Early switch from run-in treatment with vemurafenib plus cobimetinib to atezolizumab after 3 months leads to rapid loss of tumour control in patients with advanced BRAFV600-positive melanoma: The ImmunoCobiVem phase 2 randomised trial

AIM

ImmunoCobiVem investigated whether a planned switch to atezolizumab after achieving tumour control during run-in with vemurafenib + cobimetinib improves progression-free survival (PFS) and overall survival (OS) compared to continuous targeted therapy (TT) in patients with previously untreated advanced BRAF^V600-mutated melanoma.

METHODS

In this multicenter phase 2 study, patients received vemurafenib plus cobimetinib. After 3months, patients without progressive disease (PD) were randomly assigned (1:1) to continue vemurafenib + cobimetinib (Arm A) or switch to atezolizumab (Arm B) until first documented PD (PD1). Primary outcome was PFS1 (time from start of run-in until PD1 or death). OS and safety were also assessed.

RESULTS

Of 185 patients enroled between November 2016 and December 2019, 135 were randomly assigned after the run-in period (Arm A, n = 69; Arm B, n = 66). Median PFS1 was significantly longer in Arm A versus Arm B (13.9 versus 5.9months; hazard ratio [HR] 0.55; 95% confidence interval [CI], 0.37-0.84; P_Stratified=0.001). Median OS was not reached in either arm (HR 1.22; 95%CI, 0.69-2.16; P_Stratified=0.389); 2-year OS was higher in Arm B versus Arm A (67%; 95%CI, 53-78 versus 58%; 95%CI, 45-70). Grade 3/4 AEs occurred in 55% of patients in Arm A and 64% in Arm B; treatment-related AEs led to discontinuation of any drug in 7% and 9% of patients, respectively.

CONCLUSION

In patients with BRAF^V600-mutated advanced melanoma who achieve tumour control with TT, early switch at 3months to atezolizumab led to rapid loss of tumour control but provided a numerical OS benefit at 2years compared with continued TT.

Which medical disciplines diagnose and treat melanoma in Europe in 2019? A survey of experts from melanoma centres in 27 European countries

BACKGROUND AND OBJECTIVES

The incidence of melanoma is increasing. This places significant burden on societies to provide efficient cancer care. The European Cancer Organisation recently published the essential requirements for quality melanoma care. The present study is aimed for the first time to roughly estimate the extent to which these requirements have been met in Europe.

MATERIALS AND METHODS

A web-based survey of experts from melanoma centres in 27 European countries was conducted from 1 February to 1 August 2019. Data on diagnostic techniques, surgical and medical treatment, organization of cancer care and education were collected and correlated with national health and economic indicators and mortality-to-incidence ratio (MIR) as a surrogate for survival. Univariate linear regression analysis was performed to evaluate the correlations. SPSS software was used. Statistical significance was set at P < 0.05.

RESULTS

The MIR was lower in countries with a high health expenditure per capita and with a higher numbers of general practitioners (GPs) and surgeons (SURG) per million inhabitants. In these countries, GPs and dermatologists (DER) were involved in melanoma detection; high percentage of DER used dermatoscopy and were involved in the follow-up of all melanoma stages; both medical oncologists (ONC) and dermato-oncologists administered systemic treatments; and patients had better access to sentinel lymph node biopsy and were treated within multidisciplinary tumour boards.

CONCLUSION

Based on these first estimates, the greater involvement of GPs in melanoma detection; the greater involvement of highly trained DER in dermatoscopy, dermatosurgery, follow-up and the systemic treatment of melanoma; and the provision of ongoing dermato-oncology training for pathologists, SURG, DER and ONC are necessary to provide an optimal melanoma care pathway. A comprehensive analysis of the melanoma care pathway based on clinical melanoma registries will be needed to more accurately evaluate these first insights.

Cobimetinib plus atezolizumab in BRAFV600 wild-type melanoma: primary results from the randomized phase III IMspire170 study

BACKGROUND

Emerging data suggest that the combination of MEK inhibitors and immunotherapeutic agents may result in improved efficacy in melanoma. We evaluated whether combining MEK inhibition and immune checkpoint inhibition was more efficacious than immune checkpoint inhibition alone in patients with previously untreated BRAF^V600 wild-type advanced melanoma.

PATIENTS AND METHODS

IMspire170 was an international, randomized, open-label, phase III study. Patients were randomized 1 : 1 to receive cobimetinib (60 mg, days 1-21) plus anti-programmed death-ligand 1 atezolizumab (840 mg every 2 weeks) in 28-day cycles or anti-programmed death-1 pembrolizumab (200 mg every 3 weeks) alone until loss of clinical benefit, unacceptable toxicity, or consent withdrawal. The primary outcome was progression-free survival (PFS), assessed by an independent review committee in the intention-to-treat population.

RESULTS

Between 11 December 2017, and 29 January 2019, 446 patients were randomized to receive cobimetinib plus atezolizumab (n = 222) or pembrolizumab (n = 224). Median follow-up was 7.1 months [interquartile range (IQR) 4.8-9.9] for cobimetinib plus atezolizumab and 7.2 months (IQR 4.9-10.1) for pembrolizumab. Median PFS was 5.5 months [95% confidence interval (CI) 3.8-7.2] with cobimetinib plus atezolizumab versus 5.7 months (95% CI 3.7-9.6) with pembrolizumab [stratified hazard ratio 1.15 (95% CI 0.88-1.50); P = 0.30]. Hazard ratios for PFS were consistent across prespecified subgroups. In exploratory biomarker analyses, higher tumor mutational burden was associated with improved clinical outcomes in both treatment arms. The most common grade 3-5 adverse events (AEs) were increased blood creatine phosphokinase (10.0% with cobimetinib plus atezolizumab versus 0.9% with pembrolizumab), diarrhea (7.7% versus 1.9%), rash (6.8% versus 0.9%), hypertension (6.4% versus 3.7%), and dermatitis acneiform (5.0% versus 0). Serious AEs occurred in 44.1% of patients with cobimetinib plus atezolizumab and 20.8% with pembrolizumab.

CONCLUSION

Cobimetinib plus atezolizumab did not improve PFS compared with pembrolizumab monotherapy in patients with BRAF^V600 wild-type advanced melanoma.

ESMO consensus conference recommendations on the management of metastatic melanoma: under the auspices of the ESMO Guidelines Committee

The European Society for Medical Oncology (ESMO) held a consensus conference on melanoma on 5-7 September 2019 in Amsterdam, The Netherlands. The conference included a multidisciplinary panel of 32 leading experts in the management of melanoma. The aim of the conference was to develop recommendations on topics that are not covered in detail in the current ESMO Clinical Practice Guideline and where available evidence is either limited or conflicting. The main topics identified for discussion were (i) the management of locoregional disease; (ii) targeted versus immunotherapies in the adjuvant setting; (iii) targeted versus immunotherapies for the first-line treatment of metastatic melanoma; (iv) when to stop immunotherapy or targeted therapy in the metastatic setting; and (v) systemic versus local treatment for brain metastases. The expert panel was divided into five working groups to each address questions relating to one of the five topics outlined above. Relevant scientific literature was reviewed in advance. Recommendations were developed by the working groups and then presented to the entire panel for further discussion and amendment before voting. This manuscript presents the results relating to the management of metastatic melanoma, including findings from the expert panel discussions, consensus recommendations and a summary of evidence supporting each recommendation. All participants approved the final manuscript.

ESMO consensus conference recommendations on the management of locoregional melanoma: under the auspices of the ESMO Guidelines Committee

The European Society for Medical Oncology (ESMO) held a consensus conference on melanoma on 5-7 September 2019 in Amsterdam, The Netherlands. The conference included a multidisciplinary panel of 32 leading experts in the management of melanoma. The aim of the conference was to develop recommendations on topics that are not covered in detail in the current ESMO Clinical Practice Guideline and where available evidence is either limited or conflicting. The main topics identified for discussion were: (i) the management of locoregional disease; (ii) targeted versus immunotherapies in the adjuvant setting; (iii) targeted versus immunotherapies for the first-line treatment of metastatic melanoma; (iv) when to stop immunotherapy or targeted therapy in the metastatic setting; and (v) systemic versus local treatment of brain metastases. The expert panel was divided into five working groups in order to each address questions relating to one of the five topics outlined above. Relevant scientific literature was reviewed in advance. Recommendations were developed by the working groups and then presented to the entire panel for further discussion and amendment before voting. This manuscript presents the results relating to the management of locoregional melanoma, including findings from the expert panel discussions, consensus recommendations and a summary of evidence supporting each recommendation. All participants approved the final manuscript.

Inhibition of the Hedgehog pathway in lung cancer

Inhibitors of the hedgehog pathway are effective in patients with basal cell carcinoma and a subgroup of patients with medulloblastoma with active hedgehog signaling. Despite preclinical work suggesting otherwise, clinical trials in solid tumors of epithelial origin have not shown added benefit with these drugs. Here, we review the preclinical and clinical data of hedgehog pathway inhibition in the most common histologic types of lung cancer. We focus on highlighting areas of uncertainty, where further research might define a niche for hedgehog pathway inhibition in patients with lung cancer.

Abstract P4-08-13: Prognostic significance of CD8+ tumor-infiltrating lymphocytes (TILs) in patients with early breast cancer (EBC) treated with dose-dense sequential adjuvant chemotherapy (dds-CT). An observational study (ACTRN12616001043426)

Background - aim: Information on the prognostic role of cytotoxic CD8+ T cells in the era of modern adjuvant CT is limited. The primary objective of the present report is to assess the prognostic impact of CD8+ cells in patients with intermediate or high-risk EBC (T1-3N1-2M0) treated with dds-CT. Secondary endpoints are safety, disease-free survival (DFS) and overall survival (OS).

Patients and Methods: Patients (N=1,000) were treated with 4 cycles of Epirubicin, 75mg/m2, and Cyclophophamide, 600mg/m2 every 2 weeks followed by 4 cycles of Docetaxel (D), 100mg/m2 every 3 weeks with G-CSF support in all cycles. Trastuzumab was initiated concurrently with D and continued for a total of 1 year. Hormonal and radiation therapy were given post CT, as indicated. Formalin-fixed paraffin-embedded tumors were available for 642 patients (64.2%) and were centrally assessed for immunohistochemical subtypes (IHC4; N=526), stromal TILs density by morphology (N=636), as well as stromal and intratumoral cytotoxic CD8+ T cell numbers (N=554). TILs and CD8+ were assessed as continuous variables for associations and as 10% increments for outcome.

Results: In total, 901/1,000 pts (90.1%) completed 8 cycles of CT. Severe (gradeIII-IV) toxicitiesincludedneutropenia (5.6%), leucopenia (3.6%), lymphopenia (2.1%), hand-footsyndrome (2.1%), and hepatotoxicity (1.8%). Febrileneutropenia occurred in 1.6% of the patients. The 5-year DFS and OS rates were 89.5% and 93.1%, respectively. Luminal A tumors were classified in 26.2%, Luminal B in 35.2%, luminal HER2 in 9.5%; HER2-enriched in 7.2%; and, triple-negative (TNBC) in 21.9% of informative patients. Among subtypes, stromal TILs density was higher in HER2-enriched and TNBC (p&lt;0.001); intratumoral CD8+ values were higher in TNBC (p&lt;0.001); and, stromal CD8+ were higher in HER2-enriched (p=0.034). In all patients, TILs density and intratumoral CD8+ cell numbers were not associated with DFS and OS, while increased stromal CD8+ were marginally associated with prolonged DFS (HR=0.98, 95%CI 0.96-1.00, p=0.066).Adjusted for histological grade, menopausal, ER/PgR and nodal status, higher stromal CD8+ were associated with prolonged DFS (HR=0.98, 95% CI 0.96-1.00, p=0.043). In TNBC, higher stromal TILs density conferred prolonged DFS (HR=0.97, 95%CI 0.94-0.99, p=0.029), which retained its prognostic significance in multivariate analysis (HR=0.97, 95% CI 0.94-1.00, p=0.049).

Conclusions: In this study, dds-CT was well tolerated and active in patients with EBC. We confirm the presence of morphologically assessed higher TILs density, and of higher cytotoxic CD8+ T cell numbers in hormone receptor negative EBC, as well as the favorable prognostic impact of higher stromal TILs density in TNBC. In comparison to stromal TILs density, higher stromal CD8+ may confer favorable prognosis irrespectively of EBC subtype. Stromal CD8+ seems to be a marker worth further standardizing for reporting on immune cell infiltrates in EBC.

Citation Format: Kourea HP, Koletsa T, Kotoula V, Koliou G-A, Batistatou A, Pentheroudakis G, Arapantoni-Dadioti P, Zagouri F, Bobos M, Sotiropoulou M, Papoudou-Bai A, Chrisafi S, Efstratiou I, Aravantinos G, Nicolaou I, Gogas H, Visvikis A, Christodoulou C, Petraki C, Koutras A, Psyrri A, Pectasides D, Fountzilas G. Prognostic significance of CD8+ tumor-infiltrating lymphocytes (TILs) in patients with early breast cancer (EBC) treated with dose-dense sequential adjuvant chemotherapy (dds-CT). An observational study (ACTRN12616001043426) [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P4-08-13.

Access to innovative medicines for metastatic melanoma worldwide: Melanoma World Society and European Association of Dermato-oncology survey in 34 countries

According to data from recent studies from Europe, a large percentage of patients have restricted access to innovative medicines for metastatic melanoma. Melanoma World Society and European Association of Dermato-oncology conducted a Web-based survey on access to first-line recommended treatments for metastatic melanoma by current guidelines (National Comprehensive Center Network, European Society for Medical Oncology [ESMO] and European Organization for Research and Treatment of Cancer/European Association of Dermato-oncology/European dermatology Forum) among melanoma experts from 27 European countries, USA, China, Australia, Argentina, Brazil, Chile and Mexico from September 1st, 2017 to July 1st, 2018. Data on licencing and reimbursement of medicines and the number of patient treated were correlated with the data on health expenditure per capita (HEPC), Mackenbach score of health policy performance, health technology assessment (HTA), ASCO and ESMO Magnitude of clinical benefit scale (ESMO MCBS) scores of clinical benefit and market price of medicines. Regression analysis for evaluation of correlation between the parameters was carried out using SPSS software. The estimated number of patients without access in surveyed countries was 13768. The recommended BRAFi + MEKi combination and anti-PD1 immunotherapy were fully reimbursed/covered in 19 of 34 (55.8%) and 17 of 34 (50%) countries, and combination anti-CTLA4+anti-PD1 in was fully covered in 6 of 34 (17.6%) countries. Median delay in reimbursement was 991 days, and it was in significant correlation with ESMO MCBS (p = 0.02), median market price (p = 0.001), HEPC and Mackenbach scores (p < 0.01). Price negotiations or managed entry agreements (MEAs) with national authorities were necessary for reimbursement. In conclusion, great discrepancy exists in metastatic melanoma treatment globally. Access to innovative medicines is in correlation with economic parameters as well as with healthcare system performance parameters. Patient-oriented drug development, market access and reimbursement pathways must be urgently found.

Abstract P1-07-03: Evaluation of the prognostic value of CD3, CD8 and FOXP3 mRNA expression in early breast cancer patients treated with anthracycline-based adjuvant chemotherapy

Background: Tumor-infiltrating lymphocytes (TILs) have been shown to be of prognostic value in several cancer types. In early breast cancer, TILs have a prognostic utility, as well, especially in HER2-positive and triple-negative breast cancer (TNBC). TILs presence is broadly associated with improved survival, however there is controversy regarding TILs subpopulations. In general, T cell infiltration is higher in non-luminal and more aggressive tumors, like the basal-like subtype. Among TILs subpopulations, CD8-positive T cell infiltration is associated with better outcome, whereas high numbers of FOXP3-positive T regulatory cells are associated with worse outcome in ER-positive tumors and better outcome in HER2-positive and TNBC tumors.

Patients and Methods: Early breast cancer patients, treated with anthracycline-based chemotherapy within two randomized trials (HE10/97 and HE10/00) were included in the study. We evaluated, by qRT-PCR, 826 macrodissected formalin-fixed paraffin-embedded tumor tissue samples for mRNA expression of CD3, CD8 and FOXP3for potential prognostic significance in terms of disease-free survival (DFS) and overall survival (OS). TILs were evaluated in whole sections as percent of total cells.

Results: Median age was 52.7 years, while 54.2% of the patients were postmenopausal and 79.0% ER/PgR-positive. After a median follow-up of 133.0 months, 255 patients (30.9%) had died and 314 (38.0%) had disease progression. All three mRNA markers were positively correlated with TILs (Spearman's r=0.52 for CD3, 0.41 for CD8 and 0.47 for FOXP3, all p-values &lt;0.001), while Ki67 protein expression was greater in tumors with high mRNA expression (median cut-off) of the markers (Mann-Whitney, all p-values &lt;0.001). Additionally, tumors of higher histological grade and negative ER/PgR status were more frequent in patients with high CD3, CD8 or FOXP3 mRNA expression, as compared to patients with low expression, (chi-square, p-values &lt;0.010). In the univariate analysis, high CD3 and CD8 mRNA expression was found to be of favorable prognostic value for DFS (HR=0.74, 95% CI 0.59-0.92, Wald's p=0.007 and HR=0.76, 95% CI 0.61-0.95, p=0.016, respectively). In multivariate analyses, the association of high CD8 mRNA expression with increased DFS was retained (HR=0.77, 95% CI 0.60-0.99, p=0.048), whereas that of high CD3 mRNA expression was of marginal statistical significance (HR=0.77, 95% CI 0.59-1.01, p=0.059). Moreover, a significant interaction was observed between HER2 status and CD3 mRNA expression with respect to DFS (interaction p=0.032). In the HER2-positive subgroup, the hazard ratio associated with high CD3 mRNA expression was of greater magnitude (HR=0.48, 95% CI 0.30-0.76, p=0.002) compared to the hazard ratio presented above, for the entire cohort. No significant findings were observed for FOXP3 in terms of DFS, while none of the studied markers were of prognostic value for OS.

Conclusions: High CD3 and CD8 mRNA expression in early breast cancer patients is of prognostic value for decreased risk for relapse and, in the future, could potentially be of importance in deciding the most appropriate therapeutic strategy in light of the recent immune-related treatment developments.

Citation Format: Tsiatas M, Kalogeras KT, Manousou K, Wirtz RM, Gogas H, Veltrup E, Zagouri F, Lazaridis G, Koutras A, Christodoulou C, Pentheroudakis G, Petraki C, Bafaloukos D, Pectasides D, Kosmidis P, Samantas E, Karanikiotis C, Papakostas P, Dimopoulos M-A, Fountzilas G. Evaluation of the prognostic value of CD3, CD8 and FOXP3 mRNA expression in early breast cancer patients treated with anthracycline-based adjuvant chemotherapy [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P1-07-03.

Dabrafenib plus trametinib versus dabrafenib monotherapy in patients with metastatic BRAF V600E/K-mutant melanoma: long-term survival and safety analysis of a phase 3 study

Background

Previous analysis of COMBI-d (NCT01584648) demonstrated improved progression-free survival (PFS) and overall survival (OS) with combination dabrafenib and trametinib versus dabrafenib monotherapy in BRAF V600E/K-mutant metastatic melanoma. This study was continued to assess 3-year landmark efficacy and safety after ≥36-month follow-up for all living patients.

Patients and methods

This double-blind, phase 3 study enrolled previously untreated patients with BRAF V600E/K-mutant unresectable stage IIIC or stage IV melanoma. Patients were randomized to receive dabrafenib (150 mg twice daily) plus trametinib (2 mg once daily) or dabrafenib plus placebo. The primary endpoint was PFS; secondary endpoints were OS, overall response, duration of response, safety, and pharmacokinetics.

Results

Between 4 May and 30 November 2012, a total of 423 of 947 screened patients were randomly assigned to receive dabrafenib plus trametinib (n = 211) or dabrafenib monotherapy (n = 212). At data cut-off (15 February 2016), outcomes remained superior with the combination: 3-year PFS was 22% with dabrafenib plus trametinib versus 12% with monotherapy, and 3-year OS was 44% versus 32%, respectively. Twenty-five patients receiving monotherapy crossed over to combination therapy, with continued follow-up under the monotherapy arm (per intent-to-treat principle). Of combination-arm patients alive at 3 years, 58% remained on dabrafenib plus trametinib. Three-year OS with the combination reached 62% in the most favourable subgroup (normal lactate dehydrogenase and <3 organ sites with metastasis) versus only 25% in the unfavourable subgroup (elevated lactate dehydrogenase). The dabrafenib plus trametinib safety profile was consistent with previous clinical trial observations, and no new safety signals were detected with long-term use.

Conclusions

These data demonstrate that durable (≥3 years) survival is achievable with dabrafenib plus trametinib in patients with BRAF V600-mutant metastatic melanoma and support long-term first-line use of the combination in this setting.

Abstract P2-07-02: Tumor infiltrating lymphocytes density and coding mutations effects on the outcome of operable triple negative breast cancer patients

Background-Aim: Neoantigens are considered to trigger host immune responses against tumors, which may be reflected by tumor infiltrating lymphocytes (TILs) density within the tumor stroma. High TILs levels have been associated with favorable triple-negative breast cancer (TNBC) patient outcome. Herein we evaluated the presence of coding mutations and TILs density with regard to outcome in a cohort of TNBC patients treated with anthracycline-based adjuvant chemotherapy.

Patients and Methods: Paraffin TNBC tissues from 242 patients treated in the context of four prospective clinical trials were histologically reviewed and submitted to massively parallel semiconductor sequencing with a custom panel targeting 57 breast cancer (BC)-related genes. Mutations (mut) were evaluated in 210 informative samples as missense/nonsense amino acid changing variants, with minor allele frequency &lt;1% in the case of single nucleotide polymorphisms. TILs density was morphologically evaluated as percent of the stromal area in 197 tumors; lymphocyte predominant (LP) BC tumors were called for TILs &gt;50%. Disease-free survival (DFS) was used as the endpoint for the present analysis.

Results: 426 Mut were observed for 40 genes in 147 TNBC patients (70%). Among mutated genes, ranging from 1 in 97 tumors up to &gt;10 in 8 tumors, the most frequently affected were TP53 (102 tumors, 69%) and PIK3CA (40 tumors, 27%). Intriguingly, mut rate (p=0.042) and number of mut genes (p=0.018) per tumor were inversely associated with TILs density. Nineteen tumors (10%) were LP-TNBC, carrying TP53 and PIK3CA mut as the only coding alterations in 10 and 3 cases, respectively. LP-TNBC patients did not experience any relapses during a follow-up period of 46-152 months (mean 66 months). For the 90% of non-LP-TNBC, the previously reported outcome benefit for 10% increments of TILs density was only demonstrated for tumors with 31-50% TILs. In non-LP-TNBC, upon adjustment for standard clinicopathological parameters, PIK3CA mut, TP53 mut and TILs density as a continuous variable, TP53 mut and nodal status independently conferred unfavorable DFS (HR=1.89, 95% CI 1.03-3.47, p=0.040 and HR=2.89, 95% CI 1.59-5.24, p=0.001, respectively). When continuous TILs density was added in the multivariate models in the entire cohort, 10% increments significantly predicted favorable DFS (HR=0.73, 95% CI 0.59-0.91, p=0.006), while high nodal status predicted unfavorable DFS (HR=2.75, 95% CI 1.51-4.99, p&lt;0.0001).

Conclusions: In the present study, tumors with higher TILs density, including LP-TNBC, were not characterized by multiple mutations or mutated genes with the panel tested. In TNBC, increasing TILs density is a strong favorable and high nodal status a strong unfavorable prognosticator. Importantly, LP-TNBC may be regarded as a distinct subgroup with excellent prognosis concerning 10% of TNBC. In non-LP-TNBC, TP53 mut and nodal status were significant unfavorable prognosticators. These data may suggest that the level of morphologically assessed TILs density does not necessarily correspond to the tumoral mutational load and merit validation in larger cohorts.

Citation Format: Kotoula V, Fountzilas E, Chatzopoulos K, Alexopoulou Z, Timotheadou E, Xanthakis I, Gogas H, Skondra M, Christodoulou C, Papadopoulou K, Chrisafi S, Koutras A, Xepapadakis G, Venizelos V, Efstratiou I, Patsea H, Kalogeras KT, Lakis S, Fountzilas G. Tumor infiltrating lymphocytes density and coding mutations effects on the outcome of operable triple negative breast cancer patients. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P2-07-02.

Abstract P4-14-05: Genomic parameters affecting the outcome of patients with advanced breast cancer treated with trastuzumab

Background-Aim: There is an unmet need for de-selecting HER2-positive patients with advanced breast cancer (ABC), since only some of those patients benefit from the addition of anti-HER2 agents to chemotherapy. The aim of this study was to investigate candidate biomarkers, including MYC and MET, in parallel with an extended array of biomarkers previously associated with trastuzumab (T) resistance.

Patients and Methods: Two hundred and twenty-nine ABC patients treated with T and chemotherapy over a period of 13 years were included in the study. Paraffin tumors were retrospectively centrally assessed with immunohistochemistry (IHC) for breast cancer subtypes; fluorescence in situ hybridization (FISH) for HER2, TOP2A and centromere (CEN) 17, MYC and CEN8, MET and CEN7; qPCR for MYC and MET copy number (CN); and, for PI3K activation (PIK3CA mutations, PTEN and phospho-mTOR IHC). Patterns of CEN CN aberrations corresponding to chromosome "polysomy" were also evaluated, with cut-offs based on normal tissue. Time to progression (TTP) and survival were evaluated from the initiation of T as first-line treatment.

Results: Median follow-up was 70 months. Of the 229 patients treated with T as HER2-positive, central analysis identified 90 cases being HER2-negative, as per current guidelines (39.3% of the total cohort). HER2-positive patients showed a trend for survival benefit over HER2-negative patients (median 50.7 vs. 38.1 months, respectively, p=0.118). HER2-positive tumors were subtyped as Luminal-HER2 (n=77) and HER2-enriched (n=53); 156 patients presented with ABC and 65 with disease initially diagnosed at stage IV (de novo ABC). MET and MYC CN gains (≥2.5 copies) were found in 40 (25%) and 15 (9%) cases with qPCR, while MET and MYC amplification with FISH was present in 4 (2.5%) and 31 (18%) cases, respectively. Concordance between FISH and qPCR was low for MYC (kappa value 0.46) and absent for MET. Polysomy was collectively observed in 70 cases, in 54 of them (32% of all tumors) concerning any 1 of the 3 examined chromosomes. This condition, called restricted polysomy, interacted with ABC presentation, conferring decreased survival to patients with ABC (HR=2.32, 95% CI 1.43-3.76, Wald's p=0.001) but not to those with de novo ABC (interaction p=0.077). MYC CN gain was the only marker significantly associated with increased risk for progression (HR=3.22, 95% CI 1.66-6.24, p&lt;0.001) and death (HR=5.45, 95% CI 2.89-10.28, p&lt;0.001) at univariate analysis. Adjustment of all tested markers with standard clinicopathological parameters revealed that along with poor patient performance status that was associated with poor prognosis, MYC CN gain was an independent adverse prognosticator for both TTP and survival (all p-values &lt;0.001). The HER2-enriched subtype was independently associated with T benefit for TTP (p=0.001) and survival (p=0.051). The interaction between restricted polysomy and disease presentation was also independently significant for survival (p=0.041).

Conclusions: MYC CN gain is a strong unfavorable prognosticator in T-treated ABC patients. Distinguishing between HER2-positive subtypes seems important for identifing T benefit in ABC. Chromosomal polysomy may distinctly affect T benefit in patients with pre-treated and de novo ABC.

Citation Format: Gogas H, Kotoula V, Alexopoulou Z, Christodoulou C, Kostopoulos I, Bobos M, Raptou G, Charalambous E, Tsolaki E, Xanthakis I, Pentheroudakis G, Koutras A, Bafaloukos D, Papakostas P, Aravantinos G, Psyrri A, Petraki K, Kalogeras KT, Fountzilas G, Pectasides D. Genomic parameters affecting the outcome of patients with advanced breast cancer treated with trastuzumab. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P4-14-05.

Abstract P5-08-50: Associations of MYC protein expression and gene status with breast cancer subtypes and outcome in patients treated with anthracycline-based adjuvant chemotherapy

Background-Aim: Breast cancer is a heterogeneous disease and despite recent scientific progress there is still need for the identification of biomarkers associated with risk for relapse, as well as for markers identifying patients who will benefit from specific treatments. The aim of the present study was to investigate the role of MYC, as a clinically meaningful biomarker, in the outcome of breast cancer subtypes.

Patients and Methods: We have pooled the patients and the respective breast carcinomas from two randomized anthracycline-based adjuvant phase III trials, consecutively conducted by the Hellenic Cooperative Oncology Group (HE10/97 and HE10/00). The HE10/97 trial included a non-paclitaxel arm. Tissue microarrays were constructed from 1,060 formalin-fixed paraffin-embedded tumor tissue samples that were collected retrospectively in the first and prospectively in the second trial. MYC was evaluated by immunohistochemistry (IHC) and fluorescence in situ hybridization (FISH) in 986 cases.

Results: In total 61.0% of the cases showed positive cytoplasmic MYC immunostaining, while 26.5% showed positive nuclear staining. 65-80% of the patients were characterized as non-amplified or loss/normal-low gain in all FISH cut-offs examined. A weak association was observed between FISH and nuclear protein expression of MYC. High histological grade was associated with MYC protein overexpression and gene amplification. In terms of disease-free survival (DFS), low (2.5-5 copies) and high (≥5 copies) gain of MYC was of adverse prognostic value compared to loss/normal (&lt;2.5 copies) MYC (HR=1.50, 95% CI 1.13-1.98, Wald's p=0.004 and HR=1.45, 95% CI 1.07-1.97, p=0.016, respectively). Comparable results were observed for overall survival (OS) (HR=1.51, 95% CI 1.09-2.08, p=0.013 and HR=1.65, 95% CI 1.17-2.33, p=0.005, respectively). The comparison of neoplasms with CEP8 ratio ≥1.3 and polysomy 8 for MYC versus all others resulted in worse survival prognosis (HR=1.44, 95% CI 1.13-1.83, p=0.004), while tumors with nuclear protein overexpression were associated with better DFS (HR=0.77, 95% CI 0.60-0.99, p=0.039) and OS (HR=0.73, 95% CI 0.55-0.98, p=0.034). In HER2-enriched patients, MYC amplification was found to be an adverse prognostic factor for DFS (HR=2.11, 95% CI 1.09-4.07, p=0.026) and OS (HR=2.41, 95% CI 1.12-5.15, p=0.024).

Treatment with paclitaxel was found to differentiate the effect of MYC: CEP8 ratio ≥1.3 and polysomy 8 in terms of DFS and OS in our total cohort. Among patients with CEP8 ratio ≥1.3 and polysomy 8, those treated with paclitaxel performed significantly better than those not treated, while among patients not treated with paclitaxel, those with CEP8 ratio ≥1.3 and polysomy 8 performed much worse than those with CEP8 ratio &lt;1.3 or no polysomy 8.

Conclusions: Our data suggest that MYC has prognostic and predictive value in patients with breast cancer. MYC amplification and MYC protein overexpression are detected in breast cancer patients and are of adverse prognostic value for DFS and OS. Polysomy 8 is also associated with worse prognosis. Treatment with paclitaxel in the adjuvant setting benefits breast cancer patients with MYC:CEP8 ratio ≥1.3 and polysomy 8.

Citation Format: Batistatou A, Razis E, Bobos M, Tsolaki E, Timotheadou E, Alexopoulou Z, Goussia A, Gogas H, Koutras A, Karina M, Pentheroudakis G, Efstratiou I, Petraki K, Sotiropoulou M, Pavlakis K, Koletsa T, Kotoula V, Fountzilas G. Associations of MYC protein expression and gene status with breast cancer subtypes and outcome in patients treated with anthracycline-based adjuvant chemotherapy. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P5-08-50.

Demographic, behavioural and physician-related determinants of early melanoma detection in a low-incidence population

BACKGROUND

Knowledge of the factors that influence early detection of melanoma is important in developing strategies to reduce associated mortality.

OBJECTIVES

To identify sociodemographic, behavioural and medical care-related factors associated with melanoma thickness in a low-incidence population but with a high case fatality.

PATIENTS AND METHODS

In a multicentre, retrospective, survey-based study of 202 patients with a recent diagnosis of invasive melanoma (< 1 year), we collected data on demographic and behavioural factors, attitudes towards prevention, access to medical care, frequency of skin self-examination (SSE) and physician skin examination (PSE) in relation to melanoma thickness.

RESULTS

Thinner tumours (≤ 1 mm, 80 melanomas) were associated with female sex (P ≤ 0.049), nonnodular (superficial spreading melanoma, lentigo maligna melanoma, acral lentiginous melanoma) histological subtypes (P < 0.001), absence of ulceration (P ≤ 0.001), and location other than lower extremity or trunk location (P ≤ 0.004). Patients married at the time of diagnosis or who performed SSE during the year prior to diagnosis were more likely to have thinner tumours than those who did not [odds ratio (OR) 3.45, 95% confidence interval (CI) 1.48-8.04 and OR 2.43, 95% CI 1.10-5.34, respectively]. Full-body skin examination by a physician was not significantly associated with thinner melanoma (OR 1.99, 95% CI 0.66-6.07).

CONCLUSIONS

SSE was shown to be an important factor in the detection of thin melanoma, in contrast to partial or full-body PSE, which did not show any statistically significant effect on tumour thickness.

Abstract P4-04-10: Clinically relevant tumor mutation profiles in patients with triple negative breast cancer (TNBC)

TNBC account for ∼15% of breast cancers and are most difficult to treat. However, TNBC patient outcome is very heterogeneous. In an effort to characterize the biological characteristics of TNBC, we examined 190 routinely diagnosed tumor tissues from early high-risk breast cancer patients treated with adjuvant chemotherapy (anthracyclines and/or taxanes). Highly multiplexed PCR primer pools were designed for 43 genes previously implicated in TNBC with Ion Ampliseq optimized for FFPE samples. Upon library construction and clonal amplification, amplicons were massively sequenced on Ion Proton PI chips and base-called (Torrent Suite 3.6). Variants were called and annotated (Ion Reporter 1.6), and accepted for analysis upon stringent read quality filtering at p&lt;0.001. Informative results were obtained in 183 cases (96.3%). Deleterious and hot-spot mutations (Ingenuity and Oncomine databases) were observed in 39/43 genes, and were more frequent in TP53 (77%), CDH1 (29%), PIK3CA (16.4%), ARID1B (10.4%). TP53 was affected as a single gene in 55/183 (30%) of the cases. Most TNBC (103/183, 56.3%) were mutant in more than one genes; double deleterious/damaging TP53 mutations were observed in 59 (32.2%) tumors at relatively high incidence; and, 29 (15.8%) tumors had extremely variable mutation profiles with &gt;4 mutations per sample, most of them at low incidence but still indicative of dynamic clonal expansion. CDH1 mutations seldom occurred alone (2% of all tumors) and were probably non-founders, while mutations in some genes, e.g., AKT1 (9/12) and ARID1B (13/19) preferentially occurred in CDH1mutant tumors (p&lt;0.001). In comparison to the 12 patients with tumors free of mutations in any of the genes tested (no events up to 120 mo after treatment start), patients with tumors bearing any number of mutations (n = 171) had significantly shorter disease-free survival (DFS, median: 56 mo, log-rank p = 0.031). Mutations in single genes were not significantly associated with disease outcome. The 29 patients with tumors bearing &gt;4 mutations had longer median DFS (91 mo) as compared to those with 1 mutation (n = 68, median DFS 46.5 mo) or with 4 mutations (n = 21, median DFS 39 mo) (HR: 0.4; 95%CI: 0.2-0.8; Wald's p = 0.010). In comparison to patients with TP53&CDH1 non-mutant tumors (n = 26, median DFS 62 mo), patients with TP53mutant/CDH1non-mutant tumors relapsed significantly earlier (n = 103, median DFS 48 mo, HR 3.9, 95%CI 1.2-12.9, Wald's p = 0.023) and tended to have shorter overall survival. CDH1mutant/TP53non-mutant and tumors mutated in both genes did not show such associations (interaction Wald's p = 0.044). No interactive effects on patient outcome were observed between mutation markers and treatment with taxanes, adjuvant radiotherapy, or with standard clinicopathologic parameters. In conclusion, TNBC may be assigned as a TP53 disease. However, the present data underline the need for a broad assessment of tumor mutational profiles, including non-founder mutations, since they may interfere with patient outcome upon standard treatments. The application of targeted parallel sequencing on routinely processed FFPE tissue samples seems feasible and may help in assessing clinically relevant genomic variant profiles of these highly intra- and inter-heterogeneous tumors.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P4-04-10.

Full Dose Paclitaxel Plus Vinorelbine as Salvage Chemotherapy in Anthracycline-Resistant Advanced Breast Cancer: A Phase II Study

This phase II trial studied the efficacy and toxicity of full dose paclitaxel plus vinorelbine, as salvage chemotherapy in patients with metastatic breast cancer resistant to anthracyclines. Patients received vinorelbine (30 mg/m2) followed 1 hour later by full dose paclitaxel (175 mg/m2) every 3 weeks for a maximum of 8 cycles or until disease progression. Because of the heavy pretreatment of the patients, prophylactic granulocyte-colony stimulating factor (5 microg/kg) was administered daily for 5-10 days. To minimize potentially cumulative neurotoxicity due to both agents, amifostine was given prior to chemotherapy. Thirty-four patients: 8 with tumors primary resistant and 26 with tumors recurring within 3-6 months after anthracycline treatment, were evaluable for efficacy and toxicity. Objective responses occurred in 11 patients [32%; 95% confidence interval (CI): 16.3-47.7%), all partial responses. Responses were observed in lung and liver. The median response duration was 4 months (range 3-7), median time to progression was 5 months (range 3-9) and median overall survival was 8 months (range 4-24). Neutropenia was dose limiting (35% grade 3-4 toxicity). The left ventricular ejection fraction, measured and followed in 18 patients, fell less than 20% below baseline level in 9 patients (50%), but only one patient developed congestive cardiac failure. The paclitaxel-vinorelbine regimen was moderately tolerated and moderately effective in poor prognosis breast cancer patients with visceral metastases and tumors resistant to anthracyclines. The combination at these doses and schedules should be considered in the design of regimens for advanced breast cancer.

Prognostic significance of RACGAP1 mRNA expression in high-risk early breast cancer: a study in primary tumors of breast cancer patients participating in a randomized Hellenic Cooperative Oncology Group trial

PURPOSE

RACGAP1 is a Rac GTPase-activating protein involved in cell growth regulation, cell transformation and metastasis. The aim of the present study was to explore the prognostic and/or predictive significance of RACGAP1 mRNA expression on disease-free survival (DFS) and overall survival (OS) in high-risk early breast cancer patients and compare it to that of Ki67 protein expression and to the Nottingham prognostic index (NPI).

METHODS

A total of 595 high-risk breast cancer patients were treated in a two-arm trial evaluating postoperative dose-dense sequential chemotherapy with epirubicin followed by CMF with or without paclitaxel. RNA was extracted from 314 formalin-fixed paraffin-embedded primary tumor tissue samples followed by one-step quantitative RT-PCR for assessing RACGAP1 mRNA expression.

RESULTS

High RACGAP1 mRNA expression (above the median) was associated with poor DFS (log-rank, p = 0.002) and OS (p < 0.001). High histological grade, as well as high Ki67 protein expression, was more frequent in the high-expression group of RACGAP1. Results of the Cox multivariate regression analysis revealed that high RACGAP1 mRNA expression independently predicted poor overall survival (Wald's p = 0.008). High Ki67 protein expression was also an adverse prognostic factor for death (p = 0.016), while high NPI score values were not.

CONCLUSIONS

High RACGAP1 mRNA expression, as assessed by qRT-PCR, was found to be of adverse prognostic significance in high-risk early breast cancer patients treated with dose-dense sequential chemotherapy. The utility of RACGAP1 mRNA expression in patient selection for treatment with aggressive chemotherapy regimens should be further explored and validated in larger cohorts.

PD05-02: Effect of HER2/Topoisomerase II alpha (TOP2A) Gene Status or Protein Expression and Chromosome 17 (CEP17) Polysomy on the Outcome of Breast Cancer Patients Treated with Anthracycline-Containing Dose-Dense Sequential Adjuvant Chemotherapy with or without Paclitaxel – A Pooled Analysis of Two Hellenic Cooperative Oncology Group (HeCOG) Phase III Trials

Background: The HER2 gene has been established as a valid biomarker in the treatment of breast cancer patients with trastuzumab and probably with other agents, such as paclitaxel or anthracyclines. The TOP2A gene has been associated with response to anthracyclines. The relationship of HER2/TOP2A gene status in the presence of CEP17 polysomy with patients’ outcome following adjuvant treatment with anthracyclines with or without paclitaxel is not established.

Patients and methods: Formalin-fixed paraffin-embedded (FFPE) tumor tissue blocks from 1,033 patients (61.5% of 1,681 randomized patients) with high-risk operable breast cancer enrolled in two sequential phase III trials1,2 were assessed in a central laboratory for HER2/TOP2A gene amplification and CEP17 polysomy by fluorescence in situ hybridization (FISH) and tumors were categorized according to the 2007 American Society of Clinical Oncology/College of American Pathologists guidelines. HER2 and TOP2A amplification was defined as a gene/CEP17 ratio of &gt;=2.2 and &gt;=2.0, respectively or a gene copy number of &gt;6. Additionally HER2, TOP2A, ER/PgR, Ki67, CK5 and EGFR protein expression were assessed by immunohistochemistry (IHC) and all patients were classified according to their IHC phenotype. Treatment consisted of epirubicin-based dose-dense sequential adjuvant chemotherapy followed by hormonal therapy and radiation, as indicated.

Results: Disease-free survival (DFS) and overall survival (OS) did not differ significantly between treatment groups. Median follow-up was 92 months, while 5-year DFS (OS) rates were 74% (88%), 69% (81%) and 75% (86%) for the E-T-CMF, E-CMF and ET-CMF groups, respectively. HER2 amplification was found in 24.1% of the patients and TOP2A amplification in 10.3%. In total, 46.7% of HER2 amplified tumors demonstrated TOP2A co-amplification. The median (range) of HER2, TOP2A and CEP17 copy numbers was 2.55 (0.70−45.15), 2.2 (0.50−26.15) and 2.05 (0.45−26.55), respectively. 21% of the tumors were considered to be polysomic (32.5% of those with HER2 amplification). Adjusting for treatment groups in the Cox model, TOP2A amplification, CEP17 polysomy and HER2/TOP2A co-amplification were not associated with either relapse or death. Treatment with paclitaxel was associated with improved survival in the HER2−amplified subgroup (HR=0.493, interaction p=0.036; adjusting for clinicopathological prognostic factors: HR=0.553, interaction p=0.054), an association that was not apparent for DFS. Conclusions: HER2 amplification was predictive for OS benefit from adjuvant treatment with paclitaxel in patients treated with epirubicin-based dose-dense sequential adjuvant chemotherapy, but not for DFS. TOP2A amplification, CEP17 polysomy and HER2/TOP2A co-amplification were not associated with outcome.

1. Ann Oncol 16:1762–71, 2005; 2. Ann Oncol 19:853–60, 2008.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr PD05-02.

Comprehensive mutational analysis of CDKN2A and CDK4 in Greek patients with cutaneous melanoma

BACKGROUND

The penetrance of CDKN2A mutations is subject to geographical and latitudinal variation and is presumably dictated by ultraviolet radiation exposure and possibly other co-inherited genetic factors. The frequency of mutations increases with the number of family members affected and the number of primary tumours, and also fluctuates with geography. To date, little is known about the prevalence of CDKN2A mutations in patients with melanoma from Greece.

OBJECTIVE

To characterize the frequency of CDKN2A and CDK4 mutations in a hospital-based population of Greek patients with melanoma.

METHODS

Three hundred and four consecutive single primary melanoma (SPM), nine familial melanoma (FM) and seven multiple primary melanoma cases (MPM) were assessed for sequence variants in exons 1α, 1β and 2 of CDKN2A and exon 2 of CDK4.

RESULTS

Germline CDKN2A mutations were detected in 10 of 304 SPM (3·3%), in four of seven MPM (57%) and in two of nine FM (22%) cases. The most common mutation was a Northern European allele (p16 p.R24P) detected in eight individuals. Five previously unreported CDKN2A variants were also identified: -34G>C, c.41_43delins20bp, c.301G>C (p.G101R), c.301G>A (p.G101E) and c.296_297insGACC. We also describe the first report of a CDK4 p.R24H substitution in a Greek family.

CONCLUSIONS

The Greek population appears to harbour a higher prevalence of the CDKN2A mutation than other reported cohorts. This supports the notion that genetic susceptibility may play a stronger influence in a country with a relatively low incidence of melanoma. Furthermore, the identification of Northern European alleles suggests that gene migration may be responsible, in part, for the observed cases in Greece.

Prognostic significance of UBE2C mRNA expression in high-risk early breast cancer. A Hellenic Cooperative Oncology Group (HeCOG) Study

BACKGROUND

The ubiquitin-proteasome system (UPS) plays a pivotal role in tumorigenesis. Components of the UPS have recently been implicated in breast cancer progression. In the present study, we sought to explore the prognostic and/or predictive significance of UBE2C messenger RNA (mRNA) expression on disease-free survival (DFS) and overall survival (OS) in high-risk operable breast cancer patients.

METHODS

Five hundred and ninety-five high-risk breast cancer patients were treated in a two-arm trial evaluating postoperative, dose-dense sequential chemotherapy with epirubicin followed by CMF (cyclophosphamide, methotrexate and 5-fluorouracil) with or without paclitaxel (Taxol). RNA was extracted from 313 formalin-fixed primary tumor tissue samples followed by one-step quantitative RT-PCR for assessment of mRNA expression of UBE2C.

RESULTS

High UBE2C mRNA expression was associated with poor DFS (Wald's P = 0.003) and OS (Wald's P = 0.005). High tumor grade, as well as high Ki67 protein expression, was more frequent in the high-expression group of UBE2C. Results of the Cox multivariate regression analysis revealed that high UBE2C mRNA expression remained an independent adverse prognostic factor for relapse (P = 0.037) and death (P = 0.05).

CONCLUSIONS

High UBE2C mRNA expression was found to be of adverse prognostic significance in high-risk breast cancer patients. These findings need to be validated in larger cohorts.