The effect of hormonal contraception on the process of carcinogenesis is still a controversial issue and research is still being conducted in this direction. The lack of conclusive data on this subject is due, among other things, to the fact that there are a large number of factors that can influence the initiation of cancer, or to the too short period of follow-up of women using modern hormonal contraception.
Endometrial cancer and ovarian cancer
Ovarian cancer and endometrial cancer occur much less frequently than the cancers listed above. Based on research to date, it appears that hormonal contraception may increase the risk of cervical cancer and breast cancer, but decrease it for endometrial and ovarian cancer. Women's use of hormonal contraception may have an impact on the global decrease in these cancer types. Women using oral hormonal contraception were found to have a twofold lower risk of developing these cancers and this decreased with the length of use of the method. After five years of using hormonal methods, the risk of the disease decreases by two-thirds.
It is most likely that methods that reduce the frequency of ovulation also reduce the risk of cancerous changes in the ovary, while the gestagen component of contraceptives has a protective role against endometrial cancer. The protective effect persists for up to 15 years after cessation of oral hormonal contraception. Both the binary pill and the gestagen pill, used most often in women over 40 years of age, with contraindications to oestrogens and breastfeeding, also reduce the risk of endometrial and ovarian cancer. In the case of progestogen injections, the analyses carried out did not show a reduction in risk as regards ovarian cancer, but did show a reduction in the incidence of endometrial cancer.
Before starting hormonal contraception, it is important for the doctor to take a thorough history of the patient. Based on the information obtained, he or she will be able to determine a woman's current cancer risk factors. It is not without significance to obtain information on family history of cancer. Hormonal contraception may increase the risk of cancer, particularly in those with gene damage that may be a cause of a woman's susceptibility to breast, ovarian, endometrial, colorectal, thyroid or malignant melanoma cancers.
The test that detects damaged genes is the HTGR test. Having abnormal gene mutations is a contraindication to the use of hormonal contraception. It should be mentioned that there is little research into the risk of cancer in the second and subsequent generations, which is certainly related to the fact that modern hormonal contraceptives containing low doses of hormones have only been in use for a relatively short time and probably not enough time has elapsed yet to have scientific data on their distant effects on the body of people with various risk factors.
