Late Effects of the Reproductive System
The treatment of cancer in children and adolescents may adversely affect their subsequent reproductive function. Germ cell survival may be adversely affected by radiation therapy and chemotherapy. Ovarian damage results in both sterilization and loss of hormone production because ovarian hormonal production is closely related to the presence of ova and maturation of the primary follicle. These functions are not as intimately related in the testis. As a result, men may have normal androgen production in the presence of azoospermia.
Surgery, radiation therapy, and/or chemotherapy may damage testicular function. Patients who undergo unilateral orchiectomy for testicular torsion may have subnormal sperm counts at long-term follow-up.[1,2] Retrograde ejaculation is a frequent complication of bilateral retroperitoneal lymph node dissection performed on males with testicular neoplasms,[3,4] and impotence may occur following extensive pelvic dissections to remove a rhabdomyosarcoma of the prostate.
Men treated with whole-abdomen irradiation may develop gonadal dysfunction. In one study, five of ten men were azoospermic, and two were severely oligospermic when evaluated at ages 17 to 36 years following treatment with whole-abdomen irradiation for Wilms tumor at ages 1 to 11 years, with the penis and scrotum either excluded from the treatment volume, or shielded with 3 mm of lead. The testicular radiation doses varied from 796 cGy to 983 cGy. Others reported azoospermia in 100% of ten men 2 to 40 months after radiation therapy doses of 140 cGy to 300 cGy to both testes. Similarly, azoospermia was demonstrated in 100% of ten men following testicular radiation therapy doses of 118 cGy to 228 cGy. Recovery of spermatogenesis occurred after 44 to 77 weeks in 50% of the men, although three of the five with recovery had sperm counts below 20 x 106 /ml. Oligospermia or azoospermia was reported in 33% of 18 men evaluated 6 to 70 months after receiving testicular radiation doses of 28 cGy to 135 cGy. In another report, none of five men who received testicular radiation doses of less than 20 cGy became azoospermic. By contrast, two who received testicular radiation doses of 55 cGy to 70 cGy developed temporary oligospermia, with recovery to sperm counts greater than 20 x 106 /ml 18 to 24 months after treatment. In summary, a decrease in sperm counts can be seen 3 to 6 weeks after irradiation, and depending on the dosage, recovery may take 1 to 3 years. The germinal epithelium is damaged by much lower dosages (<1 Gy) of radiation than are Leydig cells (20–30 Gy). Complete sterilization may occur with fractionated irradiation greater than doses of 2 Gy to 4 Gy.
Administration of higher radiation doses, such as 2,400 cGy, which was used for the treatment of testicular relapse of acute lymphoblastic leukemia (ALL), results in both sterilization and Leydig cell dysfunction. Craniospinal irradiation produced primary germ cell damage in 17% of 23 children with ALL, but in none of four children with medulloblastoma. Total-body irradiation ([TBI] 950 cGy to 1575 cGy) and cyclophosphamide (60 mg/kg/day for 2 days) produced azoospermia in almost all men.