New studies demonstrate the potential usefulness of the neutrophil to lymphocyte ratio (NLR) in predicting outcomes after treatment for various genitourinary cancers.
Researchers have found that an elevated NLR is associated with significantly higher rates of biochemical recurrence and positive surgical margins after radical prostatectomy (RP) for prostate cancer (PCa) and a significantly increased likelihood of tumor recurrence in patients who have undergone surgery for non-muscle invasive bladder cancer (NMIBC). Other researchers demonstrated that an elevated NLR predicts a greater likelihood of malignancy in patients undergoing surgery for renal tumors.
An elevated NLR is a marker of systemic inflammation that previous research has linked to adverse outcomes in multiple malignancies. The NLR is calculated by dividing the number of neutrophils by the number of lymphocytes.
Vidit Sharma, MD, of Mayo Clinic in Rochester, Minn., and colleagues studied 8,350 PCa patients who underwent RP patients and had a median follow-up of 9.7 years. Of these, 1,568 (18.7%) had a pre-RP NLR above 5. These patients were significantly more likely than those with an NLR below 5 to have pT3/4 disease at RP (22% vs. 17.1%) and positive surgical margins (33.2% vs. 25.8%) and significantly more likely to receive adjuvant hormonal therapy (13.8% vs. 8.2%) and radiation therapy (4.7% vs. 3.2%). Patients with an NLR above 5 also were significantly more likely to receive salvage hormonal therapy during followup (14% vs. 11.4%). After controlling for age, Gleason score, preoperative PSA level, pathologic state, and use of adjuvant hormonal or radiation therapy, an NLR above 5 remained a significant predictor of biochemical recurrence, according to investigators.
Yoshihiro Nakagami, MD, and colleagues at Tokyo Medical University studied 1,010 patients with castration-resistant PCa treated with docetaxel. The patients had an average of 11 treatment courses. The median overall survival time was 21 months. In multivariate analysis, an NLR of 2.6 or higher was associated with a 1.9 times increased risk of death.
Also at AUA meeting, Vincenzo Favilla, MD, and collaborators at the University of Catania in Italy, presented findings of a prospective study of NLR in a cohort of 178 patients (mean age 69 years, 148 male and 30 female) newly diagnosed with NMIBC and who underwent transurethral resection of bladder tumor (TURBT). The median follow-up was 53 months. The median NLR was 2.55.
During follow-up, 14 patients with an NLR less than 3 (23.3%) experienced recurrence compared with 44 patients with an NLR of 3 or higher (37.9%). In multivariate analysis, an NLR below 3 was associated with a 66% decreased risk of recurrence compared with an NLR of 3 or higher. The 5-year recurrence-free survival rate was 62% for those with an NLR less than 3 compared with 49% for patients with an NLR of 3 or higher. All of these between-group differences were statistically significant. The study found no significant association between NLR and progression risk.
In a separate study, Emrah Yuruk, MD, of the Bagcilar Training and Research Hospital, Istanbul, Turkey, and colleagues reviewed the medical records of 428 consecutive bladder cancer patients who underwent TURBT. After excluding patients without a preoperative NLR or a minimum of 6 months of follow-up, as well as patients with muscle-invasive disease, the researchers had a study population that included 390 NMIBC patients with a mean age of about 66 years (range 18–95 years). Of these, 68 (17.4%) experienced disease recurrence. These patients had a significantly higher mean NLR than those who did not have recurrence (2.62 vs. 2.20).
Another Mayo Clinic team presented findings showing that an elevated NLR prior to nephrectomy for renal tumors is associated with an increased risk of RCC at the time of surgery as well as higher-grade tumors and more aggressive histologic subtypes. The study, by Boyd R. Viers, MD, and colleagues, included 2,039 patients who underwent nephrectomy for localized renal masses and had an NLR calculated 90 days prior to surgery. Results demonstrated that patients with malignant renal tumors had a significantly higher NLR than those who had benign tumors (median 3.12 vs. 2.92). The lowest NLR (median 2.48) occurred in patients with cystic clear-cell RCC; the highest NLR (median 5.99) was found in those with collecting-duct RCC. Across all RCC subtypes, the investigators observed a significant increase in NLR with larger tumor size and nuclear grade.