Therapeutic strategies to overcome EGFR mutations as acquired resistance mechanism in ALK-rearranged non-small-cell lung cancer: Case Reports

Introduction

ALK tyrosine kinase inhibitors (ALK TKIs) have improved prognosis in ALK-rearranged (ALK ⁺) non-small-cell lung cancer (NSCLC). However, drug resistance mechanisms occur inevitably during the course of treatment leading to disease progression. Activation of epidermal growth factor receptor (EGFR) bypass signaling pathway is an uncommon cause of acquired resistance to ALK TKIs.

Method

We present two patients with EML4-ALK rearranged NSCLC, developing an acquired EGFR resistance mutation after receiving multiple lines of ALK TKIs.

Results

While preclinical models have showed encouraging data, there is a critical need for clinical studies on treatment strategies to overcome this drug resistance. Three real-life therapeutic approaches were used in this report: i) using brigatinib, an inhibitor targeting both ALK and EGFR tyrosine kinases; ii) combining two ALK TKIs together; and iii) delivering doublet platinum chemotherapy. In case 1, time to treatment failure (TTF) was 9.5 months with brigatinib; in case 2, TTF was 10 months with combined TKIs (osimertinib and brigatinib), whereas TTF with chemotherapy was only 2 months. Tolerability profile TKIs combotherapy was acceptable.

Conclusion

These case reports underline the therapeutic complexity of EGFR-acquired resistance mutation in ALK⁺ NSCLC and offers some leads to solve this real-life clinical challenge.

Multimodal machine learning model prediction of “individual” response to immunotherapy in 1L stage IV NSCLC

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Background: Immunotherapy (IO) is the standard of care in 1L stage IV non-small cell lung cancer (NSCLC) cases that are not eligible for targeted therapies. Today, a level of PD-L1 expression of 50% or above is the only standard predictive biomarker for IO efficacy as monotherapy. However, a majority of patients fail to respond to the treatment and are exposed to potentially severe immune-related adverse events. There is thus an urgent need to discover new predictive signatures of response to IO in such setting. Methods: A retrospective 1-year cohort of 63 patients with advanced NSCLC, PD-L1 expression > 50%, and treated with 1L pembrolizumab monotherapy was analyzed to develop a machine learning-based algorithm predictive of response to immunotherapy. Multimodal baseline data were collected including clinical, biological, pathology, molecular, baseline CT scan data and clinical outcomes status (objective response at first evaluation, PFS, OS). For each patient, thoracic tumors were segmented in 3D by both an experimented pneumologist and a radiologist using the SOPHiA DDM for Radiomics platform. Radiomics features were then extracted following the IBSI standards and combined with the other data modalities. A filter-based variable selection method was applied before testing several machine learning algorithms to obtain an individual prediction of the response at first evaluation. The optimization criterion was the Area Under the ROC Curve (AUC). Due to the small size of the cohort, a nested leave-pair-out cross-validation was used to properly estimate the model performance. Results: A logistic regression algorithm reached an AUC of 0.85, a precision of 83%, a sensitivity of 77% and a specificity of 74% for predicting response at first evaluation. The algorithm was able to correctly predict 21 progressions among 28 observed and 27 disease controls among 35 observed. Features with highest weight were representative of the full scope of data modalities included in the model, highlighting the importance of a truly multimodal analysis. Indeed, withdrawing any specific data modality (e.g., radiomics features), led to a decrease of at least ̃10% of the AUC. Patients were then stratified into two groups, progression versus disease control, based upon their predicted response status at first evaluation. These two groups displayed a statistically significant difference in PFS (p < 0.001), suggesting that baseline multimodal data analysis could help predict long-term outcomes. Conclusions: This proof-of-concept study suggests that machine learning applied to baseline multi-modal data can help predict response to IO at the individual patient level, as well as stratify patients to inform long-term outcomes. This algorithm is being improved and validated through a large real-world multicentric international observational study including more than 4000 patients (DEEP-Lung-IV study, NCT04994795).

Independent prognostic value of ultra-sensitive quantification of tumor pre-treatment T790M subclones in EGFR mutated non-small cell lung cancer (NSCLC) treated by first/second generation TKI, depends on variant allele frequency (VAF): Results of the French cooperative thoracic intergroup (IFCT) biomarkers France project

OBJECTIVES

T790M mutations inEGFR-mutated non-small cell lung cancer (NSCLC) account for nearly 50% of acquired resistance mechanisms to EGFR-TKIs. Earlier studies suggested that tumor T790M could also be detected in TKI-naïve EGFR-mutated NSCLC. The aim of the study is to assess the prevalence and clinical significance of quantification of tumor pre-treatment T790M subclones.

MATERIALS AND METHODS

We analyzed 366 EGFR-mutated NSCLC patients of the real-life IFCT Biomarkers France study with available pre-treatment formalin-fixed paraffin-embedded (FFPE) tumor DNA before treatment by first/second-generation EGFR-TKI. We used ultra-sensitive Droplet Digital Polymerase Chain Reaction (ddPCR) QX200 (BIO-RAD®, Hercules, CA, USA). All samples were tested in duplicate.

RESULTS

ddPCR identified T790M in 19/240 specimens (8%). T790M-positive and T790M-negative populations were not different for clinical baseline characteristics. T790M Variant Allele Frequency (VAF) was > 0.01% <0.1%, > 0.1% <1%, > 1% <10%, and >10% in five (26.3%), six (31.6%), six (31.6%), and two (10.5%) patients, respectively. T790M VAF was >0.1% in 11/13 (84%) patients with rapid (<3 months) or usual progression (3-20 months) compared to 0/3 with low progression (>20 months) (p = 0.02). In a Cox model, T790M mutation positivity was correlated with overall survival (OS) and progression-free survival (PFS) for 10% > VAF >1% (hazard ratio [HR] = 2.83, 95% confidence interval [CI] 1.13-7.07, p = 0.03; HR=3.62, 95%CI 1.43-4.92, p = 0.007, respectively) and for VAF >10% (HR = 19.14, 95%CI 4.35-84.26, p < 0.001; HR = 17.89, 95%CI 2.21-144.86, p = 0.007, respectively).

CONCLUSION

Ultra-sensitive detection of tumor T790M mutation concerned 8% of EGFR-mutated TKI-naïve NSCLC patients and has a negative prognostic value only for T790M VAF over 1%.

Resistance mechanisms to osimertinib in EGFR-mutated advanced non-small-cell lung cancer: A multicentric retrospective French study

OBJECTIVES

The understanding of histo-molecular mechanisms associated with resistance to osimertinib is a critical step to define the optimal treatment strategy in advanced EGFR-mutated Non-Small-Cell-Lung-Cancer (NSCLC).

MATERIALS AND METHODS

We performed a multicentric retrospective analysis on a cohort of consecutive patients treated with osimertinib for an advanced EGFR-mutated NSCLC and collected histo-molecular data from plasma and tumor samples at the time of progression. Next-generation sequencing (NGS) was performed for all samples. Best Overall Response Rate (ORR), Progression Free Survival (PFS), Overall Survival (OS) and data on treatment post-progression efficacy were also collected.

RESULTS

Two-hundred and twenty-six patients were included from 9 Academic French Hospitals between April 2015-October 2018. Osimertinib was given in second-line or more in 219 patients (97%). Best ORR was 52% and best central nervous system ORR was 56%. Median PFS and OS were 9.5 months (IQR 4.0-17.2) and 24 months (IQR 12.4-NR) respectively. At the time of analysis, 150 patients (66%) had tumor progression. Among them, 73 contributive samples (56 tumor biopsies) were available. The most frequent molecular alterations were C797S mutation (n = 9 (13%)) and MET amplification (n = 8 (11%)). Histologic transformation occurred in 5 patients (9% of tumor biopsies). In T790M + NSCLC, loss of T790 M occurred in 68% of cases. Median PFS and OS with treatment beyond progression were 6.0 months (IQR 2.0-10.4) and 15.1 months (IQR 6.7-NR) respectively and longer in case of osimertinib continuation beyond progression.

CONCLUSION

We confirmed the efficacy of osimertinib in patients with advanced EGFR mutation positive NSCLC. At progression, the most frequent molecular alterations were MET amplification and C797S mutation.

Effects of tobacco abuse on major chromosomal instability in human papilloma virus 16-positive oropharyngeal squamous cell carcinoma

A substantial number of patients with oropharyngeal squamous cell carcinoma (OPSCC) have two oncogenic risk factors: Human papilloma virus (HPV) infection and tobacco use. These factors can be competitive or synergistic at the chromosomal and genomic levels, with strong prognostic and therapeutic implications. HPV16 has been shown in vitro to be a high‑risk HPV that induces low rates of chromosomal copy number alterations. However, chromosomal instability can be increased by smoking. Evaluating chromosomal instability in HPV‑positive patients according to their smoking status is therefore critical for assessing the prognosis and therapeutic impact. The aim of this study was to assess chromosomal instability in patients with HPV‑positive OPSCC according to smoking status. Chromosomal instability was investigated with array‑based comparative genomic hybridization (aCGH) in 50 patients with OPSCC. Differences in chromosomal alterations were examined according to the HPV and smoking status of the patients. HPV‑positive tumors (24/26 were HPV16‑positive) had fewer genomic aberrations (P=0.0082) and fewer breakpoints (P=0.048) than HPV‑negative tumors. We confirmed the association between HPV‑positive OPSCC and chromosomal losses at 11q. We verified the association between HPV‑negative OPSCC and losses at 3p and 9p and gains at 7q and 11q13. In the patients with OPSCC who were HPV‑positive, the total number of chromosomal aberrations per tumor was significantly higher in the group of patients who were smokers (P=0.003). However, the cytobands did not differ significantly according to the smoking status. On the whole, the data of this study may help to improve the stratification of HPV‑positive OPSCC patients and must be supplemented by next‑generation sequencing studies in order to describe the mutational and transcriptomic profiles of such patients according to smoking status.

Cost-effectiveness of KRAS, EGFR and ALK testing for decision making in advanced nonsmall cell lung carcinoma: the French IFCT-PREDICT.amm study

ALK rearrangement and EGFR/KRAS mutations constitute the primary biomarkers tested to provide targeted or nontargeted therapies in advanced nonsmall cell lung cancer (NSCLC) patients. Our objective was to assess the cost-effectiveness of biomarker testing for NSCLC.

Between 2013 and 2014, 843 treatment-naive patients were prospectively recruited at 19 French hospitals into a longitudinal observational cohort study. Two testing strategies were compared, i.e. with “at least one biomarker status known” and “at least KRAS status known”, in addition to “no biomarker testing” as the reference strategy. The Kaplan–Meier approach was employed to assess restricted mean survival time. Direct medical costs incurred by hospitals were estimated with regard to treatment, inpatient care and biomarker testing.

Compared with “no biomarker testing”, the “at least one biomarker status known” strategy yielded an incremental cost-effectiveness ratio of EUR13 230 per life-year saved, which decreased to EUR7444 per life-year saved with the “at least KRAS status known” testing strategy. In sensitivity analyses, biomarker testing strategies were less costly and more effective in 41% of iterations.

In summary, molecular testing prior to treatment initiation proves to be cost-effective in advanced NSCLC management and may assist decision makers in defining conditions for further implementation of these innovations in general practice.

[Correlation of genetic and cytogenetic alterations in pathological aggressiveness urothelial carcinoma of the bladder: Performance of BCA-1, a mini-array comparative genomic hybridisation-based test]

INTRODUCTION

Urothelial carcinomas are the fourth leading cause of cancer in humans. Their incidence is increasing by more than 50% in 25 years. The superficial forms (70% cases) require a close active surveillance to identify frequent recurrences and progression to invasive stage. Our main goal was to identify prognostic molecular markers for bladder cancer that could be used alone or in combination in routine clinical practice. In this aim, we evaluated the capability of the BCA-oligo test based on a CGH array to correctly classify tumoral grade/stage.

METHOD

Urinary DNA was extracted from 81 patients with superficial bladder cancer and has been hybridized on the BCA-oligo array. The results from the molecular analysis were correlated with the tumoral grade and stage.

RESULTS

Several chromosomal alterations were significantly more frequent in tumors of higher grade and more advanced stage. A significant association was observed between a high grade and the presence of one of these alterations: loss on 6p, gain on 8q or 13q, loss or gain on 9q or 11q, with an odds ratio of 6.91 (95% CI=2.20-21.64; P=0.0009). Moreover, a significant association was found between a more advanced stage (pT1) and the presence of one of these alterations: loss on 6p, gain on 8q, loss or gain on 5p, with an odds ratio of 15.2 (95% CI=3.71-62.58; P=0.0002).

CONCLUSION

Our results showed that molecular analyses of superficial bladder cancers based on urinary DNA and the BCA-oligo test could be used as prognostic factor for the tumor evolution, allowing then a more adapted clinical management.

Mutational profile of HPV-driven head and neck cancers according to tobacco consumption

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Background: HPV-driven oropharyngeal cancer (OPC) patients are characterized by a better prognosis than their HPV-negative counterparts. However, this significant survival advantage is not homogeneous and studies have highlighted that among HPV-positive patients those with a smoking history have a significantly increased risk of disease progression and death compared to those who have never smoked. The reason why tobacco consumption impacts negatively the prognosis is still elusive. Tobacco might induce additional genetic alterations leading to a more aggressive phenotype. The purpose of this study is to characterize the mutational profile of HPV-positive OPC by smoking status. We hypothesize a higher frequency of mutations affecting among smokers. Methods: Targeted next-generation sequencing of 38 oncogenes/tumor suppressor genes that are commonly mutated in cancers caused by tobacco/alcohol consumption was performed in 62 HPV-driven OPC cases stratified by smoking status. Results: The study population included 37 (60%) non-smokers and 25 (40%) smokers distributed as follows: 1 (4%) patient smoked <10 pack-year (PY), 8 (32%) patients between 10-20 PY and 16 (64%) >20 PY. Twenty (31%) patients had no mutation, 14 (23%) had 1 mutation and 28 (46%) had 2 or more mutations. The most commonly mutated genes regardless of tobacco consumption were PIK3CA (20%), MLL2 (20%), TP53 (8%), FAT 1 (15%), FBXW7 (16%), NOTCH 1 (9%) and FGFR3 (9%). Mutation rate was not significantly different in smokers compared to non-smokers even when analyses focused on heavy smokers (>20 pack-years compared to <20 pack-years). Similarly there was no significant difference in mutations patterns according to tobacco consumption. The 3 years overall survival, disease-specific-survival and loco-regional-control rates for the whole cohort are respectively 88% (95% CI: 76.4-94.1), 88% (95% CI: 76.4-94.1) and 80.6% (95% CI: 67.5-88.8). Despite a median follow-up was 4.5 years (6 months to 11.7 years), the few number of events (13 relapses, 13 deaths including 10 due to OPC) precludes detailed prognosis analyses. Conclusions: HPV-driven OPC patients with a smoking history have a comparable mutational rate than non-smokers. Smoking impact on the prognosis isn’t attributable to the mutational burden. Further studies are warranted.

Lepidic predominant adenocarcinoma and invasive mucinous adenocarcinoma of the lung exhibit specific mucin expression in relation with oncogenic drivers

OBJECTIVES

To evaluate MUC1, MUC2, MUC5B, MUC5AC, and MUC6 expression in invasive lepidic predominant adenocarcinoma (LPA) and invasive mucinous adenocarcinoma (IMA) of the lung, and the impact of oncogenic drivers.

MATERIALS AND METHODS

MUC1, MUC2, MUC5B, MUC5AC, MUC6, TTF1 and Hnf4α immunohistochemistry was performed on surgical samples from 52 patients with IMA (n=25) or LPA (n=27). We searched for EGFR, KRAS, BRAF, and HER2 mutations and ALK, ROS1, and NRG1 rearrangements.

RESULTS

MUC1, MUC2, MUC5B, MUC5AC, and MUC6 expression was detected in tumor cells in 77%, 2%, 63%, 36%, and 21% of cases, respectively. MUC1 was significantly more overexpressed in LPA. MUC5B, MUC5AC, and MUC6 were typically detected in goblet cells and overexpressed in IMA. Hnf4α-positive IMA (n=11) were TTF1-negative and typically did not expressed MUC1 and expressed MUC5AC and MUC6. Hnf4α-negative IMA (n=14) showed a reverse profile of mucins expression, with MUC1 expression and a lack of MUC5AC and MUC6 expression. EGFR-positive status was significantly associated with LPA, MUC1 expression, and no MUC5B, MUC5AC, or MUC6 expression. KRAS-positive status was significantly associated with IMA and MUC5B and MUC5AC expression.

CONCLUSIONS

LPA and IMA exhibit specific mucin expression profiles, with MUC1 being associated with LPA, while MUC5B, MUC5AC, and MUC6 were associated with IMA. Hnf4α expression and EGFR and KRAS mutations may play a role in mucin expression profiles of these lung adenocarcinoma subtypes.

NRG1 fusion in a French cohort of invasive mucinous lung adenocarcinoma

Invasive mucinous lung adenocarcinoma (IMA) is a rare subtype of lung adenocarcinoma with no effective treatment option in advanced disease. KRAS mutations occur in 28–87% of the cases. NRG1 fusions were recently discovered in KRAS‐negative IMA cases and otherwise negative for known driver oncogenes and could represent an attractive therapeutic target. Published data suggest that NRG1 fusions occur essentially in nonsmoking Asian women. From an IMA cohort of 25 French patients of known ethnicity, driver oncogenes EGFR, KRAS, BRAF, ERBB2 mutations, and ALK and ROS1 rearrangements presence were analyzed. In the IMA samples remaining negative for these driver oncogenes, an NRG1 rearrangement detection was performed by FISH. A driver oncogene was identified in 14/25 IMA, namely 12 KRAS mutations (48%), one ROS1 rearrangement (4%), and one ALK rearrangement (4%). The detection of NRG1 rearrangement by FISH was conducted in the 11 pan‐negative IMA. One sample was NRG1FISH‐positive and 100% of the tumor nuclei analyzed were positive. This NRG1‐positive patient was a 61‐year‐old nonsmoking woman of Vietnamese ethnicity and was the sole patient of Asian ethnicity of the cohort. She died 6 months after the diagnosis with a pulmonary multifocal disease. NRG1FISH detection should be considered in patients with IMA pan‐negative for known driver oncogenes. These results might suggest that NRG1 fusion is more frequent in IMA from Asian patient. Larger studies are needed.

BRAF Mutation Correlates With High-Risk Langerhans Cell Histiocytosis and Increased Resistance to First-Line Therapy

PURPOSE

Langerhans cell histiocytosis (LCH) is an inflammatory myeloid neoplasia with a broad spectrum of clinical manifestations and outcomes in children. The somatic BRAF(V600E) mutation occurs frequently, but clinical significance remains to be determined.

PATIENTS AND METHODS

BRAF(V600E) mutation was investigated in a French LCH cohort. We analyzed associations between mutation status and clinical presentation, extent of disease, reactivation rate, response to therapy, and long-term permanent sequelae.

RESULTS

Among 315 patients with successfully determined BRAF status, 173 (54.6%) carried a BRAF(V600E) mutation. Patients with BRAF(V600E) manifested more severe disease than did those with wild-type BRAF. Patients with BRAF(V600E) comprised 87.8% of patients (43 of 49) with multisystem LCH with risk organ involvement (liver, spleen, hematology), 68.6% of patients (35 of 51) with multisystem LCH without risk organ involvement, 43.9% of patients (86 of 196) with single-system LCH, and 42.1% of patients (8 of 19) with lung-involved LCH (P < .001). BRAF(V600E) mutation was also associated with organ involvement that could lead to permanent, irreversible damage, such as neurologic (75%) and pituitary (72.9%) injuries. Compared with patients with wild-type BRAF, patients with BRAF(V600E) more commonly displayed resistance to combined vinblastine and corticosteroid therapy (21.9% v 3.3%; P = .001), showed a higher reactivation rate (5-year reactivation rate, 42.8% v 28.1%; P = .006), and had more permanent, long-term consequences from disease or treatment (27.9% v 12.6%; P = .001).

CONCLUSION

In children with LCH, BRAF(V600E) mutation was associated with high-risk features, permanent injury, and poor short-term response to chemotherapy. Further population-based studies should be undertaken to confirm our observations and to assess the impact of BRAF inhibitors for this subgroup of patients who may benefit from targeted therapy.

Comparative analysis of micro-RNAs in human papillomavirus-positive versus -negative oropharyngeal cancers

BACKGROUND

Oncogenic mechanisms of human papillomavirus (HPV)-positive oropharyngeal cancer are still poorly characterized. Analysis of their microRNA expression profile might provide valuable information.

METHODS

The microRNA expression profiles were analyzed by micro-arrays in 26 oropharyngeal cancers. A microRNA signature specific to HPV-status was identified by analyzing a learning/training set consisting of 16 oropharyngeal cancers. The robustness of this signature was further confirmed by blind case-by-case classification of a validation set composed of 10 independent tumors. Putative targeted molecular pathways were proposed using DIANA miRPath online software (http://microrna.gr/mirpath).

RESULTS

We have identified 25 miRNA signatures, which discriminates HPV16-positive oropharyngeal cancer from their HPV-negative counterparts. These 25 microRNAs play a potential role in Wnt and PI3K-pathways, cell-adhesion/cell-polarity, and the cytoskeleton regulation.

CONCLUSION

Our study contributes to a better understanding of pathogenic mechanisms involved in the development of HPV-positive oropharyngeal cancer and in the identification of potential therapeutic molecular targets. © 2016 Wiley Periodicals, Inc. Head Neck 38: 1708-1716, 2016.

BRAF V600E detection in cytological thyroid samples: A key component of the decision tree for surgical treatment of papillary thyroid carcinoma

BACKGROUND

Whether preoperative knowledge of the BRAF mutation status would help to determine the extent of surgery for thyroid nodules is still under investigation.

METHODS

We developed a method to state the V600E mutation before surgery on fine-needle aspiration (FNA) stained smears checked to contain tumor cells. We evaluated the interest of the preoperative assessment of the mutation for surgical strategy of nodules, diagnosed as malignant, suspicious for malignancy or follicular neoplasms.

RESULTS

The mutation was found in 81% (79 of 97) malignant, 59% (20 of 34) suspicious nodules, and in none of follicular neoplasms (n = 29). Overall, the mutation was detected in 82% of papillary carcinomas. The sensitivity, specificity, and positive and negative predictive values for the diagnosis of malignancy were 75%, 100%, 100%, and 46%, respectively.

CONCLUSION

The preoperative knowledge of the V600E mutation status is fundamental to plan total thyroidectomy with certainty and should be part of the decision tree for the management of thyroid nodules. © 2016 Wiley Periodicals, Inc. Head Neck 38: 1017-1021, 2016.

Is there a specific phenotype associated with the different subtypes of KRAS mutations in patients with advanced non-small-cell lung cancers?

OBJECTIVES

KRAS mutations occur in 20 to 25% of non-small-cell lung cancers (NSCLC) and seem to predict a poor prognosis. There is heterogeneousness in the frequency and spectrum of KRAS mutations, which can be categorized in transitions and transversions. We wondered if subtypes of KRAS mutation were associated with specific clinical phenotypes and specific survival.

MATERIALS AND METHODS

Between July 2007 and May 2012, patients with advanced NSCLC and KRAS mutation diagnosed in two university hospitals were included. Clinical and histological characteristics, therapeutics and survival data were collected.

RESULTS

Among 635 patients screened for KRAS mutations, 90 were found to be mutated and were included. Median age was 59 years (range: 54-69). Most were males (60%), current or former smokers (63% and 33%, respectively) and had an adenocarcinoma (ADC) (80%). Eighty patients were stage IV and 10 were stage IIIB. Eighty percent of the KRAS mutations were transversions and 20% were transitions. In uni- and multivariate analyses, there was a trend for fewer smokers among patients with transitions than among those with transversions (Odds Ratio [OR]=0.28, 95% CI [0.079-0.999], p=0.05). No significant difference was noted between transitions and transversions for other clinical characteristics. Patients with transitions had more frequently squamous-cell carcinoma (SCC) compared to those with transversions, who had more frequently adenocarcinomas (OR=16.7, 95% CI [2.76-100.8], p=0.002). Seventy-nine patients (86%) had received first-line chemotherapy. No significant difference was seen for disease-control rate, median progression-free survival or overall survival between transitions and transversions.

CONCLUSION

A higher proportion of non-smokers and SCC subtypes were observed in the transitions compared to transversions. This confirms the heterogeneity of KRAS mutations and could suggest to expand KRAS testing in SCC to assess impact of RAS in SCC, which remains poorly investigated.

Induction therapy with cetuximab plus docetaxel, cisplatin, and 5-fluorouracil (ETPF) in patients with resectable nonmetastatic stage III or IV squamous cell carcinoma of the oropharynx. A GERCOR phase II ECHO-07 study

Induction TPF regimen is a standard treatment option for squamous cell carcinoma (SCC) of the oropharynx. The efficacy and safety of adding cetuximab to induction TPF (ETPF) therapy was evaluated. Patients with nonmetastatic resectable stage III/IV SCC of the oropharynx were treated with weekly cetuximab followed the same day by docetaxel and cisplatin and by a continuous infusion of 5-fluorouracil on days 1-5 (every 3 weeks, 3 cycles). The primary endpoint was clinical and radiological complete response (crCR) of primary tumor at 3 onths. Secondary endpoints were crCR rates, overall response, pathological CR, progression-free survival, overall survival, and safety. Forty-two patients were enrolled, and 41 received ETPF. The all nine planned cetuximab doses and the full three doses of planned chemotherapy were completed in 31 (76%) and 36 (88%) patients, respectively. Twelve (29%) patients required dose reduction. The crCR of primary tumor at the completion of therapy was observed in nine (22%) patients. ETPF was associated with a tumor objective response rate (ORR) of 58%. The most frequent grade 3-4 toxicities were as follows: nonfebrile neutropenia (39%), febrile neutropenia (19%), diarrhea (10%), and stomatitis (12%). Eighteen (44%) patients experienced acne-like skin reactions of any grade. One toxic death occurred secondary to chemotherapy-induced colitis with colonic perforation. This phase II study reports an interesting response rate for ETPF in patients with moderately advanced SCC of the oropharynx. The schedule of ETPF evaluated in this study cannot be recommended at this dosage.

A predictive transcriptomic signature of oropharyngeal cancer according to HPV16 status exclusively

OBJECTIVE

Human-papillomaviruses (HPV) type 16 is a causative agent in an increasing subset of oropharyngeal squamous cell carcinomas (OPSCCs). These tumors have distinct oncogenic mechanisms and a more favorable prognosis than tobacco-induced OPSCCs. Although these differences emphasize the need for a specific therapeutic approach, HPV status is still not used to guide treatment. A better characterization of the molecular profile related to HPV16-induced OPSCC might help to develop personalized treatments.

PATIENTS AND METHODS

Using a human whole-genome DNA-microarray, we have examined the gene expression profiles in 15 HPV-negative and 15 transcriptionally-active HPV-positive OPSCCs. The study was conducted in two steps. Firstly, a learning/training-set consisting of 8 HPV16-positive and 8 HPV16-negative OPSCCs was analyzed to identify a specific signature. Potentially confounding factors (stage, sex and tobacco) were equally distributed in both groups. Subsequently the robustness of this signature was confirmed by blind case-by-case classification of a validation-set composed of the 14 remaining tumors.

RESULTS

We have identified a signature composed of 224 genes, which discriminates HPV16-induced OPSCC from their HPV-negative counterparts. After the blind classification of the 14 tumours, the viral status was revealed: 13 out of 14 tumors were correctly classified according to tumor etiology, 1/14 was not determined and none were misclassified. Several of the differentially expressed genes were involved in cell-cycle regulation, DNA replication and repair, transcription regulation, immune response and apoptosis.

CONCLUSION

Our study contributes to a better understanding of pathogenic mechanisms involved in the development of HPV-positive OPSCCs and in the identification of potential therapeutic targets.

Blood vessel invasion is a major feature and a factor of poor prognosis in sarcomatoid carcinoma of the lung

OBJECTIVES

Pulmonary sarcomatoid carcinomas (SC) are highly disseminated types of non-small-cell lung carcinoma. Their prognosis is poor. New therapeutic targets are needed to improve disease management.

MATERIALS AND METHODS

From 1995 to 2013, clinical and survival data from all consecutive patients with surgically treated SC were collected. Pathological and biomarker analyses were performed: TTF1, P63, c-MET and ALK expression (immunohistochemistry), PAS staining, ALK rearrangement (FISH), and EGFR, KRAS, HER2, BRAF, PIK3CA, and MET genes mutations (PCR).

RESULTS

Seventy-seven patients were included. Median age was 61 years (53-69). Histological subtypes were pleomorphic carcinoma (78%), carcinosarcoma (12%), and giant-cell and/or spindle-cell carcinoma (10%). Blood vessel invasion (BVI) was present in 90% of cases. Morphology and immunohistochemistry were indicative of an adenocarcinoma, squamous, and adenosquamous origin in 41.5%, 17% and 11.5%, respectively, 30% remained not-otherwise-specified. KRAS, PIK3CA, EGFR, and MET mutations were found in 31%, 8%, 3%, and 3%, respectively. No tumors had HER2 or BRAF mutations, or ALK rearrangement, whereas 34% had a c-MET positive score. Five-year overall survival (OS) was 29% for the whole population. At multivariate analysis, tumor size <50mm (HR=1.96 [1.04-3.73], p=0.011), no lymph-node metastasis (HR=3.25 [1.68-6.31], p<0.0001), no parietal pleural invasion (HR=1.16 [1.06-1.28], p=0.002), no BVI (HR=1.22 [1.06-1.40], p=0.005), and no squamous component (HR=3.17 [1.48-6.79], p=0.01) were associated with longer OS. Biomarkers did not influence OS.

CONCLUSION

Dedifferentiation in NSCLC could lead to SC and an epithelial subtype component could influence outcome. BVI was present in almost all SCs and was an independent factor of poor prognosis.

Factors associated with early progression of non-small-cell lung cancer treated by epidermal growth factor receptor tyrosine-kinase inhibitors

Epidermal growth factor receptor tyrosine-kinase inhibitors (EGFR-TKI) are a therapeutic option as second-line therapy in non-small-cell lung carcinoma (NSCLC), regardless of the EGFR gene status. Identifying patients with early progression during EGFR-TKI treatment will help clinicians to choose the best regimen, TKI or chemotherapy. From a prospective database, all patients treated with gefitinib or erlotinib between 2001 and 2010 were retrospectively reviewed. Patients were classified into two groups according to their tumor response by RECIST after 45 days of treatment, progressive disease (PD) or controlled disease (CD). Two hundred and sixty-eight patients were treated with EGFR-TKI, among whom 239 were classified as PD (n = 75) and CD (n = 164). Median overall survival was 77 days (95% CI 61-109) for PD and 385 days (95% CI 267-481) for CD. Patients with PD were of younger age (P = 0.004) and more frequently current smokers (P = 0.001) had more frequently a performance status ≥2 (P = 0.012), a weight loss ≥10% (P = 0.025), a shorter time since diagnosis (P < 0.0001), a pathological classification as non-otherwise-specified NSCLC (P = 0.01), and the presence of abdominal metastases (P = 0.008). In multivariate analysis, abdominal metastases were the only factor associated with early progression (odds ratio (OR) 2.17, 95% CI [1.12-4.19]; P = 0.021). Wild-type EGFR versus mutated EGFR was associated with early progression. The presence of abdominal metastasis was independently associated with early progression in metastatic NSCLC receiving EGFR-TKI.

Rare EGFR exon 18 and exon 20 mutations in non-small-cell lung cancer on 10 117 patients: a multicentre observational study by the French ERMETIC-IFCT network

BACKGROUND

There is scarce data available about epidermal growth factor receptor (EGFR) mutations other than common exon 19 deletions and exon 21 (L858R) mutations.

PATIENTS AND METHODS

EGFR exon 18 and/or exon 20 mutations were collected from 10 117 non-small-cell lung cancer (NSCLC) samples analysed at 15 French National Cancer Institute (INCa)-platforms of the ERMETIC-IFCT network.

RESULTS

Between 2008 and 2011, 1047 (10%) samples were EGFR-mutated, 102 (10%) with rare mutations: 41 (4%) in exon 18, 49 (5%) in exon 20, and 12 (1%) with other EGFR mutations. Exon 20 mutations were related to never-smoker status, when compared with exon 18 mutations (P < 0.001). Median overall survival (OS) of metastatic disease was 21 months [95% confidence interval (CI) 12-24], worse in smokers than in non-smoker patients with exon 20 mutations (12 versus 21 months; hazard ratio [HR] for death 0.27, 95% CI 0.08-0.87, P = 0.03). Under EGFR-tyrosine kinase inhibitors (TKIs), median OS was 14 months (95% CI 6-21); disease control rate was better for complex mutations (6 of 7, 86%) than for single mutations (16 of 40, 40%) (P = 0.03).

CONCLUSIONS

Rare EGFR-mutated NSCLCs are heterogeneous, with resistance of distal exon 20 insertions and better sensitivity of exon 18 or complex mutations to EGFR-TKIs, probably requiring individual assessment.

Use of gene expression signature to discriminate oropharyngeal cancers according to HPV16 status

6055

Background: Strong evidence supports the hypothesis that high-risk human papillomavirus (HPV), particularly HPV16, is a causative agent for an increasing subset of oropharyngeal squamous cell carcinomas (OPSCC). These tumors have distinct oncogenic mechanisms and a more favorable prognosis than tobacco induced OPSCC. Although these differences emphasize the need for a specific therapeutic approach, HPV status is still not used to guide treatment. A better understanding of the molecular profile related to HPV16 induced OPSCC may help to develop personalized treatments. Methods: To identify an HPV16-related molecular signature, we compared the gene expression profile of 15 transcriptionally active HPV16-positive and 15 HPV16-negative OPSCC. The study was conducted in two steps. First, a learning set of 16 OPSCC comprising 8 HPV16-positives and 8 HPV16-negatives OPSCC was analyzed in order to identify the signature. Potentially confounding factors of stage, sex and tobacco consumption were equally distributed in both groups. Secondarily, the robustness of this signature was further confirmed by blind case-by-case classification of an independent set of 14 OPSCC. Results: We identified a signature composed of 224 genes which discriminates HPV16-induced OPSCC from their tobacco induced counterparts. After the viral status was revealed, 13 out of 14 tumors were correctly classified according to tumor etiology, 1/14 was undetermined and none were misclassified. Interestingly, deregulated genes in HPV16-positive tumors are principally involved in innate immunity, in cell cycle regulation through the TP53/RB/E2F pathway, and autophagy through mTOR regulation. Well known targets of E6 and E7 proteins are also found to be deregulated. Conclusions: Our results demonstrate that a set of selected genes can distinguish OPSCC according to etiology. These genes shed light on HPV16 induced carcinogenesis since specific molecular pathways are deregulated. Further investigations are required for a better understanding of the differing natural histories and biological properties of these tumors. These properties may be exploited as a target of novel therapeutic agents in HPV-related OPSCC.

[Lymphatic vascular system, development and lymph formation. Review]

The lymphatic vascular system is widely developed among vertebrates. Lymphatic vessels provide the interstitial fluid (20% of the body weight) drainage through interstitial prelymphatic channels, capillaries, precollectors and collectors flowing into the venous blood. Endothelial cells of capillaries are overlapped and fixed to interstitial collagen and elastic fibres by anchoring filaments facilitating the fluid transfer. Precollectors and collectors have valves controlling the lymph flux direction. In addition to external mechanisms, the lymphangions of collectors have contracting muscle cells driving the flow. Lymphatic endothelial cells are routinely identified by the expression of podoplanin, LYVE-1 and VEGFR3. In the embryo, prelymphatic endothelial cells emerge from the cardinal veins and migrate into the mesenchyma forming embryonic lymphatic sacs. Prox1, Sox18 and COUP-TFII play a major role in the endothelial speciation, VEGFC as VEGFD combined to VEGFR3 in cell migration and proliferation and FoxC2 in valves development. In cancer or inflammation, various factors secreted by cancer cells and/or inflammatory cells induce a neolymphangiogenesis. Recently it has been shown that cells from the bone marrow could be potential precursors for lymphatic endothelial cells.

Quantitative RT-PCR analysis of PSA and prostate-specific membrane antigen mRNA to detect circulating tumor cells improves recurrence-free survival nomogram prediction after radical prostatectomy

BACKGROUND

Circulating tumor cell (CTC) analysis is a potential new biomarker in prostate cancer. We hypothesize that quantitative detection of CTCs in patients pre- and post-radical prostatectomy (RP) using quantitative TaqMan® fluorogenic RT-PCR will improve the accuracy of the Kattan nomogram to predict the probability of recurrence-free survival (RFS) post-RP.

METHODS

Ninty-two patients who underwent RP between 2004 and 2009 had venous blood samples taken pre- (Day - 1) and post-operatively (Day + 7). We performed quantitative Taqman® RT-PCR to detect circulating prostate-specific antigen (PSA) and prostate-specific membrane antigen (PSMA) mRNA. We calculated both the logarithmic ratio of Day + 7/Day - 1 for PSA (PSAr) and PSMA (PSMAr) expression (log(Day+7/Day-1) ) and the Kattan nomogram predicted probability of disease recurrence for each patient. We then analyzed how the AUC-ROC analysis for the Kattan nomogram prediction alone (K) compared to the addition of the PSAr and PSMAr in predicting 5-year RFS.

RESULTS

The mean age (years), PSA (ng/ml), and follow-up (mo) was 65.1, 9.13, and 72, respectively. The AUCs for K, PSAr + K, and PSMAr + K were 0.752 (95%CI 0.620-0.860), 0.830 (95%CI 0.740-0.911), and 0.837 (95%CI 0.613-0.923), respectively (P = 0.03). The Kattan 5-year PSA RFS was 75%. The actual 5-year PSA RFS survival rate was 77%.

CONCLUSIONS

Data from modern quantitative RT-PCR to detect circulating prostate-derived PSA and PSM mRNA pre- and post-RP improves the accuracy of the Kattan nomogram to predict biochemical recurrence.

Clinicopathologic and molecular factors associated with early progressive disease after front-line platinum-doublet chemotherapy (CT) for advanced non-small cell lung cancer (NSCLC)

e18075

Background: The majority of cases of NSCLC are diagnosed at an advanced stage and treated with a platinum-doublet CT. However, some patients are resistant to this treatment and develop early progressive disease. We investigated the clinicopathologic and molecular characteristics of such patients. Methods: All consecutive patients with NSCLC IIIB−IV treated with a platinum-doublet CT between 2003 and 2006 were included. Platinum resistance was defined as early progressive disease at the first tumor assessment according to WHO criteria. The clinical, histologic and molecular characteristics (EGFR:exon 19, 20, 21 and KRAS:exon 2 by PCR sequencing; ALK by IHC, confirmed by FISH) and survival of patients with early progression (P) and controlled disease (C) were compared by univariate analysis. Factors differing between the two groups with a p-value <0.25 in univariate analysis were entered into multivariate analysis. Results: 178 patients were included (mean age 59.1 years, 66.3% male, 54.5% smokers). Platinum was associated with gemcitabine (52.2%), paclitaxel (32.6%) or docetaxel (11.8%). The first tumor assessment was carried out after a median of three cycles [range 1−4]. Forty-six (25.8%) patients had early progression. Overall survival of P-group was significantly shorter than that of C-group (median 5 months vs. 15.1 months, respectively; p <0.0001). Clinical presentation was similar in the two groups. The sarcomatoid histologic subtype was more common among P-group than C-group (10.9% vs. 1.5%, respectively; p=0.057). The proportion of EGFR (5.2% vs. 9.6%, respectively; p=0.224) and KRAS mutations (11.1% vs. 5.7%, respectively; p=0.357), and expression of ALK (6.3% vs. 2.5%, respectively; p=0.327) did not differ significantly between the two groups. In multivariate analysis, sarcomatoid histologic subtype was the only factor associated with early progression [OR=7.50, 95%CI: 1.02−55.45; p=0.048]. Conclusions: Patients with early progression had a shorter survival than controlled patients. Sarcomatoid histologic subtype was the only independent factor associated with early progressive disease.

[A simple view on lung cancer biology: The EGFR pathway]

Epidermal growth factor receptor (EGFR) is a cell membrane tyrosine kinase receptor. Activating mutations at exon 19 and 21 of the EGFR gene are associated with the occurrence and development of lung adenocarcinoma. These gain of function mutations predict responsiveness to EGFR tyrosine kinase inhibitors (TKis), erlotinib or gefitinib and are also a favorable prognostic factor in lung cancer. Sequencing is the recommended technique to detect the mutations, but other more sensitive technics are under evaluation. Treatment as first line therapy by gefitinib is limited to lung cancer patients harboring an EGFR mutation. Erlotinib can be given regardless of the EGFR status as second or third line therapy, as well as maintenance therapy in patients with a stable disease after platinum based chemotherapy. In EGFR mutated tumors, most patients present a recurrence of the disease, despite an initial response on EGFR TKis. Two mechanisms of secondary resistance have been identified, the selection of the T790M mutation in EGFR exon 20 and the MET amplification. Other molecular anomalies as the ras mutations or the EMLA-ALK protein fusion are mutually exclusive with the EGFR mutations and are associated with primary resistance to EGFR TKis.

Massive expansion of regulatory T-cells following interleukin 2 treatment during a phase I-II dendritic cell-based immunotherapy of metastatic renal cancer

Cytotoxic chemotherapy is ineffective in metastatic renal cancer. However, systemic administration of interleukin 2 (IL-2) or infusion of dendritic cells (DCs) loaded with tumor extracts can lead to some response rates with concomitant survival improvements. We report the results of a phase I-II pilot study combining DCs and IL-2 where six patients were included. DCs were derived from bone marrow CD34+ cells and loaded with autologous tumor extracts. CD34-DC vaccines were infused subcutaneously at day 45, 52, 59, 90 and 120 following surgery in combination with IL-2, that was subsequently administrated after the 3rd and 4th DC vaccinations. Preparation of tumor extracts and CD34-DCs were satisfactory in all patients but one. Due to rapid tumor progression, one patient was excluded before vaccination. In the 4 remaining patients, two received 3 vaccinations, while the 2 others received 5 vaccinations and the full IL-2 treatment. No adverse effect due to the vaccinations was observed. A specific immune response against autologous tumor cells was observed in the 2 patients who completed the treatment. Interestingly, these 2 patients had a more prolonged survival than the patients receiving 3 vaccinations. Importantly, a transient and massive increase of circulating natural regulatory T-cells (nTregs) was evidenced in 3 patients following IL-2 administration. Overall, the use of CD34-DC vaccines is feasible, safe and non-toxic. A specific anti-tumor immune response can be detected. However, our data highlights that IL-2 is a potent inducer of nTregs in vivo and as such may have a negative impact on cancer immunotherapy.

A comparison of the performance of microsatellite and methylation urine analysis for predicting the recurrence of urothelial cell carcinoma, and definition of a set of markers by Bayesian network analysis

OBJECTIVE

To compare the potential of two diagnostic methods for detecting recurrence of urothelial cell carcinoma (UCC) of the bladder, by (i) detecting alterations in microsatellite DNA markers and loss of heterozygosity (LOH), and (ii) detecting aberrant gene hypermethylation, as UCC has a high recurrence rate in the urinary tract and the disease can invade muscle if new tumours are overlooked.

PATIENTS AND METHODS

Over 1 year, urine samples were retrieved from 40 patients already diagnosed with bladder UCC (30 pTa, two pTis, eight pT1). Samples were collected 6 months after bladder tumour resection, during the follow-up schedule. We used samples to analyse nine microsatellite markers and the methylation status of 11 gene promoters. Receiver operating characteristic curves were generated and Bayesian statistics used to create an interaction network between recurrence and the biomarkers.

RESULTS

During the study, 15 of the 40 patients (38%) had a tumour recurrence and 14 were identified by cystoscopy (reference method). Overall, microsatellite markers (area under curve, AUC 0.819, 95% confidence interval, CI, 0.677-0.961) had better performance characteristics than promoter hypermethylation (AUC 0.448, 0.259-0.637) for detecting recurrence. A marker panel of IFNA, MBP, ACTBP2, D9S162 and of RASSF1A, and WIF1 generated a higher diagnostic accuracy of 86% (AUC 0.92, 0.772-0.981).

CONCLUSION

Microsatellite markers have better performance characteristics than promoter hypermethylation for detecting UCC recurrence. These data support the further development of a combination of only six markers from both methods in urinary DNA. Once validated, it could be used routinely during the follow-up for the early detection and surveillance of UCC from the lower and upper urinary tract.

Characteristics of hybrid cells obtained by dendritic cell/tumour cell fusion in a T-47D breast cancer cell line model indicate their potential as anti-tumour vaccines

Many strategies have been proposed to circumvent cancer development or prevent its growth. One of the promising strategies is to direct the immune response toward tumour antigens. This can be achieved by loading dendritic cells, the most potent antigen presenting cells, with tumour antigens. Fusion of dendritic cells (DC) with tumour cells is an attractive way to load the DC with all tumour antigens regardless of their immunogenicity status and the fact that they have, or not, been identified. The aim of our study was to characterise the immunophenotype of fused cells, monitor the evolution of the fusion interface and the distribution of surface antigens over time and assess for their maturation status and functionality in vitro. We used polyethylene glycol to fuse DC with Her2/neu positive breast cancer cell line T-47D. We demonstrate that false positive events accounted in flow cytometry can be identified using confocal microscopy to avoid an overestimation of fusion efficiency and to distinguish clearly hybrid cells from aggregated or phagocytosed cells. We used imaging means to demonstrate the conservation of presentation molecules (MHC II, CD1a), co-stimulatory molecules (CD40, CD80, CD86), as well as tumour antigens (Her2/neu, cytokeratins) in optimised conditions. Fused cells were only recognisable for 48 h as assessed by membrane staining and membranous antigen distribution. Fusion was necessary for their maturation to be accompanied by functional activity such as secretion of cytokines and perforin. These results suggest that hybrid cells generated by the fusion of DC and tumour cells can be easily identified and characterised using imaging techniques, and that, regarding functionality and cytokine secretion, they appear to be good candidates for anti-tumour therapies namely in breast cancer.

Molecular Detection of Localized Prostate Cancer Using Quantitative Methylation-Specific PCR on Urinary Cells Obtained Following Prostate Massage

PURPOSE

The diagnosis of localized prostate cancer is difficult due to a lack of cancer-specific biomarkers. Many patients require repeat prostate biopsies to diagnose the disease. We investigated whether aberrant promoter hypermethylation in prostatic fluid could reliably detect prostate cancer.

EXPERIMENTAL DESIGN

Urine samples were collected after prostate massage from 95 patients with localized prostate cancer undergoing radical prostatectomy (63 pT(1), 31 pT(2), and 1 pT(3)) and from 38 control patients. Ten genes (GSTP1, RASSF1a, ECDH1, APC, DAPK, MGMT, p14, p16, RARbeta2, and TIMP3) were investigated using quantitative real-time methylation-specific PCR. Receiver operator curves were generated.

RESULTS

The frequency of gene methylation ranged from 6.3% (p14) to 83.2% (GSTP1) in prostate cancer patients. At least one gene was hypermethylated in 93% of cancer patients. The specificity of methylation was 0.74. Methylation was significantly more frequent (P < 0.05) in cancer than control patients for all genes except p14 and p16. According to receiver operator curve analysis, the four-gene combination of GSTP1 (0.86), RASSF1a (0.85), RARbeta2 (0.80), and APC (0.74) best discriminated malignant from nonmalignant cases. The sensitivity and accuracy of this four-gene set were 86% and 89%, respectively.

CONCLUSIONS

The presence of aberrant methylation in urinary cells obtained after prostate massage is significantly associated with prostate cancer. A panel of four genes could stratify patients into low and high risk of having prostate cancer and optimize the need for repeat prostatic biopsies.

Detection of occult carcinomatous diffusion in lymph nodes from head and neck squamous cell carcinoma using real-time RT-PCR detection of cytokeratin 19 mRNA

The aim of the present study was to evaluate the occult lymph node carcinomatous diffusion in head and neck squamous cell carcinoma (HNSCC). A total of 1328 lymph nodes from 31 patients treated between 2004 and 2005 were prospectively evaluated by routine haematoxylin–eosin–safran (HES) staining, immunohistochemistry (IHC) and real-time Taqman reverse–transcriptase polymerase chain reaction (real-time RT–PCR) assay. Amplification of cytokeratin 19 (CK19) mRNA transcripts using real-time RT–PCR was used to quantify cervical micrometastatic burden. The cervical lymph node metastatic rates determined by routine HES staining and real-time RT–PCR assay were 16.3 and 36.0%, respectively (P<0.0001). A potential change in the nodal status was observed in 13 (42.0%) of the 31 patients and an atypical pattern of lymphatic spread was identified in four patients (12.9%). Moreover, CK19 mRNA expression values in histologically positive lymph nodes were significantly higher than those observed in histologically negative lymph nodes (P<0.0001). These results indicate that real-time RT–PCR assay for the detection of CK19 mRNA is a sensitive and reliable method for the detection of carcinomatous cells in lymph nodes. This type of method could be used to reassess lymph node status according to occult lymphatic spread in patients with HNSCC.

Prognostic impact of multidrug resistance gene expression on the management of breast cancer in the context of adjuvant therapy based on a series of 171 patients

Study of the prognostic impact of multidrug resistance gene expression in the management of breast cancer in the context of adjuvant therapy. This study involved 171 patients treated by surgery, adjuvant chemotherapy±radiotherapy±hormonal therapy (mean follow-up: 55 months). We studied the expression of multidrug resistance gene 1 (MDR1), multidrug resistance-associated protein (MRP1), and glutathione-S-transferase P1 (GSTP1) using a standardised, semiquantitative rt–PCR method performed on frozen samples of breast cancer tissue. Patients were classified as presenting low or high levels of expression of these three genes. rt-PCR values were correlated with T stage, N stage, Scarff–Bloom–Richardson (SBR) grade, age and hormonal status. The impact of gene expression levels on 5-year disease-free survival (DFS) and overall survival (OS) was studied by univariate and multivariate Cox analysis. No statistically significant correlation was demonstrated between MDR1, MRP1 and GSTP1 expressions. On univariate analysis, DFS was significantly decreased in a context of low GSTP1 expression (P=0.0005) and high SBR grade (P=0.003), size ⩾5 cm (P=0.038), high T stage (P=0.013), presence of intravascular embolus (P=0.034), and >3 N+ (P=0.05). On multivariate analysis, GSTP1 expression and the presence of ER remained independent prognostic factors for DFS. GSTP1 expression did not affect OS. The levels of MDR1 and MRP1 expression had no significant influence on DFS or OS. GSTP1 expression can be considered to be an independent prognostic factor for DFS in patients receiving adjuvant chemotherapy for breast cancer.

Association of CK19 mRNA detection of occult cancer cells in mediastinal lymph nodes in non-small cell lung carcinoma and high risk of early recurrence

This study was designed to screen occult cancer cells by CK19 mRNA detection using reverse transcriptase-polymerase chain reaction (RT-PCR) in mediastinal lymph nodes stations (MLNS) in non-small cell lung carcinoma (NSCLC). In 49 NSCLC patients free of mediastinal adenopathy on computed tomograph, 254 MLNS were evaluated by histopathology, immunohistochemistry (IHC) and RT-PCR. Of 225 non-tumoral MLNS on histopathology, 32 (14.2%) were positive by RT-PCR. IHC did not provide significant additional results. Seventeen patients were without mediastinal tumoral extension on histopathology and RT-PCR (Group 1), 16 were upgraded by RT-PCR (Group 2) and 16 pN2 on histopathology (Group 3). The two-year cancer-related death survival in Groups 1 (100%) and 2 (64.5%) was significantly different (P=0.04). The relative risk of recurrence in Group 2 compared with Group 1, evaluated by the Cox model multivariate analysis, was 5.61 (P=0.02). In conclusion, CK19 mRNA detected by RT-PCR in MLNS was significantly associated with an increased risk of rapid recurrence.

Similar immune responses and antitumor effects of murine dendritic cells loaded with either exogenous or endogenous-synthesized protein

Conceptually, dendritic cells (DCs) take up and process exogenous antigens that are presented on MHC (major histocompatibility complex) class II molecules to stimulate CD4+ T cells, and present endogenously-produced proteins to CD8+ T cells through an MHC class I-dependent pathway. In this study, we compared the antitumor effects generated in vivo after vaccinations with DCs either loaded with exogenous protein (DCs-exo) or presenting antigens derived from endogenous-synthesized protein (DCs-endo). We used the murine MC26SC31 colon carcinoma cell line expressing on the cell surface the human CD4 (hCD4) molecule as a model tumor-associated antigen (TAA). Bone marrow (BM)-derived DCs-endo were obtained from histocompatible transgenic mice constitutively expressing hCD4; BM-derived DCs-exo were obtained after in vitro loading DCs, from syngenic normal mice, with purified soluble hCD4 protein (shCD4). Altogether, our results show that intravenous (i.v.) administration of DCs-exo and DCs-endo can trigger similar cytotoxic and humoral protecting immune responses against a lethal tumor challenge. hCD4 antigen-specific T cell-mediated cytotoxic immune response was not accompanied by elevated INF-gamma serum levels. This suggests, in the case of DCs-exo, a possible in vivo CTL cross-priming triggering a CD8+ T cell-mediated immune response in the absence of de novo antigen synthesis within the DCs.