A Review of Pregnancy-Associated Breast Cancer: Diagnosis, Local and Systemic Treatment, and Prognosis

Pregnancy-associated breast cancer: Management of the mother, fetus and tumour

Introduction

Pregnancy-associated breast cancer (PABC) is described as breast cancer diagnosed within pregnancy or within 1 year postpartum. PABC is becoming more common due to delayed childbearing, with older maternal age increasing the likelihood of tumorigenesis coinciding with pregnancy. Our review aims to outline the important principles of managing PABC, and discusses future fertility implications, genetic testing and postnatal considera-tions that are not often considered in other existing reviews.

Method

A literature search was conducted using PubMed, Cochrane and Google Scholar databases.

Results

A persistent breast mass in pregnant women should be evaluated with a breast ultrasound. Total mastectomy is the standard treatment in the first trimester. Chemotherapy is contraindicated in the first trimesters, but can be given in the second and third trimester, and stopped before 35 weeks. Radiotherapy should be delayed until delivery, and hormone receptor therapy is contraindicated in pregnancy. A multidisciplinary team involving an obstetrician, medical oncologist and other allied health professionals is crucial. Delivery should be planned as close to 37 weeks as possible, and at least 3 weeks after the last chemotherapy cycle. Vaginal delivery is preferred, and breastfeeding can resume 14 days after the last chemotherapy regime.

Conclusion

A breast mass in a pregnant woman should not be dismissed. PABC must be managed by multidisciplinary teams at tertiary medical centres with access to surgery and chemoradiation therapies. Management strategies must include safe manage-ment and delivery of the fetus, contraception and future fertility planning.

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.

Dysregulated microRNAs in type 2 diabetes and breast cancer: Potential associated molecular mechanisms

Type 2 diabetes (T2D) is a multifaceted and heterogeneous syndrome associated with complications such as hypertension, coronary artery disease, and notably, breast cancer (BC). The connection between T2D and BC is established through processes that involve insulin resistance, inflammation and other factors. Despite this comprehension the specific cellular and molecular mechanisms linking T2D to BC, especially through microRNAs (miRNAs), remain elusive. miRNAs are regulators of gene expression at the post-transcriptional level and have the function of regulating target genes by modulating various signaling pathways and biological processes. However, the signaling pathways and biological processes regulated by miRNAs that are associated with T2D and BC have not yet been elucidated. This review aims to identify dysregulated miRNAs in both T2D and BC, exploring potential signaling pathways and biological processes that collectively contribute to the development of BC.

Sentinel lymph node biopsy for breast cancer during pregnancy: A comprehensive update

BACKGROUND

Pregnant patients diagnosed with breast cancer (PrBC) may receive substantially different treatments compared to general population, considering that certain treatment options cannot be applied during pregnancy due to their potential harmful effects to the foetus. Regarding the use of sentinel lymph node biopsy (SLNB) in pregnant patients, potential concerns include foetal harm from radiation exposure, possible teratogenic effects of blue dyes and maternal anaphylaxis to isosulfan.

OBJECTIVE

The main objective of the present systematic review is to summarize and present current knowledge and up-to-date evidence about the safety and efficacy of SLNB in PABC.

METHODS

MEDLINE, Google Scholar and UpToDate databases were searched up to 22 January 2023. Articles studying the safety and effectiveness of SLNB in patients for PrBC were eligible for inclusion in the present review.

RESULTS

In total, 63 articles that met the inclusion criteria were included in this study. Forty-seven articles were strongly in favour of performing SLNB in PABC, 4 articles were partially in favour, 10 articles were strongly against and 2 articles were partially against performing SLNB in PABC. Sub-categorization based on type of study showed that the majority of studies in favour were of higher level of evidence than those against. Furthermore, there were overall 12 studies reporting on outcomes. There were overall 382 women with PrBC that underwent SLNB. Full data were reported for 237 cases. Overall live birth rate was 95.8%, while overall neonatal complication rate was 3.4%. No case of maternal side effects or anaphylactic reaction, maternal death, stillbirth and neonatal death was reported (0%).

CONCLUSIONS

Sentinel lymph node biopsy seems to be safe and effective technique for breast cancer during pregnancy.

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 Imaging and Intervention during Pregnancy and Lactation

Physiologic changes that occur in the breast during pregnancy and lactation create challenges for breast cancer screening and diagnosis. Despite these challenges, imaging evaluation should not be deferred, because delayed diagnosis of pregnancy-associated breast cancer contributes to poor outcomes. Both screening and diagnostic imaging can be safely performed using protocols based on age, breast cancer risk, and whether the patient is pregnant or lactating. US is the preferred initial imaging modality for the evaluation of clinical symptoms in pregnant women, followed by mammography if the US findings are suspicious for malignancy or do not show the cause of the clinical symptom. Breast MRI is not recommended during pregnancy because of the use of intravenous gadolinium-based contrast agents. Diagnostic imaging for lactating women is the same as that for nonpregnant nonlactating individuals, beginning with US for patients younger than 30 years old and mammography followed by US for patients aged 30 years and older. MRI can be performed for high-risk screening and local-regional staging in lactating women. The radiologist may encounter a wide variety of breast abnormalities, some specific to pregnancy and lactation, including normal physiologic changes, benign disorders, and malignant neoplasms. Although most masses encountered are benign, biopsy should be performed if the imaging characteristics are suspicious for cancer or if the finding does not resolve after a short period of clinical follow-up. Knowledge of the expected imaging appearance of physiologic changes and common benign conditions of pregnancy and lactation is critical for differentiating these findings from pregnancy-associated breast cancer. ©RSNA, 2023 Online supplemental material is available for this article. Quiz questions for this article are available through the Online Learning Center.

MicroRNA Dysregulation in Early Breast Cancer Diagnosis: A Systematic Review and Meta-Analysis

Breast cancer continues to be the leading cause of death in women worldwide. Mammography, which is the current gold standard technique used to diagnose it, presents strong limitations in early ages where breast cancer is much more aggressive and fatal. MiRNAs present in numerous body fluids might represent a new line of research in breast cancer biomarkers, especially oncomiRNAs, known to play an important role in the suppression and development of neoplasms. The aim of this systematic review and meta-analysis was to evaluate dysregulated miRNA biomarkers and their diagnostic accuracy in breast cancer. Two independent researchers reviewed the included studies according to the preferred reporting items for systematic reviews and meta-analyses (PRISMA) guidelines. A protocol for this review was registered in PROSPERO with the registration number "CRD42021256338". Observational case-control-based studies analyzing concentrations of microRNAs which have been published within the last 10 years were selected, and the concentrations of miRNAs in women with breast cancer and healthy controls were analyzed. Random-effects meta-analyses of miR-155 were performed on the studies which provided enough data to calculate diagnostic odds ratios. We determined that 34 microRNAs were substantially dysregulated and could be considered biomarkers of breast cancer. Individually, miR-155 provided better diagnostic results than mammography on average. However, when several miRNAs are used to screen, forming a panel, sensitivity and specificity rates improve, and they can be associated with classic biomarkers such us CA-125 or CEA. Based on the results of our meta-analysis, miR-155 might be a promising diagnostic biomarker for this patient population.

Cancer in pregnancy: breast cancer

Breast cancer is the most common malignancy in women, and for women under 40, it is the leading cause of cancer-related deaths. A specific type of breast cancer is pregnancy-associated breast cancer, which is diagnosed during pregnancy, the first-year postpartum, or during lactation. Pregnancy-associated breast cancer is seen in 3/1000 pregnancies and is increasing in incidence as women delay pregnancy. This type of breast cancer is more aggressive, and not infrequently, there is a delay in diagnosis attributed to physiologic changes that occur during pregnancy and a lack of awareness among physicians. In this review, we discuss the demographics of pregnancy-associated breast cancer, provide differential considerations, and illustrate the multimodality imaging features to bring attention to the radiologist about this aggressive form of breast cancer.

Pregnancy-associated breast cancer: a multicenter study comparing clinicopathological factors, diagnosis and treatment outcomes with non-pregnant patients

PURPOSE

Pregnancy-associated breast cancer (PABC), defined as breast carcinoma diagnosed during pregnancy or in the first post-partum year, is one of the most common gestation-related malignancies with reported differences in tumor characteristics and outcomes. This multicenter study aims to review cases of PABC in Singapore, including their clinicopathological features, treatment, and clinical outcomes compared to non-PABC patients.

METHODS

Demographic, histopathologic and clinical outcomes of 93 PABC patients obtained from our database were compared to 1424 non-PABC patients.

RESULTS

PABC patients presented at a younger age. They had higher tumor and nodal stages, higher tumor grade, were more likely to be hormone receptor negative and had a higher incidence of multicentric and multifocal tumors. Histological examination after definitive surgery showed no significant difference in tumor size and number of positive lymph nodes suggesting similar neoadjuvant treatment effects. Despite this, PABC patients had worse outcomes with poorer overall survival and disease-free survival, OS (P < 0.0001) and DFS (P < 0.0001). Termination of pregnancy did not improve survival.

CONCLUSION

Patients with PABC present at a higher stage with more aggressive disease and have poorer outcomes compared to non-PABC patients. Reducing delay in diagnosis and treatment may help improve survival.

A retrospective clinical study of patients with pregnancy-associated breast cancer among multiple centers in China (CSBrS-008)

BACKGROUND

Pregnancy-associated breast cancer (PABC) is a special type of breast cancer that occurs during pregnancy and within 1 year after childbirth. With the rapid social development and the adjustment of reproductive policies in China, the average age of females at first childbirth is increasing, which is expected to lead to an increase in the incidence of PABC. This study aimed to accumulate clinical experience and to investigate and summarize the prevalence, diagnosis, and treatment of PABC based on large multicenter samples in China.

METHODS

According to the Chinese Society of Breast Surgery, a total of 164 patients with PABC in 27 hospitals from January 2016 to December 2018 were identified. The pregnancy status, clinicopathological features, comprehensive treatment methods, and outcomes were retrospectively analyzed. Survival curves were plotted using the Kaplan-Meier method.

RESULTS

A total of 164 patients of PABC accounted for 0.30% of the total number of cases in the same period; of which, 83 patients were diagnosed during pregnancy and 81 patients during lactation. The median age of PABC was 33 years (24-47 years). Stage I patients accounted for 9.1% (15/164), stage II 54.9% (90/164), stage III 24.4% (40/164), and stage IV 2.4% (4/164). About 9.1% (15/164) of patients were luminal A. Luminal B patients accounted the most (43.3% [71/164]). About 15.2% (25/164) of patients were human epidermal growth factor receptor 2 (Her-2) overexpression and 18.9% (31/164) of patients were triple-negative breast cancer. For pregnancy breast cancer, 36.1% (30/83) of patients received direct surgery and 20.5% (17/83) received chemotherapy during pregnancy. About 31.3% (26/83) chose abortion or induction of labor. The median follow-up time was 36 months (3-59 months); 11.0% (18/164) patients had local recurrence or distant metastasis and 3.0% (5/164) died.

CONCLUSIONS

It is safe and feasible to standardize surgery and chemotherapy for PABC.

Early Breast Cancers During Pregnancy Treated With Breast-Conserving Surgery in the First Trimester of Gestation: A Feasibility Study

Breast cancer is the most common malignancy occurring during gestation. In early-stage breast cancer during pregnancy (PrBC), breast-conserving surgery (BCS) with delayed RT is a rational alternative to mastectomy, for long considered the standard-of-care. Regrettably, no specific guidelines on the surgical management of these patients are available. In this study, we investigated the feasibility and safety of BCS during the first trimester of pregnancy in women with early-stage PrBC. All patients with a diagnosis of PrBC during the first trimester of pregnancy jointly managed in two PrBC-specialized Centers were included in this study. All patients underwent BCS followed by adjuvant radiotherapy to the ipsilateral breast after delivery. Histopathological features and biomarkers were first profiled on pre-surgical biopsies. The primary outcome was the isolated local recurrence (ILR). Among 168 PrBC patients, 67 (39.9%) were diagnosed during the first trimester of gestation. Of these, 30 patients (age range, 23-43 years; median=36 years; gestational age, 2-12 weeks; median=7 weeks; median follow-up time=6.5 years) met the inclusion criteria. The patients that were subjected to radical surgery (n=14) served as controls. None of the patients experienced perioperative surgical complications. No ILR were observed within three months (n=30), 1 year (n=27), and 5 years (n=18) after surgery. Among the study group, 4 (12.3%) patients experienced ILR or new carcinomas after 6-13 years, the same number (n=4) had metastatic dissemination after 3-7 years. These patients are still alive and disease-free after 14-17 years of follow-up. The rate of recurrences and metastasis in the controls were not significantly different. The findings provide evidence that BCS in the first trimester PrBC is feasible and reasonably safe for both the mother and the baby.

Clinical and pathological features and risk factors for primary breast cancer patients

BACKGROUND

Breast cancer is the most common malignancy in women all around the world. According to the latest statistics in 2018, there were more than 2.08 million new breast cancer cases all around the world and more than 620000 deaths; the proportion of breast cancer deaths in women with cancer is 15%. By studying age, clinicopathological characteristics and molecular classification, age at menarche, age at birth, number of births, number of miscarriages, lactation time, surgical history of benign breast lesions, history of gynecological diseases, and other factors, we retrospectively summarized and compared the disease history of patients with primary breast cancer and patients with benign thyroid tumors admitted to our hospital in the past 10 years to explore the clinicopathological characteristics and risk factors for primary breast cancer.

AIM

To investigate the clinical and pathological features and risk factors for primary breast cancer treated at our center in order to provide a reference for the prevention and treatment of breast cancer in the Zhuhai-Macao region.

METHODS

Through a retrospective case-control study, 149 patients with primary breast cancer diagnosed and treated at Zhuhai Hospital of Guangdong Provincial Hospital of Traditional Chinese Medicine from January 2013 to March 2020 were included as a case group, and 165 patients with benign breast tumors diagnosed and treated from January 2019 to March 2020 were included as a control group. The data collected included age, age at menarche, age at first birth, number of births, number of miscarriages, lactation time, history of surgery for benign breast lesions, history of familial malignant tumors, history of gynecological diseases, history of thyroid diseases, and the tumor characteristics of the patients in the case group including pathological diagnosis, pathological type, tumor size, lymph node metastasis, distant metastasis, stage, and molecular classification, among others. In the case group, the chi-square test was used to analyze the clinical and pathological features of patients in three age groups (< 40, 40-59, and ≥ 60 years). A multifactor logistic regression analysis was used to analyze correlations between the two groups.

RESULTS

Among 149 patients with primary breast cancer, the average age was 48.20 ± 12.06 years, and the proportion of patients at 40-59 years old was the highest, accounting for 61.8% of cases. The molecular type was mainly luminal B type, accounting for 69.2% of cases, and at the time of diagnosis, the tumor stage was mainly stage I/II, accounting for 62.4% of cases. There were no statistically significant differences in the distributions of tumor location, pathological type, tumor size, lymph node metastasis, stage, or molecular classification among the three age groups (< 40, 40-59, and ≥ 60 years) (P ≥ 0.05). The differences in the distribution of distant metastasis among the three age groups (< 40, 40-59, and ≥ 60 years) were statistically significant (P < 0.01). The differences in lactation time, history of familial malignant tumors, history of gynecological diseases, and history of thyroid diseases between the two groups were not statistically significant (P ≥ 0.05). The differences in age at disease diagnosis, age at menarche, and history of surgery for benign breast lesions were statistically significant (P < 0.01). The difference in age at first birth was also statistically significant (P < 0.05).

CONCLUSION

The highest incidence of breast cancer in the Zhuhai-Macao region is present among women aged 40-59 years. There is a larger proportion of stage I/II patients, and the luminal B type is the most common molecular subtype. Distant metastasis occurs mainly in the ≥ 60-year-old group at the first diagnosis; increased age, late age at menarche, and late age at first birth may be risk factors for primary breast cancer, and a history of surgery for benign breast lesions may be a protective factor for primary breast cancer.

Breast cancer during pregnancy: retrospective institutional case series

BACKGROUND

Pregnancy associated breast cancer is a rare disease. It presents a unique entity of breast cancer with aggressive phenotype. The main aim was to evaluate how the international guidelines were followed in daily practice.

PATIENTS AND METHODS

Data concerning patients' and tumours' characteristics, management, delivery and maternal outcome were recorded from institutional electronic database. In this paper a case series of pregnant breast cancer patients treated at single tertiary institution between 2007 and 2019 are presented and the key recommendations on managing such patients are summarized.

RESULTS

Fourteen patients met the search criteria. The majority of tumours were high grade, triple negative or HER2 positive, two patients were de novo metastatic. Treatment plan was made for each patient by multidisciplinary team. Eight patients were treated with systemic chemotherapy with no excess toxicity or severe maternal/fetal adverse effects. In all but two patients, delivery was on term and without major complications. Only one event, which was not in whole accordance with international guidelines, was identified. It was the use of blue dye in one patient.

CONCLUSIONS

Women with pregnancy associated breast cancer should be managed like non-pregnant breast cancer patients and should expect a similar outcome, without causing harm to the unborn child. To achieve a good outcome in pregnancy associated breast cancer, a multidisciplinary approach is mandatory.

Pregnancy Associated Breast Cancer Gene Expressions : New Insights on Their Regulation Based on Rare Correlated Patterns

Breast-cancer (BC) is the most common invasive cancer in women, with considerable death. Given that, BC is classified as a hormone-dependent cancer, when it collides with pregnancy, different questions may arise for which there are still no convincing answers. To deal with this issue, two new frameworks are proposed within this paper: CoRaM and Dist-CoRaM. The former is the first unified framework dedicated to the extraction of a generic basis of Correlated-Rare Association rules from gene expression data. The proposed approach has been successfully applied on a breast-cancer Gene Expression Matrix (GSE1379) with very promising results. The latter, the Dist-CoRaM approach, is a big-data processing based on Apache spark framework, dealing with correlation mining from micro-array pregnancy associated breast-cancer assays (PABC) data. It is successfully applied on the (GSE31192) gene expression matrix (GEM). The correlated patterns of gene-sets shed light on the fact that PABC exhibits heightened aggressiveness compared to cancers for Non-PABC women. Our findings suggest that higher levels of estrogen and progesterone hormones, unfortunately, are very keen to the increase of the tumor aggressiveness and the proliferation of the cancer.

Breast Cancer During Pregnancy: A Marked Propensity to Triple-Negative Phenotype

Breast and cervical cancers comprise 50% of all cancers during pregnancy. In particular, gestational breast cancer is considered one of the most aggressive types of cancers, which is a rare but fatal disease. However, the incidence of this type of cancer is increasing over the years and its prevalence is expected to rise further as more women delay childbearing. Breast cancer occurring after pregnancy is generally triple negative with specific characterizations of a poorer prognosis and outcome. On the other hand, it has been pointed out that this cancer is associated with a specific group of genes which can be used as precise targets to manage this deadly disease. Indeed, combination therapies consisting of gene-based agents with other cancer therapeutics is presently under consideration. We herein review recent progress in understanding the development of breast cancer during pregnancy and their unique subtype of triple negative which is the hallmark of this type of breast cancer.

Is It Possible to Personalize the Diagnosis and Treatment of Breast Cancer during Pregnancy?

The main goal of precision medicine in patients with breast cancer is to tailor the treatment according to the particular genetic makeup and the genetic changes in the cancer cells. Breast cancer occurring during pregnancy (BCP) is a complex and difficult clinical problem. Although it is not very common, both maternal and fetal outcome must be always considered when planning treatment. Pregnancy represents a significant barrier to the implementation of personalized treatment for breast cancer. Tailoring therapy mainly takes into account the stage of pregnancy, the subtype of cancer, the stage of cancer, and the patient’s preference. Results of the treatment of breast cancer in pregnancy are as yet not very satisfactory because of often delayed diagnosis, and it usually has an unfavorable outcome. Treatment of patients with pregnancy-associated breast cancer should be centralized. Centralization may result in increased experience in diagnosis and treatment and accumulated data may help us to optimize the treatment approaches, modify general treatment recommendations, and improve the survival and quality of life of the patients.

Real-World Data Analysis of Pregnancy-Associated Breast Cancer at a Tertiary-Level Hospital in Romania

Background and objectives: Breast cancer is among the most common cancer types encountered during pregnancy. Here, we aimed to describe the characteristics, management, and outcomes of women with pregnancy-associated breast cancer at a tertiary-level hospital in Romania. Material and Methods: We retrospectively and prospectively collected demographic, oncological, and obstetrical data for women diagnosed with cancer during pregnancy, and who elected to continue their pregnancy, between June 2012 and June 2020. Complete data were obtained regarding family and personal medical history and risks factors, cancer diagnosis and staging, clinical and pathological features (including histology and immunohistochemistry), multimodal cancer treatment, pregnancy management (fetal ultrasounds, childbirth, and postpartum data), and infant development and clinical evolution up to 2020. Cancer therapy was administered following national guidelines and institutional protocols and regimens developed for non-pregnant patients, including surgery and chemotherapy, while avoiding radiotherapy during pregnancy. Results: At diagnosis, 16.67% of patients were in an advanced/metastatic stage, while 75% were in early operable stages. However, the latter patients underwent neoadjuvant chemotherapy rather than up-front surgery due to aggressive tumor biology (triple negative, multifocal, or HER2+). No patient achieved complete pathological remission, but only one patient relapsed. No recurrence was recorded within 12 months among early-stage patients. Conclusions: In this contemporary assessment of real-world treatment patterns and outcomes among patients with pregnancy-associated breast cancer, our findings were generally consistent with globally observed treatment outcomes, underscoring the need for a multidisciplinary team and reference centers.

Breast Imaging During Pregnancy and Lactation

Breast imaging during pregnancy and lactation is important in order to avoid delays in the diagnosis and treatment of pregnancy-associated breast cancers. Radiologists have an opportunity to improve breast cancer detection by becoming familiar with appropriate breast imaging and providing recommendations to women and their referring physicians. Importantly, during pregnancy and lactation, both screening and diagnostic breast imaging can be safely performed. Here we describe when and how to screen, how to work up palpable masses, and evaluate bloody nipple discharge. The imaging features of common findings in the breasts of pregnant and lactating women are also reviewed. Finally, we address breast cancer staging and provide a brief primer on treatment options for pregnancy-associated breast cancers.

Identification of core genes and clinical roles in pregnancy-associated breast cancer based on integrated analysis of different microarray profile datasets

More women are delaying child-birth. Thus, the diagnosis of pregnancy-associated breast cancer (PABC) will continue to increase. The aim of this study was to identify core candidate genes of PABC, and the relevance of the genes on the prognosis of PABC. GSE31192 and GSE53031 microarray profile datasets were downloaded from the Gene Expression Omnibus database and differentially expressed genes were analyzed using the R package and GEO2R tool. Then, Gene Ontology and Kyoto Encyclopedia of Gene and Genome pathway enrichment analyses were performed using the Database for Annotation, Visualization, and Integrated Discovery. Moreover, the Search Tool for the Retrieval of Interacting Genes and the Molecular Complex Detection Cytoscape software plug-in were utilized to visualize protein–protein interactions and to screen candidate genes. A total of 239 DEGs were identified in PABC, including 101 up-regulated genes mainly enriched in fatty acid activation and the fibroblast growth factor signaling pathway, while 138 down-regulated genes particularly involved in activation of DNA fragmentation factor and apoptosis-induced DNA fragmentation. Fourteen hub genes with a high degree of connectivity were selected, including CREB1, ARF3, UBA5, SIAH1, KLHL3, HECTD1, MMP9, TRIM69, MEX3C, ASB6, UBE2Q2, FBXO22, EIF4A3, and PXN. Overall survival (OS) analysis of core candidate genes was performed using the Gene Expression Profiling Interactive Analysis and UALCAN websites. High ASB6 expression was associated with worse OS of PABC patients. Molecular subtypes and menopause status were also associated with worse OS for PABC patients. In conclusion, ASB6 could be a potential predictor and therapeutic target in patient with PABC.