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Veterinary Teaching Hospital

Cancer Surgery

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Can surgery cure my pet of cancer?

Cancer is a scary diagnosis for any pet owner, but there are often surgical treatment options that can improve your pet’s quality of life and, in some cases, even eliminate the cancer.

Is my pet a candidate for cancer surgery?

Whether your pet is a candidate for surgery depends on numerous factors, including the location, type, and grade of the tumor.

The behavior of tumors varies significantly depending on the type. Some tend to grow very invasively, like a plant growing long roots in all directions. Others tend metastasize by spreading to distant places and organs.

An invasive tumor type is ideally removed with at least 1-inch margins in all directions. Sometimes that means surgery often entails amputation if the tumor is located on or near an extremity, such as a limb or a paw. A tumor on the head might require removal of parts of the jaw or an eye to achieve clean margins.

How are tumors diagnosed?

Tissue samples, or biopsies, are often used to diagnose the tumor by histopathological examination before surgery, and diagnostic imagining is a valuable tool in determining the location of tumors and if they are growing close to or even into important organs. X-rays, computerized tomography (CT) and magnetic resonance imaging (MRI) are frequently used.

From a biopsy, the tumor type can often be clarified and given a grade, or an estimation of the tumor’s aggressiveness.

There are several types of biopsies:

  • Incisional biopsy – One or several little pieces of the tissue are obtained for histopathological examination.
  • Excisional biopsy – The entire tumor is taken out for examination, without or with limited surgical margin. This is in general only done if the likelihood is high the tumor is benign or the tumor is very small. If the tumor turns out to be malignant with a high likelihood of cancer cell invasion beyond what was removed, it can be much more difficult to define the appropriate margins in a follow-up surgery.
  • After tumor type is diagnosed, these surgeries are considered based on how much margin the surgeon can remove:
  • Intracapsular resection (cyto-reductive surgery or debulking) – A portion of the tumor is removed but some visible tumor is left behind. This is in general done due to the presence of important, non-resectable organs close to the tumor. Radiation is usually recommended after or before an intracapsular resection.
  • Marginal resection – The tumor is removed without margin, leaving microscopic tumor behind. Additional treatment is usually necessary.
  • Wide resection – A margin of visibly normal tissue is resected together with the tumor to minimize the risk of leaving behind tumor cells. This is the most common type of surgery when surgery is used as the only treatment for cancer. Many cancer types of low or intermediate grade can be successfully removed this way. A wide resection often entails wound reconstruction to enable closure of the wound or to ensure normal function.
  • Radical resection – The entire structure the tumor is growing in is removed. This is commonly the case when amputation is an option, but it is difficult when located in areas other than extremities.

This information is not meant to be a substitute for veterinary care. Always follow the instructions provided by your veterinarian. Washington State University assumes no liability for injury to you or your pet incurred by following these descriptions or procedures.