Phase 1 Study of Erlotinib and Metformin in Metastatic Triple-Negative Breast Cancer

Metformin-Based Combination Approaches for Triple-Negative Breast Cancer

Numerous anti-diabetic medications, including metformin, have been explored for their anticancer effects because of the substantial correlation between diabetes and cancer incidence. Metformin has recently gained interest for its anticancer effects against malignancies such as breast cancer, one of the leading causes of death among women worldwide. The cancer-related characteristics of cell proliferation, invasion, migration, and apoptosis are all targeted by metformin. Among breast cancer patients, triple-negative breast cancer (TNBC) is linked to an increased risk of early recurrence and metastases and has poor prognosis. In addition, TNBC has fewer treatment options compared to other breast cancer subtypes because it lacks hormone receptors and human epidermal growth factor receptor 2 (HER2), and it often develops resistance to available treatment options. The current review highlights the recent updates on the mechanistic insights and the efficacy of metformin and metformin-based approaches for the treatment of TNBC. We logically discuss the experimental evidence from the in vitro and in vivo studies exploring metformin's effects on metabolic pathways, and then its combination with other therapeutic agents, targeting cell signaling pathways, and approaches to enhance metformin's effects. We also present clinical studies that underscore the beneficial outcomes of metformin or its combination with other agents in TNBC patients.

Dysregulated Signaling Pathways in Canine Mammary Tumor and Human Triple Negative Breast Cancer: Advances and Potential Therapeutic Targets

In 2022, human breast cancer (HBC) and canine mammary tumors (CMTs) remained the most prevalent malignant tumors worldwide, with high recurrence and lethality rates, posing a significant threat to human and dog health. The development of breast cancer involves multiple signaling pathways, highlighting the need for effective inhibitory drugs that target key proteins in these pathways. This article reviews the dysregulation of the EGFR, PI3K/AKT/mTOR, Hippo, pyroptosis, and PD-1/PD-L1 signaling pathways in HBC and CMT, as well as the corresponding drugs used to inhibit tumor growth, with the aim of providing theoretical support for the development of more efficient drugs.

Targeting RTKs/nRTKs as promising therapeutic strategies for the treatment of triple-negative breast cancer: evidence from clinical trials

The extensive heterogeneity and the limited availability of effective targeted therapies contribute to the challenging prognosis and restricted survival observed in triple-negative breast cancer (TNBC). Recent research indicates the aberrant expression of diverse tyrosine kinases (TKs) within this cancer, contributing significantly to tumor cell proliferation, survival, invasion, and migration. The contemporary paradigm shift towards precision medicine has highlighted TKs and their receptors as promising targets for pharmacotherapy against a range of malignancies, given their pivotal roles in tumor initiation, progression, and advancement. Intensive investigations have focused on various monoclonal antibodies (mAbs) and small molecule inhibitors that specifically target proteins such as epidermal growth factor receptor (EGFR), vascular endothelial growth factor (VEGF), vascular endothelial growth factor receptor (VEGFR), cellular mesenchymal-epithelial transition factor (c-MET), human epidermal growth factor receptor 2 (HER2), among others, for combating TNBC. These agents have been studied both in monotherapy and in combination with other chemotherapeutic agents. Despite these advances, a substantial terrain of unexplored potential lies within the realm of TK targeted therapeutics, which hold promise in reshaping the therapeutic landscape. This review summarizes the various TK targeted therapeutics that have undergone scrutiny as potential therapeutic interventions for TNBC, dissecting the outcomes and revelations stemming from diverse clinical investigations. A key conclusion from the umbrella clinical trials evidences the necessity for in-depth molecular characterization of TNBCs for the maximum efficiency of TK targeted therapeutics, either as standalone treatments or a combination. Moreover, our observation highlights that the outcomes of TK targeted therapeutics in TNBC are substantially influenced by the diversity of the patient cohort, emphasizing the prioritization of individual patient genetic/molecular profiles for precise TNBC patient stratification for clinical studies.

An anti-neoplastic tale of metformin through its transport

Metformin is an attractive candidate drug among all the repurposed drugs for cancer. Extensive preclinical and clinical research has evaluated its efficacy in cancer therapy, revealing a mixed outcome in clinical settings. To fully exploit metformin's therapeutic potential, understanding cellular factors relevant to its transport and accumulation in cancer cells needs to be understood. This review highlights the relevance of metformin transporter status towards its anti-cancer potential. Metformin transporters are regulated at pre-transcriptional, transcriptional, and post-translational levels. Moreover, the tumour microenvironment can also influence metformin accumulation in cancer cells. Also, Metformin treatment can regulate its transporters by altering global DNA methylation, protein acetylation, and transcription factors. Importantly, metformin transporters not only influence chemotherapeutic drug toxicity but are also associated with the prognosis and survival of individuals having cancer. Strategic decisions based on the expression and regulation of metformin transporters holds promise for its therapeutic implications and relevance.

Small molecule agents for triple negative breast cancer: Current status and future prospects

Triple-negative breast cancer (TNBC) is a subtype of breast cancer with poor prognosis. The number of cases increased by 2.26 million in 2020, making it the most commonly diagnosed cancer type in the world. TNBCs lack hormone receptor (HR) and human epidermal growth factor 2 (HER2), which limits treatment options. Currently, paclitaxel-based drugs combined with other chemotherapeutics remain the main treatment for TNBC. There is currently no consensus on the best therapeutic regimen for TNBC. However, there have been successful clinical trials exploring large-molecule monoclonal antibodies, small-molecule targeted drugs, and novel antibody-drug conjugate (ADC). Although monoclonal antibodies have produced clinical success, their large molecular weight can limit therapeutic benefits. It is worth noting that in the past 30 years, the FDA has approved small molecule drugs for HER2-positive breast cancers. The lack of effective targets and the occurrence of drug resistance pose significant challenges in the treatment of TNBC. To improve the prognosis of TNBC, it is crucial to search for effective targets and to overcome drug resistance. This review examines the clinical efficacy, adverse effects, resistance mechanisms, and potential solutions of targeted small molecule drugs in both monotherapies and combination therapies. New therapeutic targets, including nuclear export protein 1 (XPO1) and hedgehog (Hh), are emerging as potential options for researchers and become integrated into clinical trials for TNBC. Additionally, there is growing interest in the potential of targeted protein degradation chimeras (PROTACs), degraders of rogue proteins, as a future therapy direction. This review provides potentially valuable insights with clinical implications.

Antidiabetic Drugs in Breast Cancer Patients

Diabetes is one of the leading chronic conditions worldwide, and breast cancer is the most prevalent cancer in women worldwide. The linkage between diabetes and its ability to increase the risk of breast cancer should always be analyzed in patients. This review focuses on the impact of antihyperglycemic therapy in breast cancer patients. Patients with diabetes have a higher risk of developing cancer than the general population. Moreover, diabetes patients have a higher incidence and mortality of breast cancer. In this review, we describe the influence of antidiabetic drugs from insulin and metformin to the current and emerging therapies, incretins and SGLT-2 inhibitors, on breast cancer prognosis. We also emphasize the role of obesity and the metastasis process in breast cancer patients who are treated with antidiabetic drugs.

Role of EGFR and FASN in breast cancer progression

Breast cancer (BC) emerged as one of the life-threatening diseases among females. Despite notable improvements made in cancer detection and treatment worldwide, according to GLOBACAN 2020, BC is the fifth leading cancer, with an estimated 1 in 6 cancer deaths, in a majority of countries. However, the exact cause that leads to BC progression still needs to be determined. Here, we reviewed the role of two novel biomarkers responsible for 50-70% of BC progression. The first one is epidermal growth factor receptor (EGFR) which belongs to the ErbB tyrosine kinases family, signalling pathways associated with it play a significant role in regulating cell proliferation and division. Another one is fatty acid synthase (FASN), a key enzyme responsible for the de novo lipid synthesis required for cancer cell development. This review presents a rationale for the EGFR-mediated pathways, their interaction with FASN, communion of these two biomarkers with BC, and improvements to overcome drug resistance caused by them.

Updates on Triple-Negative Breast Cancer in Type 2 Diabetes Mellitus Patients: From Risk Factors to Diagnosis, Biomarkers and Therapy

Triple-negative breast cancer (TNBC) is usually the most malignant and aggressive mammary epithelial tumor characterized by the lack of expression for estrogen receptors and progesterone receptors, and the absence of epidermal growth factor receptor (HER)2 amplification. Corresponding to 15-20% of all breast cancers and well-known by its poor clinical outcome, this negative receptor expression deprives TNBC from targeted therapy and makes its management therapeutically challenging. Type 2 diabetes mellitus (T2DM) is the most common ageing metabolic disorder due to insulin deficiency or resistance resulting in hyperglycemia, hyperinsulinemia, and hyperlipidemia. Due to metabolic and hormonal imbalances, there are many interplays between both chronic disorders leading to increased risk of breast cancer, especially TNBC, diagnosed in T2DM patients. The purpose of this review is to provide up-to-date information related to epidemiology and clinicopathological features, risk factors, diagnosis, biomarkers, and current therapy/clinical trials for TNBC patients with T2DM compared to non-diabetic counterparts. Thus, in-depth investigation of the diabetic complications on TNBC onset, development, and progression and the discovery of biomarkers would improve TNBC management through early diagnosis, tailoring therapy for a better outcome of T2DM patients diagnosed with TNBC.

A SERS/fluorescence dual-mode immuno-nanoprobe for investigating two anti-diabetic drugs on EGFR expressions

A surface-enhanced Raman scattering (SERS)/fluorescence dual-mode nanoprobe was proposed to assess anti-diabetic drug actions from the expression level of the epidermal growth factor receptor (EGFR), which is a significant biomarker of breast cancers. The nanoprobe has a raspberry shape, prepared by coating a dye-doped silica nanosphere with a mass of SERS tags, which gives high gains in fluorescence imaging and SERS measurement. The in situ detection of EGFR on the cell membrane surfaces after drug actions was achieved by using this nanoprobe, and the detection results agree with the enzyme-linked immunosorbent assay (ELISA) kit. Our study suggests that rosiglitazone hydrochloride (RH) may be a potential drug for diabetic patients with breast cancer, while the anti-cancer effect of metformin hydrochloride (MH) is debatable since MH slightly promotes the EGFR expression of MCF-7 cells in this study. This sensing platform endows more feasibility for highly sensitive and accurate feedback of pesticide effects at the membrane protein level.

EGFR as a potent CAR T target in triple negative breast cancer brain metastases

PURPOSE

There is currently no curative treatment for patients diagnosed with triple-negative breast cancer brain metastases (TNBC-BM). CAR T cells hold potential for curative treatment given they retain the cytolytic activity of a T cell combined with the specificity of an antibody. In this proposal we evaluated the potential of EGFR re-directed CAR T cells as a therapeutic treatment against TNBC cells in vitro and in vivo.

METHODS

We leveraged a TNBC-BM tissue microarray and a large panel of TNBC cell lines and identified elevated epidermal growth factor receptor (EGFR) expression. Next, we designed a second-generation anti-EGFR CAR T construct incorporating a clinically relevant mAb806 tumor specific single-chain variable fragment (scFv) and intracellular 4-1BB costimulatory domain and CD3ζ using a lentivirus system and evaluated in vitro and in vivo anti-tumor activity.

RESULTS

We demonstrate EGFR is enriched in TNBC-BM patient tissue after neurosurgical resection, with six of 13 brain metastases demonstrating both membranous and cytoplasmic EGFR. Eleven of 13 TNBC cell lines have EGFR surface expression ≥ 85% by flow cytometry. EGFR806 CAR T treated mice effectively eradicated TNBC-BM and enhanced mouse survival (log rank p < 0.004).

CONCLUSION

Our results demonstrates anti-tumor activity of EGFR806 CAR T cells against TNBC cells in vitro and in vivo. Given EGFR806 CAR T cells are currently undergoing clinical trials in primary brain tumor patients without obvious toxicity, our results are immediately actionable against the TNBC-BM patient population.

Efficacy of Metformin as Adjuvant Therapy in Metastatic Breast Cancer Treatment

Background: Metformin has been reported to have an anti-tumorigenic impact against metastatic breast cancer (MBC) cells through several mechanisms. Its effect can be evaluated by using many variables such as the response rate (RR) as well as the progression-free survival (PFS). Materials and methods: A prospective study was conducted to investigate and estimate the metformin effect on MBC. About 107 subjects were included in the study and were divided into two groups: Group A included non-diabetic MBC patients treated with metformin in conjunction with chemotherapy and group B included those treated with chemotherapy alone. Both PFS and RR were used as a criteria to evaluate the treatment outcome. Associated adverse effects of metformin were also assessed. Results: The average age of the participants in group A and group B was 50 vs. 47.5, respectively. No significant differences were detected between both cohorts concerning RR levels (regression disease (RD) 27.8% vs. 12.5%, stationary disease (SD) 44.4% vs. 41.7%, progression disease (PD) 27.8% vs. 45.8%, respectively, p = 0.074). Moreover, PFS showed no significant difference between both groups (p = 0.753). There was no significant correlation between metformin concentration and their adverse effects on the study participants. Conclusion: Metformin as an adjuvant therapy to MBC undergoing chemotherapy showed no significant survival benefit as determined by RR and PFS.

Metformin with Temozolomide for Newly Diagnosed Glioblastoma: Results of Phase I Study and a Brief Review of Relevant Studies

Glioblastoma (GBM) inevitably recurs due to a resistance to current standard therapy. We showed that the antidiabetic drug metformin (MF) can induce the differentiation of stem-like glioma-initiating cells and suppress tumor formation through AMPK-FOXO3 activation. In this study, we design a phase I/II study to examine the clinical effect of MF. We aim to determine a recommended phase II MF dose with maintenance temozolomide (TMZ) in patients with newly diagnosed GBM who completed standard concomitant radiotherapy and TMZ. MF dose-escalation was planned using a 3 + 3 design. Dose-limiting toxicities (DLTs) were assessed during the first six weeks after MF initiation. Three patients were treated with 1500 mg/day MF and four patients were treated with 2250 mg/day MF between February 2021 and January 2022. No DLTs were observed. The most common adverse effects were appetite loss, nausea, and diarrhea, all of which were manageable. Two patients experienced tumor progression at 6.0 and 6.1 months, and one died 12.2 months after initial surgery. The other five patients remained stable at the last follow-up session. The MF dose of up to 2250 mg/day combined with maintenance TMZ appeared to be well tolerated, and we proceeded to a phase II study with 2250 mg/day MF.

Epidermal growth factor receptor (EGFR) expression in the serum of patients with triple-negative breast carcinoma: prognostic value of this biomarker

Background

Epidermal growth factor receptor (EGFR) overexpression has been considered a poor prognostic factor in breast cancer.

Methodology

A prospective study of 206 women with breast cancer analysed by stages (I, II, III and IV) and by immunohistochemical subtype (Luminal A, Luminal B, HER2+ and triple-negative (TN)); 89 healthy controls with normal recent mammography were included. The EGFR measured in the serum (sEGFR) was detected by the Enzyme-Linked Immunosorbent Assay (ELISA) method (R&D Systems kit DY231) collected by blood before any treatment in patients. Kaplan-Meier method and Cox regression were carried out to obtain the prognostic value, considering significance if p < 0.05.

Results

With a median follow-up of 36.6 months, 47 deaths occurred. Multivariable Cox regression showed difference of overall survival (OS) associated with sEGFR levels (sEGFR ≤ or > 47.8 ng/mL) in patients with TN cancers, but not of Luminal A, Luminal B or HER2+ subtypes; adjusted by stage, the death risk increased by approximately 415% [hazard ratio (HR): 5.149 (1.900-13.955), p = 0.001] for patients with sEGFR > 47.8 ng/mL compared to patients with a lower sEGFR value. There was no significant correlation of sEGFR with staging, histological tumour grade (G1/G2/G3), Ki67 (< or ≥14%) or body mass index.

Conclusions

Increased sEGFR expression in patients with TN tumours is a significant predictor of lower OS and its quantification is inexpensive and straightforward.

A precision medicine approach to metabolic therapy for breast cancer in mice

Increasing evidence highlights approaches targeting metabolism as potential adjuvants to cancer therapy. Sodium-glucose transport protein 2 (SGLT2) inhibitors are the newest class of antihyperglycemic drugs. To our knowledge, SGLT2 inhibitors have not been applied in the neoadjuvant setting as a precision medicine approach for this devastating disease. Here, we treat lean breast tumor-bearing mice with the SGLT2 inhibitor dapagliflozin as monotherapy and in combination with paclitaxel chemotherapy. We show that dapagliflozin enhances the efficacy of paclitaxel, reducing tumor glucose uptake and prolonging survival. Further, the ability of dapagliflozin to enhance the efficacy of chemotherapy correlates with its effect to reduce circulating insulin in some but not all breast tumors. Our data suggest a genetic signature for breast tumors more likely to respond to dapagliflozin in combination with paclitaxel. In the current study, tumors driven by mutations upstream of canonical insulin signaling pathways responded to this combined treatment, whereas tumors driven by mutations downstream of canonical insulin signaling did not. These data demonstrate that dapagliflozin enhances the response to chemotherapy in mice with breast cancer and suggest that patients with driver mutations upstream of canonical insulin signaling may be most likely to benefit from this neoadjuvant approach.

Metformin and Cancer, an Ambiguanidous Relationship

The deregulation of energetic and cellular metabolism is a signature of cancer cells. Thus, drugs targeting cancer cell metabolism may have promising therapeutic potential. Previous reports demonstrate that the widely used normoglycemic agent, metformin, can decrease the risk of cancer in type 2 diabetics and inhibit cell growth in various cancers, including pancreatic, colon, prostate, ovarian, and breast cancer. While metformin is a known adenosine monophosphate-activated protein kinase (AMPK) agonist and an inhibitor of the electron transport chain complex I, its mechanism of action in cancer cells as well as its effect on cancer metabolism is not clearly established. In this review, we will give an update on the role of metformin as an antitumoral agent and detail relevant evidence on the potential use and mechanisms of action of metformin in cancer. Analyzing antitumoral, signaling, and metabolic impacts of metformin on cancer cells may provide promising new therapeutic strategies in oncology.

The impact of metformin use on the outcomes of locally advanced breast cancer patients receiving neoadjuvant chemotherapy: an open-labelled randomized controlled trial

Recently, several clinical trials have attempted to find evidence that supports the anticancer use of metformin in breast cancer (BC) patients. The current study evaluates the anticancer activity of metformin in addition to neoadjuvant chemotherapy (NACT) in locally advanced BC patients. Additionally, we assess the safety and tolerability of this combination and its effect on the quality of life (QoL) of BC patients. Eighty non-diabetic female patients with proven locally advanced BC were randomized into two arms. The first arm received anthracycline/taxane-based NACT plus metformin. The second arm received anthracycline/taxane-based NACT only. Overall response rate (ORR), clinical complete response (cCr), pathological complete response (pCR), and breast conservative rate (BCR) were evaluated between both groups, and correlated with serum metformin concentration. ORR, cCr, pCR, and BCR increased non-significantly in the metformin group compared to the control group; 80.6% vs 68.4%, 27.8% vs 10.5%, 22.2% vs 10.5%, and 19.4% vs 13.2%, respectively. A trend towards cCR and pCR was associated with higher serum metformin concentrations. Metformin decreased the incidence of peripheral neuropathy, bone pain, and arthralgia, although worsened the gastrointestinal adverse events. Metformin combination with NACT has no effect on the QoL of BC patients. Metformin combination with NACT is safe, tolerable, and improves non-significantly the clinical and pathological tumor response of BC patients.

Factors influencing the anticancer effects of metformin on breast cancer outcomes: a systematic review and meta-analysis

INTRODUCTION

Several clinical trials have attempted to find evidence that supports the use of metformin as an anticancer treatment. However, the observed effects on various breast cancer (BC) outcomes have been heterogeneous.

AREAS COVERED

Based on the outcomes of previous clinical trials, this review discusses the patients' characteristics, cancer intrinsic subtypes, cancer stage, and anticancer treatments that may influence the anticancer effect of metformin on BC outcomes. Additionally, the safety and tolerability of metformin addition to various anticancer regimens are reviewed.

EXPERT OPINION

Metformin is a challenging anticancer agent in BC cohorts, besides being safe and well-tolerated at antidiabetic doses. Survival benefits of metformin have been observed in BC patients with: hormone receptor-positive, human epidermal growth factor receptor-2 overexpression, and high insulin like growth factor-1 receptor expression on the tumor surface. Moreover, patients with diabetes receiving metformin experienced better survival outcomes compared to diabetic patients not receiving metformin. Additionally, metformin has anti-proliferative activity in patients with BC who have high insulin resistance and high body mass index. Besides, metformin has been shown to decrease metastatic events, and enhance the level of metabolic- and insulin-related biomarkers associated with carcinogenesis. Finally, most adverse events following metformin treatment were low-grade GIT toxicities.

Metformin and Breast Cancer: Where Are We Now?

Breast cancer is the most prevalent cancer and the leading cause of cancer-related death among women worldwide. Type 2 diabetes–associated metabolic traits such as hyperglycemia, hyperinsulinemia, inflammation, oxidative stress, and obesity are well-known risk factors for breast cancer. The insulin sensitizer metformin, one of the most prescribed oral antidiabetic drugs, has been suggested to function as an antitumoral agent, based on epidemiological and retrospective clinical data as well as preclinical studies showing an antiproliferative effect in cultured breast cancer cells and animal models. These benefits provided a strong rationale to study the effects of metformin in routine clinical care of breast cancer patients. However, the initial enthusiasm was tempered after disappointing results in randomized controlled trials, particularly in the metastatic setting. Here, we revisit the current state of the art of metformin mechanisms of action, critically review past and current metformin-based clinical trials, and briefly discuss future perspectives on how to incorporate metformin into the oncologist’s armamentarium for the prevention and treatment of breast cancer.

Rewired Cellular Metabolic Profiles in Response to Metformin under Different Oxygen and Nutrient Conditions

Metformin is a metabolic disruptor, and its efficacy and effects on metabolic profiles under different oxygen and nutrient conditions remain unclear. Therefore, the present study examined the effects of metformin on cell growth, the metabolic activities and consumption of glucose, glutamine, and pyruvate, and the intracellular ratio of nicotinamide adenine dinucleotide (NAD⁺) and reduced nicotinamide adenine dinucleotide (NADH) under normoxic (21% O₂) and hypoxic (1% O₂) conditions. The efficacy of metformin with nutrient removal from culture media was also investigated. The results obtained show that the efficacy of metformin was closely associated with cell types and environmental factors. Acute exposure to metformin had no effect on lactate production from glucose, glutamine, or pyruvate, whereas long-term exposure to metformin increased the consumption of glucose and pyruvate and the production of lactate in the culture media of HeLa and HaCaT cells as well as the metabolic activity of glucose. The NAD⁺/NADH ratio decreased during growth with metformin regardless of its efficacy. Furthermore, the inhibitory effects of metformin were enhanced in all cell lines following the removal of glucose or pyruvate from culture media. Collectively, the present results reveal that metformin efficacy may be regulated by oxygen conditions and nutrient availability, and indicate the potential of the metabolic switch induced by metformin as combinational therapy.

Autophagy Modulation and Cancer Combination Therapy: A Smart Approach in Cancer Therapy

The autophagy pathway is the process whereby cells keep cellular homeostasis and respond to stress via recycling their damaged cellular proteins, organelles, and other cellular components. In the context of cancer, autophagy is a dual-edge sword pro- and anti-tumorigenic role depending on the oncogenic context and stage of tumorigenesis. Cancer cells have a higher dependency on autophagy compared with normal cells because of cellular damages and high demands for energy. The carbon, nitrogen, and molecular oxygen are building blocks for highly proliferative cancer cells which extremely depend on glutaminolysis and aerobic glycolysis; when a cancer cell is restricted to glucose and glutamine, it initiates to activate a stress response pathway using autophagy. Oncogenic tyrosine kinases (OncTKs) and receptor tyrosine kinases (RTKs) activation result in autophagy modulation through activation of the PI3K/AKT/mTORC1 and RAS/MAPK signaling pathways. Targeted inhibition of tyrosine kinases (TKs) and RTKs have recently been considered as cancer therapy but drug resistance and cancer relapse continue to be a major limitation of tyrosine kinase inhibitors (TKIs). Manipulation of autophagy pathway along with TKIs may be a promising strategy to circumvent unknown existing drug-resistance mechanisms that may emerge in a treated patient. In this way, clinical trials are ongoing to modulate autophagy to treat cancer. This review aims to summarize the combination therapy of autophagy affecting compounds with anticancer drugs which target cell signaling pathways, metabolism mechanisms, and epigenetics modification to improve therapeutic efficacy against cancers.

Potentiating Therapeutic Effects of Epidermal Growth Factor Receptor Inhibition in Triple-Negative Breast Cancer

Triple-negative breast cancer (TNBC) is a subset of breast cancer with aggressive characteristics and few therapeutic options. The lack of an appropriate therapeutic target is a challenging issue in treating TNBC. Although a high level expression of epidermal growth factor receptor (EGFR) has been associated with a poor prognosis among patients with TNBC, targeted anti-EGFR therapies have demonstrated limited efficacy for TNBC treatment in both clinical and preclinical settings. However, with the advantage of a number of clinically approved EGFR inhibitors (EGFRis), combination strategies have been explored as a promising approach to overcome the intrinsic resistance of TNBC to EGFRis. In this review, we analyzed the literature on the combination of EGFRis with other molecularly targeted therapeutics or conventional chemotherapeutics to understand the current knowledge and to provide potential therapeutic options for TNBC treatment.