Silvia Sabattini

Osteosarcoma is the most common malignant primary bone cancer, but it is infrequently reported in cats. Feline appendicular osteosarcoma typically exhibits good prognosis when treated with surgery alone. A retrospective multi‐institutional study was conducted to identify possible prognostic factors. Cats diagnosed with appendicular osteosarcoma were included if initial staging and follow‐up information were available. Data including signalment, tumour characteristics, treatment modalities, and survival outcomes were collected and analysed. Fifty‐six cats were included; the femur was the most frequently affected bone. Eight cats had distant metastasis at admission and an additional 9 developed metastatic disease during follow‐up, resulting in an overall metastatic rate of 30%. Forty‐nine (87.5%) cats underwent surgery, and 4 also received adjuvant chemotherapy. Among operated cats, median time to local progression (TTLP), time to distant progression and tumour‐specific survival (TSS) were not reached. One‐ and 2‐year survival rates were 66% and 55%, respectively. Seven (12.5%) cats received no treatment; 1‐ and 2‐year survival rates were 25% and 0%, respectively. Operated cats had significantly longer TTLP ( P < .001) and TSS ( P = .001) compared with non‐operated cats. Among operated cats, young age negatively impacted local tumour progression, while the presence of distant metastasis at diagnosis was associated with a higher risk of tumour‐related death. This study reaffirms the good prognosis for cats with appendicular osteosarcoma undergoing surgery, but sheds light on some additional factors to consider. Accurate initial staging is recommended, as the metastatic rate may exceed many previous estimations. Surgery substantially extends survival time, whereas the role of chemotherapy remains uncertain.

Chemotherapy and cyclooxygenase inhibitors (COXi) are primary treatments for canine urethral transitional cell carcinoma (uTCC), a tumor known for its aggressiveness and poor prognosis. This retrospective study aimed to evaluate the clinico-pathological characteristics, treatment modalities, and prognostic factors of 35 dogs with confirmed uTCC that received chemotherapy and COXi. Upon admission, urethral obstruction (UO) and urinary tract infection (UTI) were observed in seven (20%) dogs each. Gemcitabine (n = 20; 57.1%) and vinblastine (n = 10; 28.6%) were commonly used as first-line therapies, with four dogs also receiving radiation therapy. Based on RECIST, one (2.9%) dog achieved complete remission, nine (25.7%) partial remission, 20 (57.14%) showed stable disease, and five (14.3%) progressed. Among dogs with UO, six (85.7%) showed resolution or improvement after the first chemotherapy dose. The median time to local progression was 171 days (range: 107–235), and the median survival time was 333 days (range: 158–508). Dogs with UO upon admission had a higher risk of local progression, while both UO and UTI were associated with an increased risk of overall disease progression and tumor-related death. Additionally, gemcitabine significantly improved metastatic control. This study identified UO and UTI as negative prognostic factors, highlighting the importance of a multimodal approach in managing uTCC.