Preoperative pyuria, ureteral tumor site, and positive surgical margins are risk factors for intravesical recurrence (IVR) in patients without a history of bladder cancer who undergo radical nephroureterectomy for upper tract urothelial carcinoma (UTUC), new study findings suggest.
Using these risk factors, investigators led by Tadashi Matsuda, MD, of Kansai Medical University in Osaka, Japan, developed a risk stratification model to predict IVR risk in patients with UTUC treated with radical nephroureterectomy.
Dr Matsuda and colleagues concluded that their “model incorporating pyuria could improve the clinical decision-making regarding the need for postoperative intravesical instillation therapy to prevent IVR,” according to a paper published in Clinical Genitourinary Cancer.
The investigators studied 268 patients with UTUC without a history of bladder cancer who underwent RNU. On multivariable analysis, the presence of preoperative pyuria (10 or more WBCs/HPF), compared with its absence, was significantly associated with a 1.7-fold increased risk for IVR.
“Although the actual mechanisms of the association between preoperative pyuria and [urothelial carcinoma] have yet to be elucidated, urine leukocytes might play a key role in cancer-associated inflammation and carcinogenesis,” the investigators noted.
Ureteral tumors were significantly associated with a 1.6-fold increased risk for IVR compared with renal pelvis tumors. “Previous studies have indicated that a ureteral tumor site is a risk factor for IVR because of the greater urine flow rate and intraluminal pressure in the ureter, which might lead to increased mechanical irritation and subsequent detachment of tumor cells,” the authors wrote. The presence of positive surgical margins, compared with their absence, was significantly associated with a 2.7-fold increased risk for IVR.
In addition, patients with both a ureteral tumor and positive surgical margin had a significant 3.2-fold higher risk for IVR compared with patients who did not these 2 factors. “Thus, rigorous follow-up is required for the early detection of IVR in such patients,” Dr Matsuda’s team stated. Using their risk stratification model, the investigators categorized patients as being at low, intermediate, or high risk for IVR. The 5-year IVR-free rates for patients in these risk groups, respectively, were 69.1%, 51.8%, and 18.8%, they reported.
In their acknowledgement of study limitations, the authors noted that their study was retrospective and included a relatively small cohort. In addition, multiple surgeons performed the nephroureterectomies, “which could have influenced the oncologic outcomes.”
Sato G, Yoshida T, Yanishi M, et al. Preoperative pyuria predicts for intravesical recurrence in patients with urothelial carcinoma of the upper urinary tract after radical nephroureterectomy without a history of bladder cancer [published online September 27, 2019]. Clin Genitourin Cancer. doi: 10.1016/j.clgc.2019.09.017