Management of Stage II Germ Cell Tumors

Impact of circulating microRNA test (miRNA-371a-3p) on appropriateness of treatment and cost outcomes in patients with Stage I non-seminomatous germ cell tumours

OBJECTIVES

To determine whether utilisation of a serum microRNA (miRNA) test could improve treatment appropriateness and cost-effectiveness for patients with Stage I non-seminomatous germ cell tumours (NSGCTs).

PATIENTS AND METHODS

A decision tree model was built to investigate treatment course, clinical and cost outcomes for patients with Stage IA (T1N0M0S0) and IB (T2-4N0M0S0) NSGCT. The model compared outcomes and cost of standard approach using histopathology, conventional serum tumour markers and radiographic staging (standard model) to a miRNA-based approach using the standard model + post-orchidectomy serum miR-371a-3p (marker model). Probabilities of expected treatment and outcomes were based on presence/absence of cancer upon entering into the model. Overtreatment was defined as adjuvant chemotherapy or primary retroperitoneal lymph node dissection in a patient without cancer. Undertreatment was defined as initial surveillance for a patient with cancer.

RESULTS

Utilising the miRNA marker-based approach, 26% of patients avoid overtreatment and 8% avoid undertreatment in Stage IA NSGCT; 27% avoid overtreatment and 23% avoid undertreatment in Stage IB disease. Appropriate treatment decision-making increased from 65% to 94% and 50% to 92% for Stage IA and IB, respectively. The miRNA-based approach remained cost-effective over a wide range of performance characteristics with savings of ~$1400 (American dollars)/patient for both Stage IA and IB disease.

CONCLUSION

A miRNA-based approach may potentially select patients with Stage I NSGCT for correct treatment in a cost-effective manner. Identification of residual teratoma-only remains an issue. Prospective studies are necessary to validate these findings.

Surgical treatment of metastatic germ cell cancer

Among young men between the ages of 15 and 40 years, germ cell cancer is the most common solid tumor [1]. The worldwide incidence of germ cell cancer is 70 000 cases. Compared to all solid tumors of men, germ cell cancer accounts for 1% of all male tumors. Nevertheless, the mortality of this rare tumor entity is about 13% since 9507 patients died worldwide of germ cell cancer. The improvement in survival of germ cell cancer patients is due to a multimodal treatment of germ cell cancer including cisplatin-based chemotherapy and surgery leading to higher cure-rates even in advanced stages [1], whereas the increasing incidence of germ cell cancers cannot be thoroughly explained. In this article we review the current indications for surgery in metastatic germ cell cancers, highlight the strength and weaknesses of techniques and indications and raise the question how to improve surgical treatment in metastatic germ cell cancer.