What This New Study Wants Us To Know About Hormones & ART

Some types of assisted reproductive technology (ART) expose women to high levels of estrogen and progesterone during treatment. Sometimes, women need multiple cycles of treatment for a successful pregnancy, which means being repeatedly exposed to these hormones.

So should you be worried? After all, hormone imbalances have been connected to many negative side effects and medical conditions, including cancer. More specifically, elevated levels of estrogen and progesterone are associated with breast, uterine and ovarian cancers. Fertility treatments are supposed to be helping women, but are they really putting health at risk?

The answer is more complicated than yes or no. Ahead, we’ll discuss a recently published study by the British Medical Journal, which specifically tracks evidence of cancer in British women who received fertility treatment.

• What’s the story?
• The bad news
• Does ART cause cancer?
• For the long-term

What’s the story

Alastair Sutcliffe, a professor at University College London Institute of Child Health, and his research team observed over 250,000 British women who used ART over the course of nine years to see if they, more than untreated women, developed cancer as a result. On average, the women underwent two treatment cycles. Of course, all these women had different situations that affected their overall success with pregnancy and the likelihood of developing cancer.

But overall, Sutcliffe and his team couldn’t find concrete proof that fertility treatments increased the risk for cancer. The results found no significant increase in the risk of breast or uterine cancer - two of the most common cancers associated with elevated hormone levels.

But that doesn’t mean guaranteed safety.

The bad news

Beware with pre-existing conditions

Women with pre-existing medical conditions such as polycystic ovary disease (PCOS) or endometriosis still found invasive and borderline ovarian tumors more frequently than women without those conditions. By “invasive and borderline,” we’re talking about malignant and potentially malignant tumors - the kind that could hurt you.

But certain pre-existing medical conditions like PCOS and endometriosis already involve skewed hormone levels. Without interference from fertility treatment, these women’s hormone levels were already off, so their tumors can’t outright be blamed on fertility treatments. “Those women were already known to be at high risk of ovarian cancer, and the finding didn’t seem to be due to those [fertility] treatments,” Sutcliffe explains.

More selectively bad news about a special type of breast cancer

Overall, fertility treatments didn’t equal an increased risk of breast and uterine cancer. However, there was an increase in one type of breast cancer.

The results suggested that the risk of in-situ breast cancer, which is considered a very treatable localized breast cancer, depended on the number of treatment cycles. According to the study, the more cycles women had, the more likely they were to develop in-situ breast cancer.

Sutcliffe approached the data cautiously, pointing out the possibility that increased surveillance could have been a contributing factor in realizing the increase in-situ breast cancer. If they hadn’t been watching so closely, the in-situ breast cancer might have gone overlooked.

So does ART cause cancer?

Cause is a strong word. While no significant increase in reproductive organ cancers have been noted, certain increases have been noted in:

• Women with pre-existing conditions developing cancer 

The research team can’t differentiate the effect of pre-existing conditions versus fertility treatments on women’s health. However, because it’s difficult to separate the two in this study, ART can’t be conclusively blamed.

• Many treatment cycles leading to a small increased risk of in-situ breast cancer. 

So while these two conditions are associated with cancer, that’s all it is - an association. The actual reason that these women develop cancer could be a combination of associated factors rather than one particular cause. Medical research is often not translated to a one-on-one cause and effect conclusion.

Dr. Wendy Kuohung, the director of the reproductive endocrinology and infertility program at Boston Medical Center, says it best. “We tell patients that we aren’t sure whether these fertility treatments will increase the risk of breast, uterine, or ovarian cancer because their diagnosis of [and reason for] infertility at baseline may be predisposing them.”

For the long-term

Though this study may have drawn new conclusions about the link between certain cancers and ART, more studies are needed to confirm these findings. Often, experiments and studies need to be repeated, mimicked, and further investigated before they’re absorbed into practice and considered as facts.

Sutcliffe is already looking ahead. Past this study and on to the next, he is considering other health factors affected by fertility treatments and hoping to research their effect on heart disease and mental health.

The takeaway? Women should discuss with their physician about the effect that fertility treatments could have on their bodies. Generally, medical practitioners urge patients to seek fertility treatment counseling to fully understand all their options and the risks associated with each method. While no clear declarations could be made about the association of fertility treatments with cancer, your specific situation could be less or more at risk.