While other studies have shown that cancer treatment can increase patients’ chances of developing the disease later in life, this is one of the first known studies to show that susceptibility can be passed down to third generations.
In the study, researchers exposed a number of young male rats to ifosfamide for three days, mimicking the course of treatment that an adolescent human cancer patient might receive. Those rats were then bred with untreated female rats. The resulting offspring were re-bred with another set of unexposed rats.
Advertising
The first-generation offspring had some exposure to the chemotherapy drug after being exposed to their father’s sperm, but the researchers found that the disease was more common in the second generation than in the first generation, which was not directly exposed to the drug.
Although there are some differences by generation and sex, associated problems include a higher incidence of kidney and testicular disease, as well as delayed puberty and abnormally low anxiety, suggesting a reduced ability to assess risk.
Chemotherapy can increase susceptibility to the disease for two generations
The researchers also analyzed the rats’ epigenomes, which are molecular processes that do not depend on DNA sequence, but on gene expression, including turning genes on or off. Previous studies have shown that exposure to toxicants, particularly during development, can cause epigenetic changes that can be transmitted through sperm and egg cells.
The results of the researchers’ analysis showed epigenetic changes in two generations associated with chemotherapy exposure of initially exposed rats. The fact that these changes appear in an older generation without direct exposure to the chemotherapy drug suggests that the adverse effects are transmitted through epigenetic inheritance.
The findings suggest that if a patient receives chemotherapy and then has children, their grandchildren and even great-grandchildren may be more susceptible to the disease because of their ancestors’ exposure to chemotherapy.
The researchers stressed that the findings should not deter cancer patients from chemotherapy, as it can be a very effective treatment.
Chemotherapy drugs kill cancer cells and prevent them from multiplying, but they have many side effects because they affect the whole body, including the reproductive system.
Given the results of this study, researchers recommend that cancer patients who plan to have children later take precautions, such as using cryopreservation to freeze sperm or eggs before starting chemotherapy.
Better knowledge of the epigenetic changes of chemotherapy may also help inform patients about the likelihood of developing certain diseases, enabling earlier prevention and treatment strategies.
Source: Eurekalert
