Abstract
Background: Parity and time since last birth influence breast cancer risk and vary by intrinsic tumor subtype, but the independent effects of these factors on prognosis have received limited attention. Methods: Study participants were 1,140 invasive breast cancer patients from phases I and II of the population-based Carolina Breast Cancer Study, with tissue blocks available for subtyping using immunohistochemical markers. Breast cancer risk factors, including pregnancy history, were collected via in-person interviews administered shortly after diagnosis. Vital status was determined using the National Death Index. The association of parity and birth recency with breast cancer-specific and overall survival was assessed using Cox proportional hazards models. Results: During follow-up (median = 13.5 years), 450 patients died, 61% due to breast cancer (n = 276). High parity (3+ births) and recent birth (<5 years before diagnosis) were positively associated with breast cancer-specific mortality, independent of age, race, and selected socioeconomic factors [parity, reference = nulliparous, adjusted HR = 1.76; 95% confidence interval (CI) = 1.13-2.73; birth recency, reference = 10+ years, adjusted HR = 1.29; 95% CI, 0.79-2.11]. The associations were stronger among patients with luminal tumors and those surviving longer than 5 years. Conclusions: Parity and recent birth are associated with worse survival among breast cancer patients, particularly among luminal breast cancers and long-term survivors. Impact: The biologic effects of parity and birth recency may extend from etiology to tumor promotion and progression.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 60-67 |
| Number of pages | 8 |
| Journal | Cancer Epidemiology Biomarkers and Prevention |
| Volume | 25 |
| Issue number | 1 |
| DOIs | |
| State | Published - Jan 1 2016 |
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ASJC Scopus subject areas
- Epidemiology
- Oncology
Cite this
Association of parity and time since last birth with breast cancer prognosis by intrinsic subtype. / Sun, Xuezheng; Nichols, Hazel B.; Tse, Chiu Kit; Bell, Mary B.; Robinson, Whitney R.; Sherman, Mark E.; Olshan, Andrew F.; Troester, Melissa A.
In: Cancer Epidemiology Biomarkers and Prevention, Vol. 25, No. 1, 01.01.2016, p. 60-67.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Association of parity and time since last birth with breast cancer prognosis by intrinsic subtype
AU - Sun, Xuezheng
AU - Nichols, Hazel B.
AU - Tse, Chiu Kit
AU - Bell, Mary B.
AU - Robinson, Whitney R.
AU - Sherman, Mark E.
AU - Olshan, Andrew F.
AU - Troester, Melissa A.
PY - 2016/1/1
Y1 - 2016/1/1
N2 - Background: Parity and time since last birth influence breast cancer risk and vary by intrinsic tumor subtype, but the independent effects of these factors on prognosis have received limited attention. Methods: Study participants were 1,140 invasive breast cancer patients from phases I and II of the population-based Carolina Breast Cancer Study, with tissue blocks available for subtyping using immunohistochemical markers. Breast cancer risk factors, including pregnancy history, were collected via in-person interviews administered shortly after diagnosis. Vital status was determined using the National Death Index. The association of parity and birth recency with breast cancer-specific and overall survival was assessed using Cox proportional hazards models. Results: During follow-up (median = 13.5 years), 450 patients died, 61% due to breast cancer (n = 276). High parity (3+ births) and recent birth (<5 years before diagnosis) were positively associated with breast cancer-specific mortality, independent of age, race, and selected socioeconomic factors [parity, reference = nulliparous, adjusted HR = 1.76; 95% confidence interval (CI) = 1.13-2.73; birth recency, reference = 10+ years, adjusted HR = 1.29; 95% CI, 0.79-2.11]. The associations were stronger among patients with luminal tumors and those surviving longer than 5 years. Conclusions: Parity and recent birth are associated with worse survival among breast cancer patients, particularly among luminal breast cancers and long-term survivors. Impact: The biologic effects of parity and birth recency may extend from etiology to tumor promotion and progression.
AB - Background: Parity and time since last birth influence breast cancer risk and vary by intrinsic tumor subtype, but the independent effects of these factors on prognosis have received limited attention. Methods: Study participants were 1,140 invasive breast cancer patients from phases I and II of the population-based Carolina Breast Cancer Study, with tissue blocks available for subtyping using immunohistochemical markers. Breast cancer risk factors, including pregnancy history, were collected via in-person interviews administered shortly after diagnosis. Vital status was determined using the National Death Index. The association of parity and birth recency with breast cancer-specific and overall survival was assessed using Cox proportional hazards models. Results: During follow-up (median = 13.5 years), 450 patients died, 61% due to breast cancer (n = 276). High parity (3+ births) and recent birth (<5 years before diagnosis) were positively associated with breast cancer-specific mortality, independent of age, race, and selected socioeconomic factors [parity, reference = nulliparous, adjusted HR = 1.76; 95% confidence interval (CI) = 1.13-2.73; birth recency, reference = 10+ years, adjusted HR = 1.29; 95% CI, 0.79-2.11]. The associations were stronger among patients with luminal tumors and those surviving longer than 5 years. Conclusions: Parity and recent birth are associated with worse survival among breast cancer patients, particularly among luminal breast cancers and long-term survivors. Impact: The biologic effects of parity and birth recency may extend from etiology to tumor promotion and progression.
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U2 - 10.1158/1055-9965.EPI-15-0864
DO - 10.1158/1055-9965.EPI-15-0864
M3 - Article
C2 - 26545404
AN - SCOPUS:84955264808
VL - 25
SP - 60
EP - 67
JO - Cancer Epidemiology Biomarkers and Prevention
JF - Cancer Epidemiology Biomarkers and Prevention
SN - 1055-9965
IS - 1
ER -