Family history and risk of pregnancy-associated breast cancer (PABC)

Abstract

The risk of breast cancer is at least two-fold increased in young women with a family history of breast cancer. Pregnancy has a dual effect on breast cancer risk; a short-term increase followed by a long-term protection. We investigated if the risk of breast cancer during and within 10 years following pregnancy is affected by a family history of breast cancer. We followed a cohort of women aged 15-44 years between 1963 and 2009 identified in Swedish population-based registers. Family history was defined as having a mother or sister with breast cancer. We estimated incidence rate ratios of breast cancer during pregnancy and time intervals up to 10 years post-delivery, with a focus on pregnancy-associated breast cancer (PABC), defined as breast cancer during pregnancy or within 2 years post-delivery. In 3,452,506 women, there were 15,548 cases of breast cancer (1208 were PABC). Compared to nulliparous women, the risk of breast cancer was decreased during pregnancy, similar during first year and increased during second year post-delivery. The pattern was similar in women with or without family history of breast cancer. A peak in risk was observed 5-6 years following the first birth regardless of family history. After a second birth, this peak was only present in women with a family history. Our results indicate that women with a family history of breast cancer do not have a different breast cancer risk during and within 10 years following pregnancy compared to women without a family history.

Prognosis of Breast Cancer in Very Young Age (Less Than 30 Years)

“…[14] The interactions between pregnancy and breast cancer are complex and variable, may be increased hormonal levels promote proliferation of existing tumours, [15] 29.8% of our patients presented with pregnancy or lactation-associated breast cancer, all presented with larger tumour size. Risk of breast cancer becomes 2 times in patients with family history of breast cancer, however, for PABC, the risk remains the same as for non PABC tumours according to Johansson et al [16] 11.6% of our patients have a positive family history of first-degree relative.…”

Characteristics and diagnosis of pregnancy and lactation associated breast cancer: Analysis of a self-reported regional registry

“…2,4 Therefore, in our second analysis, we evaluated patients diagnosed with breast cancer 1 to 5 years postpartum (PABC-II). More detailed information, in response to questions on an update questionnaire, was received from 307 patients.…”

“…17 Similar to our results, Johansson et al found that there was not an association between family history and breast cancer during or within 2 years of pregnancy and even up to 10 years post-partum. 4 As women diagnosed with breast cancer at younger ages are more likely to have a family history of breast cancer, the absence of an association in those with PABC suggests some other causative factor, possibly hormonal. Until relationships are well understood and characterized, family history should be considered when assessing risk.…”

“…2, 4, 5 Frequently, PABC is defined as diagnosis of breast cancer during or within one year of pregnancy/lactation. 3, 6–9 However, there is movement to expand this definition to include those breast cancers diagnosed within five or possibly up to fifteen years after birth.…”

Breast Cancer Arising from a Suspected Fibroadenoma during Pregnancy: A Case Report and Review of Literature

“…Family history as a strong risk factor may increase the possibility of breast cancer in young women by at least two-fold. However, studies fail to show any significant increase in the cancer risk among pregnant women with the family history of breast cancer when compared to women without a family history [31,32]. Similar to the general population the most commonly found subtype of breast cancer during pregnancy is infiltrating ductal carcinoma.…”