Prediction of Retroperitoneal Histology in Metastatic Nonseminomatous Testicular Cancer Patients after Chemotherapy Based on Clinical and Radiological Parameters

Abstract

Introduction: We retrospectively analysed the predictive value of numerous clinical and radiological parameters to identify a predictor for either necrosis or residual tumors found by retroperitoneal lymph node dissection (RPLND) histology in a collection of nonseminomatous germ cell tumor (NSGCT) patients. Materials and Methods: A database was created containing detailed clinical, radiological and histological information of all consecutive NSGCT patients, who underwent post chemotherapy RPLND between 1984 and 2007. According to the histology of the RPLND specimen, patients were assigned to the “necrosis-only” group or the “residual tumor” group. Associations between clinical and radiological parameters and histology of RPLND were analyzed. Results: Histology of dissected masses showed complete necrosis in 57.4% of patients and residual tumors in 42.6% (3.1% viable cancer and 39.5% teratoma). Univariate analysis showed significant correlation of RPLND histology and the following parameters: teratoma-positive primary tumors, pre-chemotherapy α-fetoprotein (AFP) and – less pronounced – human chorionic gonadotropin levels, size of metastatic mass, total volume of metastatic retroperitoneal lymph nodes, and percentage of volume reduction. The best prediction for necrosis in RPLND histology was in patients with no evidence of teratomatous elements in primary tumors and with normal pre-chemotherapy AFP levels and small lymph nodes. Stepwise multivariate logistic regression analysis confirmed AFP < 10 ng/ml as the best independent predictor for only necrosis in RPLND histology. Conclusions: At the present time we still consider all patients with metastatic NSGCT as candidates for a post-chemotherapy RPLND, arguing that in experienced hands mortality is negligible and morbidity is low and therefore not relevant compared to the risk of missing a residual tumor.

A meta-analysis of clinicopathologic features that predict necrosis or fibrosis at post-chemotherapy retroperitoneal lymph node dissection in individuals receiving treatment for non-seminoma germ cell tumours

“…A total of nine studies including 2,053 patients addressed the issue of the predictive value of pre-chemotherapy serum tumour marker levels on necrosis/fibrosis at pcRPLND ( 15 , 17 , 23 , 28 , 30 , 33 , 37 , 40 , 42 ), including the aforementioned meta-analysis ( 15 ). Necrosis/fibrosis was significantly more likely to be identified in post-chemotherapy residual masses when compared with teratoma or viable GCT when AFP (OR 3.22, 95% CI 2.49-4.15) ( 15 , 17 , 28 , 30 , 37 , 40 , 42 ) or bHCG (OR 1.96, 95% CI 1.62-2.36) ( 15 , 17 , 28 , 33 , 37 , 40 , 42 ) were normal at the commencement of chemotherapy. In contrast, normal LDH prior to chemotherapy was negatively associated with this necrosis/fibrosis at pcRPLND (OR 0.58, 95% CI 0.46-0.73) ( 15 , 17 , 23 , 33 , 37 , 40 ) (see Figures 3A–C ).…”

“…Necrosis/fibrosis was significantly more likely to be identified in post-chemotherapy residual masses when compared with teratoma or viable GCT when AFP (OR 3.22, 95% CI 2.49-4.15) ( 15 , 17 , 28 , 30 , 37 , 40 , 42 ) or bHCG (OR 1.96, 95% CI 1.62-2.36) ( 15 , 17 , 28 , 33 , 37 , 40 , 42 ) were normal at the commencement of chemotherapy. In contrast, normal LDH prior to chemotherapy was negatively associated with this necrosis/fibrosis at pcRPLND (OR 0.58, 95% CI 0.46-0.73) ( 15 , 17 , 23 , 33 , 37 , 40 ) (see Figures 3A–C ).…”

“…A reduction in mass size during chemotherapy was evaluated consistently in five studies as a predictor of residual mass histopathology ( 27 , 28 , 32 , 37 , 40 ), with each study permitting the development of an OR of less than or greater than 50%, 70% and/or 90% reduction in mass size during chemotherapy.…”

“…In an analysis of four studies ( 28 , 32 , 37 , 40 ), which addressed the predictive value of less than or greater than 50% reduction in mass size during chemotherapy and included 1,912 patients, a greater than 50% reduction in mass size was strongly predictive of necrosis/fibrosis over residual teratoma or viable GCT when compared to those with less than 50% reduction in mass size (OR 4.84, 95% CI 3.94-5.94) (see Figure 4A ). Similarly, in the analyses of studies evaluating less than or greater than 70% ( 27 , 28 , 32 , 37 , 40 ) and 90% ( 27 , 28 , 40 ) reduction in mass size, masses undergoing greater change were more likely to represent necrosis/fibrosis than residual teratoma or viable GCT when compared to masses undergoing lesser change (≥70%: OR 4.36, 95% CI 3.49-5.44; ≥90%: OR 2.19, 95% CI 1.16-4.11) (see Figures 4B, C ).…”

“…The size of residual mass was evaluated in several eligible papers; however, only 10 studies utilising consistent parameters for the measurement of the residual mass were evaluable ( 15 , 17 , 34 , 36 – 38 , 40 , 42 – 44 ). Each evaluable paper described the measurement of the longest transverse (axial) dimension to assign patients to groups defined as: less than or greater than 2 cm and less than or greater than 5 cm.…”