Anti-Estrogen Therapy May Cut Lung Ca Deaths

SAN ANTONIO — Women treated with anti-estrogen therapy for breast cancer appeared to have a reduced risk of dying later from lung cancer in a Swiss registry study, suggesting that the agents may be protective, Dr. Elisabetta Rapiti reported at the annual San Antonio Breast Cancer Symposium.

In a national registry of 6,655 breast cancer patients who were followed for up to 27 years, 40 women subsequently developed lung cancer. Of those, 12 had received anti-estrogen therapy and 28 had not, reported Dr. Rapiti, a medical researcher at the University of Geneva.

In comparison to the general population, the age-adjusted standardized mortality ratio for lung cancer was 0.13 (95% confidence interval, 0.02–0.47) among women who had received anti-estrogen therapy (P value of less than .001).

Breast cancer survivors who did not receive anti-estrogens had a standardized lung cancer mortality rate of 0.76 (95% CI, 0.43–1.23), a rate not significantly different from that of other women.

Calculated another way, the lung cancer mortality rate was 9.23 per 100,000 in the group that received anti-estrogen therapy, versus 44.97 per 100,000 for those who did not.

The idea that anti-estrogens might protect against lung cancer emerged from a post-hoc analysis of data from the Women's Health Initiative, since women taking combined estrogen-progestin hormonal therapy were found to have died from lung cancer at a significantly higher rate over 7.5 years of follow-up (Lancet 2009;347:1243–51).

“We thought if this [combined hormonal therapy] increased lung cancer mortality, maybe the anti-estrogens would be associated with a decreased risk of lung cancer mortality,” Dr. Rapiti said.

She and her associates examined Geneva Cancer Registry breast cancer cases diagnosed between 1980 and 2003, determining that 46% of the cases included treatment with an anti-estrogen therapy, mostly tamoxifen. Patient outcomes were tracked until the end of 2007.

Women who received anti-estrogen therapy were slightly older and more likely to be post menopause than those who did not get the therapy, and had a lower income.

Smoking histories were similar between users and nonusers and the general population, with nearly 30% reporting current smoking. About 15% of breast cancer patients were ex-smokers, again, similar to the general population in Switzerland.

The principal investigator of the WHI lung cancer mortality study, Dr. Rowan Chlebowski, commented on Dr. Rapiti's study during the question-and-answer period following her presentation. In the WHI study, most of the mortality difference was seen in patients who had non–small cell lung cancer.

An update to the WHI findings will be coming soon, tracking 4 more years of follow-up in women after they had ceased taking combination hormonal therapy, said Dr. Chlebowski of the Harbor–University of California, Los Angeles Medical Center in Torrance.

Differences in lung cancer histology have not yet been analyzed in the Geneva Cancer Registry, Dr. Rapiti noted, although that analysis is planned. Although the study was observational and retrospective, the results “further support the hypothesis that estrogen plays a role in prognosis of lung cancer.”

Dr. Rapiti reported no relevant financial disclosures in connection with her study.

SAN ANTONIO — Women treated with anti-estrogen therapy for breast cancer appeared to have a reduced risk of dying later from lung cancer in a Swiss registry study, suggesting that the agents may be protective, Dr. Elisabetta Rapiti reported at the annual San Antonio Breast Cancer Symposium.

In a national registry of 6,655 breast cancer patients who were followed for up to 27 years, 40 women subsequently developed lung cancer. Of those, 12 had received anti-estrogen therapy and 28 had not, reported Dr. Rapiti, a medical researcher at the University of Geneva.

In comparison to the general population, the age-adjusted standardized mortality ratio for lung cancer was 0.13 (95% confidence interval, 0.02–0.47) among women who had received anti-estrogen therapy (P value of less than .001).

Breast cancer survivors who did not receive anti-estrogens had a standardized lung cancer mortality rate of 0.76 (95% CI, 0.43–1.23), a rate not significantly different from that of other women.

Calculated another way, the lung cancer mortality rate was 9.23 per 100,000 in the group that received anti-estrogen therapy, versus 44.97 per 100,000 for those who did not.

The idea that anti-estrogens might protect against lung cancer emerged from a post-hoc analysis of data from the Women's Health Initiative, since women taking combined estrogen-progestin hormonal therapy were found to have died from lung cancer at a significantly higher rate over 7.5 years of follow-up (Lancet 2009;347:1243–51).

“We thought if this [combined hormonal therapy] increased lung cancer mortality, maybe the anti-estrogens would be associated with a decreased risk of lung cancer mortality,” Dr. Rapiti said.

She and her associates examined Geneva Cancer Registry breast cancer cases diagnosed between 1980 and 2003, determining that 46% of the cases included treatment with an anti-estrogen therapy, mostly tamoxifen. Patient outcomes were tracked until the end of 2007.

Women who received anti-estrogen therapy were slightly older and more likely to be post menopause than those who did not get the therapy, and had a lower income.

Smoking histories were similar between users and nonusers and the general population, with nearly 30% reporting current smoking. About 15% of breast cancer patients were ex-smokers, again, similar to the general population in Switzerland.

The principal investigator of the WHI lung cancer mortality study, Dr. Rowan Chlebowski, commented on Dr. Rapiti's study during the question-and-answer period following her presentation. In the WHI study, most of the mortality difference was seen in patients who had non–small cell lung cancer.

An update to the WHI findings will be coming soon, tracking 4 more years of follow-up in women after they had ceased taking combination hormonal therapy, said Dr. Chlebowski of the Harbor–University of California, Los Angeles Medical Center in Torrance.

Differences in lung cancer histology have not yet been analyzed in the Geneva Cancer Registry, Dr. Rapiti noted, although that analysis is planned. Although the study was observational and retrospective, the results “further support the hypothesis that estrogen plays a role in prognosis of lung cancer.”

Dr. Rapiti reported no relevant financial disclosures in connection with her study.

SAN ANTONIO — Women treated with anti-estrogen therapy for breast cancer appeared to have a reduced risk of dying later from lung cancer in a Swiss registry study, suggesting that the agents may be protective, Dr. Elisabetta Rapiti reported at the annual San Antonio Breast Cancer Symposium.

In a national registry of 6,655 breast cancer patients who were followed for up to 27 years, 40 women subsequently developed lung cancer. Of those, 12 had received anti-estrogen therapy and 28 had not, reported Dr. Rapiti, a medical researcher at the University of Geneva.

In comparison to the general population, the age-adjusted standardized mortality ratio for lung cancer was 0.13 (95% confidence interval, 0.02–0.47) among women who had received anti-estrogen therapy (P value of less than .001).

Breast cancer survivors who did not receive anti-estrogens had a standardized lung cancer mortality rate of 0.76 (95% CI, 0.43–1.23), a rate not significantly different from that of other women.

Calculated another way, the lung cancer mortality rate was 9.23 per 100,000 in the group that received anti-estrogen therapy, versus 44.97 per 100,000 for those who did not.

The idea that anti-estrogens might protect against lung cancer emerged from a post-hoc analysis of data from the Women's Health Initiative, since women taking combined estrogen-progestin hormonal therapy were found to have died from lung cancer at a significantly higher rate over 7.5 years of follow-up (Lancet 2009;347:1243–51).

“We thought if this [combined hormonal therapy] increased lung cancer mortality, maybe the anti-estrogens would be associated with a decreased risk of lung cancer mortality,” Dr. Rapiti said.

She and her associates examined Geneva Cancer Registry breast cancer cases diagnosed between 1980 and 2003, determining that 46% of the cases included treatment with an anti-estrogen therapy, mostly tamoxifen. Patient outcomes were tracked until the end of 2007.

Women who received anti-estrogen therapy were slightly older and more likely to be post menopause than those who did not get the therapy, and had a lower income.

Smoking histories were similar between users and nonusers and the general population, with nearly 30% reporting current smoking. About 15% of breast cancer patients were ex-smokers, again, similar to the general population in Switzerland.

The principal investigator of the WHI lung cancer mortality study, Dr. Rowan Chlebowski, commented on Dr. Rapiti's study during the question-and-answer period following her presentation. In the WHI study, most of the mortality difference was seen in patients who had non–small cell lung cancer.

An update to the WHI findings will be coming soon, tracking 4 more years of follow-up in women after they had ceased taking combination hormonal therapy, said Dr. Chlebowski of the Harbor–University of California, Los Angeles Medical Center in Torrance.

Differences in lung cancer histology have not yet been analyzed in the Geneva Cancer Registry, Dr. Rapiti noted, although that analysis is planned. Although the study was observational and retrospective, the results “further support the hypothesis that estrogen plays a role in prognosis of lung cancer.”

Dr. Rapiti reported no relevant financial disclosures in connection with her study.