2 Department of Medical Oncology, Institute for Oncology and Radiology of Serbia, Pasterova 14 Belgrade, Serbia and Montenegro and
3 Department of Pathology, Institute for Oncology and Radiology of Serbia, Pasterova 14 Belgrade, Serbia and Montenegro
Email: Zorica D Juranic* - email@example.com; Zora Neskovic-Konstantinovic - firstname.lastname@example.org; Tatjana P Stanojkovic - email@example.com;
Zeljko Zizak - firstname.lastname@example.org; Tatjana Srdic - email@example.com; Nevenka Stanojevic-Bakic - firstname.lastname@example.org;
Taken together, the recently reported and ongoing trials in metastatic TPBC will provide evidence to support new treatment standards for this group of patients. Finally, it could be noted that most metastatic TPBC patients were exposed to previous endo- crine treatments in a (neo)adjuvant setting and/or in previous metastatic lines. Thus, testing for activating mutations in ligand- binding domain of estrogen receptor may be helpful for rational selection of the endocrine component of their treatment ( 98 ). Targeted Treatment of Brain Metastases Brain metastases (BM) have a distinct biology and poor prognosis ( 99 , 100 ). Currently, symptomatic BM is reported in 20–40% of HER2-positive MBC ( 101 , 102 ). Additionally, up to 10% of patients may have asymptomatic BM detectable on autopsy ( 100 ). Incidence of BM is significantly higher in ER-negative than in ER-positive disease ( 99 ). Treatment of BM is based on radio- therapy and surgery, supported by systemic therapies based on cytotoxic and targeted agents ( 103 – 105 ). The backbone systemic therapy could be combined with additional medication (such as corticosteroids and anti-epileptic drugs) that is beyond the scope of this review ( 106 ). Paradoxically, treatment with trastuzumab increases incidence of brain metastases ( 107 – 110 ), while prolong- ing the time to BM ( 110 ) and overall survival of patients with BM ( 108 , 111 ). This is commonly explained by trastuzumab’s success in suppressing extracranial metastatic sites, which allows time for brain metastases to develop and manifest clinically. Importantly, while achieving good extra-cranial control, trastuzumab has limited effect on brain metastases themselves because of its poor permeability through the blood–brain barrier (BBB). Thus, under conditions of unimpaired BBB, trastuzumab’s concentration in cerebrospinal fluid could be 420 times below its concentration in serum; even when BBB is compromised by irradiation, the concentration of trastuzumab in brain is still about 50 times lower than in blood ( 112 ). In contrast, small-molecule TKIs, like lapatinib, penetrate BBB much better ( 113 ). This raised expecta- tions about a possible special role for TKIs in BM treatment and encouraged a number of small trials evaluating effect of lapatinib on BM in heavily pre-treated HER2-positive MBC patients ( 114 ). In these trials, lapatinib alone showed low CNS response rates
cisplatin in the 3 dasatinib-sensitive cell lines. In solid tumours dasatinib has been reported to synergise with capecitabine and doxorubicin in vitro (105) (115). A phase I study of dasatinib in combination with capecitabine in metastaticbreastcancerpatients showed encouraging activity (117). Other investigators have reported that in colon cancerpatients, oxaliplatin activates Src through a ROS-dependent mechanism and combination treatment with dasatinib is synergistic in a cell-line dependent manner, with the level of Src activation correlating with extent of synergy in vitro (118). To our knowledge there are no reports of synergistic activity of dasatinib with cisplatin, especially in the highly relevant area of triple negative breastcancer. This was the reason this combination was chosen for in vivo study. Unfortunately the results of the in vivo study were inconclusive due to an unanticipated effect of the vehicle alone on tumour growth, even though the vehicle used has been used in previously published studies with dasatinib (119) (120). No explanation could be found in the relevant literature explaining this unexpected event. Thus, the in vivo testing would need to be repeated with an alternative vehicle for dasatinib.
The primary goal of this research was to evaluate the impact on HRQoL of disease progression in general, and of specific sites of metastasis, in a HER-2 negative mBC population. An additional goal was to identify those symptoms most often reported as severe at base- line in this population. We focused on HER-2 negative patients because they comprise the bulk of women with breastcancer and because we believe that the HRQoL trajectory may be different in women with HER-2positive disease. We hypothesized that disease progression would be associated with a decrease in composite indicators of HRQoL and worsening of symptom burden related to fatigue, pain, and other high frequency symptoms. We also hypothesized that metastasis to different organ systems would differen- tially affect self reported patient reported outcomes (PROs).
More than 50% of HER2-positive tumours also express oestrogen receptors (66). These tumours are being increasingly recognised as a distinct group of breast cancers: “Triple PositiveBreastCancer” (TPBC) (68, 86, 87), whose unique biology is shaped by a complex interplay of HER2 and ER signalling (88-91). Optimal management of TPBC lies on the border between endocrine and HER2-targeted treatments. However, till recently, HER2-positive tumours have usually been excluded from endocrine trials, and studies of HER2-targeted agents often reported results without splitting them into ER-positive and ER-negative subgroups. So far, only a limited number of trials focused on metastatic TPBC patients (Fig 3). Three trials (TANDEM, EGF30008 and ELECTRA) showed that addition of HER2-targeting to endocrine treatment significantly prolongs PFS, although the OS improvements in these trials did not reach statistical significance (70, 71, 92, 93). No randomised study has yet performed the opposite comparison: the addition of endocrine treatment to HER2- targeting agents. However, a retrospective analysis suggests that this may improve the results of treatment (72). Endocrine treatment has low toxicity, and multiple lines of evidence suggest that ER-positive tumours may have inferior response to cytotoxic treatment (94, 95). Taken together, these data justify addition of endocrine treatment whenever possible for ER-positivebreastcancer, which led to the current ASCO and ESMO recommendations to add endocrine agents to the
The HER-2/neu (also known as ERBB2) proto-oncogene, which encodes a trans- membrane growth factor receptor with tyrosine kinase activity, has become an important subject for human cancer re- search during the last decade. The impact of HER-2 amplification and expression on prognosis (1–12) and on the response to cytotoxic (4,13–18) and hormonal (15,19–22) therapies in breastcancerpatients have been studied intensively. Studies of HER-2 represent a paradigm of how genetic findings have led to the development of a gene-specific therapy: In September 1998, the U.S. Food and Drug Administration approved trastuzamab (Herceptin), a recombinant monoclonal antibody targeting Her-2, for the treat- ment of metastaticbreastcancer. Al- though trastuzumab binds to the Her-2 receptor with high affinity, the mecha- nism of action by which it causes tumor reduction is not understood. Despite the theoretic benefits of such a targeted treat- ment, not all patients respond favorably to trastuzamab treatment in practice. Among the patients with HER-2-positive meta- static breastcancer that is resistant to con- ventional cytotoxic treatment, only about 25% benefit from trastuzamab given in combination with cisplatin (23). The ge- netic features that distinguish the HER-2- positivebreast cancers that respond to trastuzamab from those that do not remain unclear. However, it is possible that the extent of HER-2 amplification and/or overexpression in the primary tumor dif- fers from that in the metastases. The HER-2 status of the primary tumor, which is removed from the patient, determines whether or not trastuzamab treatment is prescribed. But trastuzamab works by tar- geting the metastases that remain in the patient. If at least some of the multiple metastases of an HER-2-positive primary breast tumor did not express HER-2, trastuzamab treatment would most likely not affect the course of the disease. A comprehensive, large-scale study compar- ing HER-2 gene copy numbers and pro- tein expression in primary tumors and in multiple different metastases derived from them has not been performed. To gain insight into the patterns of HER-2
Similar to our cancer-related study, several other literature studies have indicated that free ISG15 may also function to help the immune system to recognize pathogen (viruses and bacteria) infected cells for their destruction in the human body [5, 43]. For example, recent studies by Bogunovic et al. has revealed that ISG15 is essential for the secretion of IFNβ from NK cells, consequently establishing IFNβ-mediated anti-mycobacterial immunity in human MSMD (Mendelian Susceptibility to Mycobacterial Disease) patients . Based on this report and our current study, we hypothesize that free ISG15 protein, which is designed to help the immune system to protect the body against viruses and bacteria, may also aid immune cells in detecting cancer cells for their elimination in the human body. Tumor cells deregulate the function of free ISG15, probably by blocking its secretion by conjugating it to cellular proteins consequently, escaping immune surveillance.
Nab-paclitaxel (Abraxane ® for injectable suspension;
Abraxis BioScience, Los Angeles, CA, USA), an albumin- bound 130 nm particle form of paclitaxel, was developed to avoid toxicities associated with the Cremophor vehicle in sb- paclitaxel. 7–10 Preclinical data in animals have demonstrated increased antitumor activity of nab-paclitaxel compared with equitoxic doses of sb-paclitaxel. 11 These findings were con- firmed clinically, and nab-paclitaxel consistently demonstrates superior efficacy compared with sb-paclitaxel. In a phase III trial, nab-paclitaxel showed a significantly higher overall response rate (ORR), a longer time to progression (TTP), and greater OS in patients treated with second-line or greater therapy compared with patients who received sb-paclitaxel. 8 Furthermore, weekly nab-paclitaxel can be safely administered at doses exceeding those typically used for sb-paclitaxel, 12 is effective in taxane resistant patients, 13 and as a single drug is more effective than docetaxel, which was previously consid- ered the most potent drug for MBC. 14 Therefore, weekly nab- paclitaxel is becoming a standard of care for MBC patients.
Results of clinical trials, however, indicated that outcomes of the combination may depend on the cell types of tumors.
In this regard, von Minckwitz et al reported that addition of pertuzumab to a trastuzumab-containing adjuvant regimen moderately improved disease-free survival in women with breastcancer who were in poorest prognosis, 34 and Murthy et al reported that trastuzumab and pertuzumab-containing che- motherapy regimen yielded higher PCR rates in stage II–III HER-2-positivebreastcancerpatients compared to that trastu- zumab plus chemotherapy regimen. 35 In contrast, Tabernero et al reported that addition of pertuzumab to trastuzumab and chemotherapy did not significantly improve OS in patients with HER-2-positivemetastatic gastric or gastroesophageal junction cancer compared with placebo. 36 These findings suggested that studies on dual targeting on HER-2-positive tumors with pertuzumab and trastuzumab remains further investigated in different types of primary tumors.
Discordance in receptor status may be attributed to either changes in receptor expression or to errors in recep- tor assessment. 15 Intra-tumoral biomarker heterogeneity may impact the classi ﬁ cation of breastcancer, causing apparent receptor discordance. However, based on some accurate techniques (including mRNA assessment), Italian researchers found that heterogeneity is not likely to cause discordance. 16 In cases of accurate receptor assays, dis- cordance is generally believed to be driven by tumor progression/trans-differentiation owing to therapy-related stress. Certain reports suggest that poor survival in dis- cordant cases may be related to the inappropriate use of targeted therapies; 12 an Indian study has also suggested that ER/PR status may change after chemotherapy and that re-evaluation is needed after chemotherapy. 17 In a study, all anti-estrogen-treated tumors lost ER expression, parti- cularly in cases involving brain metastases. 18 In this study, we demonstrated for the ﬁ rst time that adjuvant endocrine therapy and chemotherapy may alter PR and ER receptor pro ﬁ les. Similar studies have suggested that in ER- and HER2-positivepatients, endocrine therapy and trastuzu- mab treatment are independent factors associated with discordance. 19 Reports also suggest that chemotherapy may alter ER, PR, and HER2 status. 20
cytolytic potential of CD8 + T cells, we hypothesize that the extent of maturation might be due to an effective antitumorresponse .
Pre-existing T cell responses to TAA have been reported in patients with solid tumors ; however, these responses usually involve a low frequency of anti- gen-specific T cells, not detectable in the majority of patients . In this regard, literature data on circulat- ing tumor antigen-specific T cells in breastcancerpatients are still conflicting, probably because of the pre- dominant focus on single epitopes . Circulating T cells able to recognize CD8 + epitopes of HER2 , MUC-1 , mammaglobin-A , Trag-3 , survivin , or bcl-x L  have been described in distinct papers, but the evaluation of multiepitopic antitumor responses is still lacking. We therefore assessed the amount of IFN-g-secreting CD8 + T cells specific for a broad spectrum of HLA-A*0201 peptides derived from Her2, muc-1, mam-A, trag-3, survivin, and bcl-x L . Nota- bly, we found increased IFN-g release to all screened epitopes in the global cohort of patients if compared with healthy donors, demonstrating the existence of spontaneous T cell responses against multiple TAA in locally advanced breastcancerpatients. The ability to stimulate the generation of antitumor CD8 + T cells seemed to be more pronounced in HER2 + cancers, espe- cially towards Her2-, trag-3-, muc-1-, and bcl-x L -derived epitopes. This peculiarity may be useful in the design and optimization of vaccine strategies, which could take
Phase Ib study in Japanese patients
A multicenter, single-arm, Phase Ib study (JO22992) using a combination of T-DM1 and pertuzumab was performed in
Japanese patients with HER2-positivemetastaticbreast can- cer who had received prior treatment with trastuzumab and chemotherapy. 16 Six patients received T-DM1 3.6 mg/kg with pertuzumab (a 840 mg loading dose, then a 420 mg main- tenance dose) given every 3 weeks. The median duration of treatment was eleven (range 1–32) cycles. Grade $3 adverse events included one case each of increased aspartate amino- transferase, decreased left ventricular ejection fraction, and neutropenia. A grade 3 decrease in left ventricular ejection fraction during cycle 1 led to discontinuation, but resolved within 30 days. Two serious adverse events (hemorrhagic gastric ulcer and epistaxis) occurred in one patient. The pharmacokinetic parameters of both drugs were similar to those seen in the single-agent trials. The objective response rate was 50%. In conclusion, the combination of T-DM1 and pertuzumab showed encouraging results regarding toler- ability in Japanese patients with HER2-positivemetastaticbreastcancer.
Hence, in addition to protein overexpression and gene amplification of Her2, other predictive response markers are needed to optimize its clinical use.
Since NK cell-mediated killing of the mAb-coated Her2- positive autologous tumor is part of the mechanism of action of trastuzumab, the functional state of NK cells may also critically influence the clinical outcome. We have therefore correlated this pretreatment biomarker with clinical response to trastuzumab after 6 months and 12 months. Results show that the short-term response rests on efficient NK and ADCC functions, whereas the long-term response is correlated with high NK function, but is independent of the ADCC profile.
MiR-100 was the most differentially upregulated miR in patients with dovitinib-responsive tumors (Fig. 3c). It has been shown that miR-100 inhibits the maintenance and expansion of breastcancer stem cells in basal-like cancer and plays a role in cancer free-survival, as con- firmed by a cohort analysis of patient tumors implicating low expression of miR-100 as a negative prognostic factor . Thus, the upregulation in patients with treatment responsive tumors matches with the role ascribed to this miR. Given the complex interplay of cancer and stroma that includes distinct drivers in different cancers as well as genetic and environmental differences in the patient, analysis of patterns of miRs can provide a more reliable read-out than individual miRs and will compensate for this heterogeneity. Also, rather than evaluating absolute levels of single miRs in patients with different genetic backgrounds, co-morbidities and lifestyle, our study sug- gests that it is more informative to evaluate changes in the expression patterns of a set of miRs due to therapy and during the course of the disease. Here, we assessed miR expression pattern changes in response to therapy, and evaluated whether this differs amongst patients with different courses of their disease.
Compared with hormone receptor status, discordance in the HER-2 status between primary and metastatic lesions is less common, and the impact of this discor- dance on the prognosis of recurrent breastcancer is less clear [6,7]. However, with the introduction of trastuzu- mab, the HER-2 status of metastatic disease has become one of the most important predictive and prognostic factors in patients with recurrent breastcancer. Clinical trials have shown a significant survival benefit from tras- tuzumab in addition to the chemotherapy agent in HER- 2-positive advanced breastcancer [11,12]. An institu- tional-based review also showed that women with HER- 2-positive disease who received trastuzumab had an improved prognosis compared with women who did not receive such treatment . However, it is less clear whether the reevaluation of HER -2 status in metastatic lesions has an impact on the prognosis of patients with recurrent breastcancer. In this case report, the patient was initially diagnosed with triple-negative breastcancer, but a reevaluation of the metastatic disease showed her to be HER-2-positive by FISH, and she was diagnosed with HER-2-positivemetastaticbreastcancer. Based on these findings, she was administered combination che- motherapy using weekly paclitaxel and trastuzumab, and clinically complete remission was immediately achieved and maintained for over 1 year. She is currently disease- free, and an excellent prognosis is expected. The inci- dence of a discordance in HER-2 status between
nuclear staining along with cytosolic staining for IFN-g Ra in their tumors.
If HER-2/neu-specific IFN-g producing T cells are involved in HER-2/neu loss and tumor recurrence, we might be able to detect such immune responses in patients with HER-2/neu negative breastcancer, who might have had undetectable HER-2/neu positive pre- malignant tumors in the past, that had lost HER-2/neu expression and progressed to invasive carcinoma under the immune pressure. The fact that 55-75% of patients with premalignant DCIS overexpress HER-2/neu in their tumor lesions and 75% of breast cancers are HER-2/neu negative would suggest the progression of HER-2/neu positive DCIS to HER-2/neu negative breastcancer is only in the tumor clones that express IFN-g Ra. We have already shown that T cell-mediated tumor antigen loss was due to hypermethylation of the neu promoter and loss of neu both at mRNA and protein levels [3,5].
Recently, our group has shown that MMP11 may rep- resent an ideal self-antigen for immunotherapy. It is dif- ferentially expressed in tumor versus normal tissue , although it is unclear if it is expressed in cancer cells or in the supporting stroma. A genetic vaccine against MMP11 based on DNA electro-gene-transfer technology was able to break immune tolerance and exert antitumor effects in a chemically-induced colon adenocarcinoma
Similarly, a phase Ib/II study associating trastuzumab- DM1 and pertuzumab in patients with trastuzumab resistant, HER2-positive advanced breastcancer was presented at the 2010 ASCO meeting. 146 The study included a dose-escalation phase followed by an expansion phase consisting of a formal phase II study in 60 patients. The expansion phase showed that, in the subset of patients with relapsed stage IV disease who could be evaluated for tumor response, this combination yielded a 35.7% ORR, which is an encouraging achievement. More recently, at ESMO 2010 a randomized phase III trial showed that trastuzumab DM1 has similar activity and a significantly lower toxicity in comparison with the association docetaxel and trastuzumab as frontline treatment of HER2 positivemetastaticbreast cancers. 147
docetaxel (median PFS, 14.2 vs. 9.2 months; HR = 0.594; 95% CI, 0.364-0.968; p = 0.0353). In a phase Ib/
II single-arm study, the combination of T-DM1 plus pertuzumab showed encouraging preliminary activity both in the first-line setting and in patients with relapsed MBC. 13 In first-line MBC, a phase III study is currently evaluating T-DM1 with either pertuzumab or placebo, with a third arm consisting of trastuzumab plus taxane as the control. 14 The trial has adopted a superiority design with planned non-inferiority analyses, with PFS being the primary study endpoint. At the same time, an alternative formulation of trastuzumab is also being evaluated. Preliminary data suggest that subcutaneous trastuzumab has comparable drug exposure, safety, and efficacy when compared with the intravenous formulation, with subcutaneous administration offering greater convenience. Therefore, a phase III study is currently evaluating subcutaneous versus intravenous trastuzumab in the adjuvant and neoadjuvant setting. 15 Afatinib is a TKI that irreversibly inhibits signalling through activated EGFR (ErbB1), HER2 (ErbB2) and ErbB4 receptors, and transphosphorylation of HER 3 (ErbB3). As a candidate drug for breastcancer, afatinib is currently being evaluated in a range of settings. In a phase II neoadjuvant study of patients with HER2- positive stage IIIa-c breastcancer, single-agent afatinib showed a high objective response rate, with 70% of patients achieving a PR compared with 75.0% for lapatinib and 36.4% for trastuzumab. 16 In the HER2- positive first- and second-line MBC setting, a phase III study is currently evaluating treatment with afatinib or
T he overexpression of human epi- dermal growth factor receptor 2 (HER2) in breastcancer results in more aggressive disease with a poor prognosis. 1 The humanized anti-HER2 monoclonal antibodies pertuzumab and trastuzumab are more active in combination than alone because of more comprehensive sig- naling blockade. 2,3 We investigated combination therapy with docetaxel for first-line treatment of HER2-positivemetastaticbreastcancer in the Clinical Evaluation of Pertuzumab and Tras- tuzumab (CLEOPATRA) trial. Analysis of the pri- mary end point showed that patients who re- ceived pertuzumab, trastuzumab, and docetaxel (pertuzumab group) had a significantly longer median progression-free survival, as assessed by independent reviewers, than did those who re- ceived placebo, trastuzumab, and docetaxel (con- trol group) (hazard ratio favoring the pertuzu- mab group, 0.62). 4 The second interim analysis of overall survival confirmed significantly longer survival in the pertuzumab group (hazard ratio, 0.66). 5 Safety profiles (including cardiac) were similar and consistent across the two study groups and the analysis time points. 4-6 Here we report follow-up data at a median of 50 months regarding overall survival, investigator-assessed progression-free survival and safety, and inde- pendently assessed duration of response.