Cancer in 12 yr old German Shepherd

Question
My 12 yr old, 110 lb, male German Shepherd was diagnosed with cancer recently.

He has a history of problems with his anal glands.  Last week his vet said that his left gland was infected, but she suspected the right one had a tumor and directed us to an oncologist (treatment with antibiotics helped the left gland).

A painless and hard 2-3 cm lump was found on his right gland and was aspirated. Initially the vet oncologist was hopeful that it wasn't cancer because the cells "did not look aggressive."  She proceeded with an ultrasound of his stomach and chest x-rays.  A 7-8 cm mass was located in his stomach cavity (not touching any vital organs) and a small 1 cm growth on one of his lungs.  She wasn't sure whether the mass in the stomach was cancerous or if it was caused by the anal gland tumor or vice-versa, but seeing the lump on his lung she decided that surgery was not an option.

She also did not recommend chemotherapy due to the fact that it would be very hard for the dog and it would not extend his life by that much.

She proscribed piroxicam (15 mg a day) and recommended a clinical trial for PawPaw.

I guess I am just really upset with all that has happened and was looking for a second opinion.  I can send pictures of the x-rays and ultrasound.  

I have also read that piroxicam is used for bladder cancer more and has a lot of side-effects...is this something that would be helpful for him anyway?  Are there any other drugs that might be better in this situation?

Any other suggestions to help him fight in terms of diet change, etc.?

What kind of life expectancy does he have?  

She also mentioned that the tumor on his anal gland could grow to a size where he will have a lot of trouble defecating...is there any way to minimize this...what options exist at that point?

What can be expected in terms of a turn for the worse in his health?  Will the lungs be the problem or how do things usually play out?

At this point he shows no signs of disease and is relatively active.

Thanks so much for your help.  This is a very tough time for all of us.

Answer
Dan,

I am so sorry you, your family, and PawPaw are having to go through this.  

I commend your vet for referring you to a specialist.  You have to trust that a board certified oncologist knows what they are doing.  Are they perfect? No.  But all the specialists I have ever dealt with are way above and beyond the best at their field of expertise in veterinary midecine.  As a general practiioner, I defer to their knowledge all the time.

What you are describing is very typical for a anal sac adenocarcinoma.  They are very agressive and can grow in lymph nodes in the abdomen, and once they metastasize to the lungs there is little that can be done.  Not only that, but they can cause a paraneoplastic syndrome of hypercalcemia.  When someone has a high calcium level in their blood, they are sick, sick, sick.

Personally, I can not give a second opinion because I have to have a patient/doctor relationship to be able to do that. I can not do that if I have not ever seen your pet.  When I suggest a second opinion I usually recommend a board certified veterinary specialist.  In this case, I would recommend a vet that has DACVIM (Diplomate, American College of Veterinary Internal Medicine) behind their name (or a resident that is going to sit for the test soon).  It sounds like that's what you already have.

Piroxicam is a potent Non-Steroidal Anti-Inflammatory medication that has some anti-tumor effects.  It is the drug I reach for in almost all cancer cases that can not be treated.  It seems to help, yes, more in bladder cancer cases, but I've seen it help in others as well.  There are always side effects of all medications, so if you are not seeing any in PawPaw I would not worry about those.

Diet may help a little.  We know that most cancers feed of of carbohydrates, so changing to a high protien, low carbohydrate diet could never hurt (and I'm sure PawPaw would love it).  There is a prescription diet from Science Diet called N/D.  It is expensive, but they developed it to be high in protien and low in carbs just for cancer patients.  As far as over the counter diets, you may want to compare labels for puppy diets and performance diets (high quality diets, not grocery store brands) to see which has the most protien and the least carbs.  Note that canned foods will always have less carbs than dry food, so, focus on canned only.  Antioxidants and joint supplement will never hurt.   My favorite antioxidant supplement is Missing Link Veterinary Detoxification/Recovery Formula.  And my favorite joint supplement is Cosequin.

As far as life expectancy and what to expect.  I wish I could tell you.  There are no hard and fast rules to predicting the course of disease.  As long as he is feeling fine now, I would take it one day at a time.  At some point in the future, he will start showing other symptoms.  What those will be, and when that will be is up to a Higher Power.  It's hard not knowing.  It's hard waiting and wondering.  My prayers are with you.

Teleah