Daniel Vallböhmer

Molecular Determinants of Cetuximab Efficacy

PURPOSE To investigate whether mRNA expression levels of cyclin D1 (CCND1), cyclooxygenase 2 (Cox-2), epidermal growth factor receptor (EGFR), interleukin 8 (IL-8), and vascular endothelial growth factor (VEGF), all members of the EGFR signaling pathway, are associated with clinical outcome in patients with EGFR-expressing metastatic colorectal cancer (CRC) treated with cetuximab. PATIENTS AND METHODS Thirty-nine patients with metastatic CRC, refractory to both irinotecan and oxaliplatin, were enrolled on IMCL-0144 and treated with single-agent cetuximab. The intratumoral mRNA levels of CCND1, Cox-2, EGFR, IL-8, and VEGF were assessed from paraffin-embedded tissue samples using laser-capture microdissection and quantitative real-time polymerase chain reaction. RESULTS There were 21 women and 18 men with a median age of 64 years (range, 35 to 83 years). Higher gene expression levels of VEGF were associated with resistance to cetuximab (P = .038; Kruskal-Wallis test). The combination of low gene expression levels of Cox-2, EGFR, and IL-8 was significantly associated with overall survival (13.5 v 2.3 months; P = .028; log-rank test). Both findings were independent of skin toxicity that was itself significantly correlated to survival. Patients with a lower mRNA amount of EGFR had a longer overall survival compared with patients that had a higher mRNA amount (7.3 v 2.2 months; P = .09; log-rank test). Patients with lower expression of Cox-2 had a significantly higher rate of grade 2 to 3 skin reactions under cetuximab treatment. CONCLUSION This pilot study suggests that gene expression levels of Cox-2, EGFR, IL-8, and VEGF in patients with metastatic CRC may be useful markers of clinical outcome in single-agent cetuximab treatment.

Early gastric cancer: lymph node metastasis starts with deep mucosal infiltration.

Objective:The purpose of this study was to evaluate the frequency of lymph node metastasis according to the depth of tumor infiltration of the mucosa and submucosa. Background Data:Currently some endoscopists extend the indication for endoscopic mucosal resection in gastric cancer to the submucosa. However, the decision between endoscopic mucosectomy or gastrectomy with lymphadenectomy for early gastric cancer depends especially on the probability of lymph node metastasis. Methods:One hundred twenty-six patients either had subtotal resection (n = 29) or total gastrectomy (n = 97) for T1 gastric cancer. The median number of resected lymph nodes was 21 (1–63). In the histopathologic analysis of the specimens the tumors were differentiated according to their wall penetration in the upper (m1), middle (m2), lower (m3) third of the mucosa or submucosa (sm1, sm2, sm3). The greatest diameter of the lesions, the Grading and the Goseki-, Ming-, WHO-, and Laurén classification were determined. Results:Patients with m1 (n = 3) and m2 (n = 5) layer infiltration had no lymphatic metastasis compared with 13% for m3 (n = 39). The rate of lymphatic metastasis in submucosal carcinomas was 21% for sm1 (n = 29), 16% for sm2 (n = 23) and 40% for sm3 (n = 25). Carcinomas with papillary differentiation, Grading G1 or <1 cm in diameter had no lymph node metastasis. The size of tumor <2 cm or ≥2 cm showed independent influence on the rate of lymph node metastasis. Conclusions:Endoscopic mucosectomy in m3 carcinoma is questionable and in all submucosal carcinomas and lesions ≥2 cm it is not indicated.

A multicenter study of survival after neoadjuvant radiotherapy/chemotherapy and esophagectomy for ypT0N0M0R0 esophageal cancer.

Objective:To evaluate 5-year survival of patients with locally advanced esophageal cancer (LAEC) who have undergone multimodality treatment with complete histopathologic response. Background:Patients with LAEC may obtain excellent local-regional response to multimodality therapy. The overall benefit of a complete histopathologic response, when no viable tumor is present in the surgical specimen, is incompletely understood and existing data are limited to single-center studies with relatively few patients. The aim of this multicenter study was to define the outcome of patients with complete histopathologic response after multimodality therapy for LAEC. Methods:The study population included 299 patients (229 male, 70 female; median age: 60 years) with LAEC (cT2N1M0, T3-4N0-1M0; 181 adenocarcinomas, 118 squamous carcinomas) who underwent either neoadjuvant radiochemotherapy (n = 284) or chemotherapy (n = 15) followed by esophagectomy at 6 specialized centers: Europe (3) and United States (3). All patients in the study had stage ypT0N0M0R0 after resection. Results:Esophagectomy with thoracotomy (n = 255) was more frequent than with a transhiatal approach (n = 44). The median number of analyzed lymph nodes in the surgical specimens was 20 (minimum–maximum: 1–77). Thirty-day mortality rate was 2.4% and 90-day mortality rate was 5.7%. Overall 5-year survival rate was 55%. The disease-specific 5-year survival rate was 68%, with a recurrence rate of 23.4% (n = 70; local vs distant recurrence: 3.3% vs 20.1%). Cox regression analysis identified age as the only independent predictor of survival, whereas gender, histology, type of esophagectomy, type of neoadjuvant therapy, and the number of resected lymph nodes had no prognostic impact. Conclusion:Patients with histopathologic complete response at the time of resection of LAEC achieve excellent survival.

Response Evaluation by Endoscopy, Rebiopsy, and Endoscopic Ultrasound Does Not Accurately Predict Histopathologic Regression After Neoadjuvant Chemoradiation for Esophageal Cancer

Objective:To prospectively assess the sensitivity (sens), specificity (spec), positive predictive value (ppv), negative predictive value (npv), and accuracy (acc) for clinical response evaluation by endoscopy, rebiopsy, and endoscopic ultrasound (EUS) to determine histomorphologic regression UICC T-category downstaging after neoadjuvant chemoradiation for esophageal cancer. Background:Histomorphologic regression is meanwhile established as objective parameter for response and prognosis after neoadjuvant chemoradiation for esophageal cancer. Patients and Methods:Within a prospective observation trial, 80 patients with localized esophageal cancers (cT2-4,Nx,M0) received standardized neoadjuvant chemoradiation (cisplatin, 5-fluorouracil, 36 Gy) and were resected by transthoracic en bloc esophagectomy and two-field lymphadenectomy. Tumor regression was based on the percentage of vital residual tumor cells and classified in 4 categories as reported previously. Evaluation by endoscopy and EUS was performed based on WHO/UICC criteria before starting chemoradiation and before resection and rebiopsies were taken at the time of re-endoscopy. Results:Histomorphologic response was of significant (log rank) prognostic importance (P < 0.001), whereas clinical response evaluation by endoscopy (P = 0.1), rebiopsy (P = 0.34), and EUS (P = 0.35) was not. The results of the 3 diagnostic modalities to assess histomorphologic regression by endoscopy and rebiopsy UICC ypT-category downstaging for EUS are summarized: Endoscopy: sens 60%, spec 34%, ppv 49%, npv 44%, acc 47%. Rebiopsy: sens 36%, spec 100%, ppv 100%, npv 24%, acc 47%. EUS: sens 7%, spec 79%, ppv 18%, npv 57%, acc 50%. Conclusions:Histomorphologic regression is an objective response parameter of significant prognostic importance. The diagnostic accuracy of endoscopy, rebiopsy, and EUS is inadequate for objective response evaluation after neoadjuvant chemoradiation and can be omitted for this purpose in the clinical practice.

Vascular Endothelial Growth Factor Messenger RNA Expression Level Is Preserved in Liver Metastases Compared with Corresponding Primary Colorectal Cancer

Purpose: Increased vascular endothelial growth factor (VEGF) expression is associated with colorectal cancer liver metastases. It is reasonable to expect that measurement of VEGF in liver metastases would provide the best prediction of therapy benefit for VEGF-targeted drugs, such as bevacizumab (Avastin). In this study, we evaluated how VEGF mRNA level in primary colorectal cancer was related to that in corresponding liver metastases. Thirty-one pairs of primary colorectal cancer and corresponding liver metastases were analyzed. Experimental Design: Formalin-fixed, paraffin-embedded tumor specimens were dissected by using laser-captured microdissection. RNA was extracted and cDNA was prepared by reverse transcription. Quantitation of VEGF and internal reference gene (β-actin) was done using real-time PCR (Taqman PCR). Results: There was no difference between median VEGF mRNA levels of primary colorectal cancer and liver metastases (median value 3.79 versus 3.97: P = 0.989). On an individual basis, there was a significant correlation in VEGF mRNA expression between primary colorectal cancer and corresponding liver metastases (rs = 0.6627, P < 0.0001). In addition, the VEGF mRNA levels of the patients who had two or more liver metastatic tumors were significantly higher than those of the patient who had solitary liver metastatic tumor in both primary cancer (5.02 versus 3.34: P = 0.0483) and liver metastases (4.38 versus 3.25: P = 0.0358). Conclusion: Good prediction of VEGF mRNA levels in liver metastases can be obtained by measuring those of primary colorectal cancer. The risk of multiple liver metastatic tumors might be predictable by measuring VEGF mRNA expression in primary colorectal cancer. Further study is required to confirm these preliminary results.

Options in the management of esophageal perforation: analysis over a 12‐year period

Controversies exist about the management of esophageal perforation in order to eliminate the septic focus. The aim of this study was to assess the etiology, management, and outcome of esophageal perforation over a 12-year period, in order to characterize optimal treatment options in this severe disease. Between May 1996 and May 2008, 44 patients (30 men, 14 women; median age 67 years) with esophageal perforation were treated in our department. Etiology, diagnostic procedures, time interval between clinical presentation and treatment, therapeutic management, and outcome were analyzed retro- or prospectively for each patient. Iatrogenic injury was the most frequent cause of esophageal perforation (n= 28), followed by spontaneous (n= 9) and traumatic (n= 4) esophageal rupture (in three patients, the reasons were not determinable). Eight patients (18%) underwent conservative treatment with cessation of oral intake, antibiotics, and parenteral nutrition. Twelve (27%) patients received an endoscopic stent implantation. Surgical therapy was performed in 24 (55%) patients with suturing of the lesion in nine patients, esophagectomy with delayed reconstruction in 14 patients, and resection of the distal esophagus and gastrectomy in one patient. In case of iatrogenic perforation, conservative or interventional therapy was performed each in 50% of the patients; 89% of the patients with a Boerhaave syndrome underwent surgery. The hospital mortality rate was 6.8% (3 of 44 patients): one patient with an iatrogenic perforation after conservative treatment, and two patients after surgery (one with Boerhaave syndrome, one with iatrogenic rupture). No death occurred in the 25 patients with a diagnostic interval less than 24 hours, whereas the mortality rate in the group (n= 16 patients) with a diagnostic interval of more than 24 hours was 19% (P= 0.053). In three patients, the diagnostic interval was not determinable retrospectively. An individualized therapy depending on etiology, diagnostic delay, and septic status leads to a low mortality of esophageal perforation.

Altered levels of the onco-microRNA 21 and the tumor-supressor microRNAs 143 and 145 in advanced rectal cancer indicate successful neoadjuvant chemoradiotherapy

microRNAs (miRNAs) are small non-coding RNAs with important post-transcriptional regulatory functions. miRNA-21 (miR-21) is upregulated and miR-143 and miR-145 are downregulated in colorectal carcinoma. The aim of our study was to determine if these miRNAs change their expression levels in response to neoadjuvant chemoradiotherapy in advanced rectal cancer. Forty patients with advanced rectal cancer (clinical uT3/T4 Nx) were included. All patients underwent neoadjuvant chemoradiotherapy and surgical resection. Expression of miR-21, -143 and -145 was examined in macrodissected tumor tissue before and after chemoradiotherapy and normal rectal tissue from the resection specimen. RNA was extracted from formalin-fixed and paraffin-embedded tissue by TRIzol method, polyadenylated, reverse transcribed and analyzed by real-time PCR. Therapy response was assessed according to pathological tumor regression. miR-21 was more highly expressed in tumor tissue than in non-tumorous tissue. However, there was a moderately lower expression in post-therapeutic tumor tissue compared to pre-therapeutic tumor tissue. There was a significant upregulation of miR-143 and miR-145 in post-therapeutic tumor tissue compared to pre-therapeutic tumor tissue. According to the predictive and prognostic value of the analyzed miRNAs, a significant correlation between miR-145 expression and tumor regression was seen. Patients with a low intratumoral post-therapeutic expression had significantly more often a worse response to neoadjuvant therapy compared to patients with a high expression of miR145. The present results support the hypothesis that chemoradiotherapy can profoundly alter miRNA expression profiles. miRNAs might play important roles as molecular biomarkers in the prediction of response to treatment and prognosis.

Ivor-Lewis Esophagectomy With and Without Laparoscopic Conditioning of the Gastric Conduit

BackgroundAnastomotic leakage is still the major surgical complication following transthoracic esophagectomy with intrathoracic esophagogastrostomy (Ivor-Lewis procedure). Modifications of this standard procedure aim to reduce postoperative morbidity and mortality.MethodsIn this retrospective analysis of a 12-year period, 419 patients who had an Ivor-Lewis (IL) procedure for esophageal carcinoma were included. Due to modifications of the standard procedure, two different groups were compared with respect to their mortality and anastomotic leakage rate. In 181 patients (43.1%), esophagectomy and gastric reconstruction was performed as a one-stage procedure (classical IL group). Two hundred thirty-eight patients (56.9%) underwent a modified IL procedure that included minimally invasive gastric mobilization and a two-stage operation following ischemic conditioning of the gastric conduit.ResultsThe hospital mortality rate was lower in the modified IL group without statistical significance (2.9 vs. 6.1%). Thirty-five anastomotic leaks were diagnosed postoperatively, 17 in the classical IL group (9.4%) and 18 in the modified IL group (7.6%). The rate of late leakages (after the 10th postoperative day) was higher in the modified IL group. Septic complications and mortality following anastomotic leakage were less frequent in the modified IL group. Leaks in the classical IL group predominantly required rethoracotomy, whereas leaks of the modified IL group were sufficiently treated with endoscopic stenting.ConclusionsSurgical modifications of the classical IL procedure, including a minimally invasive approach and ischemic conditioning of the gastric conduit, seem to reduce postoperative morbidity and mortality. However, due to the retrospective design of this study, the impact of other factors influencing the outcome cannot be ruled out.

Molecular determinants of irinotecan efficacy

Molecular markers predicting the efficacy of CPT‐11 based chemotherapies in patients with colorectal cancer (CRC) are unknown. Therefore, we investigated whether mRNA levels of drug targets (Topoisomerase I, TS), enzymes involved in 5‐FU metabolism (DPD), in angiogenesis (EGFR, IL‐8, VEGF) and in DNA‐repair/drug detoxification (ERCC1, GST‐P1) are associated with the clinical outcome of patients with CRC treated with first‐line CPT‐11 based chemotherapy. Thirty three patients with metastatic CRC were included in the study. Intratumoral gene expression levels were assessed from paraffin‐embedded tissue samples, using laser capture microdissection and quantitative Real‐Time PCR. Complete response was observed in 1 patient, partial response in 12 patients, stable disease in 13 patients and progressive disease in 6 patients. Response was inevaluable for 1 patient. Patients with complete response or partial response were classified as responders, while patients with stable disease or progressive disease were classified as nonresponders. High intratumoral mRNA levels of EGFR, ERCC1 and GSPT‐P1 were each significantly associated with response to CPT‐11 based chemotherapy. Recursive partitioning analysis showed that mRNA levels of EGFR and ERCC1 are primarily responsible for delineating responders from nonresponders. Also, the combination of high intratumoral gene expression levels of both EGFR and ERCC1 was significantly associated with progression‐free survival. The mRNA levels of EGFR had a significant correlation with expression levels of ERCC1, GST‐P1 and VEGF. This small retrospective study suggests that gene expression levels of EGFR, ERCC1 and GST‐P1 may be useful in predicting the clinical outcome of patients with metastatic CRC treated with first‐line CPT‐11 based chemotherapy.

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. Clin Cancer Res; 17(10); 3469–77. ©2011 AACR.