make evaluation of the impact of specific formulas more difficult, it also prevents the use of this treatment by practitioners who are not trained in TCHM. The goal of this study is to prospectively evaluate the impact of a standardized bupleurum-based herbal formula administered with vitamin D supplementation, Yunnan Pai Yao, and coriolus mushroom granular extract, in canine patients diagnosed with stage II splenic HSA following splenectomy.
It is too early to determine efficacy of the study protocol, although of the 17 patients enrolled, two are currently out over one year after diagnosis. Survival times for the nine patients who have passed away to date range from two weeks to 6.7 months. An additional eight patients are ongoing, ranging three weeks to over 15 months after splenectomy. No toxicities from the treatment have been noted to date, including one patient who received a significant repeated overdose of the herbal formula due to client non-compliance.
Dogs for whom chemotherapy has been declined, and who have had a spleen tumor that ruptured, causing documented hemoabdomen, with the tumors surgically removed and no evidence of distant metastasis, are potential candidates for enrollment. To enroll, patients must be able to travel monthly to one of the clinical trial centers (see sidebar above) for management by one of our participating veterinary oncologists. Dogs must be enrolled and starting treatment with the study protocol within three weeks of spleen removal. Early referral is, therefore, important. Full inclusion and exclusion criteria and study details can be found at MettaPets.info/clinicaltrials.