The study looked at male cancer patients who froze their sperm before starting treatment that could affect their fertility. The researchers sent surveys to 99 patients who froze sperm between 1994 and 2017. Most patients had testicular cancer or lymphoma. They found that patients with testicular cancer had lower sperm counts before treatment than those with other types of cancer. About 17% of the patients used their frozen sperm, and 58% of couples had a baby using this method. Patients who had less harmful treatments were more likely to have children naturally after cancer treatment. This study shows that freezing sperm is essential for preserving fertility in male cancer patients, and the type of cancer treatment can affect the chances of success.