Dogs Teaching Us a Thing or Two About Cancer Biology

The German shepherd standing on my front lawn, and his friends in the neighborhood, the rottweiler, the maltese, the shih tzus, the husky, and the other exotic breeds, have one thing in common: Like humans, they are living into their golden ages, and are increasingly showing up with diseases of old age, including cancer. Dogs once past the age of 10 years have a 50% chance of developing any type of cancer. (A 10 year old dog, depending on the breed, is same age as a 55-65 year old man.) 

All types of cancers seen in humans also show up in dogs. For example, take breast cancer: Like women, female dogs (those not neutered, or are at a breeder) also come down with breast cancer, generally called mammary cancer in dogs.

Further, not only the biology of cancer is similar in dogs and man, the dogs also respond to same cancer drugs that are used for humans.


Comparative Oncology

On March 31st, 2014, The New York Times profiled the Penn Vet Shelter Canine Mammary Tumor Program on its website. This innovative program, run by Dr Karin Sorenimo, the Professor of Oncology at the University of Pennsylvania, takes in shelter dogs for cancer treatment and care; the dogs in turn help advance research into the biology of cancer by ways that are impossible to do in humans.

Cancer Drugs Losing Out: Pruning the Branches, Not Cutting the Trees

An oncologist puts the cancer patient on a targeted therapy, the cancer goes away, patient goes home. But, 6 months later, the cancer is back (relapsed) and is aggressive stage IV. Biologically, the cancer cells have mutated to bypass/ignore the expensive targeted therapy.

At the molecular level, the cancer cells are constantly mutating, evolving, and generating diversity. This phenomenon of cancer evolution is central to cancer relapse, tumor escape and therapeutic failure.

New research from the Institute of Cancer Research, UK, shows extreme diversity of cancer cell types in leukemia patients: multiple cancers within a cancer. 

Common Mutations Drive 12 Different Cancer Types

Cancer types from leukemia to breast cancer, and bladder cancer to lung cancer are all driven by a common set of genes containing driver mutations. Researchers from The Cancer Genome Network (TCGN) sequenced and analyzed genomes of 3,281 tumors from 12 different cancer types and discovered 127 genes that were involved in the initiation or progression of these cancers. This research appears in the October 17, 2013, issue of the journal Nature.