Infertility occurs in about one in six couples. Cancer occurs in approximately one in three women.
Of the cancers of the sex organs, breast cancer is most common, occurring in one in eight Barbadian women.
The cause, or aetiology of breast cancer is unknown. Various factors or diseases make breast cancer more likely. Breast cancer in a mother or sister increases the risk, as does some types of non-cancerous (benign) breast lumps.
Breast cancer is more common in infertile women. Some medical research suggests that cigarette smokers are at increased risk.
Monthly breast self-examination is recommended for all women. All lumps should be investigated immediately. Most breast lumps are benign.
There is no screening method for breast cancer, although mammography detects small cancers.
Occurs in about one in 90 women. Its aetiology is also unknown.
May also occur in families in 10-15% of cases.
It is more common in infertile women.
The oral contraceptive pill decreases the risk of cancer of the ovaries. This remarkable advantage of “The Pill” occurs, not only while the woman takes The Pill, but also for at least five years after stopping The Pill. There is no effective screening method for ovarian cancer. Every woman is advised to have a gynecological examination and “Pap Smear” every two years to minimize the risk of ovarian, uterine and cervical cancers going undetected.
The lifetime risk of cervical cancer is one in 95 women.
Cervical cancer can be screened by cervical cytology, by the Pap smear.
The aetiology of cervical cancer is related to sexual activity. For this reason, every woman having sexual intercourse should have a Pap smear every two years. An increased number of sexual partners and a papilloma or wart virus infection can also increase the general risk of development of cervical cancer.
A Pap smear every two years, as well as regular gynecological and breast examinations, are currently the best methods to prevent or detect women’s cancers.
Cancer After Infertility and IVF
Doctors have used fertility drugs worldwide since the 1960s, triggering women’s ovaries to produce eggs. This approach proved successful in assisting many women with fertility problems to become pregnant and have children.
In the past 20 years the use of fertility drugs has increased markedly following the development of IVF.
Findings of an Australian Study relating to incidence of Cancer and IVF.
The growth in the number of women seeking help to become pregnant provided an opportunity for a study, the largest of its type anywhere in the world.
The study followed up 29,700 women referred to any of ten participating Australian IVF clinics between 1978 and 1993. Of this total:
– 20,656 women received fertility drugs during IVF (the “treated group”)
– 9,044 women referred for IVF did not end up having fertility drug treatment (the “untreated group”).
– Depending on the year that women joined an IVF program, the duration of follow-up ranged from one to 22 years, with the majority followed up for five to ten years.
This study was conducted to address concerns that the use of fertility drugs might be associated with an increased risk of cancer.
To see whether there was any increase in the number of cancers of the breast, ovary and uterus in women on IVF, compared with the number expected among women of the same age, followed up over the same period in the general population.
In the event that there were more of these cancers than predicted, how this might be explained.
The major finding was that cancers of the breast and ovary were no more common in IVF patients overall than in the general population. Of 29,700 who joined IVF programs, researchers predicted 155 breast cancers and found 143. For ovarian cancer, 13 cases were predicted and 13 were found.
Cancers of the uterus were more common than predicted in untreated IVF patients but were no more common than predicted in the treated group. (Among the 9,044 women in the untreated group, three cases were predicted and seven found).
More women than predicted in the treated group had breast cancer diagnosed in the first year after treatment with fertility drugs. This finding disappeared with time and is discussed below. (Among the 20,656 women, 9 breast cancer cases were predicted in the first year after treatment and 17 were found.)
Women with unexplained infertility had a significantly higher incidence of ovarian and uterine cancer, whether or not they were exposed to fertility drugs, than the general population. (Out of 3,800 women with unexplained infertility, two cases of ovarian cancer were predicted and five were found. With regard to uterine cancer, one case was predicted and five were found).
There was no evidence of any link between the number of treatment cycles or type of fertility drug used and increased cancer incidence. Changes in the types of drugs used in IVF and the amount of ovarian stimulation do not appear to have had an overall impact on cancer in participating women.
The findings provide reassurance that the incidence of breast and ovarian cancers in IVF patients are the same as that for women of the same age in the general population when considered over a five to ten-year period.
The evidence of increased numbers of cancers above, predicted in small numbers of women, in particular subgroups, needs further study. While there was no overall increase, the occurrence of above expected numbers of breast cancer in the first year after treatment is consistent with other research showing a small increase in diagnoses of breast cancer shortly after women give birth. The same effect has been seen in recent users of The Pill and hormone replacement therapy. Possible explanations for this finding after IVF treatment include earlier detection of abnormal breast changes due to close medical supervision, the biological effects of fertility drugs, or both.
Explanations for the relationship between unexplained infertility and the increase in ovarian and uterine cancers are harder to come by but research is continuing. In a bid to explore such issues, the research team has started a more detailed investigation of about 700 IVF patients, some of whom have cancer and others who do not.
The risk of cancers in women is best reduced through regular women’s health check-ups, breast examination, Pap smears and gynecological examinations – and by the use, at other times, of The Pill. The most effective way of minimizing the risk of breast and ovarian cancers in infertile women is to help them to have a baby. However, the study does reinforce the importance of women having medical check-ups at regular intervals after fertility treatment.