The role of circulating tumor cells in metastatic breast cancer: prognostic and predictive value

Prognostic Implications of MALAT1 and BACH1 Expression and Their Correlation with CTCs and Mo-MDSCs in Triple Negative Breast Cancer and Surgical Management Options

Background. Triple negative breast cancer (TNBC) is a biologically separate entity of breast cancer that cannot get benefits from targeted or endocrine therapy. Objective. To assess the expression of MALAT1 and BACH1, as well as monocyte-myeloid-derived suppressor cell (Mo-MDSC) levels and circulating tumor cell (CTC) count in TNBC to correlate these markers with the clinic-pathological criteria of TNCB patients and to evaluate their roles as predictive markers for selection of the patients that can be operated by oncoplastic conserving breast surgery. Methods. Eighty-eight TNBC were managed by modified doughnut breast oncoplastic surgery in early stages and by modified radical mastectomy for patients with late stages unsuitable for breast-conserving. All were examined for MALAT1 and BACH1 expression by immunohistochemistry and RT-PCR as well as Mo-MDSC levels and CTCs. Results. MALAT1 and BACH1 expressions are correlated with the larger size, lymph node, distance metastasis, and TNM staging ( $p<0.05$ ). $\text{CTCs}\ge 5$ and high MO-MDSCs were significantly more in TNBC with MALAT1 and BACH1 overexpression. The survival study proved that DFS for patients with both positive expression of MALAT1 and BACH1 was shorter than that of one positive expression, and both negative expression $p\le 0.001$ , $\text{CTCs}\ge 5$ , and high Mo-MDSCs are associated with poor outcomes. No significant difference between modified round block and modified radical mastectomy techniques as regards recurrence. However, all postoperative management outcomes were significantly better in patients operated by oncoplastic conserving breast surgery. Conclusion. BACH1 and MALAT1 expressions are significantly upregulated in TNBC. They are correlated with CTCs and Mo-MDCs, and all are associated with poor outcomes. Not all TNBC patients have a bad prognosis, patients negative for one of MALAT1 and BACH1 or both, have a slightly good prognosis, and so can be managed by breast oncoplastic conserving surgery.

Diagnosis and treatment monitoring in breast cancer: how liquid biopsy can support patient management

Imaging and tissue biopsies represent the current gold standard for breast cancer diagnosis and patient management. However, these practices are time-consuming, expensive and require invasive procedures. Moreover, tissue biopsies do not capture spatial and temporal tumor heterogeneity. Conversely, liquid biopsy, which includes circulating tumor cells, circulating free nucleic acids and extracellular vesicles, is minimally invasive, easy to perform and can be repeated during a patient's follow-up. Increasing evidence also suggests that liquid biopsy can be used to efficiently screen and diagnose tumors at an early stage, and to monitor changes in the tumor molecular profile. In the present review, clinical applications and prospects are discussed.

Seeding metastases: The role and clinical utility of circulating tumour cells

Peripheral human blood is a readily-accessible source of patient material in which circulating tumour cells (CTCs) can be found. Their isolation and characterization holds the potential to provide prognostic value for various solid cancers. Enumeration of CTCs from blood is becoming a common practice in informing prognosis and may guide therapy decisions. It is further recognized that enumeration alone does not capture perspective on the heterogeneity of tumours and varying functional abilities of the CTCs to interact with the secondary microenvironment. Characterizing the isolated CTCs further, in particular assessing their functional abilities, can track molecular changes in the disease progress. As a step towards identifying a suite of functional features of CTCs that could aid in clinical decisions, developing a CTC isolation technique based on extracellular matrix (ECM) interactions may provide a more solid foundation for isolating the cells of interest. Techniques based on size, charge, density, and single biomarkers are not sufficient as they underutilize other characteristics of cancer cells. The ability of cancer cells to interact with ECM proteins presents an opportunity to utilize their full character in capturing, and also allows assessment of the features that reveal how cells might behave at secondary sites during metastasis. This article will review some common techniques and recent advances in CTC capture technologies. It will further explore the heterogeneity of the CTC population, challenges they experience in their metastatic journey, and the advantages of utilizing an ECM-based platform for CTC capture. Lastly, we will discuss how tailored ECM approaches may present an optimal platform to capture an influential heterogeneous population of CTCs.

The role of circulating tumor cells and K-ras mutations in patients with locally advanced rectal cancer: a prospective study

Rectal cancer is a common malignancy with a relatively poor prognosis. We assessed the possible prognostic and predictive role(s) of circulating tumor cells (CTCs) and K-ras mutations in locally advanced rectal carcinoma (LARC) patients. CTCs number and K-ras mutation status were assessed in the Peripheral blood and tumor tissue samples of 60 patients with LARC compared to control group (normal rectal mucosa). Data were correlated to relevant clinico-pathological features, response to treatment, disease free (DFS) and overall survival (OS) rates. K-ras mutations were present in 24/60 (40%) patients. Baseline CTCs (< 5 cells/7 ml blood) were detected in 23/60 (38.3%) patients, and 37 (61.7%) had baseline CTCs (≥ 5 cells/7 ml) blood (P = 0.071). Serial sampling showed a decrease in CTCs levels in 40 (66.7%) patients and increase in 20 (33.3%) patients (P = 0.01). Patients with K-ras mutations had a significantly poor response to treatment, with reduced DFS and OS rates (P = 0.001, 0.004, and 0.001; respectively). Similarly, decreased CTCs levels during treatment associated significantly with better pathological responses (P = 0.003). Multivariate analysis demonstrated that K-ras mutation and baseline CTCs are independent prognostic factors for DFS (P = 0.014 and 0.045; respectively) and OS (P = 0.002 and 0.045; respectively). The presence of mutant K-ras and baseline CTCs ≥ 5 cells associated significantly with poor pathological response, shorter DFS and OS rates compared to those with either K-ras mutation or CTCs ≥ 5 cells only (P = 0.014, 0.005 and 0.001, respectively). K-ras mutations, baseline and serial CTCs changes represent good prognostic and predictive factors for LARC patients.