Lymph node count impacts survival following post‐chemotherapy retroperitoneal lymphadenectomy for non‐seminomatous testicular cancer: a population‐based analysis

Abstract

Objective To evaluate the prognostic significance of lymph node count (LNC) at post‐chemotherapy retroperitoneal lymphadenectomy (PC‐RPLND) in metastatic non‐seminomatous germ cell tumour (NSGCT) using the Surveillance, Epidemiology, and End Results (SEER) database and National Cancer Database (NCDB). Patients and methods SEER (2000–2013, n = 572) and NCDB (2004–2013, n = 731) identified patients undergoing PC‐RPLND for Stage II and III NSGCT. Correlation between linear or categorial variables and LNC was conducted using Spearman's rank correlation or Kruskal–Wallis test by ranks. Patients were stratified by ≤20, 21–40, and >40 LNs for Kaplan–Meier analysis. Cox proportional hazards models evaluated the association of LNC at PC‐RPLND with overall mortality (OM) in the NCDB and cancer‐specific mortality (CSM) in the SEER database. The relationship between LNC and OM or CSM was also modelled as a non‐linear function to determine a threshold for survival benefit. Results Amongst all patients, the median (interquartile range) LNC was 17 (3–26) LNs in the NCDB, and 18 (6–31) LNs in the SEER database. More recent diagnosis year, higher hospital volume, higher median income, private insurance status, and positive LNC were associated with greater total LNC in one or both databases (P < 0.05). On Kaplan–Meier analysis, >40 LNs was associated with 5‐year cancer‐specific survival (CSS) of 99% and overall survival (OS) of 96%, whereas ≤20 LNs had a 5‐year CSS of 91% and OS of 78% (CSS, P = 0.04; OS, P < 0.01). Risk‐adjusted Cox model showed increasing LNC (per node) was inversely associated with OM (hazard ratio [HR] 0.96, 95% confidence interval [CI], 0.94–0.98; P < 0.01) and CSM (HR 0.96, 95% CI, 0.94–0.99; P = 0.01). Non‐linear modelling showed the greatest benefit in OM at between 10 and 20 LNs, but continued survival benefit for OM and CSM beyond 20 LNs. Conclusions Greater LNC during PC‐RPLND appears to be associated with improved CSS and OS in NSGCT. Our data support the role of thorough RPLND for post‐chemotherapy metastatic NSGCT.

Additional surgical procedures and perioperative morbidity in post-chemotherapy retroperitoneal lymph node dissection for metastatic testicular cancer in two intermediate volume hospitals

“…Post-chemotherapy retroperitoneal lymph node dissection (PC-RPLND) is an important component of the treatment of disseminated germ cell tumor (GCT) [1][2][3][4]. It is a technically challenging procedure and is associated with significant treatment-related morbidity [5,6].…”

Association of Lymph Node Count and Survival after Primary Retroperitoneal Lymphadenectomy for Nonseminomatous Testicular Cancer

“…These findings are in line with literature also reporting improved outcomes with higher LNCs examined after RPLND in the post-chemotherapy setting. 7,8 The underlying mechanism to explain why higher LNCs translate to improved outcomes is not entirely clear. As the retroperitoneum is the initial site of metastatic spread in up to 90% of men with CS I or IIA NSGCT, a thoroughly performed RPLND has significant therapeutic and staging implications.…”

“…These findings are in line with literature also reporting improved outcomes with higher LNCs examined after RPLND in the post-chemotherapy setting. 7,8…”

The prognostic value of lymph node ratio in comparison to positive lymph node count in penile squamous cell carcinoma

“…At the end of the follow-up, 57(22.9%) patients died from PSCC. The median number of LNR, PLNC, and lymph nodes examined was 0.04 (range of 0.00-1.00), 1(range of [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18], and 17 (range of 2-78), respectively. A detailed description of the clinical-pathological characteristics of the enrolled patients is shown in Table 1.…”

“…The TNM staging system is one of the most important prognostic factors for survival, associated with tumor (T)/ lymph node metastasis (N)/distant metastasis (M) in cancers. Recently, the lymph node ratio (LNR, the ratio of metastatic to total examined lymph nodes) and positive lymph node count (PLNC, the number of metastatic lymph nodes) have been considered as powerful prognostic factors in various tumors [7][8][9][10][11][12]. However, the prognostic value of LNR versus PLNC in penile squamous cell carcinoma (PSCC) has not been well established.…”