Role of ethnic variations in TNF-α and TNF-β polymorphisms and risk of breast cancer in India

TNF-α and -β, the multi-functional pro-inflammatory cytokines, are known to play important roles in both tumor progression and destruction based on their concentrations. Growth factors and various stimuli such as cytokines regulate proliferation of the breast epithelial cells. Therefore, the polymorphisms in the genes encoding these signaling molecules could affect the risk of breast cancer. We have investigated selected genetic polymorphisms in TNF-α promoter (rs1800629, −308 G>A and rs361525, −238 G>A) and TNF-β intron 1 (rs909253, +252 A>G) in ethnically two different case–control groups from India. The study included 200 cases and 200 controls from an Indo-European (North Indian) group, and 265 cases and 237 controls from a Dravidian (South Indian) group. Genotyping of a total of 902 individuals was done by direct DNA sequencing. None of the polymorphisms showed significant association with breast cancer in the Indo-European group; however, all the three polymorphisms showed strong association with breast cancer in the Dravidian group. Further, sub-group analysis in the Indo-European group showed no significant difference between pre-menopausal cases and controls or between post-menopausal cases and controls at any of the loci analyzed. However, all the polymorphisms in the Dravidian group were significantly associated with pre-menopausal but not with post-menopausal breast cancer. In conclusion, TNF-α and -β polymorphisms are strongly associated with breast cancer in the Dravidian but not in the Indo-European group.     

TNF-α in promotion and progression of cancer

Tumour necrosis factor alpha is a member of the TNF/TNFR cytokine superfamily. In common with other family members, TNF-α is involved in maintenance and homeostasis of the immune system, inflammation and host defence. However, there is a ‘dark side’ to this powerful cytokine; it is now clear that, especially in middle and old age, TNF-α is involved in pathological processes such as chronic inflammation, autoimmunity and, in apparent contradiction to its name, malignant disease. This article will discuss the involvement of TNF-α in the inflammatory network that contributes to all stages of the malignant process, and consider the possibility that TNF-α may be a target for cancer therapy.     

The molecular contribution of TNF-α in the link between obesity and breast cancer

Obesity is a growing worldwide medical problem, as it pre-disposes the affected hosts to a number of severe diseases, including postmenopausal breast cancer. Obesity development is characterised, amongst others, by aberrant secretion of adipokines. White fat tissue infiltrating macrophages secrete tumour necrosis factor-α (TNF-α) so that its circulating levels correlate positively with body mass index (BMI). In the study presented here, the effect of TNF-α on cell proliferation, cell signalling pathway activation and cell cycle in two breast cancer cell lines and one breast epithelial cell lines was assessed to determine the contribution of TNF-α on breast cancer progression and aetiology, respectively. TNF-α acted differently on all three cell lines. In MDA-MB-231 breast cancer cells, cell proliferation and PI3-kinase activation were not affected, while MAP-kinase activation and cell cycle progression were decreased, with indications of increased apoptosis. This suggests a growth inhibitory function of TNF-α in these cells. In SK-BR-3 breast cancer cells, cell proliferation and cell signalling pathway activation increased, while cell cycle progression decreased, which contradictorily suggests both growth promoting and growth inhibiting properties of TNF-α on these cells. This makes TNF-α an unlikely candidate for a general contribution to the link between obesity and breast cancer progression, however, individual tumours may be responsive to a proliferative signal of TNF-α. In MCF-10A breast epithelial cells, cell proliferation and MAP-kinase activation increased, while cell cycle progression was unaffected. This suggests a strong proliferative response in these cells, suggesting the possibility that TNF-α may contribute to breast cancer aetiology as a novel link between obesity and increased risk of breast cancer development.     

Association of TNF-α and TNF-β gene polymorphism with steroid receptor expression in breast cancer patients

The presence of estrogen and progesterone receptors is correlated with good prognosis in breast cancer. The effect of TNF-α on down-regulation of estrogen receptor and blocking the proliferative response of breast cancer cells to estradiol have been demonstrated. However, the effect of TNFA and TNFB gene polymorphisms on the expression of steroid receptors in breast cancer cells is not well documented. Therefore, 160 breast cancer patients were recruited to investigate the association of TNFA and TNFB gene polymorphism with the level of steroid receptor expression. This association was not found to be significant for TNFA polymorphism and estrogen receptor expression (p=0.07). However, when combined genotypes of TNFA and TNFB polymorphism was considered, homozygous patients for lower TNF-α producer genotypes (TNFA1/A1 and TNFB1/B1) showed significantly higher progesterone receptor expression (p=0.041). Our findings indicate that TNFA and TNFB polymorphisms may be associated with the levels of steroid receptor expression in breast cancer patients. Further studies on a larger group of breast cancer patients are recommended.     

TNF-α and its inhibitors in cancer

Tumor necrosis factor (TNF)-α is implicated in the same time in apoptosis and in cell proliferation. TNF-α not only acts as pro-inflammatory cytokine conducing to wide spectrum of human diseases including inflammatory diseases, but can also induce tumor development. The molecular mechanisms of TNF-α functions have been intensively investigated. In this review we covered TNF-α, the molecule, its signaling pathway, and its therapeutic functions. We provide a particular insight in its paradoxical role in tumor promotion and in its use as anti-tumor agent. This review considers also the recent findings regarding TNF-α inhibitors, their pharmacokinetics, and their pharmacodynamics. Six TNF-α inhibitors have been considered here: Infliximab, Adalimumab, Golimumab, CDP870, CDP571, Etanercept, and Thalidomide. We discussed the clinical relevance of their functions in treatment of several diseases such as advanced inflammatory rheumatic and bowel disease, with a focus in cancer treatment. Targeting TNF-α by these drugs has many side effects like malignancies development, and the long-term sequels are not very well explored. Their efficacy and their safety were discussed, underscoring the necessity of close patients monitoring and of their caution use.     

Loss of ERα and FOXA1 expression in a progression model of luminal type breast cancer: insights from PyMT transgenic mouse model

The classification of breast cancer into multiple molecular subtypes has necessitated the need for biomarkers that can assess tumor progression and the effects of chemopreventive agents on specific breast cancer subtypes. The goal of this study was to identify biomarkers whose expression are altered along with estrogen receptor α (ERα) in the polyoma middle-T antigen (PyMT) transgenic model of breast cancer and to investigate the chemopreventive activity of phenethyl isothiocyanate (PEITC). The diet of PyMT female mice was fortified with PEITC (8 mmol/kg) and the mammary streak and/or gross tumors and metastases in lungs were subjected to immunohistochemical analyses for ERα, FOXA1, and GATA-3. FOXA1 is associated with luminal type A cancers, while GATA-3 is a marker of luminal progenitor cell differentiation. In both control and PEITC-treated groups, there was a progressive loss of ERα and FOXA1 but persistence of GATA-3 expression indicating that the tumors retain luminal phenotype. Overall, the PyMT induced tumors exhibited the entire gamut of phenotypes from ERα+/FOXA1+/GATA-3+ tumors in the early stage to ERα±/FOXA1-/GATA-3+ in the late stage. Thus, PyMT model serves as an excellent model for studying progression of luminal subtype tumors. PEITC treated animals had multiple small tumors, indicating delay in tumor progression. Although these tumors were histologically similar to those in controls, there was a lower expression of these biomarkers in normal luminal cells indicating delay in tumor initiation. In in vitro studies, PEITC depleted AldeFluor-positive putative stem/progenitor cells, which may partly be responsible for the delay in tumor initiation.     

TNF-α and IL-10 promoter polymorphisms, HPV infection, and cervical cancer risk

Although the implication of genetic factors in cervical cancer development remains to be elucidated, accumulative epidemiological evidence suggests that polymorphisms of cytokine genes may be involved in the etiology of cervical carcinoma. Tumor necrosis factor alpha (TNF-??) and interleukin-10 (IL-10) are two multifunctional cytokines implicated in inflammation, immunity, and cellular organization, and were proposed to play important roles in cancer biology. In order to determine whether IL-10 -1082 (G/A) and TNF-?? -238 (G/A) and -308 (G/A) polymorphisms are associated with susceptibility to cervical cancer, a case?Ccontrol study of 122 cancer patients and 176 healthy controls was conducted. Cervical samples were genotyped for both TNF-?? polymorphisms by PCR-RFLP assay. SNP-1082 from IL-10 gene was genotyped using pyrosequencing technology. The association between cervical cancer risk and the studied SNPs was evaluated by logistic regression. Under univariate analysis, none of these polymorphisms appeared associated with susceptibility of cervical cancer development or HPV infection. However, individuals carrying heterozygous genotype for TNF-?? -238 polymorphism seem to be at lower risk for cervical cancer development, with borderline significance (OR?=?0.42, P?=?0.069), as well as those carrying heterozygous genotypes for IL-10 and TNF-?? -238 (OR?=?0.40, P?=?0.08). In conclusion, these results suggest a potential effect of TNF-?? -238 G/A in the reduction of cervical cancer risk in Argentine women, but not TNF-?? -308 or IL-10. Larger studies are needed to fully understand the genetic predisposition for the development of cervical cancer.     

TNF-α promotes breast cancer cell migration and enhances the concentration of membrane-associated proteases in lipid rafts

Purpose

Tumor progression is associated with cell migration, invasion and metastasis. These processes are accompanied by the activation of specific proteases that are either linked to cellular membranes or are secreted into extracellular spaces. TNF-α is known to play an important role in various aspects of tumor progression. The aim of this work was to assess the effect of TNF-α on the migration of breast cancer cells and, in addition, to assess its association with the location of membrane-associated proteases in lipid rafts.

Methods

Wound scratch healing and Transwell migration assays were used to study the effect of TNF-α on the migration of both hormone-dependent and hormone-independent breast cancer-derived cells, i.e., MCF7 and MDA-MB-231, respectively. The expression and secretion of three matrix metalloproteases, MMP9, MMP2 and MT1-MMP, and two dipeptidyl peptidases, CD26 and FAP-α, was investigated using RT-PCR, Western blotting and gelatin zymography. In addition, activation of the MAPK/ERK signaling pathway was investigated by Western blotting.

Results

We found that a TNF-α-induced enhancement of breast cancer cell migration was accompanied by an increased secretion of MMP9, but not MMP2, into the culture media. We also found that TNF-α upregulated the expression of the dipeptidyl peptidases CD26 and FAP-α in a dose-dependent manner and, in addition, enhanced the concentration of all five proteases in lipid rafts in the breast cancer-derived cells tested, regardless of cell type. Furthermore, we found that TNF-α activated the MAPK/ERK signaling pathway by increasing the ERK1/2 phosphorylation level. Application of the MEK/ERK1/2 inhibitor U-0126 resulted in down-regulation of TNF-α-induced MMP9 secretion and abrogation of the enhanced concentration of proteases in the lipid rafts.

Conclusions

From our results we conclude that TNF-α-induced activation of the MAPK/ERK signaling pathway may promote breast cancer cell migration via both upregulation of MMP9, CD26 and FAP-α and concentration of these proteases, as also MT1-MMP and MMP2, in the lipid rafts. TNF-α may serve as a potential therapeutic target in breast cancers susceptible to TNF-α stimulation.

     

Down-regulation of IL-6, IL-8, TNF-α and IL-1β by glucosamine in HaCaT cells, but not in the presence of TNF-α

There is considerable evidence that glucosamine exerts an inhibitory effect on inflammatory cytokine expression in cells. Glucosamine has been recommended as a promising anti-inflammatory modulator, which has been applied in clinical trials for attenuation of the inflammatory process. However, it is unknown whether glucosamine reduces the expression of TNF-α-induced inflammatory cytokines in HaCaT cells. The anti-inflammatory effects of curcumin in HaCaT cells have been extensively investigated in several studies. Thus, in this study we investigated the expression of IL-6, IL-8, TNF-α and IL-1β in glucosamine-treated HaCaT cells, and the effects of glucosamine were compared to those of curcumin-treated HaCaT cells. Our data showed that the expression of IL-6, IL-8, TNF-α and IL-1β was decreased by glucosamine treatment in the HaCaT cells. In contrast, the expression of IL-6, IL-8, TNF-α and IL-1β was not attenuated by glucosamine treatment in the TNF-α-treated HaCaT cells. Notably, curcumin induced an increased expression of IL-8 and IL-1β in the HaCaT cells, but not that of IL-6 and TNF-α. On the other hand, curcumin attenuated the expression of IL-6 and IL-8 in the TNF-α-treated HaCaT cells. Our data indicated that glucosamine induced the down-regulation of IL-6, IL-8, TNF-α and IL-1β expression in the HaCaT cells. However, the stimulation of TNF-α abolished the inhibitory effects of glucosamine on the expression of inflammatory cytokines in the HaCaT cells. Thus, even though glucosamine induces the down-regulation of inflammatory cytokines in HaCaT cells, the anti-inflammatory role of glucosamine in TNF-α-mediated inflammatory skin diseases should be investigated.     

Prognosis of metastatic breast cancer: are there differences between patients with de novo and recurrent metastatic breast cancer?

Background:

We aimed to determine the prognostic impact of time between primary breast cancer and diagnosis of distant metastasis (metastatic-free interval, MFI) on the survival of metastatic breast cancer patients.

Methods:

Consecutive patients diagnosed with metastatic breast cancer in 2007–2009 in eight hospitals in the Southeast of the Netherlands were included and categorised based on MFI. Survival curves were estimated using the Kaplan–Meier method. Cox proportional hazards model was used to determine the prognostic impact of de novo metastatic breast cancer vs recurrent metastatic breast cancer (MFI ⩽24 months and >24 months), adjusted for age, hormone receptor and HER2 status, initial site of metastasis and use of prior (neo)adjuvant systemic therapy.

Results:

Eight hundred and fifteen patients were included and divided in three subgroups based on MFI; 154 patients with de novo metastatic breast cancer, 176 patients with MFI <24 months and 485 patients with MFI >24 months. Patients with de novo metastatic breast cancer had a prolonged survival compared with patients with recurrent metastatic breast cancer with MFI <24 months (median 29.4 vs 9.1 months, P<0.0001), but no difference in survival compared with patients with recurrent metastatic breast cancer with MFI >24 months (median, 29.4 vs 27.9 months, P=0.73). Adjusting for other prognostic factors, patients with MFI <24 months had increased mortality risk (hazard ratio 1.97, 95% CI 1.49–2.60, P<0.0001) compared with patients with de novo metastatic breast cancer. When comparing recurrent metastatic breast cancer with MFI >24 months with de novo metastatic breast cancer no significant difference in mortality risk was found. The association between MFI and survival was seen irrespective of use of (neo)adjuvant systemic therapy.

Conclusion:

Patients with de novo metastatic breast cancer had a significantly better outcome when compared with patients with MFI <24 months, irrespective of the use of prior adjuvant systemic therapy in the latter group. However, compared with patients with MFI >24 months, patients with de novo metastatic breast cancer had similar outcome.     

Non-pegylated liposomal doxorubicin and docetaxel in metastatic breast cancer: final results of a phase?II trial

Background  Non-pegylated liposomal doxorubicin (NPLD) has demonstrated equivalent antitumor activity to conventional doxorubicin and a significantly lower risk of cardiotoxicity when given as single agent or in combination with cyclophosphamide, but there is limited experience with the combination of NPLD and taxanes. This phase II study was performed to evaluate the efficacy and safety of the NPLD and docetaxel in patients with metastatic breast cancer. Patients and methods  A total of 51 patients were treated with NPLD (60 mg/m²) and docetaxel (75 mg/m²) in 3-weeks intervals for up to eight cycles. Results  The overall response rate was 50% and 78% of patients derived a clinical benefit. Median time to progression and overall survival were 10.0 months (95% CI, 6.9–13.1 months) and 25 months (95% CI, 22.1–29.8 months), respectively. Median duration of response was 12.0 months (95% CI 7.1–16.9). The treatment was generally well tolerated and associated with toxicities that were consistent with the known side-effects of the individual agents and of anthracycline/taxane combinations. There were no symptomatic cardiac averse events and mild asymptomatic LVEF changes were reported in five patients. Conclusions  The combination of NPLD and docetaxel is well tolerated and has high antitumour activity in MBC patients.     

Carboplatin activity in untreated metastatic breast cancer patients — results of a phase II study

Summary Due to the favourable results previously obtained with cisplatin in breast cancer (54%_response rate), we studied a second-generation platinum analogue, carboplatin, in patients with previously untreated breast cancer. A total of 20 patients were entered in the study and all were evaluable. The median age was 57 years and all patients were in menopause. Karnofsky scores of 80–100 and 40–70 were registered in 14 and 6 cases, respectively. The predominant metastatic site was soft tissue in 12 subjects, visceral organs in 5 and bone in 3; 14 patients had >2 metastatic sites. Carboplatin was given i. v. at a dose of 400 mg/m² on day 1, with a 3-week rest period. In 13 patients who did not respond or whose disease recurred after carboplatin treatment, the CMFVP, CAP or FAC regimen was given as second line treatment. Carboplatin activity was observed in 4 patients [2 complete remissions (CRs) and 2 partial responses (PRs)], for a response rate of 20% (4/20); the 2 PRs were observed in soft tissue and bone and the 2 CRs, in lung, liver and bone. Remission lasted 2–10 months ( , 4 months). CMFVP given as second-line chemotherapy to 13 patients produced 7 PRs (7/13, 54%). Toxicity was moderate, producing no drugrelated deaths. Anemia (grade I–II) was recorded in seven patients; grade I–II leukopenia, in six; and grade III–IV leukopenia in two (median leukocyte nadir, 1,600/mm³). Thrombocytopenia was observed in three cases (grades I, II and III; median platelet nadir, 47,800/mm³). Unpleasant nausca/vomiting was pronouced (12 cases of grade III–IV) in 19 subjects. There were no cases of neuro- or nephrotoxicity. Due to permanent myelosuppression, no more than five cycles could be given. Our study showed that, unlike cisplatin, carboplatin given at a dose of 400 mg/m² has low antitumorigenic activity in breast cancer patients and produces pronounced myelotoxicity. Additional first-line chemotherapy studies using carboplatin are needed to define the antitumorigenic activity of this platinum analogueAbbreviations CMFVP cyclophosphamide, methotrexate, fluorouracil, vincrisine, prednisolone - CAP cyclophosphamide, Adriamycin, platinum - FAC fluorouracil, Adriamycin, cyclophosphamide     

Does resection of an intact breast primary improve survival in metastatic breast cancer?

The recommended primary treatment approach for women with metastatic breast cancer and an intact primary tumor is the use of systemic therapy. Local therapy of the primary tumor is recommended only for palliation of symptoms. However, a series of retrospective studies examining practice patterns for this problem show that about half the women presenting with de novo metastatic disease undergo resection of the primary tumor, and suggest that women so treated survive longer than those who do not undergo resection of the intact primary. In analyses that adjust for tumor burden (number of metastatic sites), types of metastases (visceral, nonvisceral), and the use of systemic therapy, the hazard ratio for death is reduced by 40% to 50% in women receiving surgical treatment of the primary tumor. The benefit of surgical treatment appears to be confined to women whose tumors were resected with free margins. However, these results may simply reflect a selection bias (ie, younger, healthier women with a smaller tumor burden are more likely to receive surgical treatment). In addition, the role of other locoregional therapy such as axillary dissection and radiotherapy is not addressed in these studies. In view of these data, the role of local therapy in women with stage IV breast cancer needs to be reevaluated, and local therapy plus systemic therapy should be compared to systemic therapy alone in a randomized trial.     

Nanoparticle albumin-bound (nab™)-paclitaxel: improving efficacy and tolerability by targeted drug delivery in metastatic breast cancer

Breast cancer deaths in western countries are falling due to screening and adjuvant therapy, but the treatment of metastatic breast cancer (MBC) has not shown comparable advances. The most active single agents are taxanes, which extend both disease-free and overall survival. However, opportunities remain for improving outcome. Nanoparticle technology is proving a valuable addition to the pharmaceutical armamentarium, particularly in oncology. Its use to bind paclitaxel to human albumin (nanoparticle albumin-bound paclitaxel; nab-paclitaxel; Abraxane®) ensures solubility of the taxane without the use of solvents and minimizes the risk of hypersensitivity reactions without premedication. The homogeneous colloidal suspension created allows rapid dispersal of unbound drug and linear pharmacokinetics. Albumin-mediated transport of paclitaxel across the endothelium facilitates uptake of drug, and a degree of tumour selectivity is achieved by the albumin-binding propensity of SPARC (Secreted Protein Acidic Rich in Cysteine), a substance expressed on and around many breast tumours. Clinical trials in first- and second-line MBC show that nab-paclitaxel is both more effective than solvent-based taxanes and associated with less severe neutropenia. Sensory neuropathy occurs but improves rapidly when compared with that caused by conventional taxanes. A clinical development programme is investigating nab-paclitaxel in the adjuvant and neoadjuvant settings. The low incidence of neutropenia makes nab-paclitaxel a good candidate for combination with other cytotoxics. It is also being assessed when given with biologic agents such as trastuzumab and bevacizumab.     

The role of nab™-paclitaxel in managing metastatic breast cancer: a report of three cases

Options for the treatment of metastatic breast cancer (MBC) continue to grow with the advent of signal transduction modulators, new cytotoxics, and new formulations of standard agents. These developments are welcome as a means of further extending progression-free and overall survival, and as a way of allowing us to tailor therapy to characteristics of the individual patient such as the molecular biology of their tumour, treatment history, and performance status. Targeting drug delivery to the tumour is a promising means of increasing the therapeutic index of highly active agents such as the taxanes, and nanoparticle albumin-bound (nab) paclitaxel is one such advance. This paper reviews the clinical trial background for nab-paclitaxel and three individual cases in which its use was judged especially appropriate. These include a patient with prior exposure to anthracycline and docetaxel needing second-line treatment for MBC, a patient requiring first-line treatment following adjuvant anthracycline, and a patient in whom flexible dosing was a potential advantage.     

Primary metastatic breast cancer in the era of targeted therapy – Prognostic impact and the role of breast tumour surgery

BackgroundExcept for meeting the individual palliative need, the benefit of breast surgery in primary metastatic breast cancer (PMBC), also known as de novo metastatic breast cancer, on long-term outcomes remains controversial. Twenty-four hundred and one patients with metastatic breast cancer, enrolled between 2000 and 2011 in two prospective non-interventional studies on targeted therapy, were screened with respect to this question.MethodsOne study investigated trastuzumab therapy for human epidermal growth factor receptor 2 (HER2)-positive metastatic breast cancer in addition to mainly first-line chemotherapy. The other observed bevacizumab added to chemotherapy as first-line treatment for mostly HER2-negative disease.ResultsFive-hundred and seventy (24%) patients presented with PMBC, and valid information on resection of the primary tumour was available for 568 women. Out of these, 426 (75%) underwent local resection. The latter group was characterised by less overall metastatic burden and a lower proportion of T4 tumours. No major differences were observed with respect to age, hormone receptor and HER2 status, visceral disease and performance status. Numerically, the surgery group showed a slightly favourable progression-free survival (PFS, medians: 13.6 versus 11.8 months; P = 0.18) and overall survival (OS, 34.1 versus 31.7; P = 0.23). However, in multivariable analysis, including all other univariably significant parameters, no trend for better outcome after surgery remained detectable, neither for PFS (hazard ratio 0.99; P = 0.92) nor for OS (0.95; P = 0.71).ConclusionsOur findings suggest no major survival benefit for local resection in the overall PMBC population treated with modern targeted therapies. However, further analyses are warranted to define specific risk groups, which may benefit from surgical removal of the primary.     

Complete remission in metastatic breast cancer: expecting the unexpected—results of a cross-sectional study

Background

Complete response (CR) in metastatic breast cancer (MBC) is rare. This study aims at analyzing the characteristics and outcome of MBC patients achieving CR.

Methods

We performed a cross-sectional analysis of clinical data from a consecutive series of MBC patients admitted at the Division of Medical Oncology of Fondazione IRCCS Istituto Nazionale dei Tumori, Milan, Italy, achieving CR following treatment for systemic disease and with at least 2 years of follow-up.

Results

Seventy-six MBC patients with CR were identified during a calendar year. 47 patients (61.8%) achieved CR more than once, for a total of 123 cases. Median age at MBC diagnosis was 56 years (range 30–76). 52 patients (68.4%) presented with recurrent disease, 24 (31.6%) with de novo metastatic disease. The majority of patients (80.3%) had hormone receptor (HR) positive and 26 (34.2%) had HER2 overexpressing MBC. 54 patients (71.1%) had only one site of metastatic disease. 33 patients (43.4%) received a local approach as part of their treatment and 67 (54.5%) achieved CR during maintenance therapy. CRs were durable, as after a median follow-up of 8.3 years (interquartile range 5.8–11.0 years) 42 patients (55.3%) were alive with no evidence of disease.

Conclusions

Durable CRs can occur after systemic therapy alone or after combined systemic and local treatments. Most cases presented CR in the presence of limited disease spreading, not necessarily on first-line therapy. Our study highlights the crucial role of multidisciplinary approach to MBC and the benefit of maintenance treatment.