Ev­i­dence not con­clu­sive that talc causes ovar­ian can­cer

The Hazleton Standard-Speaker - - FACTS & FIGURES - Robert Ash­ley, M.D.

DEAR DOC­TOR: Some women, and ju­ries, say that talc causes ovar­ian can­cer, but doc­tors say it doesn’t. Where’s the ev­i­dence ei­ther way?

DEAR READER: Talc is a min­eral com­posed of mag­ne­sium and sil­i­cate. Tal­cum pow­der, com­monly known as baby pow­der, was first mar­keted by John­son & John­son in 1894. It was first used, and is still used, to pre­vent di­a­per rash. The con­cern re­gard­ing ovar­ian can­cer is that talc may pass into a woman’s uterus and then move up the fal­lop­ian tubes dur­ing menses. In fact, talc par­ti­cles have been found in the fal­lop­ian tubes of women who have used tal­cum pow­der on san­i­tary nap­kins or pads.

The sug­ges­tion that tal- cum pow­der may lead to ovar­ian can­cer first came from case-con­trol stud­ies. The largest of these was a com­bined anal­y­sis of eight dif­fer­ent stud­ies that com­pared 8,525 women (cases) who had ovar­ian can­cers and 9,859 women (con­trols) who did not.

In the stud­ies, re­searchers asked women if they had used tal­cum pow­der in the gen­i­tal area pre­vi­ously and how fre­quently. The au­thors con­cluded that the use of gen­i­tal pow­der was associated with a 20 to 30 per­cent in­crease in some types of ovar­ian can­cer.

One prob­lem with that anal­y­sis is that some pow­ders con­tain corn­starch, not talc. The other prob­lem is that of re­call bias. Women with ovar­ian can­cer may re­port pre­vi­ous use of pow­ders be­cause they be­lieve there may be a link be­tween the pow­der and their ovar­ian can­cer.

Fur­ther, the au­thors did not find any dose re­sponse associated with pow­der use, mean­ing that they did not find a link be­tween greater amounts of pow­der and ovar­ian can­cer.

Other case-con­trol stud­ies have come up with sim­i­lar con­clu­sions. Based on such data, many law­suits have con­tended a link be­tween tal­cum pow­der and ovar­ian can­cer. Two of these law­suits have led to judg­ments of $72 mil­lion and $55 mil­lion against John­son & John­son.

One dif­fi­culty with an­a­lyz­ing sta­tis­ti­cal links to ovar­ian can­cer is that the disease is some­what rare; over her life­time, the av­er­age woman has only about a 1 per­cent chance of de­vel­op­ing it. To truly study a po­ten­tial link be­tween ovar­ian can­cer and tal­cum pow­der, you would need large stud­ies. You would also need prospec­tive stud­ies. A prospec­tive study in this case would as­sess tal­cum pow­der use and fol­low women over time to see if they de­vel­oped ovar­ian can­cer.

Sev­eral stud­ies have at­tempted to do this. The Nurses’ Health Study in­cluded 78,683 women fol­lowed for nearly 13 years. These wom- en were asked about their use of tal­cum pow­der and, over the course of 13 years, 307 cases of ovar­ian can­cer were found.

Note that re­searchers did not find tal­cum pow­der to be associated with ovar­ian can­cer, although they did find a 9 per­cent in­crease among women who used tal­cum pow­der.

The Women’s Health Ini­tia­tive in­cluded 61,000 women fol­lowed for more than 12 years. In that study, re­searchers also found a min­i­mal in­crease in ovar­ian can­cer, but not a sta­tis­ti­cally sig­nif­i­cant one. The big­gest prob­lem with these prospec­tive stud­ies is that they need to be even larger and longer.

It’s pos­si­ble that there is a min­i­mal in­crease in ovar­ian can­cer among men­stru­at­ing women who use tal­cum pow­der. How­ever, this may have more his­tor­i­cal rel­e­vance than top­i­cal rel­e­vance be­cause fewer women are us­ing tal­cum pow­der to­day than in years past. If you do use a gen­i­tal pow­der, corn­starch pow­der would be a good al­ter­na­tive to talc.

Robert Ash­ley, M.D., is an in­ternist and as­sis­tant pro­fes­sor of medicine at the Uni­ver­sity of Cal­i­for­nia, Los An­ge­les.

Send your ques­tions to ask­the­do­c­tors@med­net.ucla .edu, or write: Ask the Doc­tors, c/o Me­dia Re­la­tions, UCLA Health, 924 West­wood Blvd., Suite 350, Los An­ge­les, CA, 90095.

Newspapers in English

Newspapers from USA

© PressReader. All rights reserved.