The impact of oxaliplatin on the gonads: from bedside to the bench

Study hypothesis: What is the impact of oxaliplatin on gonadal function?

Study finding: Our results in both the clinical and pre-clinical settings indicate that oxaliplatin exerts moderate transient gonadal toxicity.

What is known already: Recent studies have indicated a significant increase in survivorship of colorectal cancer patients of reproductive age, who may then face fertility concerns. The impact of oxaliplatin on gonadal function is yet to be discovered.

Study design, samples/materials, methods: Eleven female (<43 years) and eight male (<45 years) patients recently diagnosed with colorectal cancer, who were candidates for oxaliplatin-based protocol, were enrolled into the study. FSH, estradiol, anti-Müllerian hormone (AMH) and menstrual pattern were measured in female patients, whereas FSH, inhibin-B, testosterone, and steroid-hormone binding globulin were measured in male patients. Hormones were measured at baseline and 6 months post-treatment (last chemotherapy administration) in men and women. In the animal model, pubertal mice were injected with oxaliplatin and sacrificed 1 week, 1 month and 3 months later. Ovarian reserve was estimated by serum AMH measurements. Testicular function was evaluated by serum inhibin-B and sperm evaluation. Gonadal apoptosis (TUNEL), proliferation (Ki-67), repair (PCNA), ovarian reserve (AMH) and testicular reserve (DAZL) were measured by immunohistochemistry.

Main results and the role of chance: In all women, AMH decreased post-treatment, but remained above the detection limit in 9/11 patients (P < 0.05). FSH was elevated, but did not exceed the premenopausal range in 9/11 patients. All patients remain menstruating or resumed menstruation post-treatment. In female mice oxaliplatin induced transient apoptosis at 1-month post-treatment. In men Inhibin-B was slightly reduced post-treatment. In male mice oxaliplatin did not affect spermatozoa concentration, but was associated with transient, moderate reductions of spermatocytes-spermatogonia numbers and spermatozoa motility.

Limitations, reasons for caution: Future prospective large-scale studies are warranted in order to affirm these outcomes.

Wider implications of the findings: Due to high survival rates of colorectal cancer patients of reproductive age that were diagnosed at early stages of the disease, the issue of treatment-induced gonadotoxicity gains significance. Since at the individual level there might be a risk of infertility, a detailed discussion and referral to fertility preservation prior to initiation of treatment is recommended. Nevertheless, oxaliplatin-based protocols appear to be less gonadotoxic than other chemotherapeutic protocols.

Large scale data: None.

Study funding and competing interests: This study was supported by the Israeli Science Foundation (ISF) grant 13-1816 (I.B.-A.). There is no conflict of interest.