Prediction of microdissection testicular sperm extraction outcomes of azoospermic patients post-chemotherapy using cyclophosphamide equivalent dose.

PURPOSE: We determined the sperm retrieval rate in men with persistent azoospermia post-chemotherapy in relation to cyclophosphamide equivalent dose (CED), a unit for quantifying alkylating agent exposure.

METHODS

Medical records were retrospectively reviewed of 1098 patients diagnosed with non-obstructive azoospermia who had undergone microdissection testicular sperm extraction (mTESE) between January 2010 and 2021 at our institution. Twenty-three patients with a prior history of chemotherapy were included in the study. Oncological data, chemotherapy regime, and dosage were reviewed. The pretreatment hormone profile, CED, and mTESE outcomes were analyzed.

RESULTS

Testicular spermatozoa were successfully retrieved from 11 patients (47%). The mean patient age was 37.3 years (range, 27-41 years), and mean time interval from chemotherapy to mTESE, 11.8 years (range, 1-45 years). Patients exposed to alkylating agents had significantly lower sperm retrieval rates than those not exposed to alkylating agents (1/9, 11% vs. 10/14, 71%, p = 0.009). No men with CED > 4000 mg/m2 (n = 6) had viable sperm in the testes during mTESE. Moreover, patients diagnosed with testicular non-seminomatous germ cell tumors had a favorable sperm retrieval rate (67%) compared to patients with lymphoma (20%) or leukemia (33%).

CONCLUSION

Patients with permanent azoospermia post-chemotherapy have a lower testicular sperm retrieval rate when the chemotherapy regimen included alkylating agents. In cases where patients have undergone more intensive gonadotoxic treatments, such as higher CED, the likelihood of successful sperm retrieval is low. It is advisable to counsel such patients using the CED model prior to considering surgical sperm retrieval.