Surgery to treat cancer in cats and dogs.

Surgery for Cats and Dogs with Cancer

Introduction
Surgical removal of localized cancer can often be curative if the cancer was detected at its earliest stages, prior to
spreading to other parts of the body. Surgeons will often play a critical role in managing your pet's cancer whether it is for
obtaining a biopsy sample, performing curative surgery, or alleviating symptoms caused by the tumor.

Cancer is sometimes referred to as the disease of the elderly since its incidence dramatically increases with age. Some
veterinarians may not feel comfortable performing an aggressive surgery on an older pet because of concerns whether the
pet will withstand the surgical intervention. However, no pet should be denied treatment on the basis of age. An older pet
may be in better health than a 4 year old pet, thus the question of compatibility with surgery should be discussed in terms
of the pet's overall health and likelihood of benefiting.

Surgery is the mainstay of cancer management but it is not always necessary. Pet owners should engage in a detailed
discussion with their veterinarian and veterinary oncologist to ensure that all questions have been answered and a logical
conclusion about the necessity of a surgery was reached. Pet owners are encouraged to seek second opinions if
necessary or if in doubt about the appropriateness of the selected treatment.

Questions to ask before the surgery
Prior to scheduling a surgery for your pet, the following questions should be answered by both your pet's medical team and
your family.
1. What is the type, stage, and grade of cancer to be treated?
2. What are the expected effects of your pet's particular tumor?
3. Is cure or significant health improvement achievable without dramatically compromising your pet's quality of life?
4. Is surgery necessary or are there alternative, less invasive treatments available?
5. What is expected in terms of post-operative care?
6. Can your family handle taking care of your pet's post-operative needs? If your pet will require 24/7 care for the first few
days, can you take days off from work for the required period of time or have the resources to leave your pet in the
hospital for medical supervision?

Types of surgery
The type of surgery that will be performed on your pet will largely depend on the anatomical site of the tumor and the type,
size and stage of the tumor. It can either be performed as a single treatment or in combination with chemotherapy or
radiation to enhance the overall chance for cure.

Surgery for cure
This type of surgery will attempt to remove all traces of cancer from your pet's body. It is generally believed that the first
surgery has the best chance of cure. The surgeon will not only remove the tumor itself but also some of the surrounding
tissues to make sure that no cancer cells are left behind.

Lymph node removal
Lymph nodes are structures that drain lymphatic fluid for circulation into the lymphatic system and is one of the
mechanisms by which tumor cells can spread to other organs. In some cases, when the tumor cells were found to spread to
the nearby lymph nodes, it is desirable to remove the lymph nodes to prevent further spread of tumor cells. However, there
is still some controversy as to when such procedure should be performed. Generally speaking, lymph nodes should be
removed if they are positive for cancer cells.

Palliative surgery
This type of surgery is not aimed to cure the pet but rather improve the pet's quality of life by alleviating some of the painful
symptoms associated with the presence of cancer. It should be carefully considered how the procedure's expected risks
compare with expected benefit. If the surgical treatment will result in worse outcome than no treatment at all, other methods
of palliative care should be applied such as pain management.

Debulking surgery
This type of surgery refers to the incomplete removal of a tumor. It is usually performed to enhance the efficacy of other
types of treatment such as cryosurgery or radiation.

Miscellaneous surgical intervention in cancer management
Surgeons may also use their expertise in placing long term vascular access catheters for delivering fluids, chemotherapy
or anesthesia and pain relief agents, placing of feeding tubes or performing emergency based operations arising from
infections, bowel obstruction, bleeding or intractable pain.

Preventive surgery
Some types of cancer in pets can be prevented by surgical intervention. For example, there is evidence that spaying
female dogs and neutering male dogs will reduce the risk of breast cancer and prostate/testicular cancer, respectively. The
removal of precancerous lesions from the skin of white cats or removal of adenomatous polyps from the rectum of dogs
may also prevent subsequent cancer development.

Sources:

Withrow Stephen J, and David M. Vail. Small Animal Clinical Oncology. St Louis: Saunders Elsevier, 2007.
Morrison Wallace B. Cancer in Dogs and Cats: Medical and Surgical Management. Baltimore: Williams&Wilkins, 1998.