Comparison of intravesical chemotherapy regimens after radical nephroureterectomy for upper tract urothelial carcinoma and analysis of risk factors for postoperative recurrence.

OBJECTIVE: Upper tract urothelial carcinoma (UTUC) is a relatively rare but aggressive type of urologic cancer that includes renal pelvic tumors and ureteral tumors with a poor prognosis. Full-length nephroureterectomy plus sleeve bladder resection is the standard treatment for the disease, but patients are prone to recurrence of bladder tumors after surgery. Intravesical infusion therapy is the main means to prevent the recurrence and progression of bladder cancer. Epirubicin and gemcitabine are widely used in clinical practice as first-line or salvage therapy for intravesical chemotherapy; however, the efficacy of these agents is rarely discussed. The purpose of this study was to investigate the effects of epirubicin and gemcitabine on the occurrence of bladder cancer after radical nephroureterectomy for UTUC and to analyze the risk factors affecting the recurrence of postoperative bladder cancer. PATIENTS AND METHODS: A total of 215 patients with diagnosed UTUC and treated in our hospital from June 2019 to August 2021 were retrospectively selected as the research subjects, and they were divided into an observation group (120 cases) and a control group (95 cases) according to different treatment methods. The patients in the control group were treated with epirubicin, while those in the observation group received gemcitabine. All patients were followed up by telephone or outpatient examination for 12 months to record the occurrence of adverse reactions. The occurrence of bladder cancer was recorded at 3 months, 6 months, and 12 months after the surgery. According to the occurrence of bladder cancer after surgery, the patients were divided into a bladder cancer group (63 cases) and a non-bladder cancer group (152 cases). Multivariate Logistic regression analysis was used to analyze the risk factors of bladder cancer after surgery. RESULTS: The total incidence of adverse reactions in the control group was 49.47%, which was higher than that in the observation group with 15.00% (p<0.01). The incidence of bladder tumors in the observation group and the control group was 0.00% and 2.11% at 3 months, 5.00% and 8.42% at 6 months, 13.33% and 15.79% at 12 months, without significant difference (p>0.05). After 12 months of perfusion, the levels of acidic fibroblast growth factor (aFGF), basic fibroblast growth factor (bFGF), and vascular endothelial growth factor (VEGF) in the two groups were significantly lower than those before perfusion (p<0.05). In the observation group, the levels of these three factors were slightly decreased compared with those in the control group, without a significant difference (p>0.05). Between the bladder cancer and non-bladder cancer groups, there were significant differences in tumor location, number of lesions, tumor stage, preoperative ureteral examination, and preoperative history of bladder cancer (p<0.05). The above indexes were all risk factors for postoperative bladder cancer (p<0.05). CONCLUSIONS: Epirubicin and gemcitabine reduced the occurrence of bladder cancer and effectively inhibited tumor angiogenesis after radical nephroureterectomy for UTUC. The tumor location, number of lesions, tumor stage, preoperative ureteral examination, and preoperative history of bladder cancer were risk factors for postoperative bladder cancer.

High NH(4)(+)-N concentration wastewater treatment by shortcut nitrification-denitrification using a system of A/O inner loop fluidized bed biofilm reactors.

In this experiment, a rapid mass-transfer inner loop fluidized bed biofilm reactor (ILFBBR) was employed to treat synthetic high ammonia nitrogen-containing (NH(4)(+)-N) wastewater by shortcut nitrification-denitrification. The reactor operation was stable after a short start-up period. Ammonia oxidizing bacteria (AOB) were predominant and 65% nitrite (NO(2)(-)-N/NO(x)(-)-N) levels were achieved. During the nitrification-denitrification period, the removal rates of NH(4)(+)-N and total nitrogen (TN) reached 94 and 82%, respectively. From the material balance, it was indicated that 87% of NH(4)(+)-N was removed by shortcut nitrification. The features of ILFBBR and the benefits of shortcut nitrification were combined in this experiment, and showed an excellent removal of NH(4)(+)-N from high-concentration NH(4)(+)-N wastewater.