Over the last few years, there has been much work in attempting to improve canine cancer treatment.
One strategy has been to use lower, continuous doses of oral chemotherapy drugs. The goal in this is to lessen chemotherapy toxicity, reduce trips to the oncologist for IV injections (the medications are pills), and hopefully gaining life span and life quality gains.
This is approach is called metronomic chemotherapy. Here, lower doses of drugs such as cyclophosphamide and piroxicam have been used with some success. Initial trials show promise with cancers such as hemangiosarcoma and soft tissue sarcomas.
One of the ways this treatment works is by acting on an enzyme found in higher levels in some cancers, called COX-2. This enzyme is “turned on” during inflammation. When this enzyme is activated, cancerous cells are able to suppress the immune system and create new blood vessels to feed tumors (angiogenesis).
Many think of metronomic chemotherapy as an attack against angiogenesis.
Perhaps most importantly however, when COX-2 is active, cancer cells are able to avoid apoptosis. Apoptosis is a naturally occurring process which is coded for in normal body cell genes. When these cells become pre-cancerous, damaged, old or infected, the apoptosis genes create what is called “cell suicide”. Apoptosis is the name for this genetically programmed cell suicide directed towards clearing out unwanted cells.
Cox-2 has been found in a variety of dog cancers, such as transitional cell carcinoma, some mammary carcinomas, prostate carcinoma, squamous cell carcinoma, and carcinomas of the nasal and intestinal lining.
One of the common metronomic chemotherapy drugs is piroxicam. This drug is able to help block the effects of the COX-2 enzyme.
There are plant-derived substances that are capable of having similar effects on COX-2. These include luteolin, apigenin, and curcumin (among others). It was for this reason that these constituents were included in the Apocaps formulation.
Metronomic chemotherapy, and the use of substances that fight COX-2, are still in their early stages, and has not yet had large scale studies completed to assess its effectiveness on a wide variety of cancers. However, oncologists are using these promising strategies today for canine cancers.
One of th
Dr. Demian Dressler is internationally recognized as “the dog cancer vet” because of his innovations in the field of dog cancer management, and the popularity of his blog here at Dog Cancer Blog. The owner of South Shore Veterinary Care, a full-service veterinary hospital in Maui, Hawaii, Dr. Dressler studied Animal Physiology and received a Bachelor of Science degree from the University of California at Davis before earning his Doctorate in Veterinary Medicine from Cornell University. After practicing at Killewald Animal Hospital in Amherst, New York, he returned to his home state, Hawaii, to practice at the East Honolulu Pet Hospital before heading home to Maui to open his own hospital. Dr. Dressler consults both dog lovers and veterinary professionals, and is sought after as a speaker on topics ranging from the links between lifestyle choices and disease, nutrition and cancer, and animal ethics. His television appearances include “Ask the Vet” segments on local news programs. He is the author of The Dog Cancer Survival Guide: Full Spectrum Treatments to Optimize Your Dog’s Life Quality and Longevity. He is a member of the American Veterinary Medical Association, the Hawaii Veterinary Medical Association, the American Association of Avian Veterinarians, the National Animal Supplement Council and CORE (Comparative Orthopedic Research Evaluation). He is also an advisory board member for Pacific Primate Sanctuary.