Objective—To identify prognostic factors in cats with injection-site sarcomas (ISSs).
Design—Retrospective case series.
Animals—57 cats with ISSs.
Procedures—Medical records of cats were reviewed with regard to sex, age, anatomic site of tumor, tumor size, histologic grade, excision of a primary tumor versus excision of a recurrent ISS, use of excision alone versus excision plus adjuvant therapy, local tumor recurrence, and development of distant metastasis to predict overall survival time (ie, time from tumor excision to death).
Results—In univariate analyses, local recurrence and development of distant metastasis were significantly associated with survival time in cats. On multivariate analysis, development of distant metastasis remained a significant prognostic factor. Histologic grade was associated with distant metastasis, with cats having grade 3 tumors being significantly more likely to develop metastasis than cats with grade 1 and 2 tumors. Factors associated with local recurrence of ISSs were not identified.
Conclusions and Clinical Relevance—The development of distant metastasis, which may occur later during the course of the disease, was identified as a prognostic factor for overall survival time in cats with ISSs. In addition, cats with histologic grade 3 ISSs should be considered for further interventional studies with chemotherapy to prevent the high rate of distant metastasis.
Objective—To assess the usefulness of histologic evaluation of surgical margins to predict local recurrence of cutaneous malignant tumors in dogs and cats treated by means of surgical excision.
Design—Prospective case series.
Animals—40 dogs and 20 cats.
Procedures—60 surgically excised tumors (20 soft tissue sarcomas [STSs], 20 mast cell tumors [MCTs], and 20 carcinomas) were examined histologically. Margins were classified as clean, close, or infiltrated; histologic grade was assessed in STSs and MCTs. Recurrence rates and recurrence-free intervals (RFIs) during a 24-month follow-up period were recorded, and method accuracy was calculated.
Results—Surgical margins were clean in 29 of 60 (48%) tumors, close in 11 (18%), and infiltrated in 20 (33%). Tumors recurred in 27 of 60 (45%) animals, with a mean ± SD RFI of 229 ± 173 days. Recurrence rates for animals that had tumors with infiltrated (16/20) or close (8/11) margins were significantly higher than recurrence rate for animals that had tumors with clean margins (3/29). Margin classification was a significant predictor of RFI. Accuracy of the method to predict recurrence was 94% for carcinomas, 87% for STSs, and 76% for MCTs.
Conclusions and Clinical Relevance—Histologic assessment of margin status was useful for predicting local recurrence of cutaneous malignant tumors in dogs and cats treated by means of excision alone. Method accuracy varied among tumor types and grades. Recurrence times suggested postsurgical follow-up should continue for ≥ 2 years. Results were similar for animals with infiltrated and close tumor margins, and careful postsurgical management is recommended for both.
Objective—To evaluate whether serial determinations of serum lactate dehydrogenase (LDH) activity in dogs with lymphoma could be used to predict outcome and assist in early recognition of disease progression.
Design—Prospective cohort study.
Animals—50 dogs with lymphoma.
Procedures—LDH activity was determined in dogs with newly diagnosed lymphoma or that had not received treatment. The LDH activity was measured at time of initial diagnosis, at completion of chemotherapy, and at 1, 3, and 6 months after chemotherapy. Treatment response and recurrence were recorded. At the end of chemotherapy and at each time point thereafter, the proportion of dogs in complete remission with elevated LDH activity was compared between dogs that did or did not have recurrence within the successive 45 or 90 days. Use of the LDH activity at admission to predict disease-free and survival intervals was evaluated.
Results—The proportion of dogs in complete remission with increased LDH activity at completion of chemotherapy and at 1 month after chemotherapy with recurrence during the successive 45 days was significantly higher (3/9 and 7/9 dogs, respectively) than the proportion of dogs without recurrence (0/32 and 1/26 dogs, respectively). At 3 or 6 months, only 1 dog without recurrence within 45 days had increased LDH activity. Increased LDH activity at time of diagnosis was not associated with disease-free and survival intervals.
Conclusions and Clinical Relevance—Determination of LDH activity may help with identifying episodes of recurrence in dogs with lymphoma. Anticipation of recurrence is an appropriate reason to begin rescue treatment.
Objective—To investigate whether combined treatment with gemcitabine and piroxicam in dogs with transitional cell carcinoma (TCC) of the urinary bladder is tolerated and provides an advantage in terms of survival time over previously reported treatments.
Animals—38 dogs with TCC of the urinary bladder.
Procedures—Dogs were treated with gemcitabine (800 mg/m2, IV over 30 to 60 minutes, q 7 d) and piroxicam (0.3 mg/kg [0.14 mg/lb], PO, q 24 h). Complete blood cell counts were monitored prior to each gemcitabine treatment. All toxic effects of gemcitabine in dogs were recorded. Primary tumors were ultrasonographically reevaluated after 4 gemcitabine treatments.
Results—Dogs received a median of 8 gemcitabine treatments (range, 1 to 38 treatments/dog). In response to treatment, 10 of 38 (26.3%) dogs had grade 1 gastrointestinal tract signs, 11 (28.9%) had grade 2, and 5 (13.2%) had grade 3. Grade 1 neutropenia developed in 6 (15.8%) dogs and grade 2 and 3 neutropenia in 2 (5.3%) dogs each. Thrombocytopenia was rare. All dogs had improvement of clinical signs of disease. Two dogs had a complete tumor response, 8 had a partial response, 19 had stable disease, and 8 had progressive disease. Median survival time with treatment was 230 days.
Conclusions and Clinical Relevance—Administration of gemcitabine in combination with piroxicam treatment failed to provide a longer overall survival time in dogs with TCC of the urinary bladder, compared with previously reported treatment strategies. However, this combination of chemotherapy did provide a new treatment alternative with fewer adverse effects.
Objective—To determine factors predicting survival in dogs with high-grade multicentric lymphoma.
Design—Retrospective cohort study.
Animals—127 dogs with high-grade multicentric lymphoma evaluated at 4 veterinary hospitals from 2000 to 2009.
Procedures—Records were reviewed to identify dogs with completely staged high-grade multicentric lymphoma treated with chemotherapy. Data collected included signalment, history, hematologic findings, tumor characteristics, treatment, and outcome. Long-term survival was defined as surviving > 2 years after diagnosis. Variables were analyzed for associations with dogs living > 2 years.
Results—Among the 127 enrolled dogs, 13 (10%) survived > 2 years with a median survival time of 914 days (range, 740 to 2,058 days). Survival rates at 3, 4, and 5 years were 4%, 3%, and 1 %, respectively. At diagnosis, 11 of the 13 long-term survivors had a body weight ≥ 10 kg, PCV ≥ 35%, absence of ionized hypercalcemia, centroblastic lymphoma, immunophenotype B, absence of bone marrow involvement, and lymphoma stages I through IV and were not previously treated with corticosteroids. The same combination of factors was present in 26 of 114 (23%) dogs surviving ≤ 2 years, yielding a negative predictive value of 97.8% for long-term survivors. Four of the 6 long-term survivors that died during the study died of another cancer; 3 of them had osteosarcoma.
Conclusions and Clinical Relevance—Absence of the aforementioned combination of variables at diagnosis may help identify dogs with lymphoma that will not survive > 2 years. Other types of neoplasia, in particular osteosarcoma, may develop in long-term–surviving dogs.
Objective—To determine results of cytologic examination of fine-needle aspirates and impression smears of gastrointestinal tract tumors in dogs and cats.
Design—Retrospective case series.
Animals—38 dogs and 44 cats with histologically confirmed gastrointestinal tract tumors.
Procedures—Results of cytologic examination of fine-needle aspirates (n = 67) or impression smears (31) were compared with the histologic diagnosis, and extent of agreement was classified as complete, partial, none, or undetermined.
Results—For 48 of the 67 (72%) fine-needle aspirates, there was complete or partial agreement between the cytologic and histologic diagnoses. For 12 (18%) aspirates, the extent of agreement could not be determined because the cytologic specimen was considered unsatisfactory. For 29 of the 31 (94%) impression smears, there was complete agreement between the cytologic and histologic diagnoses, and for 2 (6%), there was partial agreement. None of the impression smears were considered unsatisfactory. Proportion of samples with complete agreement and proportion of samples with complete or partial agreement were significantly higher for impression smears than for fine-needle aspirates.
Conclusions and Clinical Relevance—Results suggest that there was moderate agreement between results of cytologic examination of fine-needle aspirates from dogs and cats with gastrointestinal tract neoplasia and the definitive histologic diagnosis. The agreement between results of cytologic examination of impression smears and the histologic diagnosis appeared to be higher.
Objective—To describe clinical characteristics, treatment, and outcome of dogs with inflammatory carcinoma (IC) and identify patient-, tumor-, and treatment-related factors associated with overall survival time.
Design—Retrospective case series.
Animals—43 client-owned dogs.
Procedures—Records of dogs with a clinical diagnosis of IC that had histologic evidence of dermal lymphatic invasion were reviewed. Data on clinical staging, treatment, toxicoses, response, and survival time were retrieved.
Results—26 (60%) dogs had primary IC and 17 (40%) had secondary IC. Thirty-five (81%) dogs had distant metastases and 2 (5%) had local metastases at the time of initial examination. Six of 29 (21%) dogs had a coagulopathy. Sixteen (37%) dogs did not receive specific treatment for IC, 24 (56%) received medical treatment only, 2 (5%) underwent surgical excision and received medical treatment, and 1 (2%) underwent surgical excision only. Forty-one (95%) dogs had progressive disease, and 2 (5%) had stable disease. Mean survival time for all dogs was 60 days (range, 1 to 300 days). Dogs with a coagulopathy survived a significantly shorter time than did dogs without a coagulopathy (odds ratio, 0.28), and dogs that received medical treatment survived significantly longer than dogs that did not (odds ratio, 2.54).
Conclusions and Clinical Relevance—Results suggested that mammary IC is a biologically aggressive condition in dogs associated with a guarded prognosis. In addition, results suggested that medical treatment may improve outcome, thereby supporting its use in dogs with IC.
To determine an optimal time interval between amputation and initiation of adjuvant chemotherapy (TIamp-chemo) in dogs with appendicular osteosarcoma without distant metastases and whether TIamp-chemo was associated with outcome.
168 client-owned dogs treated at 9 veterinary oncology centers.
Data were collected from the dogs’ medical records concerning potential prognostic variables and outcomes. Dogs were grouped as to whether they received chemotherapy within 3, 5, 7, 10, 15, 20, 30, or > 30 days after amputation of the affected limb. Analyses were performed to identify variables associated with time to tumor progression and survival time after limb amputation and to determine an optimal TIamp-chemo.
Median TIamp-chemo was 14 days (range, 1 to 210 days). Median time to tumor progression for dogs with a TIamp-chemo≤ 5 days (375 days; 95% CI, 162 to 588 days) was significantly longer than that for dogs with a TIamp-chemo > 5 days (202 days; 95% CI, 146 to 257 days). Median overall survival time for dogs with a TIamp-chemo≤ 5 days (445 days; 95% CI, 345 to 545 days) was significantly longer than that for dogs with a TIamp-chemo > 5 days (239 days; 95% CI, 186 to 291 days).
CONCLUSIONS AND CLINICAL RELEVANCE
Findings indicated that early (within 5 days) initiation of adjuvant chemotherapy after limb amputation was associated with a significant and clinically relevant survival benefit for dogs with appendicular osteosarcoma without distant metastases. These results suggested that the timing of chemotherapy may be an important prognostic variable.
Objective—To compare the Kiupel (2 categories) and Patnaik (3 categories) histologic grading systems for predicting the presence of metastasis at the time of initial examination in dogs with cutaneous mast cell tumors (MCTs).
Design—Retrospective case series.
Animals—386 client-owned dogs with cutaneous MCTs.
Procedures—Medical records of dogs with newly diagnosed, histologically confirmed cutaneous MCTs that had undergone complete clinical staging were reviewed for clinical and histopathologic data.
Results—All Patnaik grade 1 MCTs (n = 52) were classified as Kiupel low-grade MCTs, and all Patnaik grade 3 MCTs (43) were classified as Kiupel high-grade MCTs. Of the 291 Patnaik grade 2 MCTs, 243 (83.5%) were classified as Kiupel low-grade tumors, and 48 (16.5%) were classified as Kiupel high-grade MCTs. Dogs with Patnaik grade 3 MCTs were significantly more likely to have metastases at the time of initial examination than were dogs with grade 1 or 2 MCTs (OR, 5.46), and dogs with Kiupel high-grade MCTs were significantly more likely to have metastases than were dogs with Kiupel low-grade MCTs (OR, 2.54). However, 3 of 52 (5.8%) dogs with Patnaik grade 1 tumors, 48 of 291 (16.5%) dogs with Patnaik grade 2 tumors, and 44 of 295 (14.9%) dogs with Kiupel low-grade tumors had metastatic disease.
Conclusions and Clinical Relevance—Findings indicated that in dogs with cutaneous MCTs, prognostication should not rely on histologic grade alone, regardless of grading system used, but should take into account results of clinical staging.