Studies - Breast Cancer

Study Shows Abortion Linked to High Breast Cancer Risk (APJCP, Feb 2012)

Study Shows Abortion Linked to High Breast Cancer Risk

A study in the Asian Pacific Journal of Cancer Prevention shows abortion increases the risk of breast cancer for women.

C. Yanhua of the First Peoples’ Hospital of Kunming in Yunnan province and his colleagues found the abortion-breast cancer association after comparing data from 263 cases of breast cancer and 457 controls without the disease. Their analysis covers the years 2009-2011 — http://www.apocpcontrol.org/paper_file/issue_abs/Volume13_No5/2179-84%204.17%20Che%20Yanhua.pdf

The authors examined information on disease diagnosis, demographics, medical history, and reproductive characteristics of the patients involved and also looked at short menstrual cycle, old age at first live birth, never breastfeeding, history of oral contraceptive use, postmenopausal status and nulliparity to determine in abortion-breast cancer link exists.

They write that “multivariate model analysis revealed the significant independent positive associations with breast cancer of shorter menstrual cycle, older age at first live birth, never breastfeeding, history of oral contraception experience, increased number of abortion, menopause status, and nulliparities.”

“Number of abortion showed an increasing higher risk of breast cancer,” they added, while saying that women who had one live birth lowered their risk. “As far as women who had once a live birth, it showed decreased the risk of breast cancer compared to nulliparous.”

“This study showed an increased risk of breast cancer with times of abortion. The association between abortion and risk of breast cancer in a study in China showed that the risk factors of female breast cancer included abortion times more than two (Li et al., 2006),” they continued. “Another study found that risk was raised among women reporting at least one abortion, but no trend was seen with number of abortions (Heuch et al., 2008). In a meta-analysis study, pooled odds ratio for number of abortions greater than and equal three was statistically significant (95%CI:1.68-5.36) (Tao et al.,2011).”

“In conclusion, in this study the estrogen related risk factors of breast cancer included woman who had longer menstrual cycle, older age of first live birth, never breastfeeding, nulliparity, and number of abortions more than one. Therefore, it is recommended to women with these risk factors perform breast cancer screening tests earlier and regularly,” they said.

A study published in the Asian Pacific Journal of Cancer Prevention in February reported a very statistically significant increased risk of breast cancer for women with previous abortions as opposed to women who have never had one.

The study, consisting of 1,351 women and led by researcher Ai-Ren Jiang, reported a statistically significant 1.52-fold elevation in risk for women with induced abortions and a “significant dose-response relationship between (the risk) for breast cancer and number of induced abortions,” meaning the risk climbed with a higher number of previous abortions.

For premenopausal women who have had abortions, the numbers were relatively small, and the observed 16% risk elevation was not statistically significant. However, for those with three or more abortions, the risk climbed to a statistically significant 1.55-fold elevation.

Study Analysis Reproductive Variables and Risk of Breast Malignant and Benign Tumours in Yunnan Province, China
http://www.apocpcontrol.org/paper_file/issue_abs/Volume13_No5/2179-84%204.17%20Che%20Yanhua.pdf
Abstract
Introduction and aim:
To compare reproductive factor influence on patients with pathological diagnosed malignant and benign tumor in the Breast Department, The First Peoples’ Hospital of Kunming in Yunnan province, China.

Methods: A hospital-based case-control study was conducted on 263 breast cancer (BC) cases and 457 non-breast cancer controls from 2009 to 2011. The cases and controls information on demographics, medical history, and reproductive characteristics variables were collected using a self-administered questionnaire and routine medical records. Histology of breast cancer tissue and benign breast lesion were documented by pathology reports. Since some variables in data analysis had zero count in at least one category, binomial-response GLM using the bias-reduction method was applied to estimate OR’s and their 95% confidence intervals (95% CI). To adjust for age and menopause status, a compound variable comprising age and menopausal status was retained in the statistical models.

Results: multivariate model analysis revealed significant independent positive associations of BC with short menstrual cycle, old age at first live birth, never breastfeeding, history of oral contraception experience, increased number of abortion, postmenopausal status, and nulliparity. Categorised by age and menopausal status, perimenopausal women had about 3-fold and postmenopausal women had more than 5-fold increased risk of BC compared to premenopausal women.

Discussion and Conclusion: This study has confirmed the significant association of BC and estrogen related risk factors of breast cancer including longer menstrual cycle, older age of first live birth, never breastfeeding, nulliparity, and number of abortions more than one. The findings suggest that female hormonal factors, especially the trend of menopause status play a significant role in the development of BC in Yunnan women.

[Asian Pacific Journal Cancer Prevention, 13, 2179-2184; http://www.apocpcontrol.org/paper_file/issue_abs/Volume13_No5/2179-84%204.17%20Ch %20Yanhua.pdf  ]

[Ertelt | Beijing, China | LifeNews.com | 11/26/12, http://www.lifenews.com/2012/11/26/study-shows-abortion-linked-to-high-breast-cancer-risk/]

http://www.lifenews.com/2012/05/15/study-repeat-abortions-greatly-raise-breast-cancer-risk/

Study: Repeat Abortions Greatly Raise Breast Cancer Risk

A new study published in the Asian Pacific Journal of Cancer Prevention in February reported a very statistically significant increased risk of breast cancer for women with previous abortions as opposed to women who have never had one.

The study, consisting of 1,351 women and led by researcher Ai-Ren Jiang, reported a statistically significant 1.52-fold elevation in risk for women with induced abortions and a “significant dose-response relationship between (the risk) for breast cancer and number of induced abortions,” meaning the risk climbed with a higher number of previous abortions.

For premenopausal women who have had abortions, the numbers were relatively small, and the observed 16% risk elevation was not statistically significant. However, for those with three or more abortions, the risk climbed to a statistically significant 1.55-fold elevation.

“The results have revealed that induced abortion was related to increased risk of breast caner. Premenopausal women who had ≥3 times of induced abortion were at increased crude odds ratio (OR) (2.41, 95%CI: 1.09-5.42) and adjusted-OR (1.55, 95%CI: 1.15-5.68),” they wrote. “Postmenopausal women with a previou

s induced abortion were at increased crude OR (2.04, 95%CI: 1.48-2.81) and adjusted-OR (1.82, 95%CI: 1.30-2.54), and there was a significant increase trend in OR with number of induced abortions (p for trend: 0.0001).”

Karen Malec, of the Coalition on Abortion/Breast Cancer, who noted the study, said that postmenopausal women with a history of abortion experienced a statistically significant 1.82-fold elevation in risk, compared to those with no abortion history.

“Risk climbed with number of IAs (induced abortions) from a statistically significant 1.79-fold increased risk for one IA and a statistically significant 1.85-fold elevation for two IAs, to a non-statistically significant 2.14-fold elevated risk for three or more IAs,” Malec said.

“Professor Joel Brind (Baruch College, City University of New York) advised the Coalition on Abortion/Breast Cancer that earlier Chinese studies underestimated the breast cancer risk of IAs,” Malec said. “A one-child-per-couple policy is in force, and most women have abortions after first full term pregnancy. (First full-term pregnancy reduces risk by maturing 85% of the mother’s cancer-susceptible breast lobules into permanently cancer-resistant lobules.)”

Brind said it “tends to suppress the relative risk values, which makes the Jiang numbers all the more credible – underestimates if anything. Also, a place like China is good to measure the dose effect of abortion, and the statistics are strong enough to show a highly significant trend, which strengthens a causal inference.”

Malec also noted that a Chinese study in 1995 by L. Bu and colleagues, including Janet Daling of the Fred Hutchinson Cancer Research Center, reported a statistically significant 4.5-fold elevated risk among women with previous induced abortions who developed breast cancer at or before age 35, compared to older women (who experienced a statistically significant 2.5-fold elevated risk).

“Four of seven Chinese studies report statistically significant risk increases for women with IAs,” Malec concluded. “Fifty-three of sixty-nine epidemiological studies dating from 1957 report risk elevations for women with previous IAs. Biological and experimental research supports an abortion-breast cancer link.”

As other studies have shown, this new one from China indicated miscarriages do not elevate a woman’s breast cancer risk.

“Overall, spontaneous abortion did not significantly alter the risk of breast cancer, but postmenopausal women who had history of spontaneous abortion were at increased odds ratio,” they wrote. “These results suggested that relationship between breast cancer and abortions may depend on menopausal status and induced abortion played an important role in the development of breast cancer in Jiangsu’ women of China.

Citation:  Jiang AR, Gao CM, Ding JH, Li SP, Liu YT, Cao HX, Wu JZ, Tang JH, Qian Y, Tajima K. Abortions and breast cancer risk in premenopausal and postmenopausal women in Jiangsu Province of China. Asian Pacific J Cancer Prev 2012;13:33-35. Available at: http://www.apjcpcontrol.org/page/popup_paper_file_view.php?pno=MzMtMzUgMTIuMiZrY29kZT0yNzAxJmZubz0w&pgubun=i

[Ertelt | Washington, DC | LifeNews.com | 5/15/12, http://www.lifenews.com/2012/05/15/study-repeat-abortions-greatly-raise-breast-cancer-risk/]