Tumor grade and stage as prognostic variables in upper tract urothelial tumors.

Clinical and pathologic data of 54 patients with clinically localized transitional cell tumors of the upper urinary tract were reviewed to determine the significance of tumor grade and stage on patient survival. There were 43 tumors of the renal pelvis (one bilateral) and 11 tumors of the ureter. The primary tumor was staged by the new TNM classification into low stage (Ta: limited to mucosa; T1: lamina propria invasion) and high stage (T2: muscularis invasion; T3; invasion beyond the muscularis). Tumors were low stage (Ta/T1) in 28 cases (51.8%) and advanced (T2/T3) in 26 cases (48.2%). Twenty-five of 54 (46.3%) of the patients had low grade (Grades 1 and 2) and 29 of 54 (53.7%) had high grade (Grades 3 and 4) tumors. Median survival for all patients from date of diagnosis was 31 months, with a 5-year survival rate of 45.8%. Grade (low/high) matched stage (low/high) in 45 of 54 patients (83%). Median survival for patients with low grade tumors was 66.8 months compared to 14.1 months in patients with high grade tumors. Median survival for low stage tumors was 91.1 months and for high stage tumors was 12.9 months. These differences in survival related to both tumor stage (P = 0.001) and grade (P = 0.004) were statistically significant by log-rank test. Fourteen of the 54 patients (25.9%) developed local recurrence and 29 (53.7%) developed distant metastases. The lung was the most common site of metastasis. Eighteen patients (33.3%) had or developed transitional cell carcinoma of the bladder, which preceded the diagnosis of transitional cell carcinoma of the upper tract in seven cases and developed subsequently in 11 cases. Primary tumor stage by the new TNM classification is a better predictor of prognosis than tumor grade, although both variables are strongly predictive of patient course and survival. The advantages of the new TNM classification are discussed.

Polyglycolic acid mesh in repair of renal injury.

To evaluate the use of a polyglycolic acid (PGA) mesh graft for partial nephrectomy, we replaced the upper pole of the left kidney in 12 New Zealand white rabbits with a free omental fat graft and the lower pole with PGA mesh. The mesh stopped the bleeding immediately during the operation. At forty-eight hours, the fibers were still intact, with an organized clot on the surface of the mesh. Between two weeks and two months, the fibers had begun to be digested by histiocytes, with formation of giant cells and fibroblastic proliferation with collagen deposition around the mesh. At three months, there was complete resorption of the PGA mesh and formation of a new fibrous capsule. There was no renal reaction and no difference between the PGA mesh and the omental fat graft. We believe that PGA mesh can be helpful in repairing injured kidneys by securing hemostasis and serving as a scaffold for the formation of a new capsule.