Aristolochic acid-containing Chinese herbal medicine and upper urinary tract urothelial carcinoma in Taiwan: a narrative review.

PURPOSE: The high incidence of upper urinary tract urothelial carcinoma (UTUC) in Taiwan is largely due to exposure to aristolochic acid (AA), a principal component of Aristolochia-based herbal medicines. Here we systematically review the molecular epidemiology, clinical presentation and biomarkers associated with AA-induced UTUC. METHODS: This is a narrative review. Medline, Embase, and Web of Science were searched from inception to December 31, 2021. Studies evaluating the association, detection, and clinical characteristics of AA and UTUC were included. RESULTS: A nationwide database revealed 39% of the Taiwanese population had been exposed to AA-containing herbs between 1997 and 2003. Epidemiological reports revealed AA posed a significantly higher hazard for renal failure and UTUC in herbalists and the general population who ingested AA-containing herbs. The presence of aristolactam-DNA adducts and a distinctive signature mutation, A:T to T:A transversions, located predominantly on the non-transcribed DNA strand, with a strong preference for deoxyadenosine in a consensus sequence (CAG), was observed in many UTUC patients. Clinically, AA-related UTUC patients were characterized by a younger age, female gender, impaired renal function and recurrence of contralateral UTUC. To date, there are no preventive measures, except prophylactic nephrectomy, for subjects at risk of AA nephropathy or AA-related UTUC. CONCLUSION: AA exposure via Aristolochia-based herbal medicines is a problem throughout Taiwan, resulting in a high incidence of UTUC. Aristolactam-DNA adducts and a distinctive signature mutation, A:T to T:A transversions, can be used as biomarkers to identify AA-related UTUC. AA-related UTUC is associated with a high recurrence rate of contralateral UTUC.

Prognosis and risk factors of patients with upper urinary tract urothelial carcinoma and postoperative recurrence of bladder cancer in central China.

BACKGROUND: To investigate the prognostic risk factors and postoperative recurrence of bladder cancer in patients with upper urinary tract urothelial carcinomas (UTUCs). METHODS: Data of 439 UTUC patients were retrospectively analyzed. Follow-up and analysis of smoking effects, consumption of traditional Chinese medicine containing aristolochic acid, history of bladder cancer, age, sex, presence or absence of diabetes mellitus (DM), metformin use, tumor characteristics (number, location, stage, grade), and open or laparoscopic surgery on the prognosis of UTUCs were performed. Cox proportional hazard regression analysis was performed to analyze the relationship between various factors and the postoperative survival rate. The survival rate was analyzed using the Kaplan-Meier method. Moreover, logistic regression analysis was performed to analyze the relationship between the above mentioned factors and postoperative recurrence of bladder cancer. RESULTS: Overall, 439 patients met, including 236 males (53.7%) and 203 females (46.3%), the criteria for the final statistical analysis, and the average age was 66.7 years. The 1-, 3-, and 5-year overall survival rates of 439 UTUC patients were 90.0, 76.4, and 67.7%, respectively. The 5-year survival rates of T1, T2, T3, and T4 patients were 90.2%, 78%, 43.8%, and 18.5%, respectively. Factors influencing the long-term survival rate of UTUC patients were smoking, taking traditional Chinese medicine containing aristolochic acid, history of bladder cancer, age, tumor size, tumor stage, tumor grade, and lymph node metastasis. The risk factors related to postoperative bladder cancer recurrence were advanced tumor stage, high grade tumor, preoperative ureteroscopy, ureteral urothelial carcinoma, no postoperative bladder perfusion chemotherapy and DM without metformin use. CONCLUSIONS: Advanced tumor stage and presence of a high-grade tumor were risk factors for not only poor UTUC prognosis but also BC recurrence. In addition, preoperative ureteroscopy, ureteral urothelial carcinoma and DM without metformin use were high risk factors for BC recurrence, whereas regular postoperative bladder perfusion chemotherapy was a protective factor.

Recent advances in upper tract urothelial carcinomas: From bench to clinics.

Urothelial carcinoma in the upper tract is rare and often discussed separately. Many established risk factors were identified for the disease, including genetic and external risk factors. Radiographic survey, endoscopic examination and urine cytology remained the most important diagnostic modalities. In localized upper tract urothelial carcinomas, radical nephroureterectomy with bladder cuff excision are the gold standard for large, high-grade and suspected invasive tumors of the renal pelvis and proximal ureter, whereas kidney-sparing surgeries should be considered in patients with low-risk disease. Advances in technology have given endoscopic surgery an important role, not only in diagnosis, but also in treatment. Although platinum-based combination chemotherapy is efficacious in advanced or metastatic disease, current established chemotherapy regimens are toxic and lack a sustained response. Immune checkpoint inhibitors have led to a new era of treatment for advanced or metastatic urothelial carcinomas. The remarkable results achieved thus far show that immunotherapy will likely be the future treatment paradigm. The combination of immune checkpoint inhibitors and other agents is another inspiring avenue to explore that could benefit even more patients. With respect to the high incidence rate and different clinical appearance of upper tract urothelial carcinomas in Taiwan, a possible correlation exists between exposure to certain external risk factors, such as arsenic in drinking water and aristolochic acid in Chinese herbal medicine. As more gene sequencing differences between upper tract urothelial carcinomas and various disease causes are detailed, this has warranted the era of individualized screening and treatment for the disease.

Aristolochic acid-associated urothelial cancer in Taiwan.

Aristolochic acid, a potent human carcinogen produced by Aristolochia plants, is associated with urothelial carcinoma of the upper urinary tract (UUC). Following metabolic activation, aristolochic acid reacts with DNA to form aristolactam (AL)-DNA adducts. These lesions concentrate in the renal cortex, where they serve as a sensitive and specific biomarker of exposure, and are found also in the urothelium, where they give rise to a unique mutational signature in the TP53 tumor-suppressor gene. Using AL-DNA adducts and TP53 mutation spectra as biomarkers, we conducted a molecular epidemiologic study of UUC in Taiwan, where the incidence of UUC is the highest reported anywhere in the world and where Aristolochia herbal remedies have been used extensively for many years. Our study involves 151 UUC patients, with 25 patients with renal cell carcinomas serving as a control group. The TP53 mutational signature in patients with UUC, dominated by otherwise rare A:T to T:A transversions, is identical to that observed in UUC associated with Balkan endemic nephropathy, an environmental disease. Prominent TP53 mutational hotspots include the adenine bases of (5')AG (acceptor) splice sites located almost exclusively on the nontranscribed strand. A:T to T:A mutations also were detected at activating positions in the FGFR3 and HRAS oncogenes. AL-DNA adducts were present in the renal cortex of 83% of patients with A:T to T:A mutations in TP53, FGFR3, or HRAS. We conclude that exposure to aristolochic acid contributes significantly to the incidence of UUC in Taiwan, a finding with significant implications for global public health.

Analgesics, cigarette smoking, and other risk factors for cancer of the renal pelvis and ureter.

Results from a population-based case-control study of cancer of the renal pelvis and ureter are reported. Telephone interviews were conducted with 187 residents of Los Angeles County diagnosed with cancer of the renal pelvis and ureter over a 4-year period ending December 31, 1982, and with individually sex-, age- and race-matched neighborhood controls. The major risk factor identified for cancer of the renal pelvis and ureter was cigarette smoking. Subjects who smoked more than 25 years had a relative risk of 4.5 of developing these tumors, compared to nonsmokers (P less than 0.0001). Heavy use of over-the-counter analgesics was also associated with a significant increase in risk; it appears that an elevated risk was conveyed by all the major active constituents of those compounds currently marketed in the United States, aspirin, caffeine, and acetaminophen. Persons who had used these drugs for 30 consecutive days at any time in their life preceding diagnosis had twice the risk of developing cancer of the renal pelvis or ureter compared to persons not reporting such use (P less than 0.01). Heavy coffee drinkers (greater than or equal to 7 cups/day) had a 1.8-fold increase in risk compared to nondrinkers. Although risk tended to increase with increasing consumption, this result was not statistically significant. The risk associated with heavy coffee consumption was reduced to 1.3 after adjusting for smoking. Nine cases compared to no controls reported a first degree relative with kidney cancer. A history of kidney stones was associated with an increased risk of cancer of the ureter (relative risk = 2.5) that was not, however, statistically significant.