Dog cancer prognosis: What does a high mitotic index score mean?

I'm so sorry poor Barney had to have surgery! It can be common with mast cell tumors removed from the limbs to not have clean margins because there isn't a lot of tissue to work with in that area. This doesn't necessarily mean the tumor will return but it does increase the chances. If the pathologist noted that no mitosis was seen this means they did not see any cells in the active stage of dividing. With very malignant tumors there will generally be a lot of mitosis or cell division seen. I hope Barney recovers from his surgery well and that this is the only one he needs!

Mast cell tumor survival rate is entirely dependent on the stage of the mast cell and the mitosis index (seen histologically). So this is a bit more involved than you were likely anticipating it to be. So if Lady has not had a biopsy to gather this information already then there is no way of determining her survival rate unfortunately. The best prognosis is a grade 2 MCt with a mitosis index of <5 at 70 months. The worse was a grade 2 MCT with mitotic index >5 and a survival time of 5 months. Another study suggests that for high grade tumors (MCT grade 2 and above) the mean survival time is <4 months and for low grade tumors (MCT grade 1) the mean survival time is >2 hrs. I hope this helps and feel free to post your question again once you have the necessary information of grading and mitotic index so we can tell you specifically what your pets cancer survival rate is. I am sorry Lady does have mast cell cancer and I hope that you can keep her comfortable for the time being. Best wishes and take care.

It is great news that the tumor removed had clean margins! This means it is much less likely to come back in the future. Tumors are graded on how many abnormal or cancer-type cells are seen when examining the biopsy under a microscope. Grading can be different for all the tumor types, but for most tumors a grade of 2 is only moderate in severity. This means the tumor has a chance of spreading but it is not very likely. Your vet probably recommended you visit an l oncologist just to be thorough. Oncologist have a lot more up-to-date information on cancer treatments and staging then regular practitioners do. The oncologist may recommend you do chemo to be on the safe side or they may recommend that you don't need to take any further steps. I hope this helps. Thanks for using Petco Pet Education Center, formerly Petcoach. Best of luck.

A) The likelihood of reoccurrence is higher if the margins are dirty. While it may be categorized as a low grade, it would be helpful to know the mitotic index which is a quantitative measure of mitotic figures observed in the cancer cells. If the mitotic index is high, reoccurrence is more likely. B) If no further treatment is pursued, it may or may not return. C) Prior to any further surgery or treatment you need to have Barney evaluated by a veterinary oncologist to discuss the best treatment options for him.

Thanks for using Petco Pet Education Center, formerly Petcoach! This depends on many factors. It depends on where the main tumor is located, if it has spread to other organs, among many other factors. Even high grade tumors can have a good longterm outcome of years of survival when treated aggressively with surgery and chemotherapy if there is no evidence of metastasis to internal organs. However, if there is already spread to internal organs like the liver and the spleen, the survival times tend to be closer to 3-4 months even with chemotherapy. Staging to check for metastasis usually includes thoracic radiographs, abdominal ultrasound and assessment of the local lymph nodes. At the very least, I recommend medications like Pepcid, Benadryl and prednisone that can help with these cases when there is still evidence of a mass present. Good luck and have a good night!

I’m sorry to hear about Tsunami’s diagnosis. MCTs are quite common in dogs, and unfortunately due to the cell distribution around the primary tumor, incomplete margins are common. If you want to be confident you’re pursuing the best options for the best prognosis, I recommend asking your vet for an oncologist referral. A veterinary oncologist will be the best specialist to be able to present all the options and their given pros & cons, and they have access to chemo medications that most primary vets don’t carry. If you choose not to pursue referral, then I recommend reaching out to your vet again to discuss the next step. If this were my case, I would probably recommend sampling Tsunami’s lymph nodes with a needle to look for evidence of regional metastasis, and based on those findings discuss if a second surgery is appropriate. Hope this helps!

Melanoma that is found in the toes has more potential to be malignant, but this is not a definite. One thing that's in Ada's favor is that she is a Miniature Schnauzer. About 75% of melanomas in this breed are benign, which decreases the likelihood of malignancy. The biopsy results should give some indication of malignancy, so I'd double-check with the vet that gave you the results. Staging of tumors requires that a veterinarian takes samples from nearby lymph nodes and takes x-rays. If this hasn't been done, then you can ask your veterinarian if this is necessary. The prognosis will depend on the grading and staging of the tumor, so I cannot comment about that at this time. I hope this helps and all turns out OK with Ada.