Association of Impaired Spermatogenesis With the Use of Immune Checkpoint Inhibitors in Patients With Metastatic Melanoma

Abstract

This cohort study examines the potential association of the use of immune checkpoint inhibitors with testicular histopathologic conditions.

The emergence of immune checkpoint inhibitors (ICIs) has provided previously unachievable curative therapy for many patients, particularly those with metastatic melanoma.¹ However, the long-term outcomes for patients using ICIs are only beginning to be investigated. One important potential unexplored adverse effect is impaired male fertility. The current American Society of Clinical Oncology guidelines (July 2018) state that “sperm cryopreservation is effective, and health care providers should discuss sperm banking with postpubertal males receiving cancer treatment.”^2(p1995) The direct association of ICI treatment with spermatogenesis has not been explored, to our knowledge.³ It will be critical to determine the risk to future male fertility for patients undergoing ICI therapy to accurately guide pretreatment counseling. To address the association between the potential gonadotoxic effect of ICIs and spermatogenesis, to our knowledge, we performed the first retrospective review of an index patient who became infertile after ICI therapy and subsequently died, and we performed a retrospective cohort cadaver study of patients with metastatic melanoma.

Methods

We queried the Johns Hopkins Pathology database (January 1, 1985, through December 31, 2016) for untreated patients and the Johns Hopkins Legacy Gift Rapid Autopsy database (January 1, 2013, through December 31, 2016) for patients with a history of metastatic melanoma treated using immunotherapy for more than 1 month (ipilimumab, nivolumab, or pembrolizumab). Tissue specimens of the testes were retrospectively examined from deceased patients for whom autopsies were performed. Patients who had received systemic chemotherapy or radiotherapy to the thorax, abdomen, pelvis, or lower extremities were excluded. We obtained approval from the Johns Hopkins Hospital institutional review board for review of pathologic samples under a consent waiver.

A proportioned control cohort was matched for age at tissue acquisition. Control samples came from men with a history of metastatic melanoma who had never undergone immunotherapy, chemotherapy, or radiotherapy to the thorax, abdomen, pelvis, or lower extremities between January 1, 1986, and December 31, 2016. For each patient, data on demographic characteristics, time from death to autopsy, treatment history, type of immunotherapy, and duration of therapy were recorded.

Autopsy and biopsy tissues were fixed in 10% buffered formalin within 24 hours after death. The testicular pathology slides were stained with hematoxylin-eosin and observed under light microscopy by a blinded independent genitourinary pathologist (A.M.). Testicular histopathologic conditions were diagnosed for each individual, and the degree of spermatogenesis was quantified using the Johnsen scoring system.⁴ Owing to the restrictive sample size, we present descriptive data on testicular pathologic conditions. Statistical analysis was performed from February 21, 2018, to December 12, 2019. Comparisons between cohorts for age at diagnosis, age at death, and time to autopsy were performed using a Mann-Whitney test using Prism, version 8 (GraphPad Software, Inc).

Results

We queried more than 10 000 potential participants and identified a total of 13 men (median age, 54 years [range, 23-78 years]) with metastatic melanoma who had testicular autopsy tissue specimens available. Of these, 7 underwent immunotherapy and 6 were treatment naive. There was no difference between groups for age at diagnosis, age at death, and time to autopsy (Table). Six of the 7 men (86%) with metastatic melanoma who received ICI therapy had impaired spermatogenesis, including focal active spermatogenesis (n = 1), hypospermatogenesis (n = 2), and Sertoli-cell–only syndrome (n = 3). Two of the 6 men (33%) who were untreated had impaired spermatogenesis (Figure). We did not identify any increased peritubular hyalinization or fibrosis in the treated group, and there were no Leydig cell abnormalities noted in any patients.

Table. Characteristics and Testicular Morphologic Conditions of Patients With Metastatic Melanoma With or Without Immunotherapy Treatment.

Age at diagnosis, y	Age at death, y	Postmortem interval, h	Immunotherapy	Duration of immunotherapy, mo	Other agents	Spermatogenesis pathological diagnosis	Johnsen scoring4
Late 20s	Early 30s	2	Ipilimumab and pembrolizumab	4	BRAF and MEK inhibitors	Sertoli cell only	2
60s	60s	15	Ipilimumab and nivolumab	18	Cyberknife radiotherapy and vemurafenib	Sertoli cell only	2
Early 30sa	30s	NA	Ipilimumab and nivolumab	Unknown	None	Sertoli cell only	2
50s	Late 50s	5	Ipilimumab and pembrolizumab	8	Interleukin 2	Hypospermatogenesis	8
60s	60s	17	Ipilimumab and nivolumab	1	None	Hypospermatogenesis	8
Early 60s	60s	6	Ipilimumab and nivolumab	5	None	Focal active spermatogenesis	9
50s	Late 50s	4	Ipilimumab and nivolumab	11	Dabrafenib and trametinib	Normal spermatogenesis	10
Early 50s	Early 50s	24	None	None	None	Sertoli cell only	2
Late 70s	80s	6	None	None	None	Sertoli cell only	2
20s	20s	5	None	None	None	Normal spermatogenesis	10
40s	Early 50s	5	None	None	None	Normal spermatogenesis	10
40s	50s	24	None	None	None	Normal spermatogenesis	10
Late 60s	Late 60s	6	None	None	None	Normal spermatogenesis	10

Abbreviation: NA, not applicable.

^aIndex patient.

Figure. Representative Histologic Testis Images (Hematoxylin-Eosin) of Patients Who Received Immunotherapy.

A, Normal spermatogenesis. B, Hypospermatogenesis (decreased spermatogenesis at each stage including mature sperm). C, Focal active spermatogenesis (mixed pattern of seminiferous tubules in which some lack germ cells and others have complete spermatogenesis present). D, Sertoli cell only (seminiferous tubules lacking all germ cells).

Discussion

Fertility preservation is an important facet in the care of men with cancer who are within their reproductive years.^5,6 One key to improving cancer survivorship and quality of life is to anticipate potential treatment-associated sequelae. Identifying the association of ICIs with future fertility will be an important step in determining whether male fertility preservation is an essential component to pretreatment counseling. A limitation of our study was the small sample size. To our knowledge, the data herein are the first to evaluate the association of ICIs with testicular function, but prospective evaluations will be essential to determining the gonadotoxic effect of ICIs.