Cat mammary gland cancer. Any further treatment after surgery?

by NW

Dear Doctor,

My cat, Boon, had her mammary gland tumor removed 4 days ago. My husband and I discovered a hard lump 2 months ago which was growing, and some additional small lumps nearby. The diagnosis was made last week and the surgery was scheduled in 2 days.

My cat had the whole left-side mammary chain and both the upper and the lower lymph node chains removed. She is turning 9, and her general health is superb! My cat eats well and walks very fast (even with bandages all over her whole body). She is scheduled for having her stitches removed next week. The pathology revealed of adenocarcinoma with poor prognosis. We are unaware of the metastasis in any lymph nodes, though.

How much is the 5-year survival, or even longer, rate in your experience? Was the surgery enough for a cat to be free of the recurrence? Are there any other suggested modalities, such as chemotherapy or radiation, to improve prognosis? And lastly, do we need to do a second operation on the other side to remove the mammary chain? Is it worth for her to undergo another surgery?

Thanks in advance.


Dear NW,

It is not clear from your letter whether you are saying that you personally don’t know if your kitty’s mammary cancer metastasized to the lymph nodes or if the pathologist is not sure whether there was metastasis. Metastasis certainly plays a role in your cat’s overall prognosis. You also didn’t mention whether the pathologist determined that the margins were wide and clean, which of course, also contributes.

Generally speaking, yes, adding chemotherapy may give your cat a better prognosis, as could removing the other side of the cat mammary chain. However, I’m not one who weighs very heavily on statistics. Throughout the years, I have seen cats with mammary cancer survive and live very long, healthy lives with no recurrence with nothing but surgery to remove the effected chain. Conversely, I have seen cats have both mammary chains removed and go through chemotherapy and have a very quick recurrence of the cat cancer. Because of this, I am not comfortable making a prognosis.

If your veterinarian is not a board certified veterinary oncologist, your kitty’s best chance may be to be treated by a board certified veterinary oncologist. You can often find these specialists at veterinary colleges or veterinary referral and specialty centers. Because of the variety of treatment modalities and individualized prognosis of each cat with cancer, if you could find a board certified vet oncologist nearby, it would be worth your time to do so to get the best possible treatment recommendations for your cat.

I wish you and Boon all the very best and hope you will have many happy, loving years with her to come.

Kindest wishes,
Dr. Neely

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