February 24, 2016

expert reaction to reports of US court decision on case of talcum powder use and ovarian cancer

A court in the US has ordered Johnson & Johnson to pay damages of $72m to the family of a woman who died of ovarian cancer which it is claimed was caused by genital use of the company’s baby powder talc.

Prof. Paul Pharoah, Professor of Cancer Epidemiology, University of Cambridge, said:

“In my view the decision of the court is flawed for two reasons. First, the evidence of a causal association between genital talc use and ovarian cancer risk is weak. Second, even if the association were true, the strength of the association is too small to be able to say on the balance of probabilities that any cancer arising in a woman who used talc had been caused by the talc.

“Around 7,000 women are diagnosed with ovarian cancer in the UK each year. This makes ovarian cancer the 5th most common cancer in women, after breast, lung, bowel and womb cancer. Not all ovarian cancer is the same. There are several different types of ovarian cancer – serous, endometrioid, clear cell and mucinous being the main ones – and these have different risk factors and clinical features.

“The main risk factors are hormone replacement therapy use, being overweight, and having endometriosis. Smoking is associated with one of the rarer types of ovarian cancer – mucinous ovarian cancer. There are several genetic variants that are associated with an increased risk. Faults in the BRCA1 and BRCA2 genes in particular are associated with high risks.

“The use of the oral contraceptive pill during early adulthood is associated with a 50 per cent reduction in risk of ovarian cancer that persists many years after stopping the pill. Pregnancy and breast feeding are also associated with a reduction in risk, as is tubal ligation (a form of sterilisation commonly referred to as having the tubes tied).

“A possible association between talcum powder use and risk of ovarian cancer has been reported for many years. This association was based on case-control studies, which are rather prone to bias. A recent multi-study collaborative analysis of over 8,000 cases and 9,000 controls found that perineal talc use was associated with a 20% increase in the risk of ovarian cancer. There was no difference in the risk of the different types of ovarian cancer.

“Prospective studies are less prone to bias than case-control studies, though they are not bias free. There have been two prospective studies investigating this association. One found a significant association with risk of the serous type of cancer, and the other found a non-significant increase in risk of the serous type of ovarian cancer. The results of both these studies were compatible with the 20% increase in risk reported by case-control studies.

“The association is biologically plausible. Talcum powder applied to the genital area might get into the fallopian tubes and onto the ovaries and cause inflammation, which in turn could cause ovarian cancer.

“On balance, I think that it is more likely than not that there is an association between genital talc use and risk of some types of ovarian cancer, however it’s important to remember the size of the possible risk – a 20 year old woman in the UK has a risk of getting ovarian cancer at some point in her life of 18 in a thousand; a 20% increase in this risk would raise this to 22 in a thousand (assuming that the association were real).  A woman with a fault in the BRCA1 gene has a lifetime risk of ovarian cancer of about 400 in a thousand.”

Declared interests

Prof. Paul Pharoah: “I receive research funding from Cancer Research UK and the National Institutes of Health to fund my research programme in ovarian cancer.”