New Evidence That IVF Is Linked To Higher Rates Of Breast Cancer– A Leading Expert Explains Why Women Shouldn’t Necessarily Be Alarmed

The study, which was presented at the European Society of Human Reproduction and Embryology conference in Vienna, involved 59,000 women who had fertility treatment, and 567,000 females of equal age who had not. Over the 21 year period that the study spanned, less than 1 percent of the total 626,000 women were diagnosed with breast cancer, with those who had utilized IVF getting the disease at a higher rate.

But candidates for in vitro fertilization may already be at a higher risk for breast cancer than other women their age. “Women who have not achieved a pregnancy by the time they are forty, are at a much higher risk for breast cancer,” says Dr. Knopman.

Part of the reason has to do with the amount of time women spend producing eggs. “The menstrual cycle of hormones does place someone at risk for breast cancer,” says Dr. Knopman. “When you are pregnant, you are ten months out of the period game– then breast feeding.” As a result, pregnancies can help protect against cancer, by reducing the amount of period cycles women go through during their childbearing years.

And there may be another way that the data suggesting IVF is linked to cancer gets skewed. “People who do in vitro fertilization also have a better follow up, because when people come in for in vitro fertilization, we make them get a mammogram. That may put diagnoses at a falsely higher level.”

In other words, breast cancer may be detected at a higher rate in women who have had in vitro fertilization than in women who haven’t, since women who get in vitro get screened more frequently than others. That could impact the results to make it seem like they are being diagnosed with breast cancer at a higher rate.

Knopman also notes that the type of cancer that she sees most commonly with in vitro patients is very early stage, and can usually be treated if detected. “The cancers we see are ductal carcinoma in situ, meaning it was already there in a lot of cases, but the meds just brought it out. Likely, the cancer was there, and it may have grown due to the estrogen after IVF.”

Ductal carcinoma in situ (DCIS), also known as stage zero breast cancer, refers to cancer that's confined to the breast milk duct. There are two important facts about DCIS breast cancer:

1. It doesn't spread to other parts of the body.

2. The risk of death is essentially zero.

 

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