Biomarkers in the diagnosis of primary and recurrent breast cancer

Recent Contributions of Mass Spectrometry-Based "Omics" in the Studies of Breast Cancer

Breast cancer (BC) is one of the most heterogeneous groups of cancer. As every biotype of BC is unique and presents a particular "omic" signature, they are increasingly characterized nowadays with novel mass spectrometry (MS) strategies. BC therapeutic approaches are primarily based on the two features of human epidermal growth factor receptor 2 (HER2) and estrogen receptor (ER) positivity. Various strategic MS implementations are reported in studies of BC also involving data independent acquisitions (DIAs) of MS which report novel differential proteomic, lipidomic, proteogenomic, phosphoproteomic, and metabolomic characterizations associated with the disease and its therapeutics. Recently many "omic" studies have aimed to identify distinct subsidiary biotypes for diagnosis, prognosis, and targets of treatment. Along with these, drug-induced-resistance phenotypes are characterized by "omic" changes. These identifying aspects of the disease may influence treatment outcomes in the near future. Drug quantifications and characterizations are also done regularly and have implications in therapeutic monitoring and in drug efficacy assessments. We report these studies, mentioning their implications toward the understanding of BC. We briefly provide the MS instrumentation principles that are adopted in such studies as an overview with a brief outlook on DIA-MS strategies. In all of these, we have chosen a model cancer for its revelations through MS-based "omics".

RBCK1 regulates the progression of ER-positive breast cancer through the HIF1α signaling

Breast cancer is the most common malignancy in women on a global scale. It can generally be divided into four main categories, of which estrogen receptor ER-positive breast cancer accounts for most breast cancer cases. RBCK1 protein is an E3 ubiquitin ligase containing the UBL, NZF, and RBR domains. It is well known to exhibit abnormal expression in breast tumors, making it a valuable diagnostic marker and drug target. Additionally, studies have confirmed that in breast cancer, about 25 to 40% of tumors appear as visible hypoxic regions, while in hypoxia, tumor cells can activate the hypoxia-inducing factor HIF1 pathway and widely activate the expression of downstream genes. Previous studies have confirmed that in the hypoxic environment of tumors, HIF1α promotes the remodeling of extracellular matrix, induces the recruitment of tumor-associated macrophages (TAM) and immunosuppression of allogeneic tumors, thereby influencing tumor recurrence and metastasis. This research aims to identify RBCK1 as an important regulator of HIF1α signaling pathway. Targeted therapy with RBCK1 could be a promising treatment strategy for ER-positive breast cancer.

Prognostic Factors for Bone Survival and Functional Outcomes in Patients With Breast Cancer Spine Metastases

According to the Global Cancer Statistics 2020 report, breast cancer is the most commonly diagnosed cancer worldwide. Patients with mammary cancer live longer due to the continuous optimization of chemotherapy, targeted drugs, and hormone therapy, which will inevitably lead to an increase in the prevalence of metastatic bone tumors. Bone metastasis affects approximately 8% of patients with mammary cancer, with the spine being the most common site. Metastatic neoplasms can invade the centrum and its attachments, leading to local pain, spinal instability, vertebral pathological fractures, spinal cord compression, impaired neurological function, and paralysis, ultimately reducing the quality of life. Multidisciplinary and personalized management using analgesic drugs, endocrine therapy, corticosteroid therapy, chemotherapy, bisphosphonates, immunotherapy, targeted drugs, radiotherapy, and surgery has been advocated for the treatment of spinal metastases. Multiple paradigms and systems have been proposed to determine suitable treatments. In the early stages, the occurrence of metastasis indicates a terminal stage of the tumor process in patients with malignant tumors, implying that their lifespan is limited. As a result, the choice of treatment is heavily influenced by longevity. However, with the development of treatment methods, the lifespan of patients with tumors has considerably increased in recent years. This leads to the choice of patient's treatment, which depends not only on the patient's survival, but also on the radiotherapy or postoperative functional outcomes. Nevertheless, they fall short of determining the variables that affect survival and functional outcomes in histology-specific subgroups of breast cancer. To accurately predict the bone survival and functional outcomes of patients with breast cancer spine metastases a review of prognostic factors was performed.

N-glycolylneuraminic acid serum biomarker levels are elevated in breast cancer patients at all stages of disease

Background

Normal human tissues do not express glycans terminating with the sialic acid N-glycolylneuraminic acid (Neu5Gc), yet Neu5Gc-containing glycans have been consistently found in human tumor tissues, cells and secretions and have been proposed as a cancer biomarker. We engineered a Neu5Gc-specific lectin called SubB2M, and previously reported elevated Neu5Gc biomarkers in serum from ovarian cancer patients using a Surface Plasmon Resonance (SPR)-based assay. Here we report an optimized SubB2M SPR-based assay and use this new assay to analyse sera from breast cancer patients for Neu5Gc levels.

Methods

To enhance specificity of our SPR-based assay, we included a non-sialic acid binding version of SubB, SubB_A12, to control for any non-specific binding to SubB2M, which improved discrimination of cancer-free controls from early-stage ovarian cancer. We analysed 96 serum samples from breast cancer patients at all stages of disease compared to 22 cancer-free controls using our optimized SubB2M-_A12-SPR assay. We also analysed a collection of serum samples collected at 6 monthly intervals from breast cancer patients at high risk for disease recurrence or spread.

Results

Analysis of sera from breast cancer cases revealed significantly elevated levels of Neu5Gc biomarkers at all stages of breast cancer. We show that Neu5Gc serum biomarker levels can discriminate breast cancer patients from cancer-free individuals with 98.96% sensitivity and 100% specificity. Analysis of serum collected prospectively, post-diagnosis, from breast cancer patients at high risk for disease recurrence showed a trend for a decrease in Neu5Gc levels immediately following treatment for those in remission.

Conclusions

Neu5Gc serum biomarkers are a promising new tool for early detection and disease monitoring for breast cancer that may complement current imaging- and biopsy-based approaches.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-022-09428-0.

DNA Methylation Profiles and Their Diagnostic Utility in BC

Biomarkers, including DNA methylation, have shown a great potential for use in personalized medicine for BC and especially for the diagnosis of BC in developing countries. According to the bisulfite sequencing PCR in twelve specimens (BC and matched normal tissues), nine genetic probes were designed to detect the frequency of methylation of the promoters in a total of 302 paired cases of BC and matched normal breast tissues. Finally, a total of 900 serum samples were used to validate the use of these methylation biomarkers for clinical diagnosis of BC. A high frequency of promoter methylation of SFN, HOXA11, P16, RARβ, PCDHGB7, hMLH1, WNT5a, HOXD13, and RASSF1a was observed in BC tissues. The methylation frequencies of HOXD13 and hMLH1 increased with the progression of BC. The methylation frequencies of HOXD13 and WNT5a were significantly higher in BC. We found that methylation modification-positive samples were most consistently associated with luminal BC. Finally, we confirmed that RASSF1a, P16, and PCDHGB7 displayed a significant sensitivity and specificity as diagnostic biomarkers for BC (P < 0.001), and a panel that combined these three genes displayed increased significance (AUC, 0.781; P < 0.001). These data suggest that epigenetic markers in serum can potentially be used to diagnose BC. The identification of additional BC-specific methylated genes would improve the sensitivity and specificity of this approach. This study could also indicate that different molecular subtypes of BC are caused by distinct genetic and epigenetic mechanisms.

Common matrix metalloproteinase-2 gene variants and altered susceptibility to breast cancer and associated features in Tunisian women

A role for matrix metalloproteinase polymorphisms in breast cancer development and progression was proposed, but with inconclusive results. We assessed the relation of matrix metalloproteinase-2 variants with breast cancer and related phenotypes in Tunisians. This case-control retrospective study involved 430 women with breast cancer and 498 healthy controls. Genotyping of matrix metalloproteinase-2 rs243866, rs243865, rs243864, and rs2285053 was analyzed by allelic exclusion. The minor allele frequency of rs2285053 was significantly lower in women with breast cancer cases as compared to control women; minor allele frequencies of the remaining single-nucleotide polymorphisms were similar between cases and control women. The distribution of rs243865 and rs2285053 genotypes was significantly different between breast cancer patients and control subjects. This persisted when key covariates were controlled for. None of the matrix metalloproteinase-2 variants were associated with estrogen receptor positivity, progesterone receptor positivity, or with double estrogen receptor–progesterone receptor positivity in breast cancer patients. Matrix metalloproteinase-2 rs243866, rs243865, and rs243864 were positively associated with menstrual irregularity and histological type, while rs243866 and rs2285053 were negatively associated with menarche and nodal status. In addition, rs2285053 was negatively associated with triple negativity, tumor size, distance metastasis, molecular type, and chemotherapy. Haploview analysis revealed high linkage disequilibrium between matrix metalloproteinase-2 variants. Four-locus Haploview analysis identified haplotypes GCTT and GTTC to be negatively associated with breast cancer, which remained statistically after controlling for key covariates. Matrix metalloproteinase-2 alleles and genotypes, along with four-locus haplotypes, are related to reduced susceptibility to breast cancer in Tunisian women, suggesting a protective effect.

INTEND II randomized clinical trial of intraoperative duct endoscopy in pathological nipple discharge

BACKGROUND

The majority of lesions resulting in pathological nipple discharge are benign. Conventional surgery is undirected and targeting the causative lesion by duct endoscopy may enable more accurate surgery with fewer complications.

METHODS

Patients requiring microdochectomy and/or major duct excision were randomized to duct endoscopy or no duct endoscopy before surgery. Primary endpoints were successful visualization of the pathological lesion in patients randomized to duct endoscopy, and a comparison of the causative pathology between the two groups. The secondary endpoint was to compare the specimen size between groups.

RESULTS

A total of 68 breasts were studied in 66 patients; there were 31 breasts in the duct endoscopy group and 37 in the no-endoscopy group. Median age was 49 (range 19-81) years. Follow-up was 5·4 (i.q.r. 3·3-8·9) years in the duct endoscopy group and 5·7 (3·1-9·0) years in no-endoscopy group. Duct endoscopy had a sensitivity of 80 (95 per cent c.i. 52 to 96) per cent, specificity of 71 (44 to 90) per cent, positive predictive value of 71 (44 to 90) per cent and negative predictive value of 80 (52 to 96) per cent in identifying any lesion. There was no difference in causative pathology between the groups. Median volume of the surgical resection specimen did not differ between groups.

CONCLUSION

Diagnostic duct endoscopy is useful for identifying causative lesions of nipple discharge. Duct endoscopy did not influence the pathological yield of benign or malignant diagnoses nor surgical resection volumes. Registered as INTEND II in CancerHelp UK clinical trials database (https://www.cancerresearchuk.org/about-cancer/find-a-clinical-trial/a-study-looking-at-changes-inside-the-breast-ducts-of-women-who-have-nipple-discharge).

Evaluation of Prognostic Factors and Proposed Changes to the Modified Tokuhashi Score in Patients With Spinal Metastases From Breast Cancer

STUDY DESIGN

A retrospective study of all patients with histologically confirmed breast cancer spinal metastases presenting to a single institution between May 2001 and April 2012.

OBJECTIVES

The aim of this study was to investigate whether the 2014mT is more accurate than the 2005mT.

SUMMARY OF BACKGROUND DATA

The commonly used 2005 modified Tokuhashi score (2005mT) has become more inaccurate as oncologists move toward treating tumors according to their molecular and genomic profile, rather than their tissue-of-origin. In attempts to improve the accuracy of the 2005mT, a revised score (2014mT) was published, suggesting that hormone receptor negative and triple-negative breast cancer patients be given a modified Tokuhashi histological score of 3 rather than 5.

METHODS

Demographic characteristics, tumor receptor status, clinical findings in relation to the primary tumor and its metastases, and actual survival time were collated. The 2005mT was compared with the 2014mT. Univariate and multivariate Cox regression analyses were used to evaluate the influence of each parameter on survival, and receiver operating characteristic curves were used to determine predictive values of each score version.

RESULTS

Of the 185 patients included, 32 underwent operative treatment, while 153 were managed nonoperatively for their spinal metastases. The overall cohort had a median survival time of 24 months following the diagnosis of spinal metastases, with a 6-month survival rate of 90%. Hormone, HER2 and triple-negative receptor statuses were significant predictors of poorer survival upon multivariate analysis (P = 0.004, P = 0.007, P < 0.001, and P < 0.001, respectively). Age, the original Tokuhashi score components, previous breast surgery for cancer, previous radiotherapy to the breast, previous radiotherapy to the spine, previous chemotherapy, and previous immunotherapy were not significant. At 6 months, the 2005mT AUROC was 0.62, while that of the 2014mT was 0.64 (P = 0.5394).

CONCLUSION

Tumor histological subtype is crucial when prognosticating the survival of patients with breast cancer spinal metastases. Although the 2014mT was marginally more accurate than the 2005mT, its predictive ability remains poor.

LEVEL OF EVIDENCE

3.

Reliable Biomarkers to Identify New and Recurrent Cancer

Breast cancer is the most frequent cancer detected throughout both the developing and the developed world. Its incidence is on the rise in the developing world. Great strides have been made in developing biomarkers to guide therapy for women diagnosed with breast cancer. Far fewer advances have occurred with biomarker development for the early diagnosis of breast cancer. Standard screening for new and recurrent breast cancer involves clinical breast exam and breast imaging. There are no Food and Drug Administration (FDA) approved noninvasive body fluid tests for the early detection of new or recurrent breast cancer. Promising biomarker approaches include multianalyte testing of tissue for individuals diagnosed with breast cancer and body fluid analysis for both at risk women and to monitor individuals after treatment.

Survival analysis of breast cancer subtypes in patients with spinal metastases

STUDY DESIGN

We conducted a retrospective cohort study of 151 patients with breast cancer spinal metastases.

OBJECTIVE

To investigate the influence of breast cancer subtypes on survival duration of patients with breast cancer spinal metastases, and to aid spine surgeons in selecting treatments on a more precise basis.

SUMMARY OF BACKGROUND DATA

There is lack of knowledge about specific prognosis of patients with spinal metastases in various breast cancer subtypes. Estrogen receptor (ER), progesterone receptor (PgR), and human epidermal growth factor receptor 2 (Her-2) status are the key factors in determining breast cancer subtypes and predicting patients' response to adjuvant treatments.

METHODS

Until August 2013, we retrieved 151 surgically treated patients with breast cancer spinal metastases and followed up all the patients for at least 2 years. Survival duration analysis and Cox proportional hazards regression model unadjusted and adjusted by age were used.

RESULTS

Patients with ER-negative (-) breast cancer had 11 months shorter median survival duration (10.6 vs. 21.5 mo) and 48% higher mortality risk (P=0.03) than those with ER-positive (+) breast cancer. Patients with PgR (-) status had 59% higher mortality risk than those with PgR (+) status (P=0.02). Hormone receptor (HR) status is a combination of ER and PgR status. Patients with HR (-) status had an 11-month shorter median survival duration and 52% higher mortality risk (P=0.01) than patients with HR (+) status. Human epidermal growth factor receptor 2 subtypes had similar median survival duration and mortality risk. Patients with triple-negative breast cancer had a median survival duration of only 9.9 months.

CONCLUSION

Patients with spinal metastases with ER/HR (-) status and triple-negative breast cancer could be downgraded from score "5" to "3" in Tokuhashi scoring system and from "slow growth" to "moderate growth" in Tomita scoring system. Spine surgeons should be critical before performing high-risk extensive surgery in patients with ER/HR (-) status, and especially, in those with triple-negative status.

LEVEL OF EVIDENCE

3.

Proteomic approaches in biomarker discovery: new perspectives in cancer diagnostics

Despite remarkable progress in proteomic methods, including improved detection limits and sensitivity, these methods have not yet been established in routine clinical practice. The main limitations, which prevent their integration into clinics, are high cost of equipment, the need for highly trained personnel, and last, but not least, the establishment of reliable and accurate protein biomarkers or panels of protein biomarkers for detection of neoplasms. Furthermore, the complexity and heterogeneity of most solid tumours present obstacles in the discovery of specific protein signatures, which could be used for early detection of cancers, for prediction of disease outcome, and for determining the response to specific therapies. However, cancer proteome, as the end-point of pathological processes that underlie cancer development and progression, could represent an important source for the discovery of new biomarkers and molecular targets for tailored therapies.

Tropomyosin-4 correlates with higher SBR grades and tubular differentiation in infiltrating ductal breast carcinomas: an immunohistochemical and proteomics-based study

The aim of this study is to evaluate tropomyosin-4 (TM4) expression in infiltrating ductal breast carcinomas (IDCAs), as well as its prognostic significance. Using a 2-DE/MALDI-TOF mass spectrometry investigation coupled with an immunohistochemical approach, we have assessed the expression of TM4 in IDCAs, as well as in other types of breast tumors. Proteomic analyses revealed an increased expression of tropomyosin-4 in IDCA tumors. Using immunohistochemistry, overexpression of tropomyosin-4 was confirmed in 51 additional tumor specimens. Statistical analyses revealed, however, no significant correlations between tropomyosin-4 expression and clinicopathological parameters of the disease including tumor stage, patient age, estrogen and progesterone receptor status, and lymph node metastasis occurrence. A significant association was found, however, with a high Scarf-Bloom-Richardson (SBR) grade, a known marker of tumor severity. Additionally, the SBR component showing a correlation with TM4 expression was the tubular differentiation status. This study demonstrates the upregulation of tropomyosin-4 in IDCA tissues, which may highlight its involvement in breast cancer development. Our findings also support a link between tropomyosin-4 expression and aggressiveness of IDCA tumors.

Personalized medicine in screening for malignant disease: a review of methods and applications

Personalized medicine (PM) is currently a hot topic in the professional world. It is often called the medicine of the future and has already achieved resounding success in the area of targeted therapy. Nevertheless, integration of the concepts of PM into routine clinical practice is slow. This review is intended to give an overview of current and potential applications of PM in oncology. PM could soon play a decisive role, especially in screening. The relevance of PM in screening was examined in the case of four common cancers (colorectal cancer, lung cancer, breast cancer, and prostate cancer). A literature search was performed. This showed that biomarkers in particular play a crucial role in screening. In summary, it can be emphasized that there are already numerous known promising biomarkers in malignant disease. This results in several possibilities for individualizing and revolutionizing screening.