Abstract 5416: RNA-seq and proteomics to identify response to immunotherapy in advanced melanoma: a Spanish Melanoma Group Study

Background: Prediction of response to immunotherapy remains an unmet need in the field of advanced melanoma.

Methods: Computational analyses, including probabilistic graphical models, sparse k-means, and consensus cluster, were used to characterize melanoma TCGA samples. The implication of the identified processes in response to immunotherapy was then studied in an independent cohort of 53 patients with advanced melanoma and treated with PD-1 inhibitors. Paraffin samples from this cohort were analyzed using RNA-seq and mass-spectrometry proteomics.

Results: In the TCGA cohort, there were two different layers of information: one related to molecular features of the tumor (based on keratinization, melanogenesis, and extracellular space), and one related to immune status. Therefore, two independent classifications of TCGA melanoma samples were established: molecular and immune. The immune classification distinguished between responders and not responders to immunotherapy in the second cohort (p= 0.0006, HR=6.52). Finally, high-throughput proteomics was used to characterize molecular mechanisms involved in response to immunotherapy, identifying several biological processes and proteins that may be relevant in treatment selection for patients who do not respond.

Conclusions: We established that the immune information was independent of tumor molecular features in melanomas included in the TCGA. An immune classification of these tumors was established. This immune classification predicted response to immunotherapy in a new cohort of patients with advanced melanoma treated with PD-1 inhibitors. Finally, proteomics was used to identify possible targets in those patients who did not respond to immunotherapy.

Citation Format: Lucia Trilla-Fuertes, Guillermo Prado-Vazquez, Angelo Gámez-Pozo, Rocio Lopez-Vacas, Maria Isabel Lumbreras Herrera, Virtudes Soriano, Fernando Garicano, Maria Jose Lecumberri, Maria Rodriguez, Margarita Majem, Elisabeth Perez, Maria Gonzalez-Cao, Juana Oramas, Alejandra Magdaleno, Joaquin Fra, Alfonso Martin, Monica Corral, Teresa Puertolas, Juan Angel Fresno Vara, Enrique Espinosa. RNA-seq and proteomics to identify response to immunotherapy in advanced melanoma: a Spanish Melanoma Group Study [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 5416.

Intermittent BRAF inhibition in advanced BRAF mutated melanoma results of a phase II randomized trial

Combination treatment with BRAF (BRAFi) plus MEK inhibitors (MEKi) has demonstrated survival benefit in patients with advanced melanoma harboring activating BRAF mutations. Previous preclinical studies suggested that an intermittent dosing of these drugs could delay the emergence of resistance. Contrary to expectations, the first published phase 2 randomized study comparing continuous versus intermittent schedule of dabrafenib (BRAFi) plus trametinib (MEKi) demonstrated a detrimental effect of the “on−off” schedule. Here we report confirmatory data from the Phase II randomized open-label clinical trial comparing the antitumoral activity of the standard schedule versus an intermittent combination of vemurafenib (BRAFi) plus cobimetinib (MEKi) in advanced BRAF mutant melanoma patients (NCT02583516). The trial did not meet its primary endpoint of progression free survival (PFS) improvement. Our results show that the antitumor activity of the experimental intermittent schedule of vemurafenib plus cobimetinib is not superior to the standard continuous schedule. Detection of BRAF mutation in cell free tumor DNA has prognostic value for survival and its dynamics has an excellent correlation with clinical response, but not with progression. NGS analysis demonstrated de novo mutations in resistant cases.

Whether intermittent strategies of delivering drugs can improve cancer patients survival is still unclear. Here, the authors reports the results of a randomized phase II clinical trial aimed to compare the efficacy and safety of two dosing regimens (continuous and intermittent) of vemurafenib and cobimetinib combination as first-line treatment of patients with unresectable or metastatic advanced melanoma with BRAFV600 mutation

Cancer immunotherapy in special challenging populations: recommendations of the Advisory Committee of Spanish Melanoma Group (GEM)

Cancer immunotherapy based on the use of antibodies targeting the so-called checkpoint inhibitors, such as programmed cell death-1 receptor, its ligand, or CTLA-4, has shown durable clinical benefit and survival improvement in melanoma and other tumors. However, there are some special situations that could be a challenge for clinical management. Persons with chronic infections, such as HIV-1 or viral hepatitis, latent tuberculosis, or a history of solid organ transplantation, could be candidates for cancer immunotherapy, but their management requires a multidisciplinary approach. The Spanish Melanoma Group (GEM) panel in collaboration with experts in virology and immunology from different centers in Spain reviewed the literature and developed evidence-based guidelines for cancer immunotherapy management in patients with chronic infections and immunosuppression. These are the first clinical guidelines for cancer immunotherapy treatment in special challenging populations. Cancer immunotherapy in chronically infected or immunosuppressed patients is feasible but needs a multidisciplinary approach in order to decrease the risk of complications related to the coexistent comorbidities.

Abstract PO-059: COVID-19 in melanoma patients: Spanish register

Background: The COVID-19 pandemic has produced devastating effects on the health care system, also affecting cancer patient care. When the pandemic reached Spain by the end of February 2020, the scarce data about COVID-19 infection in cancer patients pointed out a higher risk of complications due to cancer diagnosis and also to cancer therapies. These conjectures led to concerns about hospital follow-up and cancer therapies of cancer patients. More recent studies have included a higher number of patients, but heterogeneous according to cancer type and tumor stage, with few melanoma patients recorded. Given that different tumor types are associated with specific comorbidities that have a known impact on COVID-19 evolution, analysis of COVID-19 by cancer types is mandatory. Similarly, analysis by tumor stage is relevant, as advanced cases could have different responses to viral infection due to tumor-related immunosuppression and general condition deterioration.

Methods: In Spain we have completed a national registry of melanoma patients infected by SARS-Cov-2 since April 1st, 2020 to June 8th, 2020. Patients with a previous diagnosis of melanoma, presenting with Sars-Cov-2 infection to our network of hospitals, were eligible for enrollment. A prospective observational study with a case registry followed by a retrospective analysis of patient data has been performed.

Results: 64 patients have been included. Median age is 68 years (range 6 to 95 years), 22 (34%) patients are females, and 35 (55%) patients have stage IV melanoma. Twenty-one (33%) patients were on active anticancer treatment with anti PD-1 antibodies, 19 (30%) patients with BRAF plus MEK inhibitors, and 24 (37%) patients were not on active treatment. Asymptomatic/paucisymptomatic evolution was recorded in 19 (30%) patients and mild severity in 13 (20%) patients, not requiring hospital admission by COVID-19. Serious and life-threatening complications were recorded in 18 (28%) and 14 (22%) patients, respectively, including 28 (44%) patients who required oxygen therapy and 3 (5%) patients who had ICU admission. COVID-19 episode is resolved in 55 cases, including 34 (53%) patients cured, eight (12%) patients who have died due to melanoma progression, and 13 (20%) patients due to COVID-19. The median age of patients who died from COVID-19 was 74 years (range 49 to 91), while for those cured it was 64 years (range 6 to 95); 85% of patients who died were males, while this rate decreased to 62% for those cured. The mortality rate from COVID-19 was 20% for both stage IV and localized melanoma, while according to melanoma treatment it was 21%, 16%, and 21% for immunotherapy, BRAF plus MEK inhibitors, and for those who were not undergoing active cancer treatment, respectively.

Conclusion: Our results show that the risk of death in melanoma patients is higher in males and older patients, and it is similar according to tumor stage and melanoma therapy. The impact of cancer diagnosis and treatments on COVID-19 evolution is lower than previously expected.

Citation Format: Maria Gonzalez-Cao, Cristina Carrera, Juan Francisco Rodriguez Moreno, Pedro Rodriguez-Jiménez, Mónica Antoñanzas Basa, Marta Feito Rodríguez, Teresa Puertolas, Eva Muñoz, José Luis Manzano, Ivan Marquez-Rodas, Juan Martín-Liberal, Ainara Soria, Pilar Lopez Criado, Almudena García Castaño, Aram Boada, Pablo Ayala de Miguel, Susana Puig, Guillermo Crespo, Pablo Luna Fra, Cristina Aguayo Zamora, Jesús Gardeazabal, Cayetana Maldonado Seral, Ana Drozdowskyj, Mariano Provencio, Alfonso Berrocal. COVID-19 in melanoma patients: Spanish register [abstract]. In: Proceedings of the AACR Virtual Meeting: COVID-19 and Cancer; 2020 Jul 20-22. Philadelphia (PA): AACR; Clin Cancer Res 2020;26(18_Suppl):Abstract nr PO-059.

Interferon gamma, an important marker of response to immune checkpoint blockade in non-small cell lung cancer and melanoma patients

Background

Programmed death-ligand 1 (PD-L1) may be induced by oncogenic signals or can be upregulated via interferon gamma (IFN-γ). We have explored whether the expression of IFNG, the gene encoding IFN-γ, is associated with clinical response to the immune checkpoint blockade in non-small cell lung cancer (NSCLC) and melanoma patients. The role of inflammation-associated transcription factors STAT3, IKBKE, STAT1 and other associated genes has also been examined.

Methods

Total RNA from 17 NSCLC and 21 melanoma patients was analyzed by quantitative reverse transcription PCR. STAT3 and Rantes, YAP1 and CXCL5, DNMT1, RIG1 and TET1, EOMES, IFNG, PD-L1 and CTLA4, IKBKE and NFATC1 mRNA were examined. PD-L1 protein expression in tumor and immune cells and stromal infiltration of CD8⁺ T-cells were also evaluated. Progression-free survival and overall survival were estimated.

Results

A total of 17 NSCLC patients received nivolumab and 21 melanoma patients received pembrolizumab. Progression-free survival with nivolumab was significantly longer in NSCLC patients with high versus low IFNG expression (5.1 months versus 2 months, p = 0.0124). Progression-free survival with pembrolizumab was significantly longer in melanoma patients with high versus low IFNG expression (5.0 months versus 1.9 months, p = 0.0099). Significantly longer overall survival was observed for melanoma patients with high versus low IFNG expression (not reached versus 10.2 months p = 0.0183). There was a trend for longer overall survival for NSCLC patients with high versus low IFNG expression.

Conclusions

IFN-γ is an important marker for prediction of response to immune checkpoint blockade. Further research is warranted in order to validate whether IFNG is more accurate than PD-L1.

Impact of vascular endothelial growth factor (VEGF) and hypoxia-inductible factor-1 alpha (HIF-1) expression on the prognosis of locally advanced cervical carcinoma (LACC) treated with radiochemotherapy

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Background: Combination of radiotherapy plus platinum-based chemotherapy (RT-CT) is considered the standard treatment in LACC. The risk of recurrence after local treatment is around 50-70%. The role of angiogenesis in tumor progression has been shown in large series. The aim of this study was to determinate the impact of the expression of VEGF and HIF-1 on disease-free survival (DFS) and overall survival (OS) in patients with LACC receiving RT-CT. Methods: Expression of VEGF and HIF–1 was assessed by an immunohistochemistry (IHC) assay in 115 cases. Inmunostainning was considered negative (< 10% of cells), slightly positive (< 25%), moderate (26%-50%) and strongly positive (> 50%). A univariate analysis was carried out for each variable using the log-rank test. Subsequently, a multivariate analysis was performed employing Cox’s proportional hazards model. Results: 115 patients (p) with LACC were included and received RT-CT between January/2003 and December/2012. IHC revealed absence of expression of VEGF in 12 (10,4%) cases, slightly positive in 34 (29,6%), moderate in 30 (26,1%) and strongly positive in 39 (33,9%). The expression of HIF-1 was negative in 63 (54,8%) cases and positive (weak or moderate) in 52 (45,2%). 76p (66,1%) showed a complete clinical response (CR), 26p (22,6%) partial response and 13p (11,3%) stable disease or progression. The median follow–up was 35 months (1-140). 56p (48,7%) relapsed. Univariate analysis indicate that ECOG > 1, tumor size ≥ 4,5 cm, FIGO stage III-IVA, lymph nodes positive, non CR, CA125 post-treatment ≥ 35 U/mL, hemoglobin levels <11 mg/dl (basal, nadir and post-treatment), strong expression VEGF and positive expression of HIF – 1 were all associated with a significant lower OS and DFS. In multivariate analysis strong expression of VEGF remained statistically significant, as tumor size, non CR and hemoglobin level post-treatment < 11g/dL. Conclusions: IHC-assessed strong expression of VEGF was independent prognostic factor of shorter OS and DFS in patients with LACC treated with RT-CT. IHC determination of VEGF could be useful in clinical practice.

Interferon-gamma (INFG), an important marker of response to immune checkpoint blockade (ICB) in non-small cell lung cancer (NSCLC) and melanoma patients

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Background: PD-L1 can be induced by oncogenic signals or up-regulated via INFG in a STAT1- and NFκB-dependent manner. STAT3 opposes STAT1-mediated anti-tumor immune responses. I kappa B kinase epsilon (IKBKE) is an interferon signaling inducer. We explored whether INFG expression in pre-treatment tumors is associated with to the efficacy of ICB in NSCLC and melanoma patients. The role of inflammation-associated transcription factors STAT3, IKBKE and STAT1 was also examined. Methods: Total RNA from 17 NSCLC and 21 melanoma patients, was analyzed by qRT-PCR. INFG, STAT3, IKBKE, STAT1 and PD-L1 mRNA were examined. PD-L1 protein expression in tumor and immune cells was evaluated (Ventana SP142 assay). Progression free survival (PFS) and overall survival (OS) were estimated. Results: 17 previously treated NSCLC patients received nivolumab; 71% lung adenocarcinoma, 71% male, 53% smokers, 35% KRAS mutant, 88% EGFR wild-type (wt). 21 previously treated melanoma patients received pembrolizumab; 67% male, 67% BRAF wt. PFS to nivolumab was significantly longer in NSCLC patients with high vs. low INFG expression (5.12 vs. 2mo, p = 0.0124). PFS to pembrolizumab was significantly longer in melanoma patients with high vs. low INFG expression (4.99 vs. 1.86mo, p = 0.0099). Significantly longer OS was observed for melanoma patients with high vs. low INFG expression (not reached vs. 3.10mo p = 0.0183). There was a trend for longer OS for NSCLC patients with high vs. low INFG expression (10.15 vs. 4.86mo, p = 0.0687). The other gene levels and PD-L1 protein levels in tumor and immune cells did not affect the outcome to ICB. IKBKE was positively correlated with INFG and PD-L1 expression (NSCLC Spearman’s ρ = 0.58 and 0.65; melanoma Spearman’s ρ = 0.61 and 0.59), and STAT3 expression was loosely anticorrelated with PD-L1 expression (NSCLC Spearman’s ρ = −0.21; melanoma Pearson’s ρ = −0.01). Conclusions: INFG is an important marker for qRT-PCR mediated prediction of response to ICB in NSCLC and melanoma patients. Further research is warranted in order to validate that INFG is more accurate than PD-L1.

Abstract 468: BRAF mutation analysis in cell free tumoral DNA (cfDNA) of melanoma patients: results from the prospective study GEM1304 (Spanish Melanoma Group)

Backgroud: Tumor-derived circulating cell-free DNA (cfDNA) is a dynamic source for determination of tumor mutation status. We have previously demonstrated the prognostic value of BRAFV600 mutation status in pretreatment cfDNA (BRAF pre-cfDNA) in advanced melanoma patients (p) treated with BRAF inhibitors (median overall survival [OS] 7 months [m] vs 22m for BRAF pre-cfDNA positive and negative p, respectively p = 0.017)1. Based on these results, the Spanish Melanoma Group conducted a prospective study in 13 centers to determine the prognostic value of BRAFV600 mutation in pre-cfDNA, the change in mutation status at time of first evaluation (BRAF early-cfDNA), and the correlation of BRAF cfDNA dynamics with clinical evolution (GEM1304) (ClinicalTrials.gov Identifier: NCT01960634).

Methods: One hundred and fifty nine plasma and serum samples from 66 stage IV BRAF mutant melanoma p were collected before and during treatment, until disease progression.

A quantitative 5’-nuclease PCR based assay was used to determine BRAFV600 mutation status in cfDNA.

Results: Most p were stage M1c (62%), treated with BRAF inhibitors (53%), and not previously treated (67%). BRAF pre-cfDNA was positive in 42 p (64%). Median OS was 6.4 m (95% CI: 10.9-23.6) and 17 m (95% CI: 3.5-9.2) for p with positive and negative BRAF pre-cfDNA, respectively (p = 0.06). Significant differences in OS were observed according to BRAF early-cfDNA negativization: 4.7 m (95%CI: 1.2-8.1) in those with persistence of BRAF in cfDNA (12 p), not reached (NR) in p with BRAF early-cfDNA negativization (11 p), and 22 m (95%CI:0.6-43.9) in those who continued to be negative (17 p) (p&lt;0.001). Median progression free survival (PFS) was 3.4 m (95% CI: 2.1-4.6), 16.8 m (95% CI: 6.9-26.8) and 15.3 (95%CI: 1.1-29.6), respectively (p&lt;0.001). There were also significant differences according to BRAF early-cfDNA among p treated with BRAF inhibitors: in p with persistence of BRAF in cfDNA (8p), median OS was 4.7 m (95% CI:16-7.8), NR for those with BRAF early-cfDNA negativization (9p), and 22 m (95%CI: 7.9-36.6) for those who continued to be negative (8 p) (p&lt;0.001). Median PFS was 3.6 m (95% CI: 2.2-5.1), 16.9 m (95% CI: 6.9-26.9) and 18 m (95% CI: 0.6-35.3), respectively (p = 0.001). In those p with serial samples taken during treatment, BRAF mutation disappeared from cfDNA in all cases who responded (18). Those with persistence of mutation during follow up had rapid progression and death (10). BRAF mutation had relapsed in cfDNA at time of progression in 6/15 cases.

Conclusions: Patients with early negativization of BRAFV600 in cfDNA have excellent prognosis, at least as good as those with negative BRAF in pre-cfDNA.

González-Cao et al. Mel Res 2015; 25:486

Citation Format: Maria Gonzalez Cao, Jose Luis Manzano, Virtudes Soriano, Teresa Puertolas, Ainara Soria, Clara Mayo, Margarita Magem, Miguel Angel Molina, Clara Montagut, Eva Muñoz, Delvys Rodriguez, Elizabeth Perez, Almudena Garcia, Javier Cortes, Nuria Jordana, Jordi Rodon, Niki Karachaliou, Rafael Rosell. BRAF mutation analysis in cell free tumoral DNA (cfDNA) of melanoma patients: results from the prospective study GEM1304 (Spanish Melanoma Group). [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 468.

Frequency and characteristics of familial melanoma in Spain: the FAM-GEM-1 Study

INTRODUCTION

Familial history of melanoma is a well-known risk factor for the disease, and 7% melanoma patients were reported to have a family history of melanoma. Data relating to the frequency and clinical and pathological characteristics of both familial and non-familial melanoma in Spain have been published, but these only include patients from specific areas of Spain and do not represent the data for the whole of Spain.

PATIENTS AND METHODS

An observational study conducted by the Spanish Group of Melanoma (GEM) analyzed the family history of patients diagnosed with melanoma between 2011 and 2013 in the dermatology and oncology departments.

RESULTS

In all, 1047 patients were analyzed, and 69 (6.6%) fulfilled criteria for classical familial melanoma (two or more first-degree relatives diagnosed with melanoma). Taking into account other risk factors for familial melanoma, such as multiple melanoma, pancreatic cancer in the family or second-degree relatives with melanoma, the number of patients fulfilling the criteria increased to 165 (15.8%). Using a univariate analysis, we determined that a Breslow index of less than 1 mm, negative mitosis, multiple melanoma, and a history of sunburns in childhood were more frequent in familial melanoma patients, but a multivariate analysis revealed no differences in any pathological or clinical factor between the two groups.

CONCLUSIONS

Similar to that observed in other countries, familial melanoma accounts for 6.6% of melanoma diagnoses in Spain. Although no differences in the multivariate analysis were found, some better prognosis factors, such as Breslow index, seem more frequent in familial melanoma, which reflect a better early detection marker and/or a different biological behavior.

Familial melanoma in Spain: Preliminary report of the FAM-GEM-1 study

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Background: In addition to environmental factors and phenotype, melanoma risk is determined by familial background. It is estimated that 5-10% of melanoma cases occur in a familial setting. High susceptibility genes like CDKN2A and intermediate risk like M1CR are the most known, but explain less than 1/3 of the cases, most of them cases with 2 or more first degree relatives involved, the classical definition for familial melanoma (FM). In Spain there are several local studies about epidemiology and characteristics of FM, but there are no studies that cover all the territory. Methods: FAM-GEM-1 is a national, observational, 2 years-registry study (2011-2013), conducted by the Spanish Multidisciplinary Melanoma Group (GEM), whose principal objective is to assess the rate of melanoma patients with family history of melanoma in Spain. Secondary objectives are to analyze whether patients with family history are different from sporadic melanoma in terms of clinical, pathological and molecular features; and to constitute a registry of FM in order to deeper characterise these patients in further studies. We present the exploratory results of the first 219 patients registered Results: See Table. Conclusions: We have found that almost 9% of patients have family history of melanoma. Of them, almost 3/4 fulfils familial melanoma criteria. It seems that there are not relevant differences among sporadic and familial melanoma in our registry, except for sex, although the preliminary nature of the results makes necessary more patients in order to determine if there are clinical and/or pathological differences between both groups. [Table: see text]

Activation of angiogenic pathway in the prediction of pathologic response to bevacizumab-based neoadjuvant therapy in breast cancer

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Background: To evaluate potential biomarkers of pathological response to bevacizumab-based neoadjuvant therapy in untreated breast cancers (BC) patients recruited in a phase II, multicenter clinical trial. Methods: Patients received a single infusion of bevacizumab (15 mg/ kg) (C1) 3 weeks prior to the beginning of neoadjuvant chemotherapy (NAC) consisting in 4 cycles of docetaxel (60 mg/mq), doxorubicin (50 mg/mq) and bevacizumab (15 mg/ kg) every 21 days (C2-C5) following by surgery. Biomarker expression was assessed by immunohistochemistry (Ki67, CD31, CD31/Ki67, VEGFR2, pVEGFR2 [Y951]) before and after bevacizumab infusion (C1). Gene expression was analyzed using Affimetrix Human Gene ST 1.0. Results: This analysis was performed on 73 patients (49 yr, range 29-70). Twenty (27%) patients obtained best response (G4-G5) whether 50 (68%) were considered as no responder (G1-G2-G3). Response was associated with negative estrogen receptors expression (p=0.02) and high Ki67 basal and after C1 expression (p=0.009 and p=0.01). Six (54%) of the triple negative tumors were responders (p=0.05). Interestingly, change in pVEGFR2 [Y951] staining induced by bevacizumab administration was found significantly associated with response (p=0.0). Decrease in the phosphorilation status of VEGFR2 (Y951) >70% yielded a receiver operating characteristic (ROC) curve area of 0.681 (95% CI: 0.536 - 0.825) with 84% sensitivity and 95% specificity. The positive and negative predictive values for this marker were 60% and 64%, respectively. The change in phosphorilation status of VEGFR2p remains a significant predictor biomarker of response in multivariate analysis (OR=0.9, IC%95 0.96-0.99, p=0.04) after adjusting for clinical-pathological characteristics. Conclusions: These findings suggest the role of the phosphorilation status of VEGFR2 as predictive biomarkers of pathological response to bevacizumab in neoadjuvant setting in breast cancer.

Dynamic contrast-enhanced MRI versus 18F-misonidazol-PET/CT to predict pathologic response in bevacizumab-based neoadjuvant therapy in breast cancer

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Background: To investigate the role of DCE-MRI versus 18F-Misonidazole (FMISO) positron emission tomography (PET/CT) in the prediction of pathological response to bevacizumab-based neodajuvant therapy. Methods: 73 chemotherapy naïve, stage II and III breast cancer (BC) patients (pts) were enrolled in a phase II, single-arm, multicenter, open-label and prospective clinical trial. Pts received single infusion of bevacizumab (15 mg/ kg) (C1) 3 weeks prior to the beginning of neoadjuvant chemotherapy (NAC) consisting of 4 cycles of docetaxel (60 mg/mq), doxorubicin (50 mg/mq) and bevacizumab (15 mg/ kg) every 21 days (C2-C5), followed by surgery. Tumor proliferation, hypoxia and perfusion were evaluated respectively using 18F-Fluorothymidine (FLT) and 18F-Misonidazole (FMISO) positron emission tomography (PET/CT) and dynamic contrast enhancement magnetic resonance (DCE-MR). Serial imaging studies were performed in parallel at several time points including baseline (BL) and 14-21 days after bevacizumab alone (C1). Results: After only one administration of bev, tumor proliferation and perfusion assessed using FLT-PET and DCE-MRI significantly decrease (-26% and -46%, p<0.001) but these changes were not found to be associated with final response. Most important, changes in tumor hypoxia induced by bevacizumab was significantly associated with pathological response (p= 0.004) and was an independent predictor of response in multivariate analysis (RR=0.95, IC 95% 0.92-0.99, p=0.02). Decrease in FMISO uptake >10% yielded a ROC curve area of 0.7 (95% CI: 0.56 - 0.85) with high specificity (94%). Conclusions: Our findings suggest a significant value of early changes in tumor hypoxia assessed by FMISO-PET as a biomarker of pathological response in bevacizumab-based neoadjuvant therapy in breast cancer.

P2-09-02: Predicting Response to Bevacizumab in Primary Breast Cancer Using 18F-Fluorothymidina (FLT) and 18F-Misonidazole (MISO) Positron Emission/Computed Tomography (PET/CT) as Imaging Biomarkers

Background: To investigate the hypothesis that early changes in tumor proliferation and hypoxic status induced by bevacizumab and assessed by imaging biomarkers might predict response to bevacizumab therapy.

Methods: 73 chemotherapy naïve, stage II-III breast cancer (BC) patients (pts) were enrolled in the training set of this phase II, single-arm, multicenter and prospective clinical trial from October 2009 until November 2010. Pts received single infusion of bevacizumab (15 mg/kg) (C1) 3 weeks prior to the beginning of neoadjuvant chemotherapy (NAC) consisting in 4 cycles of docetaxel (60 mg/mq), doxorubicin (50 mg/mq) and bevacizumab (15 mg/kg) every 21 days (C2-C5) following by surgery. Tumor proliferation and hypoxic status were evaluated using FLT and MISO PET/CT at baseline and 14–21 days after bevacizumab (C1). Standardized uptake values (SUV) for FLT and MISO and ratios to reference tissues, mediastinum (T/Me) or muscle (T/Mu), for MISO were calculated. Pathological response on surgical specimens was assessed according to Miller/Payne grading system. Pts with reduction in tumor cells &gt;30% (G3-G4-G5) or &lt;30% (G1-G2) were respectively considered as responders and no-responders. Association between pathological response, baseline and changes induced by bevacizumab (C1) in imaging biomarkers was analyzed using Mann-Whitney test. Receiver operating characteristic (ROC) curve was performed to test sensitivity and specificity of the biomarker found associated to response. Its value as independent predictor was tested in multivariate analysis using logistic regression. Results: Median baseline MISO and FLT SUV values in tumors were 1.2 (range 0.69−2.39) and 2.89 (range 0.97−7.18). Significant change after C1 was observed in FLT (2.7 vs 1.8, p&lt;0.001) but no in MISO uptake. Fifty-two (74%) pts achieved response (G3-G4-G5) whether 18 (24%) were considered as no responder (G1-G2); for 3 (4%) patients Miller/Payne tumor evaluation was not available. Response showed a trend toward an association with negative estrogen receptors (ER) expression (p=0.08) and triple negative tumors (11/73) (p=0.05). FLT SUV baseline and changes after C1 in MISO SUV, T/Mu and T/Me were all significantly associated with pathological response (p=0.057, 0.03, 0.016, 0.010). ER expression and T/Mu change remained significantly associated with response in multivariate analysis (OR=24.8, IC95% 1.8-334, p=0.01 and OR=0.95, IC 95% 0.92−0.99, p value=0.02). Decrease in MISO T/Mu uptake &gt;20% yielded a ROC curve area of 0.7 (95% CI: 0.56 - 0.85) with 94% sensitivity and 87% specificity. Conclusion: Bevacizumab determined a marked decrease in tumor proliferation. Interestingly, a decrease greater than 20% in tumor hypoxic status after C1 and assessed by MISO was found significantly associated with pathological response suggesting a potential value of early decrease in hypoxic tumor status as predictive biomarker of response. Bevacizumab, causing normalization of the tumor microvasculature, seems to potentiate the effect of cytotoxic agents on primary BC. A validation set is warranted to confirm these findings.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P2-09-02.

P2-08-05: Use of Dynamic Contrast-Enhanced MR Imaging To Predict Pathological Response in Primary Breast Cancer

Purpose: To investigate the effect of bevacizumab infusion on vascular parameters assessed by dynamic contrast-enhanced magnetic resonance (DCE-MR) imaging and to test their association with pathological response in primary breast cancer.

Materials and Methods: 73 patients (median age, 47 ys; age range, 29–70 ys) with biopsy-proven, previously untreated, primary breast cancer were recruited from October 2009 to November 2010 in this phase II, multicenter and non-randomized clinical trial. Patients (pts) received single infusion of bevacizumab (15 mg/kg) (C1) 3 weeks prior to the beginning of neoadjuvant chemotherapy consisting in 4 cycles of docetaxel (60 mg/mq), doxorubicin (50 mg/mq) and bevacizumab (15 mg/kg) every 21 days (C2-C5) following by surgery. All pts underwent DCE-MR imaging before and 14–21 days after C1. Quantitative and semiquantitative kinetic parameters were calculated at baseline and after C1, including the volume transfer constant (K(trans)), which primarily reflects the wash-in of the contrast agent, the backflow rate contrant (K(ep)), extracellular volume fraction (V(e)) and the initial area under the gadolinium concentration-time curve over 60 seconds (IAUGC(60)). Changes in the DCE-MRI kinetic parameters K(trans), K(ep), V(e) and IAUGC(60) were calculated and Wilcoxon test was used to assess significant effects induced by bevacizumab on kinetic parameters. Pathological response on surgical specimens after C5 was assessed according to Miller and Payne classification. Pts with tumor reduction &gt;30% were considered as responders (G3-G4-G5) whether tumor reduction &lt;30% were considered as no responders (G1-G2). DCE-MR imaging parameters and clinical-pathological characteristics were correlated with pathological response using Mann-Whitney test in univariate and logistic regression in multivariate analyses. Receiver operating curves (ROC) was used to define the best cut-off of the parameter found associated with pathological response.

Results: DCE-MRI was performed before (n=72) and after (n=71) C1. K(trans), K(ep), V(e) and IAUCG(60) values were significantly different at the baseline and after C1 (p&lt;0.01). Median changes were, respectively, −51, −101, −52.5 and −4.8. Fifty-two (74%) pts achieved response (G3-G4-G5) after C5 whether 18 (24%) were considered as no responder (G1-G2); for 3 (4%) patients Miller/Payne tumor evaluation was not available. At univariate analysis, negative estrogen receptor (ER) status and higher post-C1 K(ep) (p=.057) showed a trend toward an association with response. At multivariate analysis, only ER status remains a significant predictor of response (p= .04). Area under ROC curve for K(ep) was 0.65 (IC95% 0.05−0.8, p=.057)

Conclusion: Bevacizumab affects tumor vasculature, perfusion and permeability as showed by the significantly reduction in all kinetic vasculature parameters obtained in DCE-MR imaging after C1. However, in our population these changes were not associated with pathological response. On the other hand, backflow rate constant, K(ep), a perfusion-related parameter derived from DCE-MRI yielded after C1 major than 80, may be associated with higher pathological response with a specificity of 88% and sensitivity of 90%. Future studies are warranted to confirm these findings.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P2-08-05.

Phase I trial of weekly gemcitabine at 3-h infusion in refractory, heavily pretreated advanced solid tumors

Gemcitabine (2',2'-difluorodeoxycytidine) is a nucleoside analog with antitumor activity against a variety of malignancies. The critical enzyme cytidine kinase is saturated at plasma concentrations achieved after a 30-min infusion at conventional doses. Prolonged infusion time may yield higher intracellular dFdCTP concentrations. A phase I study was designed to determine the maximum tolerated dose (MTD) of gemcitabine, given by infusion for 3 h, in heavily pretreated patients. Twenty-seven patients (13 head and neck cancer, seven sarcoma, three esophageal cancer, three non-small-cell lung cancer and one ovarian cancer) were enrolled. Twenty patients were defined as refractory at first- or second-line chemotherapy. Four different entry dose levels (300, 400, 450 and 500 mg/m(2)) were evaluated for gemcitabine administered on days 1, 8 and 15 of a 28-day cycle. The MTD was defined as 450 mg/m(2), with granulocytopenia, thrombocytopenia and asthenia being dose limiting. The maximum grade III/IV patient toxicities for hemoglobin, leukocytes, neutrophils and platelets for all doses were 7, 19, 19 and 11%, respectively. Non-hematological toxicities included asthenia, nausea/vomiting and diarrhea. Thus, gemcitabine administered at a fixed 3-h infusion was well tolerated up to 450 mg/m(2) in heavily pretreated patients. Myelosupression and asthenia were dose-limiting toxicities.

Prognostic impact of bulky mediastinal lymph nodes (N2>2.5 cm) in patients with locally advanced non-small-cell lung cancer (LA-NSCLC) treated with platinum-based induction chemotherapy

A group of 70 patients with locally advanced non-small-cell lung cancer (LA-NSCLC), treated in different phase II-III trials with platinum-based chemotherapy in two institutions, have been evaluated to identify potential baseline prognostic factors predicting their survival. The eligibility criteria were patients with stage IIIA (N2)-IIIB, Eastern Cooperative Oncology Group performance status 0.1 and less than 5% weight loss. All 37 patients with stage IIIA(N2) were treated with platinum-based induction chemotherapy followed by surgery plus radiotherapy if no progression was observed. The other 33 patients with stage IIIB were treated with platinum-based induction chemotherapy followed by conventional fractionation radiotherapy if no progression was observed. The overall response rate to induction chemotherapy was 40%. Median survival of the 70 patients was 13 months, with a 4-year survival of 15%. At univariate analysis, two prognostic factors correlated with survival: partial or complete response to induction chemotherapy (P<0.00001) and bulky mediastinal lymph nodes (N2>2.5 cm) (P=0.03). At multivariate analysis, only the response to induction chemotherapy retained statistical significance (P=0.00001). Randomized well-balanced prospective trials considering initially mediastinal N2 node size are needed to clearly establish the role of chemotherapy, surgery and radiotherapy in LA-NSCLC.