Prognostic influence of pregnancy before, around, and after diagnosis of breast cancer

Maternal survival of patients with pregnancy-associated cancers in Taiwan - A national population-based study

Pregnancy-associated cancer (PAC), defined as cancers diagnosed during pregnancy or the first year after delivery, affects one to two in every 1000 pregnancies. Although PAC is expected to be a growing issue, information about PAC in the Asian population is still scarce. Women with cancer diagnosed at the age of 16-49 years between 2001 and 2015 were selected from the Taiwan Cancer Registry and linked with the National Birth Reporting Database to identify PAC patients. We compared the overall survival of patients with PAC to patients without pregnancy. Among 126,646 female cancer patients of childbearing age, 512 were diagnosed during pregnancy, and 2151 during the first postpartum year. Breast cancer was the most common PAC (N = 755, 28%). Compared with patients without pregnancy in the control group, patients with cancers diagnosed during pregnancy and the first postpartum year generally had more advanced stages (odds ratio 1.35 and 1.36, 95% confidence interval [CI] 1.02-1.77 and 1.18-1.57, respectively). For all cancer types combined and controlled for the stage, age, and year of diagnosis, patients with PAC had similar overall survival with those in the control group, with a hazard ratio (HR) of 1.07 (95% CI 0.80-1.41) for the pregnancy group and HR 1.02 (95% CI 0.88-1.18) for the postpartum group. The diagnosis of breast cancer during the first postpartum year was linked with shorter survival (HR 1.34, 95% CI 1.05-1.72). In contrast, patients with postpartum lymphoma (HR 0.11, 95% CI 0.02-0.79) and cervical cancer (HR 0.40, 95% CI 0.20-0.82) had better prognosis. In general, the diagnosis of cancer during pregnancy or the first postpartum year does not affect the survival of patients with most cancer types. Exceptions include the worse prognosis of postpartum breast cancer and the better outcome of postpartum lymphoma and cervical cancer.

Neoadjuvant Chemotherapy and Prognosis of Pregnancy-Associated Breast Cancer: A Time-Trends Study of the Korean Breast Cancer Registry Database

Purpose

Pregnancy-associated breast cancer (PABC) is rare, and its cause and prognosis are not well known. Additionally, treatment is limited with respect to the risk to the fetus. The purpose of this study was to investigate the characteristics and treatment trends of PABC and the survival rate according to the treatment.

Methods

In the Korean Breast Cancer Society Registry database, women younger than 50 years and who were diagnosed with breast cancer from 1996 to 2015 were included. PABC was defined as breast cancer diagnosed during pregnancy or within 1 year after delivery.

Results

We examined 411 patients with PABC and 83,381 patients with non-PABC. Over time, the proportions of patients undergoing breast-conserving surgery and sentinel lymph node biopsy increased, and neoadjuvant chemotherapy and radiation therapy administration rates also increased. In the past, the overall survival of patients with PABC was poorer than that of patients with non-PABC, but there was no difference in overall survival rates in more recent years. There was no difference in overall survival rates between patients who received neoadjuvant chemotherapy (hazard ratio [HR], 1.28; 95% confidence interval [CI], 0.66–2.49; p=0.459), but PABC conferred poorer prognosis than non-PABC in patients receiving adjuvant chemotherapy (HR, 1.63; 95% CI, 1.27–2.08; p<0.001).

Conclusion

There was no difference in the prognosis between patients with PABC and those with non-PABC receiving neoadjuvant chemotherapy. The increase in neoadjuvant chemotherapy according to current treatment guidelines is expected to improve the survival rate of patients with PABC.

Association of pregnancy and mortality in women diagnosed with breast cancer: A Nationwide Population Based Study in Taiwan

We examined the associations between breast cancer diagnosed during pregnancy and up to 5 years postpartum and total mortality. Breast cancer patients were identified from the Taiwan Cancer Registry (2002-2014). All pregnancies up to 5 years before breast cancer diagnosis were abstracted from the National Health Insurance database and data were then linked to the Taiwan National Death Certificate Database. Follow-up was calculated from the date of breast cancer diagnosis to the date of death or 31 December, 2014, whichever came first. The hazard ratios (HRs) and the 95% confidence intervals (CI) of the association between pregnancy and total mortality were estimated using Cox proportional hazard models. Among the 30,230 breast cancer patients, 90 were diagnosed during pregnancy, 347 within a year postpartum, and 1993 during 1-5 years postpartum. By the end of 2014, 2,920 patients were dead. The major cause of death was breast cancer (89%). Compared to patients without pregnancy records, the HRs were 1.42 (95% CI = 0.83-2.45) for patients diagnosed during pregnancy, 1.29 (0.96-1.74) for those diagnosed within a year postpartum, 1.27 (0.95-1.70) for those diagnosed within 1 to 2 years postpartum, and 1.06 (0.88-1.27) for those diagnosed ≥2 to 5 years postpartum, after adjustment for tumor characteristics and treatment. Subgroup analyses revealed an increased risk of mortality for patients diagnosed within a year postpartum in ER+ cancers (HR = 2.11, 95% CI = 1.28-3.47). Our results suggested a recent pregnancy may be associated with higher mortality among ER+ patients.

Human Chorionic Gonadotropin and Breast Cancer

Breast cancer is well known as a malignancy being strongly influenced by female steroids. Pregnancy is a protective factor against breast cancer. Human chorionic gonadotropin (HCG) is a candidate hormone which could mediate this antitumoral effect of pregnancy. For this review article, all original research articles on the role of HCG in breast cancer were considered, which are listed in PubMed database and were written in English. The role of HCG in breast cancer seems to be a paradox. Placental heterodimeric HCG acts as a protective agent by imprinting a permanent genomic signature of the mammary gland determining a refractory condition to malignant transformation which is characterized by cellular differentiation, apoptosis and growth inhibition. On the other hand, ectopic expression of β-HCG in various cancer entities is associated with poor prognosis due to its tumor-promoting function. Placental HCG and ectopically expressed β-HCG exert opposite effects on breast tumorigenesis. Therefore, mimicking pregnancy by treatment with HCG is suggested as a strategy for breast cancer prevention, whereas targeting β-HCG expressing tumor cells seems to be an option for breast cancer therapy.

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.

Decreased hormonal sensitivity after childbirth rather than the tumor size influences the prognosis of very young breast cancer patients

Purpose

There is a significant difference in the mean tumor size between very young breast cancer patients and their elder counterparts. A simple comparison may show obvious prognostic differences. We investigated the prognostic impact of age by reducing the influence of the tumor size, which is thought to be a confounding factor.

Patients and methods

We investigated 1,880 consecutive pT1-4N0-3M0 breast cancer patients treated at less than 45 years of age between 1986 and 2002 and conducted a case–control study of breast cancer subjects less than 30 years of age. Each patient (Younger than 30) was matched with a corresponding control subject (Elder counterpart) based on an age 15 years above the patient’s age, a similar tumor size and a status of being within 1 year after surgery. In addition, we assessed 47 patients with pregnancy-associated breast cancer (PABC). The levels of hormone receptors were measured using an enzyme immunoassay (EIA), and receptor-positive cases were divided into “weakly” and “strongly” positive groups based on the median value. Years from the last childbirth (YFLC) was categorized as “recent” and “past” at the time point of 8 years.

Results

There were fewer past YFLC cases, more partial mastectomy cases, a higher rate of scirrhous carcinoma or solid-tubular carcinoma in the Younger than 30 group than in the Elder counterpart group. The rates of a PgR-negative status in the Younger than 30 and Elder counterpart groups were 45.1 and 29.9%, respectively, As for the relationship between the PgR-negative rate and YFLC, the rates of a PgR-negative status in the past YFLC, nulliparous, recent YFLC and PABC groups were 31.9, 37.7, 44.4 and 65.7%, respectively. On the other hand, the rates of strongly positive cases were 42.6, 30.2, 22.2 and 8.6%, respectively. The 10-year recurrence-free survival rates in the Younger than 30, Elder counterpart and PABC groups were 61.7, 65.6 and 54.1%, respectively. The differences between the groups were not significant. In a multivariate analysis, independent prognostic facers included the number of lymph node metastases (4–9, HR:3.388, 95% CI 1.363–8.425, p = 0.0086, over 10, HR: 6.714, 2.033–22.177, p = 0.0018), solid-tubular carcinoma (HR 3.348, 1.352–8.292, p = 0.0090), scirrhous carcinoma (HR 2.294, 1.013–5.197, p = 0.0465) and past YFLC (HR 0.422, 0.186–0.956, p = 0.0387). An age younger than 30 was not found to be an independent prognostic factor.

Conclusions

The prognosis of the very young women was the same as their elder counterparts with a matched tumor size, and age was not identified to be an independent prognostic factor according to the multivariate analysis. Recent childbirth probably influences the prognosis of patients younger than 30 years of age with breast cancer by lowering hormonal sensitivity.

Tumor subtype-specific associations of hormone-related reproductive factors on breast cancer survival

PURPOSE

It is inconclusive whether reproductive factors, which are known as risk factors of breast cancer, also influence survival. We investigated overall and subtype-specific associations between reproductive factors and breast cancer survival.

METHODS

Among 3,430 incident breast cancer patients who enrolled in the Seoul Breast Cancer Study, 269 patients (7.8%) died and 528 patients (15.4%) recurred. The overall and subtype-specific associations of reproductive factors including age at menarche and menopause, duration of estrogen exposure, menstrual cycle, parity, age at first full-term pregnancy, number of children, age at last birth, time since the last birth, and duration of breastfeeding, on overall and disease-free survival (OS and DFS) were estimated by hazard ratios (HRs) and 95% confidence intervals (95% CIs) using a multivariate Cox proportional hazard model.

RESULTS

An older age at menarche (HR for OS=1.10, 95% CI=1.03-1.19), a greater number of children (≥ 4 vs. 2, HR for DFS=1.58, 95% CI=1.11-2.26), and a shorter time since last birth (<5 vs. ≥ 20 years, HR for DFS=1.67, 95% CI=1.07-2.62) were associated with worse survival while longer duration of estrogen exposure with better survival (HR for DFS=0.97, 95% CI=0.96-0.99). In the stratified analyses by subtypes, those associations were more pronounced among women with hormone receptor and human epidermal growth factor 2 positive (HR+ HER2+) tumors.

CONCLUSIONS

It is suggested that reproductive factors, specifically age at menarche, number of children, time since last birth, and duration of estrogen exposure, could influence breast tumor progression, especially in the HR+ HER2+ subtype.

Birth size in the most recent pregnancy and maternal mortality in premenopausal breast cancer by tumor characteristics

The main aim of this study was to investigate possible associations between measures of offspring size at birth in the most recent pregnancy before premenopausal breast cancer diagnosis and the risks of maternal breast cancer mortality, taking tumor characteristics into account. We also aimed to investigate if these associations are modified by age at childbirth, time since childbirth, parity, and age at diagnosis. We followed 6,019 women from their date of premenopausal breast cancer (diagnosed from 1992 to 2008) until emigration, death or December 31st, 2009, whichever occurred first. We used Cox proportional hazard regression models, adjusted for parity, age at diagnosis, and education level, to estimate associations between women pregnancy, cancer characteristics and offspring birth characteristics, and mothers' mortality risk. In stratified analyses, mortality risks were estimated by tumor stage, ER or PR status. There was no association between offspring birth weight (HR = 1.00, 95 % CI 0.99-1.01, when used as a continuous variable), birth weight for gestational age or ponderal index, and premenopausal breast cancer mortality. Similarly, in analyses stratified by tumor stage, receptor status, and time difference between last pregnancy and date of diagnosis, we found no associations between birth size and breast cancer mortality. Our findings suggest that the hypothesis that "premenopausal breast cancer mortality is associated with offspring birth characteristics in the most recent pregnancy before the diagnosis" may not be valid. In addition, these associations are not modified by tumor characteristics.

Fertility preservation outcomes may differ by cancer diagnosis

CONTEXT

Cancer survival has improved significantly and maintaining fertility is both a major concern and an important factor for the quality of life in cancer patients.

AIMS

To explore differences in oocyte stimulation for fertility preservation (FP) patients based on cancer diagnosis.

SETTINGS AND DEIGN

Between 2005 and 2011, 109 patients elected to pursue FP at a single institution.

MATERIALS AND METHOD

In vitro fertilization (IVF) outcome variables between four cancer diagnostic groups (breast, gynecologic, lymphoma/leukemia and other) and age-matched male factor or tubal factor infertility IVF control group were compared.

STATISTICAL ANALYSIS

ANOVA and Chi-square analyses were employed to compare variables between the groups that were normally distributed. Kruskal-Wallis with subsequent Mann-Whitney U-test were used for data that were not normally distributed.

RESULTS

Women with gynecologic malignancies were significantly older than the women in the other three groups, but tended to have a better ovarian response. Women with hematologic malignancies were most likely to have been exposed to chemotherapy and had the longest stimulations with a similar number of oocytes retrieved. The age-matched IVF controls had higher peak estradiol levels, number of oocytes obtained, and fertilization rates when compared to cancer patients with or without a history of prior chemotherapy.

CONCLUSIONS

Factors including age, type of cancer and chemotherapy exposure, can influence response to ovarian stimulation. Discussing these findings with patients presenting for FP may aid in setting realistic treatment expectations.

The impact of pregnancy on breast cancer survival in women who carry a BRCA1 or BRCA2 mutation

Physicians are often approached by young women with a BRCA mutation and a recent history of breast cancer who wish to have a baby. They wish to know if pregnancy impacts upon their future risks of cancer recurrence and survival. To date, there is little information on the survival experience of women who carry a mutation in one of the BRCA genes and who become pregnant. From an international multi-center cohort study of 12,084 women with a BRCA1 or BRCA2 mutation, we identified 128 case subjects who were diagnosed with breast cancer while pregnant or who became pregnant after a diagnosis of breast cancer. These women were age-matched to 269 mutation carriers with breast cancer who did not become pregnant (controls). Subjects were followed from the date of breast cancer diagnosis until the date of last follow-up or death from breast cancer. The Kaplan-Meier method was used to estimate 15-year survival rates. The hazard ratio for survival associated with pregnancy was calculated using a left-truncated Cox proportional hazard model, adjusting for other prognostic factors. Among women who were diagnosed with breast cancer when pregnant or who became pregnant thereafter, the 15-year survival rate was 91.5 %, compared to a survival of 88.6 % for women who did not become pregnant (adjusted hazard ratio = 0.76; 95 % CI 0.31-1.91; p = 0.56). Pregnancy concurrent with or after a diagnosis of breast cancer does not appear to adversely affect survival among BRCA1/2 mutation carriers.

Hypothesized role of pregnancy hormones on HER2+ breast tumor development

Breast cancer incidence rates have declined among older but not younger women; the latter are more likely to be diagnosed with breast cancers carrying a poor prognosis. Epidemiological evidence supports an increase in breast cancer incidence following pregnancy with risk elevated as much as 10 years post-partum. We investigated the association between years since last full-term pregnancy at the time of diagnosis (≤10 or >10 years) and breast tumor subtype in a case series of premenopausal Hispanic women (n = 627). Participants were recruited in the United States, Mexico, and Spain. Cases with known estrogen receptor (ER), progesterone receptor (PR), and HER2 status, with one or more full-term pregnancies ≥1 year prior to diagnosis were eligible for this analysis. Cases were classified into three tumor subtypes according to hormone receptor (HR+ = ER+ and/or PR+; HR- = ER- and PR-) expression and HER2 status: HR+/HER2-, HER2+ (regardless of HR), and triple negative breast cancer. Case-only odds ratios (ORs) and 95 % confidence intervals (CIs) were calculated for HER2+ tumors in reference to HR+/HER2- tumors. Participants were pooled in a mixed-effects logistic regression model with years since pregnancy as a fixed effect and study site as a random effect. When compared to HR+/HER2- cases, women with HER2+ tumors were more likely be diagnosed in the post-partum period of ≤10 years (OR = 1.68; 95 % CI, 1.12-2.52). The effect was present across all source populations and independent of the HR status of the HER2+ tumor. Adjusting for age at diagnosis (≤45 or >45 years) did not materially alter our results (OR = 1.78; 95 % CI, 1.08-2.93). These findings support the novel hypothesis that factors associated with the post-partum breast, possibly hormonal, are involved in the development of HER2+ tumors.

Placental weight and mortality in premenopausal breast cancer by tumor characteristics

Placental weight may be regarded as an indirect marker of hormone exposures during pregnancy. There is epidemiological evidence that breast cancer mortality in premenopausal women increases with placental weight in the most recent pregnancy. We investigated if this association differs by tumor characteristics, including expression of estrogen and progesterone receptors. In a Swedish population-based cohort, we followed 1,067 women with premenopausal breast cancer diagnosed from 1992 to 2006. Using Cox regression models, we estimated hazard ratios for the association between placental weight and risk of premenopausal breast cancer mortality. In stratified analyses, we estimated mortality risks in subjects with different tumor stages, estrogen receptor (ER) or progesterone receptor (PR) status. Compared with women with placental weight less than 600 g, women with a placental weight between 600 and 699 g were at a 50 % increased risk of mortality, however, not significant change in risk was observed for women with placental weight ≥ 700 g. Mortality risks associated with higher placental weight were more pronounced among ER(-) and PR(-) breast cancer tumors, where both a placental weight 600-699 g and ≥ 700 g were associated with a more than doubled mortality risks compared with tumors among women with placental weight less than 600 g. Moreover, stratified analyses for joint receptor status revealed that a consistent increased mortality risk by placental weight was only apparent in women with ER(-)/PR(-) breast cancer. The increased mortality risk in premenopausal breast cancer associated with higher placental weight was most pronounced among ER(-) and PR(-) tumors.

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.

Increased mortality in women with breast cancer detected during pregnancy and different periods postpartum

BACKGROUND

Because of a continued trend toward postponed childbearing, the incidence of pregnancy-associated breast cancer (PABC) is likely to increase. This study investigated the mortality in women with PABC in relation to when the tumor was detected (during pregnancy, different postpartum periods) and by time since diagnosis, compared with women with non-PABC.

METHODS

A population-based cohort study of 15,721 Swedish women diagnosed with breast cancer between ages 15 to 44 years, of whom 1,110 (7%) had a PABC (diagnosed during or within two years after pregnancy). Information on outcome and potential confounders was obtained from population-based health registers. Mortality rates and HRs with 95% CIs were estimated.

RESULTS

Women with PABC had higher mortality compared with women with non-PABC diagnosed at the same age and calendar period. Among women with PABC, 46% died within 15 years after diagnosis, whereas 34% died among non-PABC patients. The mortality in both groups peaked at around two years after diagnosis, with the highest peak occurring in women diagnosed 4 to 6 months after delivery (HR = 3.8, 95% CI: 2.4-5.9). An increased mortality among women with PABC remained until 10 years after diagnosis.

CONCLUSIONS

Women with PABC had a poorer prognosis compared with women with breast cancer and no recent birth. The mortality increase was most pronounced in the subgroup of women diagnosed shortly after delivery.

IMPACT

An increased awareness among clinicians may help reduce the mortality in women with PABC, for example, by avoiding undue delays in diagnosis and treatment.

miR-21 Expression in Pregnancy-Associated Breast Cancer: A Possible Marker of Poor Prognosis

Aims: microRNAs (miRNAs) are a class of small noncoding RNAs that can act as key modulators in tumorigenesis-related genes. Specifically, it has been suggested that miR-21 overexpression plays a role in the development and progression of breast cancer. So far, the role of miRNAs in pregnancy-associated breast cancer (PABC) has not been investigated.

Methods and Results: We evaluated miR-21 expression by quantitative RT-PCR in 35 patients, 25 with PABC and 10 control breast cancer cases not pregnancy-associated with similar clinicopathological features. We then analyzed protein expression for PTEN, BCL2 and PDCD4 as miR-21 target genes by IHC, and finally correlated the results with patients' clinicopathological features.

Significant overexpression of miR-21 in PABC tumors compared to normal adjacent tissue was found. Overexpression of miR-21 was frequently found in high grade tumors with loss of hormone receptor expression and was significantly associated with positive lymph nodes (p=0.025). In PABC patients, PTEN, BCL2 and PDCD4 target protein expression was decreased in 80%, 76% and 40% respectively.

Conclusion: Our study supports the involvement of miR-21 in breast cancer progression and metastasis formation in PABC implying a role of this miRNA as a marker for poor prognosis in PABC patients.

Trends in the survival of patients diagnosed with breast cancer in the Nordic countries 1964-2003 followed up to the end of 2006

BACKGROUND

Breast cancer is the leading cancer among women worldwide in terms of both incidence and mortality. European patients have generally high 5-year relative survival ratios, and the Nordic countries, except for Denmark, have ratios among the highest.

MATERIAL AND METHODS

Based on the NORDCAN database we present trends in age-standardised incidence and mortality rates of invasive breast cancer in the Nordic countries, alongside 5- and 10-year relative survival for the period of diagnosis 1964-2003 followed up to the end of 2006. Excess mortality rates are also provided for varying follow-up intervals after diagnosis. The analysis is confined to invasive breast cancer in Nordic women.

RESULTS

Incidence increased rapidly in all five countries, whereas mortality remained almost unchanged. Both incidence and mortality rates were highest in Denmark. Between 1964 and 2003 both 5- and 10-year relative survival increased by 20-30 percentage points in all countries, and 10-year survival remained around 10 percentage points lower than 5-year survival. Relative survival was lowest in Denmark throughout the period, with a 5-year survival of 79% for years 1999-2003, but 83-87% in the other countries. From 1964 the youngest women had the highest survival ratios up until the introduction of screening, when a shift occurred towards higher survival among age groups 50-59 and 60-69 in each country, except for Denmark. Excess death rates during the first months after diagnosis were highest in Denmark.

CONCLUSION

Breast cancer survival is high and rising in the Nordic countries, and probably relates to the early implementation of organised mammography screening in each country except Denmark and a high and relatively uniform standard of living, diagnosis and treatment. Denmark stands out with higher mortality and poorer survival. The major determinants may include a failure to instigate national breast screening and a greater co-morbidity resulting from a higher prevalence of both tobacco smoking and alcohol consumption.

Effect of childbirth after treatment on long-term survival from breast cancer

Background

This study quantified long-term absolute and relative mortality risks of survivors of breast cancer with subsequent childbirth.

Methods

The Singapore Birth Register (n = 319 437), Swedish Multi-Generation Register (n = 11 million) and population-based cancer registries were linked to identify 492 women with childbirth after breast cancer. For these women, cumulative mortality risks and standardized mortality ratios (SMRs) were calculated and compared with those of 8529 women aged less than 40 years with breast cancer without subsequent childbirth, and with those predicted by Adjuvant! Online.

Results

Women with subsequent childbirth had a lower 15-year cumulative overall mortality rate than other women with breast cancer (16·8 (95 per cent confidence interval (c.i.) 13·3 to 20·9) versus 40·7 (39·5 to 41·9) per cent), but a higher relative mortality risk than the background population (SMR 13·6, 95 per cent c.i. 10·6 to 17·3). Mortality risks decreased significantly with increasing interval between diagnosis and subsequent childbirth. Mean 10-year cumulative mortality risks of women with subsequent childbirth were within the range of 10-year mortality predicted by Adjuvant! Online for women with T1 N0 tumours in otherwise perfect health.

Conclusion

This study reinforced the view that pregnancy after breast cancer is not detrimental to survival. However, women who gave birth after this diagnosis had substantially higher mortality risks than young women in the general population. This information may be a valuable addition to routine mortality estimates.

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.

Prognosis for patients diagnosed with pregnancy-associated breast cancer: a paired case-control study

CONTEXT AND OBJECTIVE

Previous studies have suggested that the occurrence of pregnancy concomitantly with a diagnosis of breast cancer may affect the evolution of the neoplasia. The present study aimed to compare pregnancy-associated breast cancer (PABC) patients with non-pregnant cancer patients (controls) in relation to the time taken to diagnose the disease, tumor characteristics and mortality.

DESIGN AND SETTING

A retrospective, paired case-control study was conducted at the Hospital da Santa Casa de Misericórdia and Centro de Quimioterapia Antiblástica e Imunoterapia in Belo Horizonte, Brazil.

METHODS

The study involved 87 PABC and 252 control patients. The influence of covariables (interval between first symptoms and diagnosis, tumor histology, size of primary tumor, distant metastasis, grade of malignancy, hormone receptor status and axillary lymph node involvement) and the pregnancy variable on overall survival was investigated using univariate and multivariate analyses.

RESULTS

The median overall survival for PABC patients of 30.1 months (95% confidence interval, CI: 19.4-40.9 months) was significantly different (P = 0.005) from that of the control group (53.1 months; 95% CI: 35.1-71.0 months). The cumulative overall survivals after five and ten years were, respectively, 29.7 and 19.2% for PABC patients, and 47.3 and 34.8% for control patients (P = 0.005). Tumor size, grade of malignancy, distant metastasis and pregnancy were independent factors that significantly modified disease prognosis.

CONCLUSIONS

Pregnancy was an independent prognostic factor. The overall survival of PABC patients was shorter than that of non-pregnant patients.

Macrophages in breast cancer: do involution macrophages account for the poor prognosis of pregnancy-associated breast cancer?

Macrophage influx is associated with negative outcomes for women with breast cancer and has been demonstrated to be required for metastasis of mammary tumors in mouse models. Pregnancy-associated breast cancer is characterized by particularly poor outcomes, however the reasons remain obscure. Recently, post-pregnancy mammary involution has been characterized as having a wound healing signature. We have proposed the involution-hypothesis, which states that the wound healing microenvironment of the involuting gland is tumor promotional. Macrophage influx is one of the prominent features of the involuting gland, identifying the macrophage a potential instigator of tumor progression and a novel target for breast cancer treatment and prevention.

Placental weight and breast cancer survival in young women

A growing body of evidence indicates that reproductive history influences survival in breast cancer, especially among women diagnosed during or shortly after a pregnancy. However, little is known about the underlying mechanisms. We hypothesized that increasing placental weight, as an indirect marker of exposure to elevated hormone levels during pregnancy, would be associated with reduced survival in breast cancer. A cohort of 1873 women with at least one pregnancy after January 1st, 1973, and a subsequent breast cancer diagnosis before the end of 1991 were followed up for death or emigration through 2006. Information on placental weight and potential confounding factors were collected from medical records and from nationwide registers, which resulted in data on placental weight in the most recent pregnancy before diagnosis for 1,057 cases. For each 100-gram increase in placental weight, the adjusted hazard ratio of death was 1.09 [95% confidence interval (CI), 0.99-1.19]. The association was stronger among primiparous women (adjusted hazard ratio, 1.26; 95% CI, 1.09-1.47), and among women diagnosed during pregnancy or within 2 years from last birth (adjusted hazard ratio, 1.30; 95% CI, 1.06-1.59). Increasing placental weight is associated with reduced breast cancer survival. These findings are consistent with the hypothesis that the reduced survival in breast cancer among women with a recent childbirth is linked to pregnancy hormone exposure.

Recent trends in breast cancer among younger women in the United States

Increases in the incidence of postmenopausal breast cancers have been linked to screening and menopausal hormone use, but younger women have received less attention. Thus, we analyzed trends in breast cancer incidence (N = 387 231) using the National Cancer Institute's Surveillance, Epidemiology, and End Results Program 13-Registry database (1992-2004). Whites had higher incidence rates than blacks after age 40 years, but the reverse was true among younger women (black-white crossover). Among younger women, the rate per 100,000 woman-years was 16.8 for black vs 15.1 for white women; the highest black-white incidence rate ratio (IRR) was seen among women younger than 30 years (IRR = 1.52, 95% confidence interval = 1.34 to 1.73). This risk pattern was not observed in other ethnic groups. The black-white crossover among younger women was largely restricted to breast cancers with favorable tumor characteristics. The annual percentage change in the incidence of invasive breast cancers decreased modestly among older women but increased among younger (<40 years) white women. Continued surveillance of trends is needed, particularly for molecular subtypes that preferentially occur among young women.

Pregnancy after treatment of breast cancer--a population-based study on behalf of Danish Breast Cancer Cooperative Group

BACKGROUND

Estrogen is an established growth factor in breast cancer and it has been hypothesized that pregnancy associated estrogens may increase the risk of recurrence of breast cancer. In 1997 we published a population-based Danish study indicating no negative prognostic effect of pregnancy after breast cancer treatment. The present study is a ten-year update.

MATERIAL AND METHODS

Danish Breast Cancer Cooperative Group has since 1977 collected population-based data on tumour characteristics, treatment regimes, and follow-up status on Danish women with breast cancer. Pregnancy history was added from the Danish Civil Registration System, the National Birth Registry, and the National Induced Abortion registry. Cox regression was used to estimate the risk ratio of dying among women with a pregnancy after breast cancer treatment compared with women without such experience.

RESULTS

In all, 10 236 women with primary breast cancer aged 45 years or less at the time of diagnosis were followed for 95 616 person years. Among these, 371 women experienced pregnancy after treatment of breast cancer. In a multivariate analysis that included age at diagnosis, stage of disease, and pregnancy history prior to diagnosis, women who had a full-term pregnancy subsequent to breast cancer treatment were found to have a reduced risk of dying (relative risk: 0.73; 95% confidence interval: 0.54-0.99) compared with other women with breast cancer. The effect was not significantly modified by age at diagnosis, tumour size, nodal status, or pregnancy history before diagnosis of breast cancer. Neither spontaneous abortions nor induced abortions subsequent to breast cancer treatment had a negative impact on prognosis.

CONCLUSION

In line with our previous study, but based on more than twice the patient material, we found no evidence that a pregnancy after treatment of breast cancer has a negative influence the prognosis.

Ovarian function and childbearing issues in breast cancer survivors

The increasing number of breast cancer survivors makes the issues of ovarian dysfunction and childbearing ability more and more relevant for the quality of life of these patients. The incidence of ovarian dysfunction is related to patient age, the specific agents used and the total dose administered, especially the dose of alkylating agents such as cyclophosphamide. Amenorrhea rates following combination chemotherapy consisting of cyclophosphamide + methotrexate + 5-flurouracil (CMF regimen) range from 21 to 71% in women aged 40 years and younger, and from 40 to 100% in older ones. In most series anthracycline-based adjuvant chemotherapy regimens appear to have a lower incidence of amenorrhea, which is probably due to the lower cumulative cyclophosphamide dose administered compared with that given in the CMF regimen. Few data are currently available regarding ovarian function in women treated with taxane-based chemotherapy. In a recent retrospective study on 191 patients, the amenorrhea rate was 64% for women who received doxorubicin + cyclophosphamide (AC regimen) followed by a taxane, compared with 55% (p = 0.05) for those treated with AC alone. Forty percent of women aged 40 years or younger resumed menstruation, whereas the amenorrhea was more likely to be irreversible in older women; however, the addition of a taxane did not change the reversibility rate. Ovarian reserve can be tested with serum assays of follicle-stimulating hormone, inhibin B, estradiol and anti-Müllerian hormone, as well as by ultrasound assessment of antral follicle count. A review of literature data failed to show that a subsequent pregnancy increases the risk of recurrence and death in breast cancer survivors, and some series have even detected longer survival for patients who get pregnant after breast cancer treatment. This apparent survival benefit, probably due to a selection bias called the 'healthy mother effect', suggests that breast cancer survivors who subsequently conceive are a self-selecting group of women with better prognosis. The little available information appears to show no increase in the incidence of prematurity, stillbirth or congenital malformations in their babies. In conclusion, future pregnancy is a viable option for a woman treated for early-stage breast cancer and does not appear to be detrimental to either the mother or her offspring.

Current controversies in the management of early breast cancer

Medical professionals in general, and medical oncologists in particular, have highly stressful practices because they are under constant pressure to have the highest-quality, up-to-date evidence available in order to make the right decision for each individual patient. From a practical point of view, being updated on oncological and other medical specialties may seem an insurmountable task because the number of scientific publications has increased dramatically. The use of systematic reviews of randomised controlled trials or the application of results obtained from high-quality randomised controlled trials are some of the most common ways to address this need. Unfortunately, they do not cover all complex clinical situations that the majority of medical oncologists face in their outpatient consultations. In this review, we report the conclusions achieved in a multiexpert meeting where five important controversies in the treatment of breast cancer were analysed. Five highly experienced medical oncologists were required to defend an affirmative answer and another five were required to defend a negative answer for each of the clinical questions. After that, a one-day meeting was organised to debate each clinical question and to reach a consensus. We report here the content of this multi-expert meeting along with the conclusions drawn.

Fertility and pregnancy after breast cancer

The mortality rate from breast cancer has decreased over the last two or three decades and issues of survivorship have become increasingly important. Approximately 1 in 200 women under the age of 40 develop breast cancer, and with the increasing age at first and subsequent pregnancies in the UK and Europe the issue of fertility for young women who may not have started their families may be a major consideration. The increasing use of adjuvant chemotherapy in breast cancer means that many women diagnosed with breast cancer will undergo temporary or permanent chemotherapy-induced amenorrhoea. This may be associated with physical, psychological and psychosocial implications, with women experiencing the acute toxicities associated with menopause as well as long-term health risks including loss of bone mineral density and possibly some increased cardiovascular risk. Following chemotherapy very few women become pregnant, and this may partly be due to concerns about the risks of pregnancy, both to themselves and in relation to their potential future offspring. Modern techniques used to preserve fertility in the general population may be applicable to some women with breast cancer. The use of such techniques needs to be considered on an individual basis for each woman in light of the recommended systemic adjuvant treatment, the woman's age and her own risk of recurrence with and without systemic treatment. Further clinical research is necessary to substantiate the safety of these approaches to fertility in women who have been diagnosed with breast cancer.

Microenvironment of the involuting mammary gland mediates mammary cancer progression

Breast cancer diagnosed after a completed pregnancy has higher metastatic potential and therefore a much poorer prognosis. We hypothesize that following pregnancy the process of mammary gland involution, which returns the gland to its pre-pregnant state, co-opts some of the programs of wound healing. The pro-inflammatory milieu that results, while physiologically normal, promotes tumor progression. In this review, the similarities between mammary gland involution after cessation of milk-production and pathological tissue remodeling are discussed in light of emerging data demonstrating a role for pathological tissue remodeling in cancer.

Pregnancy-associated breast cancer and metastasis

Pregnancy-associated breast cancer, which has a poor prognosis, is often overlooked by clinicians and researchers alike. With the trend towards delayed child-bearing, an increase in the occurrence of breast cancer complicated by pregnancy is anticipated. The mechanisms that have been proposed to account for this poor prognosis, including increased hormone exposure, might not contribute significantly to the observed increase in metastasis seen in these patients. Instead, the mammary microenvironment might become tumour-promoting after pregnancy because of the remodelling of the mammary gland to its pre-pregnant state. This remodelling, which is associated with pro-inflammatory and wound-healing mechanisms, is proposed to support tumour-cell dissemination. This hypothesis will be discussed.

Remodeling of the mammary microenvironment after lactation promotes breast tumor cell metastasis

The mammary gland microenvironment during postlactational involution shares similarities with inflammation, including high matrix metalloproteinase activity, fibrillar collagen deposition, and release of bioactive fragments of fibronectin and laminin. Because inflammation can promote tumorigenesis, we evaluated whether the tissue microenvironment of the involuting gland is also promotional. Extracellular matrix was isolated from mammary glands of nulliparous rats or rats with mammary glands undergoing weaning-induced involution. Using these matrices as substratum, nulliparous matrix was found to promote ductal organization of normal mammary epithelial MCF-12A cells in three-dimensional culture and to suppress invasion of mammary tumor MDA-MB-231 cells in transwell filter assays. Conversely, involution matrix failed to support ductal development in normal cells and promoted invasiveness in tumor cells. To evaluate the effects of these matrices on metastasis in vivo, MDA-MB-231 cells, premixed with Matrigel, nulliparous matrix, or involution matrix, were injected into mammary fat pads of nude mice. Metastases to lung, liver, and kidney were increased in the involution matrix group, and correlated with a twofold increase in tumor vascular endothelial growth factor expression and increased angiogenesis. These data suggest that the mammary gland microenvironment becomes promotional for tumor cell dissemination during involution, thus providing a plausible mechanism to explain the high rate of metastases that occur with pregnancy-associated breast cancer.

Vaginal oestrogen therapy after breast cancer: is it safe?

The increasing number of breast cancer patients who suffer from menopausal symptoms is mainly due to the extensive use of adjuvant treatments in the younger women. Both short and long-term side effects of oestrogen deficiency may severely impact on the quality of life of these women and should not be underestimated. Hormonal treatments are contraindicated in breast cancer survivors mainly due to the concern that dormant micrometastases may be stimulated to grow. Alternative non-hormonal remedies are now available to alleviate symptoms and to prevent chronic diseases associated with oestrogen deficiency. Urogenital atrophy is an important consequence of oestrogen deprivation that can be effectively treated by vaginal estrogens, although systemic absorption occurs with conventional doses. Preliminary data suggest that much lower doses of vaginal estrogens can alleviate urogenital atrophy without influencing serum estrogenic levels. Further research is warranted to confirm whether vaginal estrogens are safe in symptomatic breast cancer patients who are non-responsive to alternative treatments.

Female breast cancer incidence and survival in Utah according to religious preference, 1985-1999

Background

Female breast cancer incidence rates in Utah are among the lowest in the U.S. The influence of the Church of Jesus Christ of Latter-day Saint (LDS or Mormon) religion on these rates, as well as on disease-specific survival, will be explored for individuals diagnosed with breast cancer in Utah from 1985 through 1999.

Methods

Population-based records for incident female breast cancer patients were linked with membership records from the LDS Church to determine religious affiliation and, for LDS Church members, level of religiosity. Incidence rates were age-adjusted to the 2000 U.S. standard population using the direct method. Cox proportional hazards model was used to compare survival among religiously active LDS, less religiously active LDS, and non-LDS with simultaneous adjustment for prognostic factors.

Results

Age-adjusted breast cancer incidence rates were consistently lower for LDS than non-LDS in Utah from 1985 through 1999. Rates were lower among LDS compared with non-LDS across the age span. In 1995–99, the age-adjusted incidence rates were 107.6 (95% CI: 103.9 – 111.3) for LDS women and 130.5 (123.2 – 137.9) for non-LDS women. If non-LDS women in Utah had the same breast cancer risk profile as LDS women, an estimated 214 (4.8%) fewer malignant breast cancer cases would have occurred during 1995–99. With religiously active LDS serving as the reference group, the adjusted death hazard ratio for religiously less active LDS was 1.09 (0.94 – 1.27) and for non-LDS was 0.86 (0.75 – 0.98).

Conclusion

In Utah, LDS lifestyle is associated with lower incidence rates of female breast cancer. However, LDS experience poorer survivability from breast cancer than their non-LDS counterparts. Parity and breastfeeding, while protective factors against breast cancer, may contribute to poorer prognosis of female breast cancer in LDS women.

Progression of pregnancy-dependent mouse mammary tumors after long dormancy periods. Involvement of Wnt pathway activation

Mouse mammary tumor virus (LA) induces pregnancy-dependent mammary tumors that progress toward autonomy. Here we show that in virgin females, pregnancy-dependent tumor transplants are able to remain dormant for up to 300 days. During that period, these tumors synthesize DNA, express high levels of estrogen and progesterone receptors (ER+PR+) and are able to resume growth after hormone stimulation. Surprisingly, in a subsequent transplant generation, all these tumors are fully able to grow in virgin females, they express low levels of ER and PR (ER-PR-) and have a monoclonal origin; i.e., show all of the features we have described previously in pregnancy-independent tumors. Histologically, mouse mammary tumor virus (LA)-induced tumors are morphologically similar to genetically engineered mouse (GEM) mammary tumors that overexpress genes belonging to the Wnt pathway. Interestingly, in the virus-induced neoplasias, pregnancy-independent passages arising after a dormant phase usually display a lower level of glandular differentiation together with epithelial cell trans-differentiation, a specific feature associated to Wnt pathway activation. In addition, dormancy can lead to the specific selection of Int2/Fgf3 mutated and overexpressing cells. Therefore, our results indicate that during hormone-dependent tumor dormancy, relevant changes in cell population occur, allowing rapid progression after changes in the animal internal milieu.