To the Editor:
We thank the distinguished author for bringing attention to our work.
As Dr. Schlegel points out, a natural conclusion to draw from the manuscript is that a male factor evaluation is of critical importance for a man’s reproductive and overall health (1). Indeed, it is estimated that 20% of infertile couples do not receive a male evaluation in the U.S.(2) As is noted, the current estimates may be an underestimate of a man’s lifetime risk. The current analysis followed men for a relatively short period of time (up to 15 years) compared with a man’s complete lifespan (76.3 years) (3, 4). Thus, it is possible that his lifetime risk of cancer would continue to rise as he ages.
Dr. Schlegel does point out some limitations related to the granularity of information on each man. As is noted, infertile men are generally of higher socioeconomic status compared with the general population (5). However, access to care should be independent of semen parameters. Thus it is unlikely that the elevated cancer risk seen in azoospermic men could be entirely explained by socioeconomic factors. We look forward to seeing other groups substantiate our findings.
Michael Louis Eisenberg, M.D. , Stanford University School of Medicine, Stanford, California
Paul Betts, M.S., Cancer Epidemiology and Surveillance Branch, Texas Cancer
Registry, Texas Department of State Health Services, Austin, Texas
Danielle Herder, M.D., Baylor College of Medicine, Houston, Texas
Dolores Lamb, Ph.D., Baylor College of Medicine, Houston, Texas
Larry Lipshultz, M.D., Baylor College of Medicine, Houston, Texas
1. Schlegel PN. The relevance of increased cancer risk in infertile men. Fertil Steril 2013.
2. Eisenberg ML, Lathi RB, Baker VL, Westphal LM, Milki AA, Nangia AK. Frequency of the male infertility evaluation: data from the national survey of family growth. J Urol 2013;189:1030-4.
3. Murphy SL, Xu J, Kochanek KD. Deaths: final data for 2010. Natl Vital Stat Rep 2013;61:1-167.
4. Eisenberg ML, Betts P, Herder D, Lamb DJ, Lipshultz LI. Increased risk of cancer among azoospermic men. Fertil Steril 2013.
5. Hotaling JM, Davenport MT, Eisenberg ML, VanDenEeden SK, Walsh TJ. Men who seek infertility care may not represent the general U.S. population: data from the National Survey of Family Growth. Urology 2012;79:123-7.
Published online in Fertility and Sterility doi:10.1016/j.fertnstert.2013.06.025