Heightened risk of breast cancer following pregnancy: could lasting systemic immune alterations contribute?

Multidisciplinary Management of Pregnancy-Associated Breast Cancer

Breast cancer during pregnancy is uncommon; however, it is one of the most common malignancies affecting pregnant women. Pregnancy-associated breast cancer (PABC) is a complex entity characterized by unique risk factors, presentation, and pathology. Furthermore, although management generally aims to mirror that for nonpregnant patients, there are distinct aspects of oncologic care delivery specific to PABC. The focus is on optimizing maternal outcomes while maximizing maternal and fetal safety. A multidisciplinary approach is key, and the timing of various treatment modalities is critical. Postdelivery care and counseling are also imperative to address issues such as contraception, breastfeeding, and future fertility. In the present review, we discuss the current knowledge base and the diagnostic and treatment landscape for PABC, including recent literature and practice pattern updates.

Dual role of pregnancy in breast cancer risk

Reproductive history is one of the strongest risk factors for breast cancer in women. Pregnancy can promote short-term breast cancer risk, but also reduce a woman's lifetime risk of breast cancer. Changes in hormone levels before and after pregnancy are one of the key factors in breast cancer risk. This article summarizes the changes in hormone levels before and after pregnancy, and the roles of hormones in mammary gland development and breast cancer progression. Other factors, such as changes in breast morphology and mammary gland differentiation, changes in the proportion of mammary stem cells (MaSCs), changes in the immune and inflammatory environment, and changes in lactation before and after pregnancy, also play key roles in the occurrence and development of breast cancer. This review discusses the dual effects and the potential mechanisms of pregnancy on breast cancer risk from the above aspects, which is helpful to understand the complexity of female breast cancer occurrence.

Breast cancer in pregnancy: concurrent cesarean section, nipple-sparing mastectomy, and immediate breast reconstruction-case report

Background

Pregnancy-associated breast cancer (PABC), with an incidence rate from 1:3,000 to 1:10,000 deliveries, is the most frequent cancer during pregnancy. PABC appropriate management must take into consideration both the maternal oncological safety and the fetal health, thus posing a challenge for the mother, the baby, and the clinicians. The treatment should adhere as closely as possible to the breast cancer (BC) guidelines. Therefore, surgery is a mainstay, and, when mastectomy is required, breast reconstruction (BR) is a topic of debate. To minimize the risks to the baby, most surgeons postpone BR to delivery. However, a delayed breast reconstruction (DBR) could affect the outcome. In the present case, we report cesarean section concurrent with mastectomy and immediate breast reconstruction (IBR).

Methods

A 37-year-old patient, at the 36th week of pregnancy with PABC, underwent simultaneous cesarean delivery, nipple-sparing mastectomy, and IBR. To minimize risks for the newborn, cesarean was firstly performed under spinal anesthesia. Immediately after, breast surgery, including mastectomy and IBR, was performed under general anesthesia. Partial submuscular IBR with an acellular porcine dermal matrix concluded the surgical procedure. Lactation was inhibited, and adjuvant chemotherapy and hormone therapy were administered to the patient.

Results

In a single surgical session, cesarean delivery, subcutaneous mastectomy, axillary dissection, and IBR were successfully carried out. No early or late postoperative complications were reported for both the patient and the newborn. Histopathological investigation reported a multifocal and multicentric infiltrating ductal carcinoma. After a 6-year follow-up, the patient is alive and well.

Conclusion

To the best of our knowledge, this is the first reported case of concomitant cesarean delivery, PABC mastectomy, axillary dissection, and IBR. This surgical strategy allowed PABC treatment by the BC guideline, minimizing the newborn's disadvantage and permitting, at the same time, the best final BR outcome.

Breast Carcinogenesis during Pregnancy: Molecular Mechanisms, Maternal and Fetal Adverse Outcomes

Breast cancer is a common type of cancer diagnosed during pregnancy, with increasing incidence over the last years, as more women choose to delay childbearing. Compared to breast cancer in general population, pregnancy-associated breast cancer (PABC) is significantly different in its terms of epidemiology, diagnostic and therapeutic management, while it exhibits particularly aggressive behavior, deriving from its unique molecular and biological profile. Although not fully elucidated, the pathophysiological basis of PABC can be traced back to a combination of hormonal and immune changes during pregnancy, breast involution and altered gene expression. There is considerable controversy in the existing literature about the influence of PABC on pregnancy outcomes, regarding both short- and long-term effects on maternal and fetal/neonatal health. The majority of PABC patients have advanced-stage disease at initial diagnosis and face a significantly poorer prognosis, with decreased survival rates. The most commonly reported adverse obstetrical–fetal events are preterm delivery and prematurity-associated neonatal morbidity, while other neonatal treatment-associated complications might also occur, even when safe therapeutic options are applied during pregnancy. The objective of the present comprehensive review was to summarize current knowledge and up-to-date evidence about the pathophysiological, molecular and biological basis of PABC, as well as its association with adverse maternal, obstetrical, fetal and neonatal outcomes.

Characterization of Organoid Cultures to Study the Effects of Pregnancy Hormones on the Epigenome and Transcriptional Output of Mammary Epithelial Cells

The use of mouse derived mammary organoids can provide a unique strategy to study mammary gland development across a normal life cycle, as well as offering insights into how malignancies form and progress. Substantial cellular and epigenomic changes are triggered in response to pregnancy hormones, a reaction that engages molecular and cellular changes that transform the mammary epithelial cells into "milk producing machines". Such epigenomic alterations remain stable in post-involution mammary epithelial cells and control the reactivation of gene transcription in response to re-exposure to pregnancy hormones. Thus, a system that tightly controls exposure to pregnancy hormones, epigenomic alterations, and activation of transcription will allow for a better understanding of such molecular switches. Here, we describe the characterization of ex vivo cultures to mimic the response of mammary organoid cultures to pregnancy hormones and to understand gene regulation and epigenomic reprogramming on consecutive hormone exposure. Our findings suggest that this system yields similar epigenetic modifications to those reported in vivo, thus representing a suitable model to closely track epigenomic rearrangement and define unknown players of pregnancy-induced development.

Pregnancy-Associated Breast Cancer: A Multidisciplinary Approach

The diagnosis of breast cancer (BC) during pregnancy is uncommon. It has varied among different studies from 1:10,000 to 1:3000 of all pregnancies, with a median age of 33 years. Pregnancy-associated BC represents a challenge in terms of clinical management to guarantee both maternal and fetal security in choosing the right treatment. This situation is complex and requires a multidisciplinary approach, including the surgeon, anesthesiologist, oncologist, radiotherapist, psychologist, and maternal-fetal medicine specialist. In the present review, we examined the management of pregnancy-associated BC, focusing on pathophysiologic background, risk factors, diagnosis, staging procedures, anesthesia, surgical management, and systemic treatment.

Pregnancy reprograms the epigenome of mammary epithelial cells and blocks the development of premalignant lesions

Pregnancy causes a series of cellular and molecular changes in mammary epithelial cells (MECs) of female adults. In addition, pregnancy can also modify the predisposition of rodent and human MECs to initiate oncogenesis. Here, we investigate how pregnancy reprograms enhancer chromatin in the mammary epithelium of mice and influences the transcriptional output of the oncogenic transcription factor cMYC. We find that pregnancy induces an expansion of the active cis-regulatory landscape of MECs, which influences the activation of pregnancy-related programs during re-exposure to pregnancy hormones in vivo and in vitro. Using inducible cMYC overexpression, we demonstrate that post-pregnancy MECs are resistant to the downstream molecular programs induced by cMYC, a response that blunts carcinoma initiation, but does not perturb the normal pregnancy-induced epigenomic landscape. cMYC overexpression drives post-pregnancy MECs into a senescence-like state, and perturbations of this state increase malignant phenotypic changes. Taken together, our findings provide further insight into the cell-autonomous signals in post-pregnancy MECs that underpin the regulation of gene expression, cellular activation, and resistance to malignant development.

Mammary epithelial cells are epigenetically modified during pregnancy, these changes can influence the pre-disposition to cancer. Here, the authors examine the epigenetic landscape of mammary epithelial cells pre and post pregnancy and identify changes to the epigenetic landscape, which can protect mice from Myc induced cancer.

Associations of reproductive factors with breast cancer prognosis and the modifying effects of menopausal status

Reproductive factors associated with breast cancer risk may also affect the prognosis. This study aimed to evaluate the associations of multiple reproductive factors with breast cancer prognosis and the modifying effects of menopausal status. We obtained data from 3805 breast cancer patients recruited between October 2008 and June 2016 in Guangzhou. The subjects were followed up until 30 June 2018. The hazard ratios (HRs) and 95% confidence intervals (95% CIs) were calculated using multivariate Cox models to estimate the associations. It was found that there were U‐shaped patterns for the associations of age at first birth and durations from first/last birth to diagnosis with breast cancer prognosis. The adverse effects of old age at first birth [>30 years vs 23‐30 years, HR (95% CI): 1.59 (1.01‐2.50)] and long intervals from first [≥20 years vs 10‐19 years, HR (95% CI): 1.55 (1.07‐2.27)] or last [≥20 years vs 10‐19 years, HR (95% CI): 1.63 (1.08‐2.46)] birth to diagnosis on progression‐free survival (PFS) were significantly more pronounced among premenopausal women. Additionally, long interval (>5 years) between first and second birth was associated with a better PFS [HR (95% CI): 0.64 (0.42‐0.97)]. These results suggested that age at first birth, durations from first/last birth to diagnosis, and intervals between first and second birth should be taken into account when following the patients and assessing the prognosis of breast cancer, particularly for premenopausal patients. These findings would also have implications for further insight into the mechanisms of breast cancer development.

Acute promyelocytic leukemia during pregnancy: A case report and 10-year institutional review of hematologic malignancies during pregnancy

Acute promyelocytic leukemia (APL) manifesting during pregnancy is a very rare but highly challenging gestational complication in part due to its associated profound coagulopathy. We present the case of a 23-year-old Gravida 3 Para 2002 woman admitted to our hospital at 26 weeks of gestation for severe pre-eclampsia with documentation of intrauterine fetal demise (IUFD), thrombocytopenia, and placental abruption. A peripheral blood smear revealed promyelocytes with azure granules, highly concerning for APL. Additional peripheral blood studies confirmed APL. Placental examination also revealed circulating blasts in decidual vessels and scattered blast entrapment in diffuse perivillous fibrinoid deposits, but none in the chorionic villi. Treatment for APL was initiated immediately and she is in complete molecular remission. Our case underscores the importance of close collaboration among obstetric, hematology, and pathology teams in the care of patients with pre-eclampsia, thrombocytopenia, and postpartum coagulopathy. We also describe five additional cases of gestations complicated by hematologic malignancies identified upon a 10-year institutional retrospective review.

Prognostic Impact of Pregnancy in Korean Patients with Breast Cancer

BACKGROUND

Pregnancy concurrent with, shortly before, or after breast cancer poses unique challenges because hormonal changes in pregnancy potentially interact with breast cancer outcomes.

MATERIALS AND METHODS

We studied a cohort of 3,687 female patients of reproductive age (<50 years) with breast cancer, linking a large institutional database and the nationwide claims database to comprehensively capture exposure status and tumor characteristics. Exposures included breast cancer during pregnancy, postpartum breast cancer (<12 months after delivery), and pregnancy after breast cancer.

RESULTS

Forty-five patients with postpartum breast cancer were significantly more likely to have advanced stage, hormone receptor-negative tumor and to be younger than 35 years at diagnosis than those without postpartum breast cancer. This trend was not observed with 18 patients with breast cancer during pregnancy. The unadjusted 5-year survival rates were 77% versus 96% for patients with postpartum breast cancer versus their counterparts, 89% versus 96% for patients with breast cancer during pregnancy versus their counterparts, and 98% versus 96% for patients with pregnancy after breast cancer versus their counterparts, respectively. In the multivariable analyses, postpartum breast cancer exhibited hazard ratios for death of 1.57 (95% confidence interval [CI], 0.82-2.99), whereas those for breast cancer during pregnancy and pregnancy after breast cancer were 1.09 (95% CI, 0.15-7.91) and 0.86 (95% CI, 0.26-2.83), respectively.

CONCLUSION

Postpartum breast cancer, but not breast cancer during pregnancy, was associated with advanced stage, younger age at diagnosis (<35 years), hormone receptor-negative disease, and poorer survival. Pregnancy after breast cancer did not compromise overall survival.

IMPLICATIONS FOR PRACTICE

Although pregnancy around the time of diagnosis of breast cancer is expected to become increasingly common with maternal age at first childbirth on the rise, data on the prognostic impact of pregnancy have been inconsistent and rare from Asian populations. In this investigation of a Korean patient cohort with breast cancer, pregnancy-associated breast cancer was associated with advanced stage, younger age at diagnosis (<35 years), hormone receptor-negative disease, and poorer survival. This adverse impact of pregnancy on the prognosis was apparent with postpartum breast cancer but not observed with breast cancer during pregnancy. Pregnancy after breast cancer did not compromise overall survival.

Pregnancy-associated breast cancer: the risky status quo and new concepts of predictive medicine

The paper is motivated by severe concerns regarding currently applied care of the pregnancy-associated breast cancer (PABC) characterised by particularly poor outcomes of the disease. Psychological and ethical aspects play a crucial role in PABC: the highest priority not to damage the foetus significantly complicates any treatment generally, and it is quite usual that patients disclaim undergoing any breast cancer treatment during pregnancy. Although, due to global demographic trends, PABC is far from appearing rarely now, severe societal and economic consequences of the disease are still neglected by currently applied reactive medical approach. These actualities require creating new strategies which should be better adapted to the needs of the society at large by advancing the PABC care based on predictive diagnostic approaches specifically in premenopausal women, innovative screening programmes focused on young female populations, targeted prevention in high-risk groups, and optimised treatment concepts. The article summarises the facts and provides recommendations to advance the field-related research and medical services specifically dedicated to the PABC care.

Evaluation and management of the pregnant patient with suspected primary musculoskeletal tumor or metastatic carcinoma to bone

Primary musculoskeletal cancer and metastatic disease to bone in pregnant patients presents major treatment challenges. Although uncommon, musculoskeletal malignancies in pregnant women have been reported. When diagnosing and treating these patients, the mother's health must be managed appropriately while ensuring that fetal development is not deleteriously affected. Extensive radiographic imaging and more advanced techniques are often necessary to fully characterize the extent of disease. When possible, magnetic resonance imaging should be used instead of computed tomography to limit exposure of the conceptus to radiation. If treatment is needed, therapeutic radiation, chemotherapy, and surgery should be considered. Surgical resection is the foundation of treatment of early-stage primary bone tumors and soft-tissue sarcomas during pregnancy. With surgery, anesthesia and thromboprophylaxis are important considerations. If chemotherapy is required, administration should be avoided in the first trimester to limit harm to the fetus. Therapeutic radiation should similarly be avoided during the first trimester and often can be postponed until after delivery.

Acute promyelocytic leukemia during pregnancy: a systematic analysis of outcome

The outcomes of acute promyelocytic leukemia (APL) in pregnancy are largely unknown. The MEDLINE database was systematically searched to obtain 43 articles with 71 patients with new-onset APL during pregnancy. Induction therapy included various regimens of all-trans retinoic acid (ATRA), cytarabine, and anthracycline and resulted in a complete remission rate of 93%. Obstetric and fetal complications included pre-term deliveries (46%), spontaneous/therapeutic abortion/intrauterine death (33.3%) and other neonatal complications (25.9%). Mothers diagnosed in the first trimester were more likely to experience obstetric (p < 0.01) and fetal (p < 0.01) complications. To our knowledge, this is the largest systematic review of APL in pregnancy. The vast majority of APL patients in pregnancy may achieve remission with initial induction therapy. APL or its therapy in pregnancy, however, is associated with a high risk of fetal and obstetrical complications. The results of our study may help in patient counseling and informed decision-making.

Mortality in women with pregnancy-associated malignant melanoma

BACKGROUND

Malignant melanoma (MM) is one of the most common malignancies in young women. It remains debated whether a MM diagnosed during pregnancy or lactation has a worse prognosis.

OBJECTIVE

We sought to examine mortality in women with pregnancy-associated MM (PAMM) (diagnosed during pregnancy and up to 2-years postpartum).

METHODS

This was a population-based cohort study based on information retrieved from the Swedish Cancer and Multi-Generation Registers. Hazard ratios with 95% confidence intervals adjusted for age, period, education, parity, and tumor location were estimated.

RESULTS

In total, 6857 women and girls aged 15 to 44 years with a diagnosis of cutaneous MM between 1963 and 2009 were identified. Of these, 1019 cases were classified as PAMM. The cause-specific mortality did not differ between PAMM and MM not diagnosed near childbirth (adjusted hazard ratio 1.09, 95% confidence interval 0.83-1.42).

LIMITATIONS

Information on stage at diagnosis was available only for a subset of patients

CONCLUSION

Overall, the cause-specific mortality in women and girls with PAMM did not differ from that in women and girls with non-PAMM. The current findings do not provide evidence of an adverse prognostic influence of pregnancy or a recent birth.

Ação da melatonina sobre a dinâmica sanguínea de ratas prenhes e sobre a histogênese do baço e do timo da prole

Investigou-se a influência da melatonina sobre o hemograma de ratas prenhes e dos filhotes e sobre a histogênese e morfometria do baço e do timo dos filhotes. A melatonina foi administrada na dose 0,5mg/kg de peso corporal, dissolvida em 0,1mL de etanol e diluída em 0,3mL de solução salina. Para análise do hematócrito, contagem total de hemácias e contagem total e diferencial dos leucócitos, amostras de sangue foram coletadas no sétimo, 14ºe 21ºdias de prenhez e aos 10 dias de nascimento dos filhotes. Cortes histológicos do baço e do timo da prole foram utilizados para histoquímica e morfometria. A ausência da melatonina promoveu alterações no hemograma apenas no terço final da gestação, sem interferir no hemograma dos filhotes, e induziu modificações morfológicas e morfométricas no timo e no baço nos primeiros dias de vida dos filhotes. Concluiu-se que a melatonina materna é importante para a modulação do hemograma em ratas prenhes e para o desenvolvimento normal do baço e do timo dos filhotes.

Myeloid-derived suppressor cells are implicated in regulating permissiveness for tumor metastasis during mouse gestation

Metastasis depends on the ability of tumor cells to establish a relationship with the newly seeded tissue that is conducive to their survival and proliferation. However, the factors that render tissues permissive for metastatic tumor growth have yet to be fully elucidated. Breast tumors arising during pregnancy display early metastatic proclivity, raising the possibility that pregnancy may constitute a physiological condition of permissiveness for tumor dissemination. Here we have shown that during murine gestation, metastasis is enhanced regardless of tumor type, and that decreased NK cell activity is responsible for the observed increase in experimental metastasis. Gene expression changes in pregnant mouse lung and liver were shown to be similar to those detected in premetastatic sites and indicative of myeloid cell infiltration. Indeed, myeloid-derived suppressor cells (MDSCs) accumulated in pregnant mice and exerted an inhibitory effect on NK cell activity, providing a candidate mechanism for the enhanced metastatic tumor growth observed in gestant mice. Although the functions of MDSCs are not yet understood in the context of pregnancy, our observations suggest that they may represent a shared mechanism of immune suppression occurring during gestation and tumor growth.