An article in press in Fertility and Sterility is getting a lot of media attention. The study connected men seeking infertility care to a cancer registry in the State where the clinic was located. The researchers found that men with infertility had almost twice the chance of getting cancer and almost three times the chance if the man had no sperm in his ejaculate.
The authors of the study have a few theories about why cancer and male infertility may be connected. Cells need to divide just right to make sperm in the testes, and problems with division could lead to both problems with making sperm and the kind of bad division that makes cancer. It could also be that toxic substances in the environment may lead to both infertility and cancer.
Whatever the reason, we’re beginning to understand that problems with male fertility are just a tip of a much bigger iceberg that involves health in general. It’s more than just about the testicles.
The U.S. Preventative Health Task Force is issuing guidelines today about the blood test PSA and its use in screening for diagnosis. While I respect those doctors involved in making the guidelines, I don’t entirely agree that PSA shouldn’t ever be used. ABC Chicago interviewed me this morning, and the segment can be found here.
It’s a big day for sperm science. In the journal Nature today, scientists from Japan describe how they were able to mature mouse sperm in a petri dish outside of the testis.
The sperm assembly line is a complicated series of steps that takes about two months from start to finish. Sperm start off as big, round immature cells called “spermatogonia” whose main job is to multiply. At some point, cells decide to turn into full-fledged sperm, becoming cells known as “spermatocytes”. A spermatocyte splits into halves, becoming a “spermatid” in a process called meiosis, which will allow its precious genetic cargo ultimately to combine with its complementary other half waiting in an egg. The spermatid half cells finally transform their shape, growing propellers, outboard motors and egg-digesting caps in becoming “spermatozoa”.
Until now, scientists were unable to get immature sperm cells to grow outside the body into those exquisitely shaped torpedo half cells. That’s where Takuya Sato and fellow scientists have succeeded. By carefully controlling the conditions for the growing sperm’s bed, these scientists discovered how to make mature sperm outside the body.
The practical implications are enormous. Sperm can be frozen before chemotherapy to spare a man’s fertility, but only from an adult man already making mature sperm. We don’t yet have a similar way to preserve the future fertility of a boy who has yet to go through puberty, and this discovery may someday allow doctors to freeze a small piece of testis from a boy about to have chemotherapy and then mature his sperm in a petri dish later in his life. For men with “maturation arrest“, where the sperm assembly line stops midstream, it might be possible to grow their sperm to completion in a petri dish, and use the grown sperm in in-vitro fertilization.
The distance between Sato and his fellow scientists’ discovery and practical use is not small. Men are different than mice, and trying to shepherd science into the doctor’s office always brings unforeseen challenges. But this discovery is a big leap for sperm science.
A writer for the NCI Cancer Bulletin interviewed me yesterday about Dr. Peter Schlegel’s recent article in the Journal of Clinical Oncology reporting success in getting sperm using microdissection testis sperm extraction from the testis of men who have had chemotherapy for cancer. Even if no sperm were found on testis biopsy, sperm could still be retrieved from a number of men using the microdissection technique. About two of every five men had a successful retrieval that had chemotherapy in the past.
That’s great news for the men who had chemotherapy for cancer who were lucky enough to have a successful sperm retrieval, and says a lot about how far we’ve come in retrieving sperm even in difficult conditions. But the best option would have been to have sperm frozen before beginning chemotherapy. Unfortunately, even today only about half of medical oncologists discuss freezing sperm with men before chemotherapy. There’s no good reason for that fact: a man can freeze sperm without delaying chemotherapy, and if he does, he can preserve his ability to have children in the future.
Medical oncologists save lives with cancer treatment. A life saved should be a full one, with a family if a man so desires. If you’re a medical oncologist, please talk about freezing sperm with men before beginning chemotherapy. If you’re a man facing the challenge of cancer and want to preserve your fertility, ask your doctor about freezing sperm.