Thursday, October 12, 2017

The Purrfect 10: Things To Know About Breast Cancer in Cats

We love reading and researching anything and everything about cats, and wanted to find a fun and unique way to share the interesting facts we learn with you! Since top 10 lists are very popular in the blogosphere, we created The Purrfect 10 as a way to present 10 educational or fascinating tidbits about a wide variety of cat-related topics, everything from health issues to cat breeds to famous felines.


October is Breast Cancer Awareness Month. Every one of us knows someone whose life has been changed by this dreaded disease, but you might be surprised to learn that it's also frighteningly common in our beloved cats. Here's what you need to know...

1) Breast cancer is the third most common cancer in cats (after lymphoma and skin cancer), and over 85% of mammary tumors are found to be malignant.

2) Most of the time the patient is female, either unspayed or spayed well into adulthood. The average age at onset is 10-12, but these tumors can strike at any age with reported incidents from 9 months to 20 plus years old.

3) Cats have two “chains” of four mammary glands and nipples running parallel on each side of their belly. The first sign of breast cancer a cat owner might notice is a lump in, on or near one of these glands in the shape of a pebble or dried pea. These tumors, most commonly adenocarcinomas, can spread rapidly to adjacent glands, the nearest set of lymph nodes and beyond. Unfortunately it can be months before a growth is detected because in it's initial stage it can be very hard to feel, it won't be painful to your cat, and won't show any obvious clinical signs.


4) Cat parents should check their cat's mammary area for lumps on a regular basis. (A great excuse for extra tummy rub time!) When found, these tumors need to be removed as soon as possible, followed by chemotherapy. Left alone, they get larger and harder and eventually ulcerate the skin, resulting in a strong odor as infection sets in. Small tumors might be removed via lumpectomy, but your vet may remove the entire mammary gland and nearby lymph nodes, if not the entire chain on that side (the feline version of a mastectomy), the surgical method of choice because it significantly reduces the chance of local tumor recurrence. If caught early and a cure is possible, the opposite side may be removed after a few weeks.

5) Life expectancy following removal of a mammary tumor varies, with tumor size being the most important factor. According to the Ohio State University Veterinary Medical Center, cats with tumors larger than 3 cm in diameter have a median survival time of 4 to 6 months; cats with tumors 2 to 3 cm in diameter have a median survival time of about 2 years, and cats with tumors less than a 2 cm in diameter tumor have a median survival time of over 3 years. Early diagnosis and treatment is key, but even when tumors are caught early and appear to be successfully treated, the long term prognosis is guarded. Over 60 percent of tumors that have been removed will redevelop within 12 months.

6) While very rare (less than 1% of cases), male cats can also get breast cancer, and any suspicious lumps should be reported to your vet.

7) Sex hormones are the greatest risk factor for mammary tumors in cats, so spaying at an early age is the most significant way to prevent breast cancer: spaying prior to 6 months results in a 91% reduction risk, and before one year old an 86% reduction.



8) Siamese have twice the risk of developing breast cancer than other breeds, developing tumors at a younger age and with higher rate of lymphatic invasion than other cats. Persians also develop tumors frequently.

9) In Scandinavian countries mammary tumors are especially prolific because domestic cats are not commonly spayed and the female hormone progesterone is often used to prevent pregnancy. In fact, until 1988 it was illegal for Swedes to remove the reproductive organs of their dogs and cats unless medically necessary!

10) Pulmonary metastasis (spread of the cancer to the lungs) is the most common cause of mammary-cancer related deaths, and cats presenting with advanced lung involvement at diagnosis have a reported median survival time of only one month.

Have you ever had a cat diagnosed with breast cancer? 

22 comments:

Lone Star Cats said...

Interesting facts - we've never had a kitty wif breast cancer. It's good to know what to look out for.

Summer at sparklecat.com said...

I'm so glad I was spayed at 5 months - my chances of developing breast cancer are way less that way!

The Menagerie Mom said...

This is such an informative, significant post. I wish more people realized that the sooner a kitty is spayed, the better. I'll always remember a kitty at the clinic where I used to work, who had lived a rough life until she was adopted by a wonderful woman. Just months into their happy life together, though, the kitty developed mammary cancer that spread to her lungs, all because her first owners did not have her spayed until she was older.

Thank you so much for sharing wonderful facts like these, Mudpie and Melissa!

Unknown said...

Great post! The possibility of a mammary tumor had us really scared over the summer when Paisley's routine vet visit turned into a "What's this lump?" investigation. Fortunately, it was not breast cancer and she is fine. :)

The Island Cats said...

Interesting. We don't hear as much about this as we should. And another good reason to spay/neuter your cat!

Johnny said...

I'll be honest, I didn't even know cats get breast cancer. Thank you for the share.

Patricia T said...

Very informational. Thanks, Melissa (and Mudpie)!

The Swiss Cats said...

Great post, and great information ! Purrs

Priscilla King said...

Objection! I don't believe that any animal's having a natural unaltered body *causes* cancer. Surgery may prevent diseases to which we're naturally vulnerable, but not having surgery is not the *cause* of those diseases...not even genetic diseases like celiac sprue, and certainly not cancer.

Veterinary research that was actually dedicated to the goal of keeping cats healthy, rather than eliminating domestic animal species (yes, that's been a stated goal of some people who are currently old rich funders), would ask: What unnatural factors outside cats' bodies are exposing these cats to carcinogens (maybe ingredients and additives in cat food? ground-up tumors?!)? What natural antioxidants are helping cats fend off the carcinogens?

Cancer in cats seems to have much in common with cancer in humans...I'm sure spaying middle school girls would reduce our risk of breast cancer too, and prostate removal would protect the boys...but most of us continue to seek other answers.

(Just fyi...I'm not opposed to all spaying, although I am opposed to Humane Pet Genocide through mandatory sterilization for all pets. But I cry foul when someone tries to blame a cat's not being spayed for her developing cancer!)

Melissa, Mudpie and Angel Truffles (Mochas, Mysteries and Meows) said...

Ms King, I could not disagree with you more. The "pet genocide" is happening in our nation's shelters every single day because of people who DON'T neuter their animals...and it's far, far from humane. Spaying your cat or dog is just responsible pet ownership.

Cathy Keisha said...

My furrend Jessie Janie is a breast cancer survivor. I'm not sure what age she was spayed at. It's true that estrogen fuels breast cancer even in humans but humans do develop it after "the change" which could be due to environmental chemicals and parabens in soaps, deodorants and beauty products. Nonetheless, I'm glad I'm spayed and so are the peeps—glad I'm spayed, that is.

Random Felines said...

actually hormones do play a part in cancer. using the term "genocide" when it comes to spaying cats however seems overly reactive. spay and neuter of domestic animals is the best way to stop them from dying of overpopulation every day in shelters.

Random Felines said...

great post. we had no idea about the Sweden thing (really??) or that it is more common in certain breeds. just another reason to advocate early spay/neuter

pilch92 said...

Excellent post. I am disturbed by #9, how sad that is. I worry about this with my cats because many were not fixed until I found them.

Eastside Cats said...

Angel was spayed before 6 months. Sweetie arrived on our doorstep in 2009, already pregnant. She's been with us ever since, and she's probably 9-10 years old. Thankfully, she now allows me to pet her all over, so I will make sure I give her a good exam to make sure we catch anything that might need veterinary care. Great post; keep up the good work!

Lola The Rescued Cat said...

This was a really interesting post and we learned a lot. You can bet we'll be getting extra belly rubs!

M Dawson said...

Genocide is an emotive word and certainly not one I would use in this context. 'Humane Pet Genocide is the most astonishingly stupid thing I have ever heard. Get a grip woman.

M Dawson said...

Thank you for a fascinating post. I am just sorry you had an absolute flake rant in the middle of it.

Furries said...

Very interesting, especially #9...who'd have thought!

AnnStaub said...

My family's kitty had breast cancer, but I still learned a few things from this that I didn't know. It was recommended she have a full mastectomy, but it was too expensive... even with a discount as a working employee at a vet clinic. After we found the lump, I tried to manage it as best as I could until it was time to let her go. She lived for much longer than I might have expected her to. I've seen it a lot in dogs and the tumors when not removed become some of the most gruesome looking things.

Lola The Rescued Cat said...

Not spaying or neutering your pets is irresponsible for many reasons. I'm sure the feral cats in my neighborhood who endure harsh winters outside with little to no shelter would agree. Spaying and neutering is NOT genocide.

Alisonkeyss said...

This is such an significant post. I wish people realized that the sooner a kitty is spayed, the better cat illnesses is very common now. I remember a kitty at the clinic where I used to work, who had lived a rough life until she was adopted by a wonderful woman. Just months into their happy life together, though, the kitty developed mammary cancer that spread to her lungs, all because her first owners did not have her spayed until she was older.