Clinical relevance of specialist pathologic testicular tumor review.

Abstract

4599 Background: Therapeutic options in stage IA/B testicular cancer include surveillance, retroperitoneal lymph node dissection, and adjuvant chemotherapy/radiotherapy; clinician and patient choice is guided by recurrence risk. Specialist pathologic review is important in informing this decision as it may alter diagnosis and staging. Methods: Analysis of a prospective supraregional database of 627 testicular tumors diagnosed in Oxford or referred for central review between 2004 and 2012. Tumor histology, stage (AJCC 7th ed.), and other factors predictive of relapse were compared between referring and final pathology reports. Results: Of 402 cases referred from 11 hospitals during the study period, 370 primary testicular tumors with an informative initial pathology report were analysed. There was a discrepancy between referring and final reports in 116 cases (31.4%), with significant variation between referring units in the frequency of discordance (20.0-89.9%, p<0.0001, x2). Changes to histological diagnosis in 34 cases (9.2%) were minor alterations in type and proportion of non-seminomatous germ cell tumor (NSGCT) elements of no clinical significance, with exception of one classical seminoma reclassified as spermatocytic seminoma. For seminomas (n=201) the commonest discrepancies were in identification of rete testis invasion (RTI) (15.9%); lymphovascular invasion (LVI) (9.5%); and spermatic cord invasion (SCI) (5.0%). RTI was more frequently under-reported (14.4%), and LVI over-reported (8.0%) on initial assessment. Disparity of tumor size in 2 cases (1.0%) was of no clinical significance. For NSGCT (n=150) the commonest discrepancies were in RTI (9.3%), LVI (7.3%) and SCI (6.7%), with LVI typically over-reported (4.0%) and RTI and SCI under-reported (6.7%, 5.3% respectively) on primary analysis. Central review resulted in change of primary tumor stage in 45 cases (12.1%). 12 (6.0%) and 16 (8.0%) seminomas, and 12 (8.0%) and 5 (3.3%) NSGCTs were upstaged and downstaged respectively. Conclusions: Central pathology review results in frequent alteration of factors predictive of relapse in stage IA/B testicular cancer. Particular attention should be directed to review of RTI, LVI and SCI to ensure accurate prognostication.