Resection of small, residual retroperitoneal masses after chemotherapy for nonseminomatous testicular cancer: a decision analysis.

BACKGROUND: After chemotherapy for metastatic, nonseminomatous testicular cancer, small, retroperitoneal lymph nodes still harbor mature teratoma or viable cancer cells in less than half of patients with normal tumor markers. Surgical resection is an effective treatment to remove residual masses, but observation may also be considered.
METHODS: Using a decision analysis model, the authors estimated the survival achieved with either resection or observation for patients with residual masses measuring 0-20 mm. Prognostic estimates were obtained from an international data set containing 362 patients with masses < or =20 mm and from 10 clinical experts.
RESULTS: According to the model, resection prolonged life expectancy by more than 2 years for masses 11-20 mm and by more than 1 year for masses 0-10 mm. The estimated gains in 5-year survival were 4.3% and 2.7%, respectively. In a sensitivity analysis, these results appeared rather robust for changes in the estimates of the experts. The magnitude of the gain in survival, however, depended on the probabilities of the residual histologies, which could be estimated with several well-known predictors, and the assumed benefit of resection for residual mature teratoma or cancer.
CONCLUSIONS: Resection may on average be beneficial for patients with small, residual masses. The expected benefit depends on the probability and risks of residual malignancy, regarding which further research is required. For decision-making regarding individual patients, the morbidity and costs of resection and a patient's individual preferences should be considered in addition to any assumed gain in survival.