Clinical Stage of Breast Cancer by Parity, Age at Birth, and Time Since Birth: A Progressive Effect of Pregnancy Hormones?

Survival of Women Previously Diagnosed of Melanoma with Subsequent Pregnancy: A Systematic Review and Meta-Analysis and a Single-Center Experience

Melanoma incidence has increased over the last few decades. How the prognosis of a previously diagnosed melanoma may be affected by a woman’s subsequent pregnancy has been debated in the literature since the 1950s, and the outcomes are essential to women who are melanoma survivors in their childbearing years. The main objective of this systematic review is to improve the understanding of whether the course of melanoma in a woman may be altered by a subsequent pregnancy and to help clinicians’ diagnosis. Eligible studies for the systematic review were clinical trials, observational cohort studies and case-control studies that compared prognosis outcomes for non-pregnant patients with melanoma, or pregnant before melanoma diagnosis, versus pregnant patients after a diagnosis of melanoma. The search strategy yielded 1101 articles, of which 4 met the inclusion criteria for the systematic review. All the studies were retrospective non-randomised cohorts with patients with melanomas diagnosed before pregnancy. According to our findings, a subsequent pregnancy was not a significant influence on the outcome of a previous melanoma. However, given the small number of identified studies and the heterogeneous data included, it is recommended to approach these patients with caution, and counselling should be given by known prognostic factors. We also reviewed the medical records of 84 patients of childbearing age (35.8 ± 6.3 years, range 21–45 years) who were diagnosed with cutaneous invasive melanoma in our hospital between 2008 and 2018 (N = 724). Of these, 11 (13.1%) had a pregnancy after melanoma diagnosis (age at pregnancy: 35.6 ± 6.3 years). No statistical differences in outcome were detected.

Reproductive issues in carriers of germline pathogenic variants in the BRCA1/2 genes: an expert meeting

BACKGROUND

Healthy individuals and patients with cancer who are carriers of germline pathogenic variants in the BRCA1/2 genes face multiple reproductive challenges that require appropriate counseling and specific expertise.

MAIN BODY

On December 5th-7th, 2019, patient advocates and physicians with expertise in the field of reproductive medicine, fertility preservation, and oncology were invited to "San Giuseppe Moscati" Hospital in Avellino (Italy) for a workshop on reproductive management of women with germline pathogenic variants in the BRCA1/2 genes. From the discussion regarding the current evidence and future prospective in the field, eight main research questions were formulated and eight recommendations were developed regarding fertility, fertility preservation, preimplantation genetic testing, and pregnancy in healthy carriers and patients with cancer.

CONCLUSION

Several misconceptions about the topic persist among health care providers and patients often resulting in a discontinuous and suboptimal management. With the aim to offer patient-tailored counseling about reproductive issues, both awareness of current evidences and research should be promoted.

BC200 overexpression contributes to luminal and triple negative breast cancer pathogenesis

Background

Long non coding RNAs (lncRNAs) are RNA molecules longer than 200 nucleotides that are not translated into proteins, but regulate the transcription of genes involved in different cellular processes, including cancer. Epidemiological analyses have demonstrated that parous women have a decreased risk of developing breast cancer in postmenopausal years if they went through a full term pregnancy in their early twenties. We here provide evidence of the role of BC200 in breast cancer and, potentially, in pregnancy’s preventive effect in reducing the lifetime risk of developing breast cancer.

Methods

Transcriptome analysis of normal breast of parous and nulliparous postmenopausal women revealed that several lncRNAs are differentially expressed in the parous breast. RNA sequencing of healthy postmenopausal breast tissue biopsies from eight parous and eight nulliparous women showed that there are 42 novel lncRNAs differentially expressed between these two groups. Screening of several of these 42 lncRNAs by RT-qPCR in different breast cancer cell lines, provided evidence that one in particular, lncEPCAM (more commonly known as BC200), was a strong candidate involved in cancer progression. Proliferation, migration, invasion and xerograph studies confirmed this hypothesis.

Results

The poorly studied oncogenic BC200 was selected to be tested in vitro and in vivo to determine its relevance in breast cancer and also to provide us with an understanding of its role in the increased susceptibility of the nulliparous women to cancer. Our results show that BC200 is upregulated in nulliparous women, and breast cancer cells and tissue. The role of BC200 is not completely understood in any of the breast cancer subtypes. We here provide evidence that BC200 has a role in luminal breast cancer as well as in the triple negative breast cancer subtype.

Conclusion

When overexpressed in luminal and triple negative breast cancer cell lines, BC200 shows increased proliferation, migration, and invasion in vitro. In vivo, overexpression of BC200 increased tumor size. Although treatment for cancer using lncRNAs as targets is in its infancy, the advancement in knowledge and technology to study their relevance in disease could lead to the development of novel treatment and preventive strategies for breast cancer.

Drivers of advanced stage at breast cancer diagnosis in the multicountry African breast cancer - disparities in outcomes (ABC-DO) study

Breast cancer (BC) survival rates in sub-Saharan Africa (SSA) are low in part due to advanced stage at diagnosis. As one component of a study of the entire journey of SSA women with BC, we aimed to identify shared and setting-specific drivers of advanced stage BC. Women newly diagnosed in the multicountry African Breast Cancer-Disparities in Outcomes (ABC-DO) study completed a baseline interview and their stage information was extracted from medical records. Ordinal logistic regression was used to estimate odds ratios (OR) and 95% confidence intervals (CI) for advanced stage (I, II, III, IV) in relation to individual woman-level, referral and biological factors. A total of 1795 women were included from Nigeria, Uganda, Zambia, and the multiracial populations of Namibia and South Africa, 1091 of whom (61%) were stage III/IV. Stage was lower in women with greater BC knowledge (OR 0.77 (95% CI: 0.70, 0.85) per point on a 6 point scale). More advanced stage was associated with being black (4.00 (2.79, 5.74)), having attended Collapse

Key Words

• breast cancer
• stage at diagnosis
• sub-Saharan Africa
• survival

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MESH Headings

• Africa
• Breast Neoplasms/diagnosis
• Breast Neoplasms/pathology
• Female
• Health Services Accessibility
• Humans
• Logistic Models
• Middle Aged
• Neoplasm Staging/methods
• Odds Ratio
• Population Groups
• Prospective Studies
• Referral and Consultation

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Grants

• 001 World Health Organization
• R01 CA192627 NCI NIH HHS

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Affiliation(s)

Fiona McKenzie Section of Environment and RadiationInternational Agency for Research on CancerLyonFrance
Annelle Zietsman Windhoek Central HospitalWindhoekNamibia
Moses Galukande Makerere UniversityKampalaUganda
Angelica Anele Federal Medical CentreOwerriNigeria
Charles Adisa Abia State University Teaching HospitalAbaNigeria
Groesbeck Parham University of North CarolinaChapel HillUSA
Leeya Pinder University of North CarolinaChapel HillUSA
Herbert Cubasch University of the Witwatersrand, Chris Hani Baragwanath Academic HospitalJohannesburgSouth Africa
Maureen Joffe University of the Witwatersrand, Chris Hani Baragwanath Academic HospitalJohannesburgSouth Africa
Frederick Kidaaga Namibian Institute of PathologyWindhoekNamibia
Robert Lukande Makerere UniversityKampalaUganda
Awa U. Offiah Abia State University Teaching HospitalAbaNigeria
Ralph O. Egejuru Federal Medical CentreOwerriNigeria
Aaron Shibemba University Teaching HospitalLusakaZambia
Joachim Schuz Section of Environment and RadiationInternational Agency for Research on CancerLyonFrance
Benjamin O. Anderson Fred Hutchinson Cancer Research CenterSeattleWashingtonUSA
Isabel dos Santos Silva Department of Non‐Communicable Disease EpidemiologyLondon School of Hygiene & Tropical MedicineLondonUK
Valerie McCormack Section of Environment and RadiationInternational Agency for Research on CancerLyonFrance

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Lactation opposes pappalysin-1-driven pregnancy-associated breast cancer

Pregnancy is associated with a transient increase in risk for breast cancer. However, the mechanism underlying pregnancy‐associated breast cancer (PABC) is poorly understood. Here, we identify the protease pappalysin‐1 (PAPP‐A) as a pregnancy‐dependent oncogene. Transgenic expression of PAPP‐A in the mouse mammary gland during pregnancy and involution promotes the deposition of collagen. We demonstrate that collagen facilitates the proteolysis of IGFBP‐4 and IGFBP‐5 by PAPP‐A, resulting in increased proliferative signaling during gestation and a delayed involution. However, while studying the effect of lactation, we found that although PAPP‐A transgenic mice lactating for an extended period of time do not develop mammary tumors, those that lactate for a short period develop mammary tumors characterized by a tumor‐associated collagen signature (TACS‐3). Mechanistically, we found that the protective effect of lactation is associated with the expression of inhibitors of PAPP‐A, STC1, and STC2. Collectively, these results identify PAPP‐A as a pregnancy‐dependent oncogene while also showing that extended lactation is protective against PAPP‐A‐mediated carcinogenesis. Our results offer the first mechanism that explains the link between breast cancer, pregnancy, and breastfeeding.

The Premenopausal Breast Cancer Collaboration: A Pooling Project of Studies Participating in the National Cancer Institute Cohort Consortium

Breast cancer is a leading cancer diagnosis among premenopausal women around the world. Unlike rates in postmenopausal women, incidence rates of advanced breast cancer have increased in recent decades for premenopausal women. Progress in identifying contributors to breast cancer risk among premenopausal women has been constrained by the limited numbers of premenopausal breast cancer cases in individual studies and resulting low statistical power to subcategorize exposures or to study specific subtypes. The Premenopausal Breast Cancer Collaborative Group was established to facilitate cohort-based analyses of risk factors for premenopausal breast cancer by pooling individual-level data from studies participating in the United States National Cancer Institute Cohort Consortium. This article describes the Group, including the rationale for its initial aims related to pregnancy, obesity, and physical activity. We also describe the 20 cohort studies with data submitted to the Group by June 2016. The infrastructure developed for this work can be leveraged to support additional investigations. Cancer Epidemiol Biomarkers Prev; 26(9); 1360-9. ©2017 AACR.

Reproductive history and breast cancer prevention

The hormonal milieu of an early full-term pregnancy induces lobular development, completing the cycle of differentiation of the breast. This process induces a specific genomic signature in the mammary gland that is represented by the stem cell containing a heterochomatin condensed nucleus (HTN). Even though differentiation significantly reduces cell proliferation in the mammary gland, the mammary epithelium remains capable of responding with proliferation to given stimuli, such as a new pregnancy. The stem cell HTN is able to metabolize the carcinogen and repair the induced DNA damage more efficiently than the stem cell containing an euchromatinic structure (EUN), as it has been demonstrated in the rodent experimental system. The basic biological concept is that pregnancy shifts the stem cell EUN to the stem cell HTN that is refractory to carcinogenesis. Data generated by the use of cDNA micro array techniques have allowed to demonstrate that while lobular development regressed after pregnancy and lactation, programmed cell death genes, DNA repair genes, chromatin remodeling, transcription factors and immune-surveillance gene transcripts all of these genes are upregulated and are part of the genomic signature of pregnancy that is associated with the preventive effect of this physiological process.

Pregnancy history and risk of premenopausal breast cancer-a nested case-control study

BACKGROUND

Reproductive factors are well-known risk factors for premenopausal breast cancer (PBC). It is unknown whether these associations are modified by familial factors, including genetic and early environment factors.

METHODS

Using Swedish health registries, we performed a nested case-control study with two control groups: sister controls and population controls. The study population included women with live singleton births between 1973 and 2010, who also had a full sister who gave birth during this period. All women subsequently diagnosed with PBC were selected as cases (n = 8327). Sisters with the least age difference and without PBC at the time of her sister's diagnosis were selected as sister controls. For each incident case, one population control without previous PBC was selected.The population controls were individually matched with the sister controls on year of birth. Conditional logistic regression was used to estimate associations between reproductive factors and PBC.

RESULTS

Increasing parity was inversely associated with PBC using population controls, and multiparity was a risk factor using sister controls. Very preterm delivery (≤ 31 weeks) was associated with a slightly higher PBC risk using sister controls. Preeclampsia was associated with a slightly protective effect using population controls. With respect to other factors, there were no substantial differences in risks of PBC by choice of control group.

CONCLUSIONS

The divergent results with regard to parity and PBC risk when using sister and population controls suggest that the influence of childbearing may be modified by genotype. Selection bias when using different control groups must also be considered.

A functional genetic variant in fragile-site gene FATS modulates the risk of breast cancer in triparous women

Background

The fragile-site associated tumor suppressor (FATS, formerly known as C10orf90), a regulator of p53-p21 pathway has been involved in the onset of breast cancer. Recent data support the idea that the crosstalk between FATS and p53 may be of physiological importance for reproduction during evolution. The aim of the current study was to test the hypothesis that FATS genetic polymorphism can influence the risk of breast cancer.

Methods

We conducted population-based studies in two independent cohorts comprising 1 532 cases and 1 573 controls in Tianjin of North China, and 804 cases and 835 controls in Guangzhou of South China, coupled with functional validation methods, to investigate the role of FATS genetic variant in breast cancer risk.

Results

We identified a functional variant rs11245007 (905C > T, 262D/N) in fragile-site gene FATS that modulates p53 activation. FATS-262 N exhibited stronger E3 activity to polyubiquitinate p53 than did FATS-262D, leading to the stronger transcriptional activity of p53 and more pronounced stabilization of p53 protein and its activation in response to DNA damage. Case–control studies found that CT or TT genotype was significantly associated with a protective effect on breast cancer risk in women with parity ≥ 3, which was not affected by family history.

Conclusions

Our findings suggest the role of FATS-p53 signaling cascade in suppressing pregnancy-related carcinogenesis and potential application of FATS genotyping in breast cancer prevention.

Electronic supplementary material

The online version of this article (doi:10.1186/s12885-015-1570-9) contains supplementary material, which is available to authorized users.

Effects of interval between age at first pregnancy and age at diagnosis on breast cancer survival according to menopausal status: a register-based study in Korea

Background

The influence of parity and time interval between age at first pregnancy (AFP) and age at diagnosis on breast cancer survival is not established in the same way as their influence on breast cancer risk. We aimed to investigate the association of time interval or parity with prognosis in pre- and postmenopausal women in Korea.

Methods

We conducted a retrospective study of 29,167 women with breast cancer through the Korean Breast Cancer Registry from 1993–2009. Information on reproductive factors, including breastfeeding, AFP, and parity were collected from a routine questionnaire. Conditional logistic regression was used to estimate the associations between menopausal status and overall mortality (OM) and breast-cancer-specific mortality (BCSM), adjusting for treatment and stage.

Results

High parity (≥5) increased the hazard ratios (HR) of BCSM (HR = 1.33, 95% confidence interval (CI): 0.83–2.11, p < 0.001) and OM (HR = 1.20, 95% CI: 0.85–1.68.73, p < 0.001) in premenopausal and postmenopausal women (BCSM, HR: 1.62, 95% CI: 0.93–2.82, p < 0.001; OM, HR = 1.58, 95% CI: 1.14–2.21, p <0.001). A longer time interval between age at breast cancer diagnosis and AFP reduced the HRs of BCSM (HR = 0.97, 95% CI: 0.96–0.98, p = 0.001) and OM (HR = 0.98, 95% CI: 0.97–0.98, p < 0.001) in premenopausal women, but had an adverse effect on the HR of OM (HR = 1.03, 95% CI: 1.02–1.03, p < 0.001) in postmenopausal women.

Conclusions

High parity (≥5) was associated with poor breast cancer prognosis in both pre- and postmenopausal women. The time intervals between reproductive events had different effects on breast cancer outcomes depending on menopausal status.

Electronic supplementary material

The online version of this article (doi:10.1186/1472-6874-14-113) contains supplementary material, which is available to authorized users.

Molecular pathways involved in pregnancy-induced prevention against breast cancer

Pregnancy produces a protective effect against breast cancer in women who had their first full term pregnancy (FTP) in their middle twenties. The later in life the first delivery occurs, the higher the risk of breast cancer development. Also, transiently during the postpartum period, the risk of developing breast cancer increases. This transient increased risk is taken over by a long-lasting protective period. The genomic profile of parous women has shown pregnancy induces a long-lasting "genomic signature" that explains the preventive effect on breast cancer. This signature reveals that chromatin remodeling is the driver of the differentiation process conferred by FTP. The chromatin remodeling process may be the ultimate step mediating the protection of the breast against developing breast cancer in post-menopausal years.

Do reproductive factors influence T, N, and M classes of ductal and lobular breast cancers? A nation-wide follow-up study

BACKGROUNDS

The clinical tumor-node-metastasis (T, N and M) classes of breast cancers provide important prognostic information. However, the possible association of TNM classes with reproductive factors has remained largely unexplored. Because every woman has a reproductive history, implications to outcome prediction are potentially significant.

METHODS

During the study period from 2002 through 2008, 5,614 pre- and 27,310 postmenopausal patients were identified in the Swedish Family-Cancer Database. Ordinal logistic regression analysis was used to estimate odds ratios (ORs) for TNM classes of breast cancers by histology. The reproductive variables were parity, age at first and last childbirth and time interval between first and last childbirth.

RESULTS

Among postmenopausal patients, the ORs for high-T class (T2-T4) (tumor size ≥2 cm) and metastasis were decreased by parity. A late age at first and last childbirth associated with high-T class and the effects were higher for lobular (OR for late age at first childbirth  = 2.85) than ductal carcinoma. Overall, long time interval between first and last childbirth was related to high-T class and metastasis. However, a short time interval between first and last childbirth in patients with late age at first or last childbirth increased the risk of metastasis. Late age at last childbirth was associated with increased occurrence of lobular carcinoma in situ. Among premenopausal ductal carcinoma patients, nulliparity and early age at first childbirth were associated with high-T class.

CONCLUSIONS

Increasing parity was protective against high-T class and metastasis; late ages at first and last childbirth were risk factors for high-T class in postmenopausal breast cancers. The current decline in parity and delayed age at first childbirth in many countries may negatively influence prognosis of breast cancer.

Pathological and epidemiological factors associated with advanced stage at diagnosis of breast cancer

BACKGROUND

Breast cancer is a highly heterogeneous disease, but the stage at presentation significantly influences outcome. It is important to dissect the pathobiological and epidemiological factors that influence the stage at presentation in order to develop effective strategies to improve clinical outcome.

SOURCES OF DATA

PubMed references relating to breast cancer subtypes, molecular classification of breast cancer, genetic susceptibility, young women and breast cancer.

AREAS OF AGREEMENT

HER-2 positive, basal-like tumours and inflammatory breast cancers (IBC) more frequently present as late stage disease. Socioeconomic, cultural and ethnic background also influence stage at presentation.

AREAS OF CONTROVERSY

The biology of IBC is poorly understood. Relative contribution of social and genetic factors in certain ethnic groups. GROWING POINTS Molecular determinants of breast cancer behaviour. Genetic and biological factors influencing disease phenotype in different ethnic groups.

AREAS TIMELY FOR DEVELOPING RESEARCH

Biology of basal-like tumours and IBC. Role of predisposition of genetic variants in determining breast cancer phenotypes. Biological differences in breast cancer from different ethnic groups.

Reproductive history and breast cancer risk

The fact that reproductive factors have significant influence on the risk of breast cancer is well known. Early age of first full-term birth is highly protective against late-onset breast cancers, but each pregnancy, including the first one, increases the risk of early-onset breast cancer. Estradiol and progesterone induce receptor activator of NF-kappa B ligand (RANKL) in estrogen receptor (ER)- and progesterone receptor (PgR)-positive luminal cells. RANKL then acts in a paracrine fashion on the membranous RANK of ER/PgR-negative epithelial stem cells of the breast. This reaction cascade is triggered by chorionic gonadotropin during the first trimester of pregnancy and results in the morphological and functional development of breast tissue. On the other hand, the administration of non-steroidal anti-inflammatory drugs in the early steps of weaning protects against tumor growth through reduction of the acute inflammatory reaction of post lactation remodeling of breast tissue. This is experimental evidence that may explain the short-term tumor-promoting effect of pregnancy. The protective effect of prolonged breast feeding may also be explained, at least in a part, by a reduced inflammatory reaction due to gradual weaning. Delay of first birth together with low parity and short duration of breast feeding are increasing social trends in developed countries. Therefore, breast cancer risk as a result of reproductive factors will not decrease in these countries in the foreseeable future. In this review, the significance of reproductive history with regard to the risk of breast cancers will be discussed, focusing on the age of first full-term birth and post lactation involution of the breast.

Association of time since last birth, age at first birth and parity with breast cancer survival among parous women: a register-based study from Norway

Reproductive factors that have a well-documented effect on breast cancer risk may also influence the prognosis of the disease, but previous studies on breast cancer survival have yielded conflicting results. We combined information from two population-based registries and obtained information on 16,970 parous women with invasive breast cancer. Cox regression analysis was used to assess breast cancer survival in relation to age at diagnosis, age at first birth, time since last birth and parity. We stratified the analyses by age at diagnosis (<50 and ≥ 50 years) as an approximation for menopausal age. In women diagnosed before 50 years of age, breast cancer survival was reduced with younger age at diagnosis (p for trend <0.001), whereas in women diagnosed at 50 years or later, survival was reduced with older age at diagnosis (p for trend 0.011). For breast cancer diagnosed before 50 years, survival was poorer in women with four or more births compared to women with one or two births (hazard ratio 1.3, 95% confidence interval 1.1-1.6). A short time since last birth was associated with reduced survival (p for trend 0.05), but adjustment for stage and grade attenuated the association. Among women diagnosed at 50 years or later, we found no association with survival for any of the reproductive factors. In summary, reproductive factors were associated with survival from breast cancer diagnosed before but not after age 50 years. Young women had a particularly poor prognosis throughout the study period.

Endocrine-active chemicals in mammary cancer causation and prevention

Endocrine-active chemicals alter or mimic physiological hormones. These compounds are reported to originate from a wide variety of sources, and recent studies have shown widespread human exposure to several of these compounds. Given the role of the sex steroid hormone, estradiol, in human breast cancer causation, endocrine-active chemicals which interfere with estrogen signaling constitute one potential factor contributing to the high incidence of breast cancer. Thus, the aim of this review is to examine several common endocrine-active chemicals and their respective roles in breast cancer causation or prevention. The plastic component, bisphenol A (BPA), the synthetic estrogen, diethylstilbestrol (DES), the by-product of organic combustion, 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), the soy component, genistein, and the red grape phytoalexin, resveratrol, have some degree of structural similarities to each other and estradiol. However, despite these structural similarities, the in vitro and in vivo properties of each of these chemicals vary greatly in terms of breast cancer causation and prevention. Early life exposure to BPA and DES increases rodent susceptibility to chemically induced mammary carcinogenesis, presumably through retardation of normal mammary gland maturation and/or disrupting the ratio of cell proliferation and apoptosis in the mammary gland. On the other hand, early exposures to genistein and resveratrol protect rodents against chemically induced and spontaneous mammary cancers. This is reported to occur through the ability of genistein and resveratrol to accelerate mammary gland maturation. Interestingly, TCDD, which is the most structurally dissimilar to the above chemicals and functions as an anti-estrogen, also increases chemically induced mammary carcinogenesis through retardation of mammary gland maturation. This article is part of a Special Issue entitled 'Endocrine disruptors'.

Pregnancy-induced changes in breast cancer risk

Breast cancer is the malignant disease most frequently diagnosed in women of all races and nationalities. Since the 1970s the worldwide incidence of this disease has increased 30-40% in postmenopausal women, in whom, paradoxically, the risk of developing breast cancer is significantly reduced by an early first full term pregnancy (FTP) as compared to nulliparous and late parous women. Although the cause of breast cancer is not known, the mechanisms mediating the protection conferred by an early FTP have been identified to reside in the breast itself, and to be modulated by endogenous and environmental exposures that might negatively affect this organ during specific windows in its development that extend from prenatal life until the first pregnancy. Soon after conception the embryo initiates the production of human chorionic gonadotropin (hCG), the glycoprotein hormone that is diagnostic of pregnancy. HCG in conjunction with ovarian steroid hormones primes the hypothalamic neuroendocrine system for maintaining the pregnancy. Higher levels of hCG during the first trimester of pregnancy have been associated with a reduction in maternal breast cancer incidence after age 50. In preclinical studies it has been demonstrated that both FTP and hCG treatment of virgin rats prevent the development of chemically-induced mammary tumors, a phenomenon mediated by the differentiation of the mammary gland epithelial cells prior to carcinogen exposure. Complete differentiation proceeds through complex morphological, physiological and molecular changes that occur during pregnancy and lactation, that ultimately result in increased DNA repair capabilities of the mammary epithelium, activation of genes controlling differentiation and programmed cell death and imprinting in the breast epithelium a specific and permanent genomic signature of pregnancy. This signature is indicative of a reduced breast cancer risk and serves as a molecular biomarker of differentiation for evaluating the potential use of chemopreventive agents.

Histological type and grade of breast cancer tumors by parity, age at birth, and time since birth: a register-based study in Norway

Background

Some studies have indicated that reproductive factors affect the risk of histological types of breast cancer differently. The long-term protective effect of a childbirth is preceded by a short-term adverse effect. Few studies have examined whether tumors diagnosed shortly after birth have specific histological characteristics.

Methods

In the present register-based study, comprising information for 22,867 Norwegian breast cancer cases (20-74 years), we examined whether histological type (9 categories) and grade of tumor (2 combined categories) differed by parity or age at first birth. Associations with time since birth were evaluated among 9709 women diagnosed before age 50 years. Chi-square tests were applied for comparing proportions, whereas odds ratios (each histological type vs. ductal, or grade 3-4 vs. grade 1-2) were estimated in polytomous and binary logistic regression analyses.

Results

Ductal tumors, the most common histological type, accounted for 81.4% of all cases, followed by lobular tumors (6.3%) and unspecified carcinomas (5.5%). Other subtypes accounted for 0.4%-1.5% of the cases each. For all histological types, the proportions differed significantly by age at diagnoses. The proportion of mucinous and tubular tumors decreased with increasing parity, whereas Paget disease and medullary tumors were most common in women of high parity. An increasing trend with increasing age at first birth was most pronounced for lobular tumors and unspecified carcinomas; an association in the opposite direction was seen in relation to medullary and tubular tumors. In age-adjusted analyses, only the proportions of unspecified carcinomas and lobular tumors decreased significantly with increasing time since first and last birth. However, ductal tumors, and malignant sarcomas, mainly phyllodes tumors, seemed to occur at higher frequency in women diagnosed <2 years after first childbirth. The proportions of medullary tumors and Paget disease were particularly high among women diagnosed 2-5 years after last birth. The high proportion of poorly differentiated tumors in women with a recent childbirth was partly explained by young age.

Conclusion

Our results support previous observations that reproductive factors affect the risk of histological types of breast cancer differently. Sarcomas, medullary tumors, and possible also Paget disease, may be particularly susceptible to pregnancy-related exposure.

[Comparison of breast cancer in young and old women based on clinicopathological features]

The two far ends of the age at the diagnosis of breast cancer are the age of younger than 35, and that of older than 70. Most probably, these two groups of patients differ in many ways. The aim of our present study was to underline the fact that age at the diagnosis of breast cancer is indeed a prognostic factor. Between October 1995 and March 2009, 80 old and 51 young breast cancer patients were treated at the Department of Diagnostic Radiology and Oncotherapy, Semmelweis University, Budapest. The prognostic and predictive factors of the tumors were analysed together with the disease-free and overall survival data. There were statistically significant differences between the two groups concerning the menstrual and reproductive factors, histological characteristics and immunophenotype of the tumors. Tumor size, nodal status and the Nottingham Prognostic Index did not show statistically significant differences. A trend to a shorter disease-free survival, higher rate of distant metastases and disease-specific death was seen in the group of young patients, but it was not significant. Overall survival was significantly shorter in the group of young patients. Therefore, we can state that young patients have a more aggressive disease and worse outcome. There is an increased importance of self examination in these groups, since both age groups are beyond the age limits of the screening population in Hungary. The media and primary school education as well should be involved in educating women concerning this aspect. The individual follow-up of young patients with positive family history should also be established.

Parity and age at first childbirth in relation to the risk of different breast cancer subgroups

The aim of the present study was to examine parity and age at first childbirth, in relation to the risk of specific breast cancer subgroups. A prospective cohort, The Malmö Diet and Cancer Study, including 17,035 women were followed with linkage to Swedish Cancer Registry until December 31, 2004. A total of 622 incident breast cancers were diagnosed during follow-up and were evaluated regarding invasiveness, tumour size, axillary lymph node status, Nottingham grade, tumour proliferation (Ki67), HER2, cyclin D1 and p27. The tumours were also examined for WHO type and hormone receptor status. Nulliparity was associated with an overall increased risk of breast cancer, although not statistically significant (the relative risk was 1.39 with a 95% confidence interval of 0.92-2.08). Nulliparity was also associated with large tumours (>20 mm) (1.89: 0.91-3.91), high Ki67 levels (1.95: 0.93-4.10), high cyclin D1 levels (2.15: 0.88-5.27), grade III (2.93: 1.29-6.64) and HER2 positive tumours (3.24: 1.02-10.25). High parity was not statistically significantly associated with any specific breast cancer subgroup. Older age at first childbirth (>30) was associated with a slightly increased risk of breast cancer (1.39: 0.94-2.07). There was a statistically significant association between late first childbirth and lobular type (2.51: 1.01-6.28), grade III tumours (2.67: 1.19-6.02), high levels of cyclin D1 (2.69: 1.18-6.12) and low levels of p27 (2.23: 1.15-4.35). We conclude that nulliparity and late first childbirth are associated with relatively more aggressive breast cancer subgroups.

Birth intervals and breast cancer risk

Background:

The interval between successive births (birth interval) may affect breast cancer risk, whereas interval from last birth to cancer onset may modify its behaviour.

Methods:

The study cohort consisted of 29 488 Finnish grand multiparous (GM) women, including 628 women with breast cancer. Conditional logistic regression for case–control design nested within the cohort was used to estimate proportional hazards (referred as relative risks, RR). Age at first birth and parity were co-variables.

Results:

Short interval (<1 year) between first and second birth increased the risk of advanced ductal breast cancer at ages < 50 years (RR=5.29; 95% CI 2.00–14.0) as compared to interval 3+ years. The risk of advanced ductal cancer was also large (RR = 4.00; 95% CI 1.19–13.4) shortly (<3 years) after last birth as compared with the period 15+ years.

Conclusions:

Short birth interval-associated excess breast cancer risk may be related to stimulatory effects of female steroid hormones produced during two closely connected pregnancies, or defective breast maturation owing to failures in breastfeeding.

Cause-Specific Survival for Women Diagnosed With Cancer During Pregnancy or Lactation: A Registry-Based Cohort Study

Purpose

To assess if cancers diagnosed during pregnancy or lactation are associated with increased risk of cause-specific death.

Patients and Methods

In this population-based cohort study using data from the Cancer Registry and the Medical Birth Registry of Norway, 42,511 women, age 16 to 49 years and diagnosed with cancer from 1967 to 2002, were eligible. They were grouped as not pregnant (reference), pregnant, or lactating at diagnosis. Cause-specific survival for all sites combined, and for the most frequent malignancies, was investigated using a Cox proportional hazards model. An additional analysis with time-dependent covariates was performed for comparison of women with and without a postcancer pregnancy. The multivariate analyses were adjusted for age at diagnosis, extent of disease, and diagnostic periods.

Results

For all sites combined, no intergroup differences in cause-specific death were seen, with hazard ratio (HR) of 1.03 (95% CI, 0.86 to 1.22) and HR 1.02 (95% CI, 0.86 to 1.22) for the pregnant and lactating groups, respectively. Patients with breast (HR, 1.95; 95% CI, 1.36 to 2.78) and ovarian cancer (HR, 2.23; 95% CI, 1.05 to 4.73) diagnosed during lactation had an increased risk of cause-specific death. Diagnosis of malignant melanoma during pregnancy slightly increased this risk. For all sites combined, the risk of cause-specific death was significantly decreased for women who had postcancer pregnancies.

Conclusion

In general, the diagnosis of most cancer types during pregnancy or lactation does not increase the risk of cause-specific death. Breast and ovarian cancer diagnosed during lactation represents an exception. We confirmed the “healthy mother effect” for women with a postcancer pregnancy.

MMTV-induced pregnancy-dependent mammary tumors : early history and new perspectives

Almost 60 years ago, Foulds carefully described for the first time a particular type of mouse mammary tumor that appeared in the glands of pregnant females and disappeared shortly after delivery. Since then, the attention that researchers paid to the Mouse Mammary Tumor Virus (MMTV)-induced pregnancy-dependent tumors has not vanished through the years. This was because the information obtained from mice carrying MMTV variants that were able to induce pregnancy-dependent tumors was meaningful for studying different aspects of mammary tumor biology. In addition, mice infected with these viral variants provided some of the few chances to use fully hormone-dependent estrogen receptor positive breast cancer models in the mouse. In the analysis of the association between tumor morphology and behavior, the mechanisms underlying progression towards autonomy, the impact of different genes during cancer initiation and development, and the relevance of host genetic background for tumor incidence and hormone-dependence, mouse strains carrying these MMTV variants have been very important tools that could not have been replaced with any other available model. The goal of this article is to provide a succinct chronicle of the experiments and observations made in the MMTV-induced pregnancy-dependent models that most significantly contributed to the mouse mammary tumor biology field. In addition, the possibility to use these MMTV variants as alternative models for analyzing mammary tumor stem cells and pregnancy-associated breast cancer in women is discussed.

Relationship of time since childbirth and other pregnancy factors to premenopausal breast cancer prognosis

OBJECTIVE

To investigate the influence of time since childbirth and other pregnancy factors on the prognosis of premenopausal breast cancer.

METHODS

Women who delivered an infant in Nova Scotia, Canada, between 1980 and 2001 were identified from a provincial perinatal database and linked to the Nova Scotia Cancer Registry to determine primary breast cancer diagnoses among women aged younger than 50 years. Relative risks and Cox proportional hazards ratios were calculated to quantify the relationship of time from childbirth to diagnosis and other pregnancy factors to the extent of disease at diagnosis and on survival after breast cancer diagnosis.

RESULTS

Of the 123,323 women who delivered an infant during the study period, 716 women were diagnosed with invasive breast cancer. Women with less than 5 years between their last delivery and diagnosis were more likely to be diagnosed with later-stage disease and had poorer survival even after adjusting for stage of disease (less than 2 years, adjusted hazards ratio 2.1, 95% confidence interval 1.2-3.9; 2-4 years, hazards ratio 1.6, 95% confidence interval 0.9-2.8) compared with women with 5 years or more. For every 13 women with less than 2 years between delivery and diagnosis, one excess death will occur, compared with women with 5 or more years between delivery and diagnosis.

CONCLUSION

A time interval of less than 2 years (and 2-4 years) between childbirth and breast cancer diagnosis worsens the prognosis in a dose-response fashion. Clinicians should be aware of these findings when examining women in the first 5 years after a delivery.

LEVEL OF EVIDENCE

II.

Prolactin does not cause breast cancer and may prevent it or be therapeutic in some conditions

The polypeptide hormone prolactin (PRL), ubiquitous and multifunctional in vertebrates, always interested biologists, was of restricted concern to clinicians and researched little compared to insulin and growth hormone. PRL in lactation initially aroused relatively little interest, but it rose when with ovarian steroids and chemical carcinogens, it was implicated in rodent mammary carcinoma. It declined when PRL suppression did not counter breast cancer. Meanwhile, long-known, estrogen-related cancers in the ovary and breast did not deter wide estrogen use for contraception and supplementation despite risk, and estrogen blockers and inhibitors have improved treatment and are on trial for prophylaxis, despite serious short and long term side-effects. Despite the great differences between steroid and polypeptide, research on PRL and breast cancer mirroring that on estrogens is now growing. This is mainly negative, much due to recent prospective research reporting minor rises in plasma levels as a basis, together with some recent laboratory research, for a hypothesis that PRL induces post-menopausal breast cancer. That view contradicts a reproductive biology that evolved to benefit women and offspring. Elevated PRL in pregnancy and probably that in lactation, reduce risk. Many exogenous chemical and physical PRL-stimulants also do not increase risk. It has not been shown that PRL increases risk of breast cancer and some older and recent cell and tissue data suggest it may be the key, two-sided, in human breast tissue homeostasis. Excessive disturbance of this is unlikely to originate in PRL itself. The natural biology of PRL, the reproductive woman's hormone par excellence, and research in various fields, suggest a positive potential in the PRL family for direct prevention and treatment of breast cancer, possibly greater than that in the estrogens. It is time to debate and research this.

Genetic and epigenetic alterations in breast cancer: what are the perspectives for clinical practice?

The worldwide incidence of breast cancer affects 1.2 million women each year. In contrast to the high occurrence of this malady, a decline in mortality is reported among industrialized countries. In this respect, both awareness campaigns and substantial progress achieved in therapy and diagnosis allowed for the enhancement of the survival rate in patients with breast cancer. Undoubtedly, oncology research programs played a relevant role in the improvement of therapeutics and diagnostics for breast cancer. Major strides were reported, especially over the last decade and a half, in better understanding molecular and cellular biology events involved in breast cancer pathogenesis and progression of the disease. However, therapeutic approaches for the treatment of patients with breast cancer need further improvement. Therapeutic interventions can chronically compromise both the state of health and quality of life of breast cancer survivors. In addition, current therapeutic approaches have not significantly improved the survival rate in patients with metastatic disease. On these grounds, it is necessary to develop more efficient therapeutics and diagnostic tools, which can improve the health and quality of life of breast cancer survivors and increase the survival rate in patients with metastatic disease. In this respect, the field of cancer research has placed a particular emphasis on the elucidation of genetic and epigenetic alterations that may lead to the pathogenesis of breast cancer and contribute to its progression.

Breast-feeding after breast cancer in childbearing women

According to the American Cancer Society in 2007, about 178,000 women are diagnosed with breast cancer each year in the United States. Of these, 25% have tumors in their childbearing years and may desire future opportunities for pregnancy and lactation. Although there is a multitude of options related to preserving fertility, little is known about the residual effects of breast cancer treatment and the ability to breast-feed afterward. This article describes the epidemiological relationship between breast cancer and pregnancy and lactation. Basic types of treatment for breast cancer including surgery, chemotherapy, and radiation are reviewed. Practical information on how to support breast-feeding after breast cancer is included.

Risk of familial breast cancer is not increased after pregnancy

Risk of breast cancer is temporarily elevated shortly after pregnancy and the available limited data suggest that a family history of breast cancer may reinforce the risk. We used the nation-wide Swedish Family-Cancer Database to estimate the relative risk (RR) for invasive breast cancer following childbirth among women with or without a family history. The RRs were defined using Poisson regression model of person-years as offset, adjusted for age, period and age at first childbirth. For women without a family history, RRs for breast cancer showed a U-shaped pattern after last pregnancy. Among the 5,217 patients with a first-degree family history the familial risk was 1.77; there was no evidence of increased RRs immediately after last pregnancy. The present study is by far the largest one published on the theme. It shows that pregnancy is not an additional risk factor for women with a family history.

Family history of breast cancer and short-term effects of childbirths on breast cancer risk

The long-term protective effect of a pregnancy on breast cancer risk is preceded by a short-term adverse effect, possibly reflecting a promoting effect of pregnancy hormones. In the present study, we explore whether a family history of breast cancer modifies time-related effects of pregnancies, with special emphasis on the transient increase in risk of breast cancer shortly after birth. Our study cohort comprises 1,067,289 Norwegian women aged 20-74 years. The mean follow-up time was 18 years. Incidence rate ratios were estimated by Poisson regression analyses of person-years at risk. Of the 7,377 women diagnosed with breast cancer during follow-up, a total of 828 (11%) had a mother or a sister with breast cancer diagnosis. Women with a family history of breast cancer had a 2-3-fold higher risk of breast cancer than did women without any affected family member, highest for those with a relative diagnosed before they were 50 years. Similar to women without a familial excess risk, increasing parity was associated with an overall protective effect among women with a familial predisposition, regardless of age at diagnosis of the relative. Whereas women with no familial excess risk experienced a transient increase in risk mainly after late age births, women with a family history of breast cancer experienced an adverse effect of pregnancies also at younger ages. The present results give further support to the hypothesis that the adverse effect of a term birth can be explained by a promoting effect of pregnancy hormones.

Pregnancy and breast cancer: the other side of the coin

Early full-term pregnancy is thought to be one of the most effective means of decreasing lifetime breast cancer risk. Paradoxically, young women diagnosed with breast cancer shortly after giving birth have a higher risk of dying from their disease. These seemingly opposing effects have been largely attributed to mammary epithelial stem cell differentiation and precancerous cell proliferation, respectively, induced by pregnancy-associated hormonal changes. However, recent studies suggest that remodeling of the cellular microenvironment and extracellular matrix during pregnancy and involution may contribute to the enhanced invasive and metastatic potential of breast carcinomas and thus lead to their worse clinical outcome.