No Increased Risk of Womb or Breast Cancer After Fertility Treatment

No increased risk of womb cancer or invasive breast cancer was associated with assisted reproduction, compared with the general population, found new study.

Fertility treatments alone dont increase the risk of womb or breast cancer, revealed study of over 250,000 British women published by The BMJ today.

Assisted reproduction is practiced worldwide and more than five million children have been born as a result. But it usually involves exposure to high levels of hormones, which can carry an increased risk of breast, endometrial (womb), and ovarian cancers.

Breast Cancer Screening using Mammogram
Breast cancer if detected early can be completely cured. Mammography is used to screen women for breast cancer.

‘Small increased risks of non-invasive breast and ovarian tumours were found, but the researchers say these results may not be due to the treatment itself and require further investigation.’

Results of previous studies on risks of reproductive cancers in women who have undergone assisted reproduction are inconsistent. So a team led by Professor Alastair Sutcliffe at UCL Great Ormond Street Institute of Child Health in London, set out to investigate the risks of ovarian, breast and womb (corpus uteri) cancer in women who have had assisted reproduction.

Using Human Fertilisation and Embryology Authority (HFEA) records, they identified all women who had assisted reproduction in Britain between 1991 and 2010 and then linked this information to national cancer records.

In total, 255,786 women were followed up over an average of 8.8 years. Average age at first treatment was 34.5 years and women had an average of 1.8 treatment cycles.

Invitro Fertilisation
During IVF fertilization takes place invitro, in an incubated petri dish. The resulting embryo is transferred back to the uterus on Day 3 at the 6-8 cell stage. Sometimes the embryo transfer in done at the blastocyst stage on Day 5. The embryo is drawn into a specialized catheter along with a small amount of culture medium and is transferred to the uterus.

Cause of infertility involved at least one female factor in 111,658 (44%) women. Infertility was unexplained in 47,757 (19%) women, and was due only to male factors in 84,871 (33%).

An increased risk of non-invasive (in situ) breast cancer was detected (absolute excess risk of 1.7 cases per 100,000 person years), which was associated with an increasing number of treatment cycles.

Drug that Treats Breast Cancer may Up Womb Cancer Risk
Breast cancer patients have an increased risk of developing endometrial (womb) cancer with an extended use of tamoxifen treatment.

An increased risk of ovarian cancer, both invasive and borderline, was also detected (absolute excess risk of 5 cases per 100,000 person years), but this was limited to women with other known risk factors, suggesting this may be due to underlying patient characteristics, rather than assisted reproduction itself.

The researchers found no overall increased risk of womb cancer.

Quiz on Male Infertility
Infertility affects 1 in 6 couples who are trying to conceive. In about 50% of these cases, male infertility is a major contributing factor.

Many disorders and factors could contribute towards male infertility and treatment pattern may vary in several cases. However, in many instances treatment may also not work at all. Infertility may be attributed to testicular damage and thereby affecting its ability to produce sperm. In such cases, testicles may not gain its usual sperm-making ability back and thus can't be treated. Other than testicular damage, prime causes of male infertility are less sperm production and poor sperm quality.

They point out that this is an observational study, so no firm conclusions can be drawn about cause and effect, and they outline some limitations that could have affected the results. However, strengths include the large sample size and long follow up period, which enabled them to adjust for potentially influential factors. And they conclude that ongoing monitoring of these important outcomes in this ever growing population is essential.

Source-Eurekalert