Cancer and Fertility: Why Men Should Take Preventive Measures Early On

A cancer diagnosis brings with it numerous physical and emotional challenges. For many men, however, there is another important question: Will I still be able to become a father later on? In fact, both the cancer itself and its treatment can significantly impair male fertility. For this reason, oncologists often recommend freezing sperm before treatment begins. So-called cryopreservation is now considered the most important measure for preserving the chance of future biological fatherhood.

How Cancer Can Affect Fertility

Many people assume that it is primarily cancer treatment that affects fertility. In fact, however, the cancer itself can significantly impact sperm production—even before treatment begins.

Cancer affects not only the local area but the entire body. The body often reacts to the disease with inflammatory processes, hormonal changes, and altered metabolic conditions. At the same time, weight loss, loss of appetite, and general weakness can cause the body’s energy balance to become disrupted. All these factors can impair the delicate process of sperm formation in the testicles, as this is highly dependent on a stable hormonal and physical environment.

These connections are particularly well documented in systemic diseases such as leukemias and lymphomas. These blood cancers affect the entire body and often lead to significant strain caused by inflammatory reactions and stress hormones. As a result, sperm quality may already be reduced at the time of diagnosis.

In addition, many patients with severe cancers suffer from a generally weakened state of health anyway. This so-called “systemic stress” can further impair testicular function and reduce both the number and the motility of sperm. In some cases, therefore, significantly impaired fertility values are already evident in the semen analysis before therapy begins.

Cancer Treatments can Cause Permanent Damage

In addition to the disease itself, cancer treatments in particular pose a risk to fertility. Chemotherapy specifically targets rapidly growing cells. However, since the cells from which sperm are produced also divide particularly rapidly, they are often damaged as well. The consequences range from a temporary reduction in sperm count to permanent limitations on fertility.

Radiation therapy can also affect the testicles or other reproductive organs. Depending on the radiation dose and the area treated, the damage can be temporary or permanent. In addition, certain surgeries—particularly procedures in the pelvic area or the removal of lymph nodes in cases of testicular cancer—can impair ejaculation and thus limit natural fertility.

Testicular Cancer Frequently Affects Men of Reproductive Age

The issue of fertility is particularly relevant in cases of testicular cancer. It is the most common solid cancer in men between the ages of approximately 15 and 40 and thus often occurs at a stage of life when many affected individuals have not yet started a family or have not yet completed their family planning. According to estimates, up to half of patients already have impaired sperm counts before treatment begins. This means that fertility is often already compromised by the disease itself and not just by chemotherapy, radiation, or surgery.

Although testicular cancer usually affects only one testicle, the disease can have far-reaching effects on the entire reproductive system. Researchers suspect that hormonal changes, inflammatory processes, and other systemic stresses on the body can impair the function of the healthy testicle. This can reduce both the sperm count and the motility and quality of the sperm.

In addition, some patients may already be suffering from impaired testicular function prior to diagnosis. Scientists have been discussing the so-called “testicular dysgenesis hypothesis” for years, according to which certain developmental abnormalities of the testicles could increase the risk of both testicular cancer and fertility problems. This would explain why some men already show abnormalities in their semen analysis before cancer treatment.

Treatment can further exacerbate the situation. While the surgical removal of a diseased testicle does not completely impair fertility in many men, chemotherapy, radiation therapy, or further surgeries can significantly reduce sperm production or even cause permanent damage. For this reason, specialists often recommend considering measures to preserve fertility immediately after diagnosis and, if possible, having sperm cryopreserved before the start of therapy.

Freezing Sperm as a Precaution

Experts consider sperm cryopreservation to be the gold standard for preserving fertility. The procedure is relatively straightforward: The patient provides one or more semen samples at a fertility clinic, which are then frozen and can be stored for many years.

If the desire to have children arises later, the samples can be thawed and used in assisted reproductive technologies such as in vitro fertilization (IVF) or intracytoplasmic sperm injection (ICSI).

Many clinics have now developed standardized procedures to ensure that as little time as possible is lost between the cancer diagnosis and the start of treatment. Often, the referral for sperm preservation occurs automatically immediately after diagnosis.

In addition, shipping solutions are now available. The patient receives a special collection kit at home, can collect the sample in a private setting, and then send it via express shipping to a laboratory, where it is prepared for long-term storage.

If No Sperm Was Frozen Before Treatment

Not every patient has the opportunity to freeze sperm before starting cancer treatment. Sometimes the therapy is so urgent that there is no time for fertility preservation measures. In other cases, the issue only becomes relevant after treatment has begun or been completed, when the desire to have children becomes more concrete.

However, even after surviving cancer, there are often still options available. The first step usually involves a semen analysis to determine whether sperm are present in the ejaculate. If no sperm are found, doctors refer to this as azoospermia.

In such cases, a microsurgical procedure may be considered: microdissection testicular sperm extraction (microTESE). In this procedure, the testicular tissue is systematically examined under a surgical microscope to locate even the smallest areas of active sperm production. Even if sperm production is severely limited overall, there may still be functioning “islands” in individual tissue regions.

If sperm are discovered there, they can be retrieved, frozen, and subsequently used for assisted reproductive technologies such as IVF or ICSI. This means that some patients still have the possibility of fathering a biological child despite severe fertility limitations. microTESE is therefore considered an important option in modern reproductive medicine, particularly for men in whom no sperm is initially detectable in the ejaculate following cancer treatment.

The Search for the Last Sperm

During a microTESE procedure, the surgeon examines the testicular tissue under high-magnification microscopy. The goal is to identify the smallest areas where sperm are still being produced despite prior cancer treatment.

Even if these quantities are too small to be detectable in the ejaculate, individual sperm can often be retrieved directly from the testicle. If such cells are found, they can be frozen and later used for artificial insemination. For many men, this represents the last chance to have children with their own genetic material.

Successful procedures can create very moving moments. Reproductive medicine specialists frequently report cases of patients who were initially considered infertile following intensive cancer treatments but in whom individual sperm could be found through microTESE. In combination with modern IVF procedures, the birth of a healthy child is still possible in some cases.

Hope Despite Cancer

Advances in reproductive medicine have significantly expanded the options for preserving fertility in recent years. While cancer can significantly impair fertility, a cancer diagnosis today does not necessarily mean the end of the hope for children. Early consultation and timely planning of fertility-preserving measures can play a decisive role in ensuring that men retain the chance to start a family of their own even after successful cancer treatment.