Is there anybody out there: what do senior surgeons expect of their youngsters?

Surgery is indeed one of the most fascinating medical professions. However, it is also a stressful field of work with a high workload, and often leaves little time for personal and family needs. Within the last decade, a noticeable decline occurred in the willingness of medical students to enter a surgical residency. In fact, Generation Y is highly interested in a medical career with a respectful working atmosphere and balanced work and private life, as published in several recent papers. Therefore, surgery must evolve with the times to retain its attractiveness as a career choice for medical students and to compete for the best talents from Generation Y. However, little is known about what senior surgeons really expect from young surgical residents. On the basis of a recent survey by the Professional Association of German Surgeons, this paper tries to give some insights in this very relevant topic and a perspective on how to increase the attractiveness of our fascinating specialty. In fact, in this survey, senior surgeons defined a very clear requirement profile for surgical residency applicants. While the colleagues defined accurate applicant documents, a previous internship, self-motivation, and impressions from the job interview as the most important factors for a successful application for a surgical residency, a standard period of study or a dissertation was deemed of lower importance.

Disseminated tumour cells with highly aberrant genomes are linked to poor prognosis in operable oesophageal adenocarcinoma.

BACKGROUND: Chromosomal instability (CIN) has repeatedly been identified as a prognostic marker. Here we evaluated the percentage of aberrant genome per cell (PAG) as a measure of CIN in single disseminated tumour cells (DTC) isolated from patients with operable oesophageal adenocarcinoma (EAC), to assess the impact of CINhigh DTCs on prognosis. METHODS: We isolated CK18positive DTCs from bone marrow (BM) or lymph node (LN) preparations of operable EAC patients. After whole-genome amplification, single DTCs were analysed for chromosomal gains and losses using metaphase-based comparative genomic hybridisation (mCGH). We calculated the PAG for each DTC and determined the critical threshold value that identifies high-risk patients by STEPP (Subpopulation Treatment Effect Pattern Plot) analysis in two independent EAC patient cohorts (cohort #1, n=44; cohort #2; n=29). RESULTS: The most common chromosomal alterations observed among the DTCs were typical for EAC, but the DTCs showed a varying PAG between individual patients. Generally, LNDTCs displayed a significantly higher PAG than BMDTCs. STEPP analysis revealed an increasing PAG of DTCs to be correlated with an increased risk for short survival in two independent EAC cohorts as well as in the corresponding pooled analysis. In all three data sets (cohort #1, cohort #2 and pooled cohort), PAGhigh DTCs conferred an independent risk for a significantly decreased survival. CONCLUSIONS: The analysis of PAG/CIN in solitary marker-positive DTCs identifies operable EAC patients with poor prognosis, indicating a more aggressive minimal residual disease.

Expression of wingless-type mouse mammary tumor virus integration site family pathway effectors in lymphatic and hepatic metastases of patients with colorectal cancer: Associations with the primary tumor.

The wingless-type mouse mammary tumor virus integration site family (Wnt) pathway plays a major role in the carcinogenesis of colorectal cancer (CRC). Its most important effector, the nuclear ß-catenin, influences not only transcription but also the proliferation and dedifferentiation of the colonic mucosa. This induces an epithelial-mesenchymal transition which ultimately can lead to the development of cancer and the formation of metastases. However, little is known about the exact interaction and context-sensitive expression of Wnt-pathway effectors in the primary tumor and corresponding metastasis. Therefore, this study assessed the expression of the three most important effectors of the Wnt pathway, ß-catenin, adenomatous polyposis coli (APC) and Wnt-1, in the primary tumor and corresponding metastasis of patients with CRC. Immunohistochemical staining of ß-catenin, APC and Wnt-1 was performed in paraffin-embedded tissue samples of the primary tumor, and the corresponding hepatic and nodal metastasis samples from 24 patients with metastatic CRC. Isotype antibodies were used as negative controls. The results were visualized using the ABC-method. Analysis of the primary tumor comprised of a separate evaluation of the central tumor area as well as the invasion front. There was a significant overexpression of nuclear ß-catenin at the tumor invasion front (P<0.001). Compared to normal colonic mucosa, expression of cytoplasmic ß-catenin was significantly higher in the primary tumor (P<0.001) as well as all the corresponding hepatic and lymphatic metastases (hepatic metastases, P=0.001; nodal metastases, P=0.017). By contrast, APC expression was significantly lower in all analyzed tumor compartments compared with normal colonic mucosa (primary tumor, P=0.022; hepatic metastases, P=0.006; nodal metastases, P=0.012). Finally, Wnt-1 protein expression was significantly lower in liver metastases but not in the primary tumor or lymphatic metastases compared with normal colonic mucosa (P=0.003). The present study demonstrates that the major Wnt-effector proteins, ß-catenin, APC and Wnt-1, are heterogeneously expressed in the primary tumor and corresponding hepatic as well as nodal metastases of patients with CRC. This context-sensitive diverse expression of Wnt-effector proteins may be important for future individualized targeted therapies.

Serum microRNA profiles as prognostic or predictive markers in the multimodality treatment of patients with gastric cancer.

Despite the implementation of multimodality treatment strategies, the persistently poor prognosis of gastric cancer patients is predominantly caused by the lack of predictive markers for response assessment in the neoadjuvant setting, preventing individualized therapy. Therefore, the identification of novel predictive and prognostic markers for application in the multimodality treatment of gastric cancer patients is required. The aim of the present study was to characterize the serum microRNA (miRNA/miR) profile of gastric cancer patients undergoing multimodality therapy to identify possible prognostic and predictive markers. The study consisted of 32 patients with gastric cancer who had undergone either primary surgical resection (n=14) or neoadjuvant therapy followed by surgical resection (n=18). Histopathological regression was defined as a major histopathological response when the resected specimens contained <10% vital residual tumor cells. Intratumoral miRNA was isolated from pre-operative or post-neoadjuvant blood serum samples. Initially, microarray analyses were performed in six of the patients that received neoadjuvant treatment (three responders versus three non-responders), to assess the amplification profile of dysregulated miRNAs. Based on these findings, possible predictive or prognostic markers were validated in all study patients by performing single reverse transcription-polymerase chain reaction (RT-PCR) analysis. Depending on the extent of the histopathological regression, a differential miRNA expression profile was identified in the microarray analyses. Based on the amplification profile, miR-21, miR-29a and miR-221 were selected for additional validation. However, the single RT-PCR measurements of the three selected miRNAs did not exhibit any prognostic or predictive value in the patients treated with primary resection or neoadjuvant therapy and resection. Thus, the current pilot study failed to identify a prognostic or predictive value in selected miRNAs using single RT-PCR measurements, however, the microarray results revealed a differential microRNA expression profile depending on the histopathological regression. The findings of the present study may have been affected by the small sample size.

Serum microRNA profiles as prognostic/predictive markers in the multimodality therapy of locally advanced adenocarcinomas of the gastroesophageal junction.

Neoadjuvant multimodality treatment is frequently applied to improve the poor prognosis of locally advanced adenocarcinomas of the gastroesophageal junction. This study aimed to asses if serum microRNA profiles are useable as response indicators in this therapeutic setting. Fifty patients with locally advanced adenocarcinomas of the gastroesophageal junction were included in the study. All patients received neoadjuvant therapy and subsequently underwent surgical resection. Histomorphologic regression was defined as major histopathological response when resected specimens contained less than 10% vital residual tumor cells. Circulating RNA was isolated from pretherapeutic/post-neoadjuvant blood serum samples. RNA from nine patients was applied to PCR microarray analyses Based on these findings possible predictive miRNA markers were validated by quantitative RT-PCR analyses. Depending on the histomorphologic regression, a differential serum microRNA profile was identified by microarray analyses. Based on the divergent miRNA pattern, miR-21, miR-192, miR-222, miR-302c, miR-381 and miR-549 were selected for further validation. During neoadjuvant therapy, there was a significant increase of miR 222 and miR-549. Although on an expanded patient cohort, the six microRNAs could not be validated as markers for therapy response, there was a significant correlation between a high miR-192 and miR-222 expression with a high T-category as well as miR-302c and miR-222 expression significantly correlated with overall survival. Comprehensive miRNA profiling showed a differential microRNA expression pattern depending on the histomorphologic regression in the multimodality therapy of locally advanced adenocarcinomas of the gastroesophageal junction. Moreover, using single RT-PCR analyses a prognostic impact of miR-222 and miR-302c was detected.

Integrin expression in esophageal squamous cell carcinoma: loss of the physiological integrin expression pattern correlates with disease progression.

The integrins are a family of heterodimeric transmembrane signaling receptors that mediate the adhesive properties of epithelial cells affecting cell growth and differentiation. In many epithelial malignancies, altered integrin expression is associated with tumor progression and often correlates with unfavorable prognosis. However, only few studies have investigated the role of integrin expression in esophageal squamous cell carcinoma (ESCC). Using a novel quantifying immunofluorescence-staining assay, we investigated the expression of the integrins α2ß1, α3ß1, α6ß1, and α6ß4 in primary ESCC of 36 patients who underwent surgical resection. Magnitude and distribution of expression were analyzed in primary tumor samples and autologous esophageal squamous epithelium. The persistence of the physiologically polarized expression of the subunits α6, ß1, and ß4 in the tumor tissue was significantly associated with prolonged relapse-free survival (p = 0.028, p = 0.034, p = 0.006). In contrast, patients with reduced focal α6 expression at the tumor invasion front shared a significantly shortened relapse-free survival compared to patients with strong α6 expression at their stromal surfaces, as it was regularly observed in normal esophageal epithelium (p = 0.001). Multivariate regression analysis identified the maintenance of strong α6 immunoreactivity at the invasion front as an independent prognostic factor for increased relapse-free and disease-specific survival (p = 0.003; p = 0.003). Our findings suggest that alterations in both pattern and magnitude of integrin expression may play a major role in the disease progression of ESCC patients. Particularly, the distinct expression of the integrins α6ß4 and α6ß1 at the invasion front as well as the maintenance of a polarized integrin expression pattern in the tumor tissue may serve as valuable new markers to assess the aggressiveness of ESCC.

Surgical strategies in the therapy of non-small cell lung cancer.

Lung cancer represents the leading cause of cancer mortality worldwide. Despite improvements in preoperative staging, surgical techniques, neoadjuvant/adjuvant options and postoperative care, there are still major difficulties in significantly improving survival, especially in locally advanced non-small cell lung cancer (NSCLC). To date, surgical resection is the primary mode of treatment for stage I and II NSCLC and has become an important component of the multimodality therapy of even more advanced disease with a curative intention. In fact, in NSCLC patients with solitary distant metastases, surgical interventions have been discussed in the last years. Accordingly, this review displays the recent surgical strategies implemented in the therapy of NSCLC patients.

Clinically staged cT2 adenocarcinomas of the gastroesophageal junction: accuracy of staging and therapeutic consequences.

BACKGROUND: Multimodality treatment options in locally advanced adenocarcinomas of the esophagogastric junction (AEGs) have been established in the last years. However, the therapeutic approach in patients with clinically staged cT2 tumors remains controversial. The most important determinant is the accuracy of clinical staging. We aimed to evaluate the association of clinical and histopathological staging in patients with cT2 tumors in respect of possible therapeutic consequences. PATIENTS AND METHODS: Between 2001 and 2011, 71 patients with AEG tumors were clinically staged as cT2 (cN0 = 48 (68%); cN+ = 23 (32%)) and underwent surgical resection. RESULTS: A primary tumor resection was performed in 59 (83%) patients while 12 (17%) patients received neoadjuvant therapy. Primarily resected patients showed the following pT/pN categories: pT1: 13 (22%), pT2: 35 (59%), pT3: 11 (19%), pN0: 23 (39%), whereas the clinical/histopathological pN category included 55% of the patients. Neoadjuvantly treated patients showed the following pT/pN categories: ypT0: 3 (25%), ypT1: 3 (25%), ypT2: 6 (50%), ypN0: 6 (50%). The overall survival of primarily resected patients compared with patients undergoing neoadjuvant therapy was not significantly different. CONCLUSIONS: The accuracy of clinical staging in patients with cT2 tumors of the gastroesophageal junction is poor. As in primarily resected patients, over- and understaging balance each other; correct pretherapeutic staging occurs in just about 60% of the patients. Moreover, our study suggests that a radical surgical resection with adequate lymphadenectomy seems to be appropriate for cT2N0 and even in cT2N+ tumors, since down-categorizing and prognosis are not improved for neoadjuvantly treated patients. However, the data have to be interpreted with caution because of the small patient numbers.

Multimodal treatment of hepatocellular carcinoma.

Hepatocellular carcinoma (HCC) represents the most common liver cancer with an increasing incidence and it accounts for the third most common cause of cancer-related death worldwide. Even though the clinical diagnosis and management of HCC improved significantly in the last decades, this malignant disease is still associated with a poor prognosis. It has to be distinguished between patients with HCCs, which developed from liver cirrhosis, and patients without underlying liver cirrhosis as classification systems, prognosis estimation and therapy recommendations differ in-between. In case of HCC in patients with liver cirrhosis in Europe, treatment allocation and prognosis estimation are mainly based on the Barcelona-Clinic Liver Cancer (BCLC) staging system. Based on this staging system different surgical, interventional radiological/sonographical and non-interventional procedures have been established for the multimodal treatment of HCC. The BCLC classification system represents a decision guidance; however because of its limitations in selected patients treatment allocation should be determined on an individualized rather than a guideline-based medicine by a multidisciplinary board in order to offer the best treatment option for each patient. This review summarizes the current management of HCC and illustrates controversial areas of therapeutic strategies.

New therapeutic strategies for squamous cell cancer and adenocarcinoma.

This paper presents commentaries on neoadjuvant treatment esophagectomy; the prognostic and predictive effects of single nucleotide polymorphisms (SNP) in the multimodality therapy of esophageal cancer; optimal preoperative treatment prior to surgery for esophageal cancer; a possible role for trastuzumab in treating esophageal adenocarcinoma or any esophageal dysplasia/intra-epithelial neoplasia; surgery after chemoradiation in resectable esophageal cancer; whether para-aortic lymph node dissection should be performed in esophagogastric junction (EGJ) tumors; and transhiatal esophagectomy in treatment of the esophageal cancer.

High EpCAM expression is linked to proliferation and lauren classification in gastric cancer.

BACKGROUND: The association of EpCAM expression with the progression of gastric cancer remains unclear. Here, we investigated the expression of EpCAM in gastric cancer subtypes and correlated the data to tumor cell proliferation and clinicopathologic factors. METHODS: The intratumoral expression of EpCAM was assessed in 163 primary gastric cancers (61 diffuse-, 62 intestinal-, 32 mixed-type and 8 unclassified tumors) by immunohistochemistry, using the monoclonal antibody Ber-EP4. Intensity of staining was classified according the HercepTest-score using a standardized scoring system. Ki-67 was used to examine the proliferation in tumor tissue. RESULTS: Strong EpCAM expression was observed in 77% of the tumors and in 85% of the corresponding lymph nodes. Of the primary tumors, 58% (n=74) presented a homogeneous intratumoral EpCAM expression while 42% were characterised by a heterogenous expression pattern. Tumors with high EpCAM expression at the invasive front were associated with significantly (p=0.03) higher proportion of lymph node metastases and lower median overall survival (p=0.001). Diffuse type tumors presented a significantly higher EpCAM expression at the invasion front compared with the tumor centre (p=0.036). Multivariate survival analysis identified high EpCAM expression at the invasive front as an independent prognostic factor.We observed a significant (p=0.001) correlation between high EpCAM expression and higher tumor cell proliferation. CONCLUSION: High EpCAM expression associates with proliferation and progression of gastric cancer, especially in the diffuse type. Considering the discontenting results of the current adjuvant concepts for gastric cancer patients, EpCAM might be target in the adjuvant therapy of this malignant disease.

Snail1 expression in colorectal cancer and its correlation with clinical and pathological parameters.

BACKGROUND: Snail1 is a transcription regulator of E-cadherin. The loss of E-cadherin seems to be a crucial step in the process of Epithelial-mesenchymal transition (EMT). EMT initiates invasion and proliferation in many tumours. Overexpression of Snail1 is known to be associated with poor outcome in several solid tumours. The aim of this study was to analyse its expression profile and prognostic significance in colorectal cancer. METHODS: Tissue microarrays (TMA) containing paraffin-embedded primary colorectal cancer (CRC) tissue samples from 251 patients were used in this study. The expression of Snail1 and E-cadherin was assessed by immunohistochemistry in different tumour compartments, corresponding lymph node metastases and normal colonic mucosa. Intensity of staining was classified according to the Remmele score (standardized scoring system) as well as the semiquantitative score established by Blechschmidt et al. RESULTS: Snail1 expression was observed in 76% of the CRC. Loss of E-cadherin was noted in 87% of the CRC. Snail1 positive tumours were significantly correlated with Snail1 positive lymph node metastases (p=0.03). There was no significant correlation between loss of E-cadherin and Snail1 expression, or between N-stage or grading and Snail1 expression. Kaplan-Meier survival analysis identified no prognostic impact of Snail1 expression on overall survival. CONCLUSION: Snail1 expression was detectable in most of the CRC but showed no significant association with E-cadherin loss, clinical pathological characteristics or overall survival. The observed loss of E-cadherin could be explained by effects of other important EMT pathways, such as the Wnt-signalling cascade.

Prognostic significance of EpCAM-positive disseminated tumor cells in rectal cancer patients with stage I disease.

Here we evaluated the prevalence and prognostic impact of epithelial cell adhesion molecule (EpCAM)-positive disseminated tumor cells (DTCs) in stage I rectal cancer. Further we tested the association of these single tumor cells or small tumor cell groups with the extent of peritumoral lymphangiogenesis. A total of 845 regional lymph nodes (LN) of 44 patients classified as negative on conventional histopathology were retrospectively reanalyzed with immunohistochemistry (IHC) using the monoclonal antibody Ber-Ep4 directed against EpCAM for the detection of DTCs. The degree of lymphangiogenesis in the primary tumors was assessed by IHC of the primary tumor tissue using the monoclonal antibody D2-40, which reacts with the lymphatic endothelium. The IHC results were correlated with clinico-pathologic parameters and clinical follow-up data. EpCAM-positive DTCs in LNs were detected in 8 (18.2%) of the 44 patients. During a median follow-up of 59 months, 3 (37.5%) of the 8 patients with EpCAM-positive DTCs relapsed, whereas none of the DTC-negative patients developed tumor recurrence (P=0.004). Survival analysis revealed a significant effect of the prevalence of DTCs on overall survival (P=0.0009) and on recurrence-free survival (P=0.0001). Finally, the prevalence of EpCAM-positive DTCs in perirectal LNs was significantly correlated with a high density of peritumoral lymphatic vessels (P=0.015). Our results show that DTCs may occur in stage I of rectal cancer and are associated with poor prognosis. Their occurrence seems to be linked to a high density of newly formed lymphatic vessel at the primary tumor site. According to our data, patients with DTCs in their LN might benefit from adjuvant therapy.

Neoadjuvant radiochemotherapy in adenocarcinoma of the esophagus: ERCC1 gene polymorphisms for prediction of response and prognosis.

INTRODUCTION: Neoadjuvant radiochemotherapy (RT/CTx) regimens were primarily designed for treatment of squamous cell carcinoma of the esophagus. Own preliminary results demonstrate that also patients with locally advanced adenocarcinoma of the esophagus may achieve a major response in 30% with a 3-year survival rate of 80%. To identify these patients, ERCC1 (rs11615) gene polymorphisms were analyzed. ERCC1 is a key enzyme of the nucleotide excision and repair (NER) complex to prevent DNA inter- and intra-strand crosslinks. PATIENTS AND METHODS: Genomic DNA from 217 patients with cT3/4 adenocarcinoma of the esophagus was extracted from paraffin-embedded tissues. Of these patients, 153 underwent neoadjuvant RT/CTx (CDDP, 5-FU, 36 Gy). For analysis of ERCC1 single nucleotide polymorphisms (SNPs), allelic discrimination was performed by quantitative real-time PCR. Two allele-specific TaqMan probes in competition were used for amplification of ERCC1 (rs11615). Allelic genotyping was correlated with histomorphologic tumor regression after neoadjuvant RT/CTx and survival. Major response (MaHR) was defined as <10% vital residual tumor cells (VRTC). RESULTS: Analysis of tumor regression revealed a MaHR in 56/153 (36.6%) patients with a 5-year survival rate (5-YSR) of 74% (p < 0.001). ERCC1 gene polymorphisms for all patients showed the following expression pattern: ERCC1 polymorphism (rs11615) CC: n = 27 (12.4%), TT: n = 98 (45.2%), C/T: n = 92 (42.4%). ERCC1 polymorphism CT was identified as a predictor for response to the neoadjuvant RT/CTx (p < 0.001). The 5-YSR for patients with C/T genotype was 51%. Contrary to this, the 5-YSR for the group of patients with a CC/TT polymorphism decreased to 34%. CONCLUSION: Analysis of ERCC1 (rs11615) gene polymorphisms reveals a significant correlation with response and survival in patients with adenocarcinoma of the esophagus treated with a neoadjuvant radiochemotherapy. Single nucleotide polymorphisms of ERCC1 (rs11615) could therefore be applied to further individualize therapy in esophageal cancer.

Roles of thymidylate synthase and dihydropyrimidine dehydrogenase expression in blood as predictors of response to multimodal therapy in esophageal cancer.

BACKGROUND: Thymidylate synthetase (TS) and dihydropyrimidine dehydrogenase (DPD) RNA expression in peripheral blood was examined as a noninvasive molecular predictor of response to neoadjuvant radiochemotherapy in patients with locally advanced cancer of the esophagus. METHODS: Blood samples were drawn from 29 patients with esophageal cancer (10 squamous cell carcinomas and 19 adenocarciomas) before neoadjuvant radiochemotherapy. After extraction of cellular tumor RNA from blood samples, quantitative expression analysis of TS and DPD was performed with quantitative real-time reverse-transcription polymerase chain reaction. RESULTS: Twenty of 29 (68%) of patients had a minor histopathologic response, and 9 of 29 (32%) had a major response to neadjuvant radiochemotherapy. RNA expression in the blood of patients was detectable for TS in 86%, for DPD in 97%, and in 100% for ß-actin. No significant associations were detected between TS and DPD expression levels and clinical variables of the patients. A high expression level for TS was associated with a minor response to neoadjuvant treatment (P = .046), while there was no significant association between DPD and response to therapy. Combined analysis of TS and DPD expression increased the specificity for the prediction of response to 100%. No major responder to therapy had high expression levels for both genes in their peripheral blood. CONCLUSION: Quantitation of TS and DPD in peripheral blood may be a highly specific analysis to identify a subset of patients who do not respond to neoadjuvant radiochemotherapy and may therefore prevent expensive, noneffective, and potentially harmful therapies in a substantial number of patients with esophageal cancer.

Barrett's esophagus: treatments of adenocarcinomas II.

The following topics are explored in this collection of commentaries on treatments of adenocarcinomas related to Barrett's esophagus: the importance of intraoperative frozen sections of the margins for the detection of high dysplasia; the preferable way for sentinel node dissection; the current role of robotic surgery and of video-endoscopic approach; the value of the Siewert's classification of adenocarcinomas; the indications of two-step esophagectomy; the evaluation of pathological complete response; the role of PET scan in staging and response assessment; the role of p53 in the selection of adenocarcinomas patients; chemotherapy regimens for adenocarcinomas; the use of monoclonal antibodies in the control of cell proliferation; he attempt to define a stage-specific strategy, and the possible indications of selective therapy; and changes in mortality rates from esophageal cancer.

Predicting response to neoadjuvant therapy in esophageal cancer.

Despite improvements in preoperative staging, surgical techniques and postoperative care, the 5-year survival rate of patients with locally advanced esophageal cancer remains only approximately 15-40%. Therefore, multimodality treatment options have been widely promoted in the therapy of this malignant disease. However, recent meta-analyses evaluating randomized trials of neoadjuvant therapy protocols prior to surgery for patients with advanced esophageal cancer showed only modest improvement of survival for the whole treatment group. Among these patients, those with excellent histopathologic response seem to benefit greatly from neoadjuvant regimens. Therefore, predictive markers to allow individualization of multimodality therapy in locally advanced esophageal cancer are needed to identify those who will benefit the most. Unfortunately, there is still a great lack of markers for response assessment in patients with esophageal cancer undergoing multimodality therapy. Endoscopy, endoscopic biopsies, computed tomography and endoscopic ultrasound do not seem to provide reliable information for assessing the response to neoadjuvant therapy. Whether (18)F-fluorodeoxyglucose-PET can effectively characterize responders in neoadjuvant therapy protocols remains controversial. Finally, although results of mostly retrospective studies on molecular factors for response assessment in esophageal cancer patients are promising, these markers do not yet provide a reliable and cost-effective molecular tool for utilization in clinical practice.

EGF61 polymorphism predicts complete pathologic response to cetuximab-based chemoradiation independent of KRAS status in locally advanced rectal cancer patients.

BACKGROUND: Cetuximab has shown significant clinical activity in metastatic colon cancer. However, cetuximab-containing neoadjuvant chemoradiation has not been shown to improve tumor response in locally advanced rectal cancer patients in recent phase I/II trials. We evaluated functional germline polymorphisms of genes involved in epidermal growth factor receptor pathway, angiogenesis, antibody-dependent cell-mediated cytotoxicity, DNA repair, and drug metabolism, for their potential role as molecular predictors for clinical outcome in locally advanced rectal cancer patients treated with preoperative cetuximab-based chemoradiation. METHODS: 130 patients (74 men and 56 women) with locally advanced rectal cancer (4 with stage II, 109 with stage III, and 15 with stage IV, 2 unknown) who were enrolled in phase I/II clinical trials treated with cetuximab-based chemoradiation in European cancer centers were included. Genomic DNA was extracted from formalin-fixed paraffin-embedded tumor samples and genotyping was done by using PCR-RFLP assays. Fisher's exact test was used to examine associations between polymorphisms and complete pathologic response (pCR) that was determined by a modified Dworak classification system (grade III vs. grade IV: complete response). RESULTS: Patients with the epidermal growth factor (EGF) 61 G/G genotype had pCR of 45% (5/11), compared with 21% (11/53) in patients heterozygous, and 2% (1/54) in patients homozygous for the A/A allele (P < 0.001). In addition, this association between EGF 61 G allele and pCR remained significant (P = 0.019) in the 59 patients with wild-type KRAS. CONCLUSION: This study suggested EGF A+61G polymorphism to be a predictive marker for pCR, independent of KRAS mutation status, to cetuximab-based neoadjuvant chemoradiation of patients with locally advanced rectal cancer.

Biomarkers for cetuximab-based neoadjuvant radiochemotherapy in locally advanced rectal cancer.

PURPOSE: Phase II trials in locally advanced rectal cancer have shown that cetuximab-based neoadjuvant radiochemotherapy is feasible but without an improvement in complete pathologic response rates. Our goal was to identify patients who would benefit from cetuximab-based neoadjuvant chemoradiation measuring gene expression levels of proteins involved in tumor growth [endothelial growth factor receptor (EGFR)], angiogenesis [VEGF, VEGF receptors 1 and 2 (VEGFR1, VEGFR2)], DNA repair [excision repair cross-complementing 1 (ERCC1)], and drug metabolism [thymidylate synthetase (TS)]. We also determined mutation status of KRAS and BRAF. EXPERIMENTAL DESIGN: This study was carried out on 130 patients with locally advanced rectal cancer who were enrolled in 4 different phase II clinical trials, using cetuximab-based chemoradiation. Tumor tissues were obtained before neoadjuvant and at surgical therapy. After microdissection, intratumoral gene expression levels and KRAS/BRAF mutation status were analyzed. RESULTS: A significant decrease of TS, VEGFR1, and VEGFR2 gene expression was seen following neoadjuvant therapy (P < 0.03). High pretreatment VEGF gene expression levels were associated with nonresponse (P = 0.070). KRAS mutations were found in 42% and mutant KRAS (KRAS mt) was significantly associated with pathologic nonresponse (P = 0.037). In patients with wild-type KRAS (KRAS wt), low EGFR was significantly associated with higher nonresponse and VEGF mRNA expressions were associated with complete pathologic response (P = 0.012; P = 0.06). KRAS transversion (KRAS tv) was associated with tumor regression: nonresponse was more common in patients with KRAS tv than with KRAS wt (P = 0.007). BRAF V600E mutations were not detected in any of the patients. CONCLUSION: This study suggests that pretreatment intratumoral EGFR and VEGF mRNA expression levels as well as KRAS mutation status are predictive markers of pathologic response to neoadjuvant cetuximab-based chemoradiation in locally advanced rectal cancer.