432
Where does talc come from?
The likely reason you are reading this post is because you have come across the news about courts in the United States (US) ordering multinational company Johnson & Johnson (J&J) to payout millions to litigants over the past few months. So far, there are three separate verdicts in US based courts that have associated J&J’s baby powder with ovarian cancer. While official statements from the company have said that these verdicts will be challenged in the higher court, there are over 1000 such lawsuits that are pending in the courts and litigants and their legal counselors are waiting to get similar verdicts in the future.
The gist of all three verdicts is that the all complainants or litigants were users of J &J’s talcum powder for two to three decades to keep their genital region dry and odorless and developed ovarian cancer. The complaint also said that the company was well aware of the risks that the talcum powder carried and the company failed to notify the users of potential hazards.
Pictoral representation of ovarian cancer. Image credit: Genetics Home Reference (GHR) |
While court verdicts always come with a lot of legal jargon, technicality and other subtleties, the major questions remain:
- Is the company’s talcum powder actually carcinogenic?
- Does is cause ovarian cancer? And
- Should we continue to use the powder on children as the cases progress?
To answer these questions we need to go back in the past the first studies came out linking ovarian cancer with use of talcum powder. It all began in 1971 when Henderson et al reported finding talc in human ovarian cancer tissue. Back then, laboratory and surgical gloves were dusted with talcum powder to keep them from sticking to each other and to their inner walls and therefore the authors followed up their initial report with a short publication in 1979 in the Lancet reaffirming that the talc they found in the tissue was for real and not a result of contamination. Ovarian cancer was still fairly new then, its aetiology was unknown and everything that a patient came in contact with was a suspect. It is interesting to note that the Lancet report does end saying that regular talcum powder usage/ exposure would not lead to cancer. Needless to say, this was a preliminary report, almost 50 years ago.
Where does talc come from?
The reason why talc was a big deal in this paper was because of the potentially harmful effects it can have on the human cells. First and foremost, talc, a mineral of magnesium and silicon, needs to be mined and can found be found with the infamous, asbestos. In order to be approved for regular use, talc needs to be purified of the asbestos, after which it can be used for a wide variety of applications, starting with talcum powder, ceramics, paper making and even food.
A block of talc Image credit: Wikipedia |
Effect of talc on human health, and especially cancer, has been a topic of study even after 1979 paper but has also been used in sterile form as treatment for pleural effusions, even before 1970. This 1988 report studied various environmental factors that women with ovarian cancers were exposed to and found that women using talcum powder on their genital area to keep it dry / odorless had a relative risk of 1.4 of getting ovarian cancer, which is almost the same as that of any other woman, whether she uses talcum powder or not.
The same study also found that women who drank coffee for 40 years or more were 3.4 more likely to get ovarian cancer when compared to women who never had coffee (but so far, we have not heard of anybody suing Starbucks or Costa Coffee for causing ovarian cancer). Interestingly, the International Agency for Research on Cancer (IARC), a World Health Organization funded body, lists, talc and coffee in the same category of potentially carcinogenic substances for which conclusive evidence is not available.
Talc and Ovarian Cancer
Evidence for the link between talc and cancer comes from the 1993 toxicology report carried out under National Toxicology Program with the aim to determine the risk of exposure to talc as an occupational hazard. For the study, various groups of rats were exposed to various concentrations of talc aerosols (which did not contain asbestos) for prolonged periods. At the end of the study, multiple rat groups were found to develop various ailments of the lungs and respiratory tract, including cancer, but not anywhere else and definitely not ovarian cancer.
Many clinicians/ physicians are aware of the risk associated with inhalation of talc over prolonged periods and therefore advice against exposure of infants to talcum powder (a segment where J&J is extremely popular choice). But nobody is actually doing it to avoid cancer in children.
There are reports where usage of talcum powder has been associated with low to moderate increase in risk of ovarian cancer. Like the 1992 report that put women using talcum powder in the genital area a risk ratio of 2.8 if they had made 10,000 or more applications of talcum powder during their ovulating years. However, this applied to only 14% of women who had ovarian cancer, leaving a major chunk of explaining to do for the causative agent in rest of the women.
While there are many other studies attribute using talcum powder to increased risk of getting ovarian cancer, what one must realize is the difference between, “increasing your risk” to “actually causing cancer”. Talc is not classified as a carcinogen, it does not cause cancer by itself. Yes, it may increase your chance of getting cancer, but so does coffee (like we mentioned earlier).
If we really want to know if talc causes cancer, we need to study its effect in a clinical trial like setting, where we test the effect of the substance over a long term use. To do this, we actually need to register people to use the talcum powder and check how many people get cancer. But such a study involving human subjects would never be approved by a ethics committee. Although, mothers of neonates are doing this everyday, the usage of talcum powder would stop immediately, if they were informed of the main idea behind collecting such data from them. Would you use a product on your child even if it had the remotest chance of giving your child cancer in the future?
This is probably also the greatest hurdle in unearthing the fact about talcum usage and cancer. All studies on this topic are retrospective and basically involve asking participants particular questions to determine if they had anything in common, prior to the development of their disease. Although, researcher take extreme care to avoid misleading their subjects, there is a recollection bias among patients, looking to link their current condition to past habits, which usually results in increased risk ratios. This is also why major cancer research institutes are not taking a side on this matter because there is no clarity, if talc merely increases your risk or is actually the causative agent of cancer. From the studies that we have looked into so far, it does not look like talc is the culprit here, but scientific research is always looking for more information and the story might change in the future, as we understand the disease better. But even if that were the case, why single just one talcum powder manufacturer out. All other manufacturer’s or users of talc in their products should also be dragged to court.
There is also the legal obligation of the company using such a product to inform its users about the potential hazards of the product contents and this is where J&J seems to have lost ground. Instead of putting a warning label on its product and completing its formal responsibility, the company has chosen to stand with the scientific data that it possesses, which is also nice to see. In my opinion, merely labeling a product as potentially harmful is not simply not enough. We have seen it with cigarettes and alcohol. Labeling, even with disturbing pictures of cancerous tissue is not enough to stop people from indulging into these products and labeling its product would just have been an easy way out. Instead, it would be nice to see J&J submit further data to support their beliefs and move forward scientifically.
As for the original question asked in this blog post, Johnson and Johnson’s baby powder is as safe as any other talcum powder you might pick from a supermarket.
References:
- Henderson WJ, Joslin CA, Turnbull AC, & Griffiths K (1971). Talc and carcinoma of the ovary and cervix. The Journal of obstetrics and gynaecology of the British Commonwealth, 78 (3), 266-72 PMID: 5558843
- Henderson WJ, Hamilton TC, & Griffiths K (1979). Talc in normal and malignant ovarian tissue. Lancet (London, England), 1 (8114) PMID: 85089
- Whittemore AS, Wu ML, Paffenbarger RS Jr, Sarles DL, Kampert JB, Grosser S, Jung DL, Ballon S, & Hendrickson M (1988). Personal and environmental characteristics related to epithelial ovarian cancer. II. Exposures to talcum powder, tobacco, alcohol, and coffee. American journal of epidemiology, 128 (6), 1228-40 PMID: 3195564
- National Toxicology Program . (1993). NTP Toxicology and Carcinogenesis Studies of Talc (CAS No. 14807-96-6)(Non-Asbestiform) in F344/N Rats and B6C3F1 Mice (Inhalation Studies). National Toxicology Program technical report series, 421, 1-287 PMID: 12616290
- Harlow BL, Cramer DW, Bell DA, & Welch WR (1992). Perineal exposure to talc and ovarian cancer risk. Obstetrics and gynecology, 80 (1), 19-26 PMID: 1603491