Fertility Preservation In Gynecologic Cancer Patients
An important aspect in cancer care in men and women below 40 years is that apart from the cancer management, fertility preservation should also be thought of simultaneously. With better management of various cancers, survival has improved tremendously and thus life expectancy in pre menopausal women is also improved, resulting in large number of growing population of cancer survivors. They may face problem of infertility due to several reasons. Overall statistic shows that one in 250 cancer patients are young cancer survivors. 8-10 % of cancer patients are below 40 years and 1% below 20 years. There are three ways in which cancer is treated. Surgery, Radio therapy and chemotherapy separately or in combination.
SURGERY – Mostly, we remove reproductive organs when a diagnosis of cancer is made in any part of reproductive tract. In recent years the tendency towards more conservative treatment is prevalent. For cancer of the cervix, in young women desiring kids, conservative surgery like conisation or Radical Trachelectomy is advised for early disease. Endometrial cancer is treated with high dose of hormone therapy instead of hysterectomy when patient is young and disease is in early stage. For ovarian cancer conservative treatment is advised in very early ovarian cancers, border line malignancy or germ cell tumors.
CHEMO THERAPY- It produces significant effect on patient’s fertility by their cyto toxic effect on oocytes. The extent of damage depends on dose and type of drugs used, single or combination and age of the patient. Chemo-therapeutic drugs are of three types – low risk, intermediate risk or high risk. Low risk drugs have least toxicity and may be used whenever possible. Another way of reducing toxicity in the oocyte is by suppressing ovarian function with drugs like GnRh Agonists.
RADIO THERAPY- A dose of 6 Gy in women less than 30 years or 14.3 Gy over 30 years can damage the oocytes. Radio therapy causes reduced blood supply to the uterus causing atrophy of endometrium resulting in difficulty in implantation of fertilized embryo. Ovarian transposition can be done prior to starting radiation treatment, where ovary is removed from the radiation field and can be protected.
CRYO PRESERVATION OF EMBRYOS: It is most recent technology which has given good results. Embryo survival upto 95% and success of embryo transfer in 60% of patients.
CRYO PRESERVATION OF OOCYTES: Unfertilized oocytes are cryo preserved. Although, single oocyte can be preserved but for better result, multiple oocytes should be obtained after ovarian stimulation. Success rates of upto 27% have been obtained.
OVARIAN TISSUE CRYO PRESERVATION: This is most difficult. Cortical strips from ovary are removed laproscopically or during laparotomy and cryo preserved. As and when pregnancy is required, this tissue is implanted in the pelvis or subcutaneously. Oocytes are harvested, fertilized and implanted in the uterus.
Despite the progress that has been made, the preservation of fertility in cancer patients is an emerging discipline; more awareness is required among oncologist, immunologist and endocrinologist. The patient should be counseled for option of fertility preservation at the outset.