Mason Canine Cancer Immunotherapy Research Laboratory

Dr. Nicola Mason, Penn VetCancer is the leading cause of death in dogs over the age of 10. Currently, three main types of cancer treatment exist for dogs and cats – surgery, radiation, and chemotherapy. These treatments are used either alone or in combination to eliminate cancer cells from the body. Despite these treatments, some cancer cells usually survive leading to disease relapse or progression. Unfortunately, most patients usually die of relapsed, drug-resistant metastatic disease.

Another type of therapy that is rapidly gaining attention in the treatment of cancer in people is immunotherapy. In this therapeutic approach, the patient’s own immune system is used to target and kill cancer cells in the body.

Dr. Nicola Mason B.Vet.Med., PhD, DACVIM (Internal Medicine), associate professor at Penn Vet, runs a translational research laboratory that focuses on ways to train the immune system to recognize and kill cancers in veterinary species.

Most of Dr. Mason’s current work focuses on the use of “cancer vaccines” in dogs with lymphoma or osteosarcoma. The goal of these vaccines is to “kick start” the immune system so that it will recognize cancer cells and kill them.

Furthermore, by using the immune system, it is hoped that such vaccines will stimulate immune “memory,” meaning that if and when the cancer does return, the immune system will recognize the cancer cells again and eliminate them.

Dr. Mason’s work not only helps bring novel effective immunotherapies into the canine cancer clinics but also has important translational relevance for human patients suffering from similar cancers.


Focusing on canine cancer, Dr. Nicola Mason and her team of researchers are developing novel approaches to generate functional, tumor-specific cytotoxic T lymphocytes.

One approach involves active immunization using whole tumor RNA loaded CD40 activated B cells, aimed at activating tumor specific T cells in vivo.

A second approach involves the passive adoptive transfer of genetically modified autologous T cells that are capable of MHC-independent tumor antigen recognition and activaton/effector function in the absence of co-stimulatory ligands.

A second related focus of Dr. Mason’s lab is to identify novel tumor-associated antigens and to develop single-chain fragment variable targeting systems that can be used alone or in concert with cell based therapies to target spontaneous occurring tumors.

Through innovative clinical trials in canine cancer patients, the lab works in concert with clinical oncologists to evaluate the safety and efficacy of both active immunization and passive adoptive transfer of genetically modified T cells in the treatment of spontaneously occurring cancer.

Study: Golden Retriever lymphoma

The Mason lab at the University of Pennsylvania School of Veterinary Medicine is Golden Retriever, Nicola Mason's cancer studiesinvestigating the possibility that a gammaherpesvirus can infect dogs and may contribute to lymphoma. The virus is thought to be highly similar to Epstein-Barr Virus that infects the majority of humans.

In most humans, infection is asymptomatic (no clinical signs), but in a very small subset of people, the virus is associated with lymphomas. Mason’s lab has shown that some dogs (like people) can be infected with an EBV-like virus and that this appears to be associated with lymphoma in some cases (Evidence of an oncogenic gammaherpesvirus in domestic dogs. Huang et al. Virology. 2012 Mar 7).

Using a relatively simple blood test, Mason’s lab can determine whether dogs have been exposed to an EBV-like virus. They now aim to screen approximately 500 healthy Golden Retriever dogs between 6 and 8 years of age to determine whether they are infected with the virus. Participating dogs will be evaluated every 6 months for 2 years to determine whether the presence of increasing amounts of virus and antibodies to the virus predicts which dogs many go on to develop lymphoma.

The study aims to provide very important information about a possible environmental cause of cancer and may lead to future anti-viral therapies for cancer. This study is supported by the National Institutes of Health.

We invite All Owners of Golden Retrievers to Take Part in This Study

All owners of healthy Golden Retrievers are invited to participate in an unprecedented study to investigate the possibility that a particular virus (a gammaherpesvirus) can infect Golden Retriever dogs and that this infection contributes to the development of lymphoma in some dogs.


If you have a healthy Golden Retriever dog that has not been previously diagnosed with cancer, and is between 6 and 8 years of age you may be eligible to participate in this study. Complete information regarding the study and study eligibility can be found on the consent form (download below).

Samples Required for the Study

The study involves taking a blood sample from your dog once every six months for two years.

 If your dog develops lymphoma while on the study, a biopsy of the malignant lymph node tissue will be taken and used to confirm the diagnosis and determine whether this virus is involved in the tumor.

 Blood samples and lymph node biopsies can be taken at your local veterinarian and sent to the University of Pennsylvania School of Veterinary Medicine.

About Costs:

 Please note that we do not have funds to cover any costs associated with visits to your veterinarian or costs associated with lymph node biopsies or blood samples. Funds are available to pay for shipping of samples to UPenn from your local veterinarian and for all laboratory tests that look for the virus in the blood and in any tumor tissue.

Study Participant Information for Golden Retriever Dogs

If you would like to participate in the study, please download:

  • the consent form (PDF)
  • the examination form and sample submission instructions (PDF)

Take these to your veterinarian. Please complete the consent form and ask your veterinarian to complete the examination form.

Both forms should be submitted to UPenn with your samples.
All samples should be sent overnight to the following address:

Attention: Dr. Nicola Mason
Room 335, Hill PavilionUniversity of Pennsylvania School of Veterinary Medicine380 South University Avenue
Philadelphia, PA 19107
Contact Information

Golden Retriever owners may also contact Rhonda Hovan (GRCA Health Committee member) by telephone at 330-668-0044 or 330-338-4236 (cell) or by e-mail at RhondaHovan@aol.com.

Related Resources

  • Learn more about Dr. Nicola Mason
  • Golden Retriever Club of America
  • Penn Vet Veterinary Clinical Investigation Center (VCIC)
  • Penn Vet Mari Lowe Comparative Oncology Center

 Support Canine Cancer Research

If you would like to contribute to canine cancer research in the Mason laboratory, please send your check made payable to the Trustees of the University of Pennsylvania and note that it should be designated to the Mason Cancer Research Fund. Please mail to:

Office of Advancement
Penn Vet
University of Pennsylvania
3800 Spruce Street, Suite 172E
Philadelphia, PA 19104

Study: Evaluation of a recombinant bacteria vaccine to treat bone cancer in dogs


The purpose of this study is to determine whether a recombinant L. moncytogenes vaccine can elicit anti-tumor immunity and prolong survival in dogs with cancer of their long bones (appendicular osteosarcoma (OSA)).

Sponsor: Advaxis, Inc.

Enrollment criteria and baseline evaluation of patients

We are actively recruting patients for a pilot study to determine the safety and efficiacy Dr. Mason's osteosarcoma study, Penn Vetof a new bacteria based vaccine to stimulate an immune response against osteosarcoma and prolong survival in dogs with bone cancer. Only those dogs with a histological diagnosis of osteosarcoma and who have undergone limb amputation and standard chemotherapy (4 doses of carboplatin) for the treatment of osteosarcoma will be eligible for inclusion in the study. In addition, only those patients whose tumors express the target antigen “Her-2/neu” will be eligible for inclusion in this study.

Up to 18 privately owned dogs with long bone cancer (appendicular OSA) and confirmed expression of Her2-neu will be enrolled. At enrollment (3 weeks following the last dose of carboplatin chemotherapy), all eligible dogs will receive basic clinical laboratory tests including a Complete Blood Count (CBC), Chemistry Screen (CS) and urinalysis (UA) and a baseline evaluation of cardiac function by echocardiography and measurement of cardiac-specific Troponin I (cTnI) levels. Thoracic radiographs will be taken to determine whether pulmonary metastases are present. At the time of enrollment, a blood sample will be taken to assess immune function and baseline levels of anti-tumor immunity.

L.m recombinant treatment

All dogs will be vaccinated, there is no placebo control. The first vaccine will be given three weeks after the last dose of routine chemotherapy. Patients will receive a total of 3 vaccines given three weeks apart. Patients will stay in the hospital for 48 hours following vaccine administration for observation.

The study pays for the following:
  • Complete staging of disease at the time of enrollment (includes CBC, CS, UA, immune function assessment, thoracic radiographs, cardiac evaluation)
  • Three vaccines
  • Hospitalization for observation
  • CBC, CS, UA and cardiac evaluation every three weeks for a total of 9 weeks
  • Routine staging every 2 months following last vaccine administration (includes CBC, CS, UA, immune assessment, thoracic radiographs, cardiac evaluation)

Contact Us

If you are interested in learning more about this study, please contact the Prinicipal Investigator Dr. Nicola Mason at 215 898 3996 or nmason@vet.upenn.edu

Bone Cancer Study:

Sasha is the first dog to receive this cancer vaccine. You can follow her progress on a blog written by her owners, Carlos and Liliana Ruano. Visit Sasha's blog...

Read more about this innovative study in the Philadelphia Inquirer.