Veterinary Surgery and Cancer Treatment

Surgery is often used to treat cancer in companion animals. The main goal is to take out the cancer cells (tumor) from the animal’s body. Today, surgery can be used in conjunction with radiation therapy and/or chemotherapy. Your veterinarian may recommend surgery for several reasons. These include complete removal of a tumor, partial removal of a tumor, or exploration of a particular area to obtain a sample of tumor tissue and evaluate the extent of normal tissue involvement. In all cases, any tissue removed by surgery is submitted for biopsy (i.e., given to a pathologist to obtain a specific diagnosis).

Types of Surgery in Veterinary Oncology

• Complete cancer removal: Surgery is the standard, and often the only, form of treatment for most benign and some malignant cancers. In these instances, the goal of surgery is to remove all of the tumor cells present in a given location, thereby curing the patient or at the least relieving symptoms for an extended period of time. Surgery is most successful when the cancer is only in the original location and has not spread to other areas. If the tumor is in a difficult location, for instance in an area that requires the removal of a vital organ, your veterinarian may consider using chemotherapy and/or radiation therapy to preserve quality of life
• Debulking (partial removal of cancer): Some cancers are too large or are in locations where they cannot be removed completely by surgery alone. In these cases, surgery is used to remove as much of the cancer as possible, while minimizing damage to surrounding normal tissues and vital structures. Debulking may help increase the mobility of the affected area, and decrease pain. Because cancer cells have been left behind, some additional form of cancer treatment is used following debulking surgery, such as radiation or chemotherapy. When there are fewer cancerous cells present, there is a higher rate of success.
• Exploratory surgery: When cancers are located within the body cavities (i.e., the chest and abdomen), it may be impossible to determine prior to surgery whether complete tumor removal can be accomplished. In these cases, surgery is used to explore, or get a better look at, the tumor and make a decision intraoperatively as to the best surgical approach. This may be a complete removal, debulking, or simply a small biopsy for diagnostic purposes. Before exploratory surgery is considered, the pet owner, oncologist, and surgeon should discuss the various treatment options available depending on what is found during surgery.

Anesthesia

Most pets having surgery get general anesthesia. Veterinary surgeons will usually administer sedatives to relieve anxiety and pain before anesthesia. The anesthetic is placed intravenously, and a breathing tube is placed through the trachea (windpipe). Anesthetic protocols are individually tailored to each pet's medical status, which takes into account such factors as age, liver, kidney, and heart function, and any underlying medical problems. Most pets are at minimal risk for problems associated with general anesthesia.

Recovery From Surgery

All pets experience mild pain and discomfort after surgery. The veterinary surgeon may prescribe pain medication to maintain a level of comfort for your pet after surgery. Most surgical wounds require little or no care beyond observation and simple hygiene.

Each specific surgery and tumor type has its own set of potential complications. Not all of these potential complications are predictable; however, unforeseen complications are rare. If risk factors are present, supportive measures before, during, and after surgery are employed. Prior to surgery, your veterinarian will discuss with you any recognized risk factors and known potential complications relevant to your pet.

Follow-up Care

Depending on many factors, such as cancer type, completeness of surgical removal, and the likelihood of cancer spread, additional treatments may be recommended for your pet, and you will be referred to the appropriate cancer specialists to discuss these options. If surgery is the only treatment indicated at this time, your veterinarian will recommend an appropriate re-examination schedule and follow-up testing to monitor your pet for recurrence of cancer. The type of tests and frequency of re-examination vary with each case and will be discussed on an individual basis.