Urokinase-Type Plasminogen Activator Receptor (uPAR) Cooperates with Mutated KRAS in Regulating Cellular Plasticity and Gemcitabine Response in Pancreatic Adenocarcinomas.

BACKGROUND: Pancreatic ductal adenocarcinoma (PDAC) remains one of the most lethal cancers. Given the currently limited therapeutic options, the definition of molecular subgroups with the development of tailored therapies remains the most promising strategy. Patients with high-level gene amplification of urokinase plasminogen activator receptor (uPAR/PLAUR) have an inferior prognosis. We analyzed the uPAR function in PDAC to understand this understudied PDAC subgroup's biology better. METHODS: A total of 67 PDAC samples with clinical follow-up and TCGA gene expression data from 316 patients were used for prognostic correlations. Gene silencing by CRISPR/Cas9, as well as transfection of uPAR and mutated KRAS, were used in PDAC cell lines (AsPC-1, PANC-1, BxPC3) treated with gemcitabine to study the impact of these two molecules on cellular function and chemoresponse. HNF1A and KRT81 were surrogate markers for the exocrine-like and quasi-mesenchymal subgroup of PDAC, respectively. RESULTS: High levels of uPAR were correlated with significantly shorter survival in PDAC, especially in the subgroup of HNF1A-positive exocrine-like tumors. uPAR knockout by CRISPR/Cas9 resulted in activation of FAK, CDC42, and p38, upregulation of epithelial makers, decreased cell growth and motility, and resistance against gemcitabine that could be reversed by re-expression of uPAR. Silencing of KRAS in AsPC1 using siRNAs reduced uPAR levels significantly, and transfection of mutated KRAS in BxPC-3 cells rendered the cell more mesenchymal and increased sensitivity towards gemcitabine. CONCLUSIONS: Activation of uPAR is a potent negative prognostic factor in PDAC. uPAR and KRAS cooperate in switching the tumor from a dormant epithelial to an active mesenchymal state, which likely explains the poor prognosis of PDAC with high uPAR. At the same time, the active mesenchymal state is more vulnerable to gemcitabine. Strategies targeting either KRAS or uPAR should consider this potential tumor-escape mechanism.

Comparing Apparent Diffusion Coefficient and FNCLCC Grading to Improve Pretreatment Grading of Soft Tissue Sarcoma-A Translational Feasibility Study on Fusion Imaging.

Histological subtype and grading are cornerstones of treatment decisions in soft tissue sarcoma (STS). Due to intratumoral heterogeneity, pretreatment grading assessment is frequently unreliable and may be improved through functional imaging. In this pilot study, 12 patients with histologically confirmed STS were included. Preoperative functional magnetic resonance imaging was fused with a computed tomography scan of the resected specimen after collecting core needle biopsies and placing radiopaque markers at distinct tumor sites. The Fédération Nationale des Centres de Lutte Contre le Cancer (FNCLCC) grading criteria of the biopsies and apparent diffusion coefficients (ADCs) of the biopsy sites were correlated. Concordance in grading between the specimen and at least one biopsy was achieved in 9 of 11 cases (81.8%). In 7 of 12 cases, fusion imaging was feasible without relevant contour deviation. Functional analysis revealed a tendency for high-grade regions (Grade 2/3 (G2/G3)) (median (range) ± standard deviation: 1.13 (0.78-1.70) ± 0.23 × 10-3 mm2/s) to have lower ADC values than low-grade regions (G1; 1.43 (0.64-2.03) ± 0.46 × 10-3 mm2/s). In addition, FNCLCC scoring of multiple tumor biopsies proved intratumoral heterogeneity as expected. The ADC appears to correlate with the FNCLCC grading criteria. Further studies are needed to determine whether functional imaging may supplement histopathological grading.

Gene-expression profiles of pretreatment biopsies predict complete response of rectal cancer patients to preoperative chemoradiotherapy.

PURPOSE: Preoperative (neoadjuvant) chemoradiotherapy (CRT) and total mesorectal excision is the standard treatment for rectal cancer patients (UICC stage II/III). Up to one-third of patients treated with CRT achieve a pathological complete response (pCR). These patients could be spared from surgery and its associated morbidity and mortality, and assigned to a "watch and wait" strategy. However, reliably identifying pCR based on clinical or imaging parameters remains challenging. EXPERIMENTAL DESIGN: We generated gene-expression profiles of 175 patients with locally advanced rectal cancer enrolled in the CAO/ARO/AIO-94 and -04 trials. One hundred and sixty-one samples were used for building, training and validating a predictor of pCR using a machine learning algorithm. The performance of the classifier was validated in three independent cohorts, comprising 76 patients from (i) the CAO/ARO/AIO-94 and -04 trials (n = 14), (ii) a publicly available dataset (n = 38) and (iii) in 24 prospectively collected samples from the TransValid A trial. RESULTS: A 21-transcript signature yielded the best classification of pCR in 161 patients (Sensitivity: 0.31; AUC: 0.81), when not allowing misclassification of non-complete-responders (False-positive rate = 0). The classifier remained robust when applied to three independent datasets (n = 76). CONCLUSION: The classifier can identify >1/3 of rectal cancer patients with a pCR while never classifying patients with an incomplete response as having pCR. Importantly, we could validate this finding in three independent datasets, including a prospectively collected cohort. Therefore, this classifier could help select rectal cancer patients for a "watch and wait" strategy. TRANSLATIONAL RELEVANCE: Forgoing surgery with its associated side effects could be an option for rectal cancer patients if the prediction of a pathological complete response (pCR) after preoperative chemoradiotherapy would be possible. Based on gene-expression profiles of 161 patients a classifier was developed and validated in three independent datasets (n = 76), identifying over 1/3 of patients with pCR, while never misclassifying a non-complete-responder. Therefore, the classifier can identify patients suited for "watch and wait".

Cure Is Possible: Extensively Metastatic HER2-Positive Gastric Carcinoma with 5 years of Complete Remission after Therapy with the FLOT Regimen and Trastuzumab.

Gastric cancer (GC) represents one of the most fatal neoplasms in gastrointestinal oncology and affected patients can only hope for cure in limited disease. In a metastatic situation however, patients have a worse prognosis finally resulting in cancer-related death. Some improvements were made by using intensified chemotherapy such as the FLOT protocol (5-FU, leucovorin, oxaliplatin and docetaxel). However, a breakthrough in the treatment of advanced GC has been achieved by pre-therapeutical tumor analysis for potentially targetable alterations. Microsatellite instability, PD-L1 expression, Epstein Barr virus, and human epidermal growth factor receptor-2 (HER2) overexpression or amplification are the most beneficial targets, if addressed, can prolong survival in a palliative situation. Whether the combination of these targeted therapeutics with chemotherapy can bring long-term survival or even a chance of cure in a metastatic situation is not clear. Here, we report the case of a 30-year-old man with GC and extensive metastases who was cured by anti-HER2 antibody Trastuzumab combined with the FLOT regime. Initial staging showed an exophytic Siewert type III tumor and extensive hepatic metastases. Histology resulted in gastric adenocarcinoma with HER2 overexpression (2+, FISH positive). Twelve courses of chemotherapy comprising Trastuzumab and FLOT were administered. After treatment, the extensive liver metastases had disappeared with no evidence of residual tumor growth on the CT scans. Monotherapy of Trastuzumab was continued until gastrectomy with D2 lymph node dissection and probing of liver tissue, which revealed no residual tumor cells. Five years after surgery, there is continued complete remission. In conclusion, Trastuzumab in combination with FLOT may have curative potential even for metastatic stages of HER-2-positive GC.

Effectiveness of fourth-line dual immunotherapy in hepatocellular carcinoma with simultaneous steroid administration for immune-related hepatitis.

Medical therapy of advanced hepatocellular carcinoma (HCC) remains an emerging subject, but therapeutic sequences together with toxicity management are rarely described. Herein, we report the case of a therapeutic sequence and toxicity management in a 72-year old White male with advanced non-cirrhotic HCC. The HCC of this patient was refractory against treatment with several tyrosine kinase inhibitors, including lenvatinib and cabozantinib or immune combination of pembrolizumab and lenvatinib. Double immune combination of nivolumab and ipilimumab was effective in fourth-line treatment but resulted in immunotherapy-related grade 4 hepatitis. This toxicity responded well to high doses of corticosteroids, and reinduction of dual immune combination remained effective despite continuation of high-dose corticosteroids in a non-cirrhotic HCC. This case demonstrated the efficacy of double immune therapy in higher treatment lines in advanced non-cirrhotic HCC even if the patient was treated with other immune modulatory therapies earlier. Moreover, it can remain effective under concomitant administration of high-dose corticosteroids.

MicroRNA-182-5p and microRNA-205-5p as potential biomarkers for prognostic stratification of p16-positive oropharyngeal squamous cell carcinoma.

BACKGROUND: MicroRNAs constitute promising biomarkers. OBJECTIVE: The aim was to investigate diagnostic and prognostic implications of miR-182-5p and miR-205-5p in p16-positive and p16-negative oropharyngeal squamous cell carcinomas (OPSCCs). METHODS: Expression of miR-182-5p, miR-205-5p were determined via quantitative real-time-PCR in fresh frozen tissues of 26 p16-positive, 19 p16-negative OPSCCs and 18 HPV-negative oropharyngeal controls. Associations between miRNA-expression, clinicopathological characteristics and prognosis were analyzed. RESULTS: Higher miR-182-5p expression was associated with significant inferior disease-specific survival for p16-positive OPSCCs (HR = 1.98E+09, 95% CI 0-Inf; P= 0.028) and a similar trend was observed for p16-negative OPSCCs (HR = 1.56E+09, 95% CI 0-Inf; P= 0.051). Higher miR-205-5p expression was associated with an inferior progression-free survival (HR = 4.62, 95% CI 0.98-21.83; P= 0.034) and local control rate (HR = 2.18E+09, 95% CI 0-Inf; P= 0.048) for p16-positive OPSCCs. CONCLUSIONS: Results indicate that miR-182-5p and miR-205-5p can further stratify patients with p16-positive OPSCC into prognostic groups.

Surgical treatment of metastatic VIPoma: a case report.

VIPoma, a neuroendocrine tumour mostly occurring in the human pancreas and producing high levels of vasoactive intestinal peptide, is a rare disease that presents with a wide spectrum of symptoms, including intense diarrhoea, hypokalaemia, and cardiac complications, with life-threatening consequences. In most cases, metastatic lesions are present at VIPoma diagnosis. Treatment options include symptomatic therapy, chemotherapy, radiation and surgery. Due to its low incidence, there are no evidence-based therapy recommendations to date. Here, we present a case of a 39-year-old woman with severe symptoms due to VIPoma of the pancreas with diffuse hepatic metastasis, who underwent simultaneous resection of the primary tumour, extensive liver resection and radiofrequency ablation. The patient was released in good health and was recurrence-free during 12 months surveillance. According to the existing literature and our own experience, surgical procedures appear to be the most promising therapy option for cases with diffuse hepatic metastasis, offering patients relief from their symptoms and (chemo)therapy-free time.

Interferon-driven brain phenotype in a mouse model of RNaseT2 deficient leukoencephalopathy.

Infantile-onset RNaseT2 deficient leukoencephalopathy is characterised by cystic brain lesions, multifocal white matter alterations, cerebral atrophy, and severe psychomotor impairment. The phenotype is similar to congenital cytomegalovirus brain infection and overlaps with type I interferonopathies, suggesting a role for innate immunity in its pathophysiology. To date, pathophysiological studies have been hindered by the lack of mouse models recapitulating the neuroinflammatory encephalopathy found in patients. In this study, we generated Rnaset2-/- mice using CRISPR/Cas9-mediated genome editing. Rnaset2-/- mice demonstrate upregulation of interferon-stimulated genes and concurrent IFNAR1-dependent neuroinflammation, with infiltration of CD8+ effector memory T cells and inflammatory monocytes into the grey and white matter. Single nuclei RNA sequencing reveals homeostatic dysfunctions in glial cells and neurons and provide important insights into the mechanisms of hippocampal-accentuated brain atrophy and cognitive impairment. The Rnaset2-/- mice may allow the study of CNS damage associated with RNaseT2 deficiency and may be used for the investigation of potential therapies.

Human microRNA-182-5p and kinectin 1: Potential biomarkers for prognosis in oral squamous cell carcinoma.

BACKGROUND: The prognostic impact of hsa-miRNA-182-5p in oral cancer remains unexplored. Therefore, the aim of this study was to investigate the prognostic value of hsa-miRNA-182-5p and its predicted target kinectin 1 (KTN1) in oral squamous cell carcinoma (OSCC). METHOD: Expression level of hsa-miRNA-182-5p was analyzed in tumor tissue (n = 36) and healthy oral mucosal tissue (n = 17) using quantitative real-time polymerase chain reaction. Protein level of the predicted target KTN1 was detected via immunohistochemistry. Results were validated in a cohort of The Cancer Genome Atlas (TCGA). RESULTS: After dividing the data into a subgroup with high and low hsa-miRNA-182-5p expression level, a significant better overall (p = 0.016), recurrence-free (p = 0.009), and progression-free survival (p = 0.004) was observed in an upregulation of hsa-miRNA-182-5p. Staining intensity of KTN1 showed a reciprocal impact on the prognosis. Validation in a TCGA cohort confirmed these results. CONCLUSION: Our results indicate hsa-miRNA-182-5p and KTN1 as potential biomarkers for OSCC.

Cancer Stem Cell Markers in Squamous Cell Carcinomas of the Salivary Glands.

BACKGROUND: Cancer stem cells (CSC) are cells that exhibit stem cell properties and are pivotal in tumor biology. CSC markers have been described for many tumorous entities. However, to this date, there is no data on CSC markers in respect to squamous cell carcinomas (SCC) of the salivary glands. METHODS: Histologic samples from patients with salivary gland SCCs were stained for CSC markers (ALDH-1/BMI-1/SOX-2/CD-44/vimentin) and divided into high and low expression subgroups. These were then correlated with tumor and patient characteristics as well as overall survival (OS), disease-specific survival, recurrence-free survival and local control rates (LCR) after 3 and 5 years. RESULTS: Overall, 31 samples were included. CD-44 and ALDH-1 expression were associated with tumor origin (metastatic/primary disease, p = 0.048 and p = 0.011, respectively). Strong BMI-1 expression was associated with poorer OS (62.9 vs. 27.3%, p = 0.029), strong SOX-2 expression was associated with poorer LCR (62.5 vs. 21.9%, p = 0.007). CONCLUSION: CD-44 and ALDH-1 may be useful in differentiating between primary SCCs and metastatic disease. BMI-1 and SOX-2 are correlated with poorer prognosis.

Enhancer of Zeste Homolog 2 in Colorectal Cancer Development and Progression.

BACKGROUND: Colorectal cancer (CRC) is the leading gastrointestinal malignancy. The development from premalignant intraepithelial lesions leading to invasive cancer is paradigmatic for the stepwise carcinogenesis of epithelial cancers, but the knowledge of the underlying mechanism of carcinogenesis and progression of CRC is still incomplete. The understanding of epigenetic mechanisms of carcinogenesis has led to new therapeutic approaches during the last years. Enhancer of zeste homolog 2 (EZH2) is one central epigenetic silencer of the polycomb repressor complex 2 (PRC2) that is already in clinical use as a novel drug target and is associated with poorer prognosis in several cancer entities. PATIENTS AND METHODS: The protein expression of EZH2 and other members of the PRC2 as well as resulting posttranslational modifications were investigated by immunohistochemistry in 187 patients with CRC and in 94 patients with premalignant colorectal lesions and correlated with their clinical outcome. Furthermore, the corresponding mRNA expression levels were analyzed in 217 patients with rectal cancer that were enrolled in a prospective clinical trial. RESULTS: We found a weak expression of EZH2 in normal colon mucosa that increased in low grade, peaked in high grade intraepithelial neoplasia, and decreased again in invasive CRC. The posttranslational modification caused by EZH2 as a measure of EZH2 activity showed the same behavior. Strong protein and mRNA expression of EZH2 were significantly correlated with favorable prognosis in both investigated cohorts. CONCLUSION: The expression and activity of EZH2 are associated with colorectal carcinogenesis and most expressed in intraepithelial high-grade lesions. Strong expression of EZH2 is associated with a significantly favorable prognosis in patients suffering from CRC.

Intensified Histopathological Work-Up after Pancreatic Head Resection Reveals Relevant Prognostic Markers.

INTRODUCTION: Local recurrence remains a major problem after pancreatic head resection. Intensified histopathological work-up of surgical specimens after pancreatic head resection has revealed an increased number of incomplete resections (R1) depending on tumor infiltration front at the resection margins (RMs). It remains unclear to which extent the increased R1 resection rate has a clinical relevance for the patients' prognosis. MATERIALS AND METHODS: Pancreatic head resections between 2006 and 2012 were histologically intensively worked-up by a previously described protocol. The distance between the tumor infiltration front and the resection planes or organ surfaces was documented. The impact of the size of the tumor and an additional portal vein resection was analyzed. The effect of a R1 resection status on development and type of recurrence was evaluated. RESULTS: A total of 203 pancreatic head resections were evaluated. Different definitions of R1 resection were applied. These led to significantly different prognosis for patients. A greater distance between the tumor infiltration front and the resection plane or organ surface was associated with a better outcome for the patients. For the ventral surface, the mesopancreas and the pancreatic body these differences were statistically significant comparing the different R1 definitions. For the dorsal surface, a significant difference in prognosis was found if the tumor was >2 mm away from the resection surface. A tumor size of 3 cm was identified to play a relevant role for the prognosis. Patients who had a portal vein resection without a histologically proven infiltration showed a statistically significant higher overall survival. Patients with R1 resection were at highest risk for developing local recurrence as well as distant metastasis. CONCLUSION: Intensified histopathological work-up with an increased number of R1 resections has a clinical relevance for patients' prognosis. Tumors with a smaller size or with a greater distance to the organ surface or RM have a better outcome.

Cancer stem cell markers in adenocarcinoma of the salivary glands - reliable prognostic markers?

PURPOSE: Adenocarcinoma of the salivary glands is of low incidence and a broad range of histopathological subtypes. Cancer stem cell markers (CSC) might serve as novel prognostic parameters. To date, only a few studies examined the expression of CSC in adenocarcinoma of the salivary glands with diverging results. To further investigate the reliability in terms of prognostic value, a histopathological analysis of CSCs on a cohort of patients with adenocarcinomas of the major salivary glands was performed. METHODS: Tumor samples of 40 consecutive patients with adenocarcinoma of the major salivary gland treated with curative intend at one tertiary center were stained with the CSCs ALDH1, BMI-1, CD44, Nanog, and SOX2. Expression of these markers was correlated with clinicopathological parameters and survival estimates. RESULTS: Correlation of high expression of ALDH1 with higher grading (p < 0.001) and high expression of CD44 with the localization of the neoplasm (p = 0.05), larger tumor size (p = 0.006), positive pN-category (p = 0.023), and advanced UICC stage (p = 0.002) was found. Furthermore, high expression of SOX2 correlated with a negative perineural invasion (p = 0.02). No significant correlation of any investigated marker with survival estimates was observed. CONCLUSION: In conclusion, our study did not find a significant correlation of the investigated CSCs with survival estimates in adenocarcinoma of the major salivary glands. Recapitulating the results of our study in conjunction with data in the literature, the CSCs ALDH1, BMI-1, CD44, Nanog, and SOX2 do not seem to serve as reliable prognostic parameters in the treatment of adenocarcinoma of the salivary glands.

Role of cancer stem cell markers ALDH1, BCL11B, BMI-1, and CD44 in the prognosis of advanced HNSCC.

PURPOSE: Cancer stem cells (CSCs) are held accountable for the progress of head and neck squamous cell carcinoma (HNSCC). In the presented study, the authors evaluated the prognostic value of CSC markers in two particular HNSCC cohorts. METHODS: This two cohort study consisted of 85 patients with advanced stage HNSCC, treated with primary radio(chemo)therapy (pRCT), and 95 patients with HNSCC, treated with surgery and partially adjuvant radio(chemo)therapy. Overall survival (OS), disease-free survival (DFS), and disease-specific survival (DSS) were assessed. Samples were assessed for the expression of different molecular stem cell markers (ALDH1, BCL11B, BMI­1, and CD44). RESULTS: In the pRCT cohort, none of the baseline patient and tumor features exhibited a statistically significant relation with survival in either the cohort or the human papillomavirus (HPV)-stratified subcohorts. High expression of BMI­1 significantly decreased OS and DFS, while high expression of CD44 decreased all modes of survival. Multivariate analysis showed significant prognostic influence for all tested CSC markers, with high BMI­1 and CD44 decreasing survival (BMI-1: OS, DFS, DSS; CD44: OS, DFS) and high ALDH1 and BCL11B showing a beneficial effect on survival (ALDH1: OS, DFS; BCL11B: OS, DSS). In the surgical cohort, classical prognosticators such as HPV status, R1 resection, and nodal status in HPV-negative HNSCC played a significant role, but the tested CSC markers showed no significant effect on prognosis. CONCLUSION: Although validation in independent cohorts is still needed, testing for CSC markers in patients with advanced or late stage HNSCC might be beneficial, especially if many comorbidities exist or disease is irresectable. The findings might guide the development and earlier use of targeted therapies in the future.

Prognostic impact of additional HPV diagnostics in 102 patients with p16-stratified advanced oropharyngeal squamous cell carcinoma.

PURPOSE: p16 overexpression was considered as surrogate marker to identify human papillomavirus (HPV)-associated oropharyngeal squamous cell carcinoma (OPSCCs). METHODS: 102 patients with advanced stage OPSCCs treated primarily by transoral lasermicrosurgery were included. Prognostic associations of p16- and HPV-status were analyzed separately and combined. RESULTS: In contrast to p16, the HPV-status resulted in no significant survival discrepancies (5-year overall survival (OS) HPV-positive 64.9%, HPV-negative 78.7%). Combining both markers, p16-positive (p16-positive/HPV-positive, p16-positive/HPV-negative) and p16-negative/HPV-negative groups demonstrated comparable high survival (OS 78.1% vs. 85.6% vs. 73.6%). Lowest survival was observed for patients with p16-negative/HPV-positive OPSCCs (OS 40.8%). Never smoking patients with p16-positive OPSCCs demonstrated the highest survival, whereas within former/current smokers with p16-positive and p16-negative disease it was comparable low (OS 90.0% vs. 63.0% vs. 57.4%). CONCLUSIONS: p16- and HPV-status should not be considered as equivalent markers for a better prognosis. Furthermore, they should not generally predominate patient associated factors like smoking.

Pluripotent Stem Cell-Derived Mesenchymal Stem Cells Show Comparable Functionality to Their Autologous Origin.

A multimodal therapeutic approach involving radiotherapy is required when treating head and neck squamous cell carcinoma. However, radiotherapy is restricted due to its high risk for damages to the surrounding healthy tissue of the treated area. Tissue regeneration and wound healing is promoted by the survival and regenerative capacities of tissue-resident or invading stem cells. Mesenchymal stem cells (MSCs) exhibit a promising therapeutic potential in the field of cell-based tissue engineering and regenerative medicine due to their immunomodulatory properties and differentiation capacity. However, the generation of MSCs for therapeutic applications is still a major challenge. We aimed to produce highly homogeneous induced pluripotent stem cell-derived mesenchymal stem cells (iP-MSCs) in an autologous manner from initially isolated human mucosa mesenchymal stem cells (mMSCs) of the upper respiratory tract. Therefore, mMSCs were reprogrammed into induced pluripotent stem cells (iPSCs) by non-integrative chromosomal technologies and differentiated into corresponding iP-MSCs. We demonstrated that mMSCs and iP-MSCs show similar cell characteristics in terms of morphology, clonogenic potential, differentiation, and surface phenotype. Moreover, iP-MSCs demonstrated related immunosuppressive capacity as mMSCs including the secretion of cytokines, and T cell inhibition. Therefore, generating iP-MSCs in an autologous manner may be a novel personalized treatment option in regenerative medicine.

KRAS mutation status concordance between the primary tumor and the corresponding metastasis in patients with rectal cancer.

INTRODUCTION: Oncogenic mutation within the KRAS gene represents a negative predictor for treatment response to anti-epidermal growth factor receptor (EGFR) in patients with colorectal cancer. Recently, we have shown no relevant heterogeneity for KRAS mutation status within and between pre- and posttherapeutic samples from the primary tumor in patients with locally advanced rectal cancer. The aim of this study was to evaluate the intertumoral heterogeneity of KRAS mutation status between the primary tumor and the corresponding metastasis or local recurrence in the similar cohort and to evaluate the ideal representative tissue for KRAS mutation testing. MATERIALS AND METHODS: KRAS mutation status was analyzed from 47 patients with locally advanced rectal cancer, which were enrolled in the CAO/ARO/AIO-94 or CAO/ARO/AIO-04 trial. Mutations in KRAS codons 12, 13, and 61 were analyzed by using the KRAS RGQ PCR Kit (therascreen® KRAS test). Six patients needed to be excluded due to incomplete follow up data. 11 patients showed a relapse of the disease during the follow up presented by distant metastases or local recurrence. DNA from representative areas of metastatic tissue was obtained from formalin-fixed paraffin-embedded specimens. RESULTS: The mean patient age was 64.13 ± 10.64 years. In total, 19 patients showed a KRAS mutation (46.34%) in the primary tumor. Of the eleven patients with a metastatic disease or local recurrence, five patients showed a KRAS mutation whereas six patients had a KRAS wildtype status. Metastatic localizations included the liver (n = 2), lung (n = 4), local recurrence (n = 1), liver + lung (n = 3), lung + local recurrence (n = 1). For these eleven patients with paired data available for the primary tumor and metastatic tissue, a significant KRAS mutation status concordance was detected in 81.18% (9/11) of the patients (p = 0.03271). Only two patients showed intertumoral heterogeneity, which harbored in one patient a KRAS G12C mutation status in the primary tumor, but a G12V KRAS mutation status in the corresponding lung lesion, and in the other patient a G12A mutation in the primary lesion and a WT in the lung metastasis. CONCLUSIONS: We show a significant concordance of the KRAS mutation status between tumor samples obtained from the primary tumor and the corresponding metastasis and/ or local recurrence in patients with rectal cancer indicating no relevant intertumoral heterogeneity. Our data suggest that sampling either the primary (pre- or posttherapeutical tumor tissue) or metastatic lesion may be valid for the initial evaluation of KRAS mutation status predicting the response to anti-EGFR treatment and guiding clinical decisions.

Benefit of postoperative radiotherapy for early tumors with single ipsilateral lymph node metastasis.

OBJECTIVES/HYPOTHESIS: Indication for postoperative radiotherapy in patients with locally circumscribed tumors (pT1-pT2) and a single ipsilateral lymph node metastasis (pN1) is debatable. The aim of this study was to evaluate the oncological long-term outcome of patients with pT1-pT2 pN1 squamous cell carcinoma (SCC) of the oral cavity, the oropharynx, and the hypopharynx without extracapsular spread (ECS) after a margin-negative surgical resection, who either received or did not receive postoperative (chemo)radiotherapy. STUDY DESIGN: Retrospective case series. METHODS: The oncological outcome of patients with pT1-pT2 pN1 SCC without ECS was evaluated retrospectively. All patients underwent primary tumor resection that included transoral laser microsurgery and neck dissection at an academic tertiary referral center. RESULTS: Of 65 identified patients treated between 1986 and 2015 (18 oral cavity, 30 oropharynx, 17 hypopharynx), 21 (32%) received postoperative radiotherapy, and 44 (68%) were treated by surgery alone. The group of patients receiving postoperative treatment showed a significantly superior 5-year disease-specific (94.4% vs. 73.2%, P = .029) and recurrence-free survival (85.2% vs. 43.2%, P = .002), as well as a higher local control rate (90.2% vs. 64.9%, P = .042). The overall survival was 71.4% vs. 62.6% (P = .53). The mean follow-up was 80.7 months. CONCLUSIONS: Patients with locally circumscribed carcinomas and a single ipsilateral ECS-negative lymph node metastasis seem to benefit from postoperative radiotherapy. LEVEL OF EVIDENCE: 4 Laryngoscope, 130:E530-E538, 2020.