Infertility/Andrology: Are vasectomy and prostate Ca linked?

Joseph Alukal, MDMicrodissection testicular sperm extraction retrieval rates, adolescent varicocele repair, and evaluation of testosterone replacement therapy and prostate cancer are additional of noteworthy topics in this field. The Infertility/Andrology take home messages were presented by Joseph Alukal, MD, of New York University Urology Associates, New York. 

Using the Subfertility and Assisted Reproduction Study database, co-linked to the Utah Population Database, investigators found a significantly higher risk of childhood cancer (Hodgkin's lymphoma, brain cancer, and acute lymphocytic leukemia) in siblings of men with oligozoospermia.

In an examination of vasectomy and risk of prostate cancer in the Prostate, Lung, Colorectal, and Ovarian Cancer Trial, no increased risk of prostate cancer with prior vasectomy was found in the screening arm, but an increased risk was observed (adjusted HR: 1.11, 95% CI: 1.03-1.20) in the usual care arm. The authors said the association was likely related to increased detection of prostate cancer based on patterns of care rather than a biologic effect of vasectomy.

In a retrospective review of 230 patients undergoing microdissection testicular sperm extraction (microTESE) for nonobstructive azoospermia, the retrieval rate was 45.7%. Of 83 patients who advanced to intracytoplasmic sperm injection, the pregnancy rate was 43.8%, with a live birth rate of 17.3%. There was no significant difference in pregnancy or live birth rates between use of fresh or frozen sperm.

In men with nonobstructive azoospermia and a history of cryptorchidism, sperm was retrieved in 62% of cases of microTESE, with a pregnancy rate of 47%. Serum follicle-stimulating hormone level and testis size were not predictive of retrieval.

In a study of adolescent varicocele repair, the paternity rate was 77.3% in the repair group versus 48.4% in control group (p<.005), with statistically significant differences in improvement of semen parameters.

Continue to the next page for more take home messages.

• Men with varicocele had a higher incidence of heart disease compared with men who underwent infertility testing (HR 1.22, 95% CI 1.03-1.45) as well as men who underwent vasectomy (HR: 1.32, 95% CI: 1.13-1.54). The varicocele group also had a higher risk of diabetes (HR 1.73, 95% CI 1.37-2.18) and hyperlipidemia (HR: 1.15, 95% CI: 1.03-1.28) than the vasectomy group.

• A novel mutation in an intraflagellar transport protein (IFT140) was identified in two infertile brothers from a consanguineous family via whole exome sequencing and validated with Sanger sequencing. Using the ExAC database, researchers reported that the mean allele frequency of the mutation in the population was 0.1%.

• The ten-eleven translocation protein enzymatic pathway is active during spermatogenesis and is responsible for DNA demethylation in the sperm pronucleus, enabling epigenetic programming. Decreased levels of TET1 mRNA were found in sperm from subfertile men, and correlated to low sperm motility. Low levels of TET3 mRNA were also identified, and correlated to poorer sperm concentration and poorer fertilization rates after ICSI.

• An examination of the relationship between testosterone replacement therapy (TRT) and incident prostate cancer among U.S. hypogonadal veterans showed no association between TRT and risk of all prostate cancer (adjusted HR: 0.90, 95% CI: 0.81-1.01) nor between TRT and aggressive prostate cancer (adjusted HR: 0.89, 95% CI: 0.70-1.13).

• TRT was not associated with a higher risk of cardiovascular events at over 5.1 years of follow-up in a retrospective matched cohort study. Men with the lowest TRT exposure had the highest cardiovascular risk compared with controls.

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