Pioneering use of genetic analysis for CDH1 to identify candidates for prophylactic total gastrectomy to prevent hereditary diffuse gastric cancer.

Worldwide, gastric cancer results in significant morbidity and mortality. Ten per cent of patients with gastric cancer have a strong family history of the disease. CDH1 (E-cadherin) has been identified as a key gene whose mutation leads to hereditary diffuse gastric cancer. We overviewed 33 articles with prophylactic total gastrectomy and assessed the outcomes and benefits. Families with mutations in CDH1 may benefit from early prophylactic total gastrectomy. Dr Mark Duncan has applied his experience as a high-volume gastric cancer surgeon to treat not only individual patients, but several generations of patients within a family. This use of prophylactic total gastrectomy is well tolerated by patients and prevents the future development of gastric cancer.

Colorectal Cancer Develops Inherent Radiosensitivity That Can Be Predicted Using Patient-Derived Organoids.

Identifying colorectal cancer patient populations responsive to chemotherapy or chemoradiation therapy before surgery remains a challenge. Recently validated mouse protocols for organoid irradiation employ the single hit multi-target (SHMT) algorithm, which yields a single value, the D0, as a measure of inherent tissue radiosensitivity. Here, we translate these protocols to human tissue to evaluate radioresponsiveness of patient-derived organoids (PDO) generated from normal human intestines and rectal tumors of patients undergoing neoadjuvant therapy. While PDOs from adenomas with a logarithmically expanded Lgr5+ intestinal stem cell population retain the radioresistant phenotype of normal colorectal PDOs, malignant transformation yields PDOs from a large patient subpopulation displaying marked radiosensitivity due to reduced homologous recombination-mediated DNA repair. A proof-of-principle pilot clinical trial demonstrated that rectal cancer patient responses to neoadjuvant chemoradiation, including complete response, correlate closely with their PDO D0 values. Overall, upon transformation to colorectal adenocarcinoma, broad radiation sensitivity occurs in a large subset of patients that can be identified using SHMT analysis of PDO radiation responses. SIGNIFICANCE: Analysis of inherent tissue radiosensitivity of patient-derived organoids may provide a readout predictive of neoadjuvant therapy response to radiation in rectal cancer, potentially allowing pretreatment stratification of patients likely to benefit from this approach.

A SMAD4-modulated gene profile predicts disease-free survival in stage II and III colorectal cancer.

BACKGROUND: Colorectal cancer is the second-leading cause of cancer-related mortality in the United States and a leading cause of cancer-related mortality worldwide. Loss of SMAD4, a critical tumor suppressor and the central node of the transforming growth factor-beta superfamily, is associated with worse outcomes for colorectal cancer patients; however, it is unknown whether an RNA-based profile associated with SMAD4 expression could be used to better identify high-risk colorectal cancer patients. AIM: Identify a gene expression-based SMAD4-modulated profile and test its association with patient outcome. METHODS AND RESULTS: Using a discovery dataset of 250 colorectal cancer patients, we analyzed expression of BMP/Wnt target genes for association with SMAD4 expression. Promoters of the BMP/Wnt genes were interrogated for SMAD-binding elements. Fifteen genes were implicated and three tested for modulation by SMAD4 in patient-derived colorectal cancer tumoroids. Expression of the 15 genes was used for unsupervised hierarchical clustering of a training dataset and two resulting clusters modeled in a centroid model. This model was applied to an independent validation dataset of stage II and III patients. Disease-free survival was analyzed by the Kaplan-Meier method. In vitro analysis of three genes identified in the SMAD4-modulated profile (JAG1, TCF7, and MYC) revealed modulation by SMAD4 consistent with the trend observed in the profile. In the training dataset (n = 553), the profile was not associated with outcome. However, among stage II and III patients (n = 461), distinct clusters were identified by unsupervised hierarchical clustering that were associated with disease-free survival (p = .02, log-rank test). The main model was applied to a validation dataset of stage II/III CRC patients (n = 257) which confirmed the association of clustering with disease-free survival (p = .013, log-rank test). CONCLUSIONS: A SMAD4-modulated gene expression profile identified high-risk stage II and III colorectal cancer patients, can predict disease-free survival, and has prognostic potential for stage II and III colorectal cancer patients.

Evaluating the Validity of the Clavien-Dindo Classification in Colectomy Studies: A 90-Day Cost of Care Analysis.

BACKGROUND: The Clavien-Dindo classification is widely used to report postoperative morbidity but may underestimate the severity of colectomy complications. OBJECTIVE: The purpose of this study was to assess how well the Clavien-Dindo classification represents the severity of all grades of complications after colectomy using cost of care modeling. DESIGN: This was a retrospective cohort study. SETTINGS: The study was conducted at a comprehensive cancer center. PATIENTS: Consecutive patients (N = 1807) undergoing elective colon or rectal resections without a stoma performed at Memorial Sloan Kettering Cancer Center between 2009 and 2014 who were followed up for ≥90 days, were not transferred to other hospitals, and did not receive intraperitoneal chemotherapy were included in the study. MAIN OUTCOME MEASURES: Complication severity was measured by the highest-grade complication per patient and attributable outpatient and inpatient costs. Associations were evaluated between patient complication grade and cost during 3 time periods: the 90 days after surgery, index admission, and postdischarge (<90 d). RESULTS: Of the 1807 patients (median age = 62 y), 779 (43%) had a complication; 80% of these patients had only grade 1 or 2 complications. Increasing patient complication grade correlated with 90-day cost, driven by inpatient cost differences (p < 0.001). For grade 1 and 2 patients, most costs were incurred after discharge and were the same between these grade categories. Among patients with a single complication (52%), there was no difference in index hospitalization, postdischarge, or total 90-day costs between grade 1 and 2 categories. LIMITATIONS: The study was limited by its retrospective design and generalizability. CONCLUSIONS: The Clavien-Dindo classification correlates well with 90-day costs, driven largely by inpatient resource use. Clavien-Dindo does not discriminate well among patients with low-grade complications in terms of their substantial postdischarge costs. These patients represent 80% of patients with a complication after colectomy. Examining the long-term burden associated with complications can help refine the Clavien-Dindo classification for use in colectomy studies. See Video Abstract at http://links.lww.com/DCR/B521. EVALUACIN DE LA VALIDEZ DE LA CLASIFICACIN DE CLAVIENDINDO EN ESTUDIOS DE COLECTOMA ANLISIS DEL COSTO DE LA ATENCIN EN DAS: ANTECEDENTES:La clasificación de Clavien-Dindo es utilizada ampliamante para conocer la morbilidad posoperatoria, pero puede subestimar la gravedad de las complicaciones de la colectomía.OBJETIVO:Evaluar que tan bien representa la clasificación de Clavien-Dindo la gravedad de todos los grados de complicaciones después de la colectomía utilizando un modelo de costo de la atención.DISEÑO:Estudio de cohorte retrospectivo.ENTORNO CLÍNICO:Centro oncológico integral.PACIENTES:Pacientes consecutivos (n = 1807) sometidos a resecciones electivas de colon o recto sin estoma realizadas en el Memorial Sloan Kettering Cancer Center entre 2009 y 2014 que fueron seguidos durante ≥ 90 días, no fueron transferidos a otros hospitales y no recibieron quimioterapia intraperitoneal.PRINCIPALES MEDIDAS DE VALORACION:Gravedad de la complicación medida por la complicación de mayor grado por paciente y los costos atribuibles para pacientes ambulatorios y hospitalizados. Se evaluó la asociación entre el grado de complicación del paciente y el costo durante 3 períodos de tiempo: posterior a la cirugía (hasta 90 días), a su ingreso y posterior al egreso (hasta 90 días).RESULTADOS:De los 1807 pacientes (mediana de edad de 62 años), 779 (43%) tuvieron una complicación; El 80% de estos pacientes tuvieron solo complicaciones de grado 1 o 2. El aumento del grado de complicación del paciente se correlacionó con el costo a 90 días, impulsado por las diferencias en el costo de los pacientes hospitalizados (p <0,001). Para los pacientes de grado 1 y 2, la mayoría de los costos se incurrieron después del alta y fueron los mismos entre ambas categorías. Entre los pacientes con una sola complicación (52%), no hubo diferencia en el índice de hospitalización, posterior al alta o en el costo total de 90 días entre las categorías de grado 1 y 2.LIMITACIONES:Diseño retrospectivo, generalizabilidad.CONCLUSIONES:La clasificación de Clavien-Dindo se correlaciona bien con los costos a 90 días, impulsados en gran parte por la utilización de recursos de pacientes hospitalizados. Clavien-Dindo no discrimina entre los pacientes con complicaciones de bajo grado en términos de sus costos sustanciales posterior al alta. Estos pacientes representan el 80% de los pacientes aquellos con una complicación tras la colectomía. Examinar la carga a largo plazo asociada a las complicaciones puede ayudar a mejorar la clasificación de Clavien-Dindo para su uso en estudios de colectomía. Consulte Video Resumen en http://links.lww.com/DCR/B521.

A Claudin-Based Molecular Signature Identifies High-Risk, Chemoresistant Colorectal Cancer Patients.

Identifying molecular characteristics that are associated with aggressive cancer phenotypes through gene expression profiling can help predict treatment responses and clinical outcomes. Claudins are deregulated in colorectal cancer (CRC). In CRC, increased claudin-1 expression results in epithelial-to-mesenchymal transition and metastasis, while claudin-7 functions as a tumor suppressor. In this study, we have developed a molecular signature based on claudin-1 and claudin-7 associated with poor patient survival and chemoresistance. This signature was validated using an integrated approach including publicly available datasets and CRC samples from patients who either responded or did not respond to standard-of-care treatment, CRC cell lines, and patient-derived rectal and colon tumoroids. Transcriptomic analysis from a patient dataset initially yielded 23 genes that were differentially expressed along with higher claudin-1 and decreased claudin-7. From this analysis, we selected a claudins-associated molecular signature including PIK3CA, SLC6A6, TMEM43, and ASAP-1 based on their importance in CRC. The upregulation of these genes and their protein products was validated using multiple CRC patient datasets, in vitro chemoresistant cell lines, and patient-derived tumoroid models. Additionally, blocking these genes improved 5-FU sensitivity in chemoresistant CRC cells. Our findings propose a new claudin-based molecular signature that associates with poor prognosis as well as characteristics of treatment-resistant CRC including chemoresistance, metastasis, and relapse.

KRAS mutant rectal cancer cells interact with surrounding fibroblasts to deplete the extracellular matrix.

Somatic mutations in the KRAS oncogene are associated with poor outcomes in locally advanced rectal cancer but the underlying biologic mechanisms are not fully understood. We profiled mRNA in 76 locally advanced rectal adenocarcinomas from patients that were enrolled in a prospective clinical trial and investigated differences in gene expression between KRAS mutant (KRAS-mt) and KRAS-wild-type (KRAS-wt) patients. We found that KRAS-mt tumors display lower expression of genes related to the tumor stroma and remodeling of the extracellular matrix. We validated our findings using samples from The Cancer Genome Atlas (TCGA) and also by performing immunohistochemistry (IHC) and immunofluorescence (IF) in orthogonal cohorts. Using in vitro and in vivo models, we show that oncogenic KRAS signaling within the epithelial cancer cells modulates the activity of the surrounding fibroblasts in the tumor microenvironment.

Mismatch Repair-Deficient Rectal Cancer and Resistance to Neoadjuvant Chemotherapy.

PURPOSE: Evaluate response of mismatch repair-deficient (dMMR) rectal cancer to neoadjuvant chemotherapy. EXPERIMENTAL DESIGN: dMMR rectal tumors at Memorial Sloan Kettering Cancer Center (New York, NY) were retrospectively reviewed for characteristics, treatment, and outcomes. Fifty patients with dMMR rectal cancer were identified by IHC and/or microsatellite instability analysis, with initial treatment response compared with a matched MMR-proficient (pMMR) rectal cancer cohort. Germline and somatic mutation analyses were evaluated. Patient-derived dMMR rectal tumoroids were assessed for chemotherapy sensitivity. RESULTS: Of 21 patients receiving neoadjuvant chemotherapy (fluorouracil/oxaliplatin), six (29%) had progression of disease. In comparison, no progression was noted in 63 pMMR rectal tumors (P = 0.0001). Rectal cancer dMMR tumoroids reflected this resistance to chemotherapy. No genomic predictors of chemotherapy response were identified. Of 16 patients receiving chemoradiation, 13 (93%) experienced tumor downstaging; one patient had stable disease, comparable with 48 pMMR rectal cancers. Of 13 patients undergoing surgery, 12 (92%) had early-stage disease. Forty-two (84%) of the 50 patients tested positive for Lynch syndrome with enrichment of germline MSH2 and MSH6 mutations when compared with 193 patients with Lynch syndrome-associated colon cancer (MSH2, 57% vs 36%; MSH6, 17% vs 9%; P < 0.003). CONCLUSIONS: Over one-fourth of dMMR rectal tumors treated with neoadjuvant chemotherapy exhibited disease progression. Conversely, dMMR rectal tumors were sensitive to chemoradiation. MMR status should be performed upfront in all locally advanced rectal tumors with careful monitoring for response on neoadjuvant chemotherapy and genetic testing for Lynch syndrome in patients with dMMR rectal cancer.

A rectal cancer organoid platform to study individual responses to chemoradiation.

Rectal cancer (RC) is a challenging disease to treat that requires chemotherapy, radiation and surgery to optimize outcomes for individual patients. No accurate model of RC exists to answer fundamental research questions relevant to patients. We established a biorepository of 65 patient-derived RC organoid cultures (tumoroids) from patients with primary, metastatic or recurrent disease. RC tumoroids retained molecular features of the tumors from which they were derived, and their ex vivo responses to clinically relevant chemotherapy and radiation treatment correlated with the clinical responses noted in individual patients' tumors. Upon engraftment into murine rectal mucosa, human RC tumoroids gave rise to invasive RC followed by metastasis to lung and liver. Importantly, engrafted tumors displayed the heterogenous sensitivity to chemotherapy observed clinically. Thus, the biology and drug sensitivity of RC clinical isolates can be efficiently interrogated using an organoid-based, ex vivo platform coupled with in vivo endoluminal propagation in animals.

Genomic stratification beyond Ras/B-Raf in colorectal liver metastasis patients treated with hepatic arterial infusion.

BACKGROUND: Resection of colorectal liver metastases (CLM) can cure disease, but many patients with extensive disease cannot be fully resected and others recur following surgery. Hepatic arterial infusion (HAI) chemotherapy can convert extensive liver disease to a resectable state or decrease recurrence risk, but response varies and no biomarkers currently exist to identify patients most likely to benefit. METHODS: We performed a retrospective cohort study of CLM patients receiving HAI chemotherapy whose tumors underwent MSK-IMPACT sequencing. The frequency of oncogenic alterations and their association with overall survival (OS) and objective response rate were analyzed at the individual gene and signaling pathway levels. RESULTS: Three hundred and seventy patients met inclusion criteria: 189 (51.1%) who underwent colorectal liver metastasectomy followed by HAI + systemic therapy (Adjuvant cohort), and 181 (48.9%) with unresectable CLM (Metastatic cohort) who received HAI + systemic therapy, consisting of 63 (34.8%) with extrahepatic disease and 118 (65.2%) with liver-restricted disease. Genomic alterations were similar in each cohort, and no individual gene or pathway was significantly associated with objective response. Patients in the adjuvant cohort with concurrent Ras/B-Raf alteration and SMAD4 inactivation had worse prognosis while in the metastatic cohort patients with co-alteration of Ras/B-Raf and TP53 had worse OS. Similar findings were observed in a validation cohort. CONCLUSIONS: Concurrently altered Ras/B-Raf and SMAD4 mutations were associated with worse survival in resectable patients, while concurrent Ras/B-Raf and TP53 alterations were associated with worse survival in unresectable patients. The mutual exclusivity of Ras/B-Raf, SMAD4, and TP53 may have prognostic value for CLM patients receiving HAI.

SMAD4 Loss in Colorectal Cancer Patients Correlates with Recurrence, Loss of Immune Infiltrate, and Chemoresistance.

PURPOSE: SMAD4 has shown promise in identifying patients with colorectal cancer at high risk of recurrence or death.Experimental Design: A discovery cohort and independent validation cohort were classified by SMAD4 status. SMAD4 status and immune infiltrate measurements were tested for association with recurrence-free survival (RFS). Patient-derived xenografts from SMAD4-deficient and SMAD4-retained tumors were used to examine chemoresistance. RESULTS: The discovery cohort consisted of 364 patients with stage I-IV colorectal cancer. Median age at diagnosis was 53 years. The cohort consisted of 61% left-sided tumors and 62% stage II/III patients. Median follow-up was 5.4 years (interquartile range, 2.3-8.2). SMAD4 loss, noted in 13% of tumors, was associated with higher tumor and nodal stage, adjuvant therapy use, fewer tumor-infiltrating lymphocytes (TIL), and lower peritumoral lymphocyte aggregate (PLA) scores (all P < 0.04). SMAD4 loss was associated with worse RFS (P = 0.02). When stratified by SMAD4 and immune infiltrate status, patients with SMAD4 loss and low TIL or PLA had worse RFS (P = 0.002 and P = 0.006, respectively). Among patients receiving 5-fluorouracil (5-FU)-based systemic chemotherapy, those with SMAD4 loss had a median RFS of 3.8 years compared with 13 years for patients with SMAD4 retained. In xenografted mice, the SMAD4-lost tumors displayed resistance to 5-FU. An independent cohort replicated our findings, in particular, the association of SMAD4 loss with decreased immune infiltrate, as well as worse disease-specific survival. CONCLUSIONS: Our data show SMAD4 loss correlates with worse clinical outcome, resistance to chemotherapy, and decreased immune infiltrate, supporting its use as a prognostic marker in patients with colorectal cancer.

MASTL induces Colon Cancer progression and Chemoresistance by promoting Wnt/ß-catenin signaling.

BACKGROUND: Chemotherapeutic agents that modulate cell cycle checkpoints and/or tumor-specific pathways have shown immense promise in preclinical and clinical studies aimed at anti-cancer therapy. MASTL (Greatwall in Xenopus and Drosophila), a serine/threonine kinase controls the final G2/M checkpoint and prevents premature entry of cells into mitosis. Recent studies suggest that MASTL expression is highly upregulated in cancer and confers resistance against chemotherapy. However, the role and mechanism/s of MASTL mediated regulation of tumorigenesis remains poorly understood. METHODS: We utilized a large patient cohort and mouse models of colon cancer as well as colon cancer cells to determine the role of Mastl and associated mechanism in colon cancer. RESULTS: Here, we show that MASTL expression increases in colon cancer across all cancer stages compared with normal colon tissue (P < 0.001). Also, increased levels of MASTL associated with high-risk of the disease and poor prognosis. Further, the shRNA silencing of MASTL expression in colon cancer cells induced cell cycle arrest and apoptosis in vitro and inhibited xenograft-tumor growth in vivo. Mechanistic analysis revealed that MASTL expression facilitates colon cancer progression by promoting the ß-catenin/Wnt signaling, the key signaling pathway implicated in colon carcinogenesis, and up-regulating anti-apoptotic proteins, Bcl-xL and Survivin. Further studies where colorectal cancer (CRC) cells were subjected to 5-fluorouracil (5FU) treatment revealed a sharp increase in MASTL expression upon chemotherapy, along with increases in Bcl-xL and Survivin expression. Most notably, inhibition of MASTL in these cells induced chemosensitivity to 5FU with downregulation of Survivin and Bcl-xL expression. CONCLUSION: Overall, our data shed light on the heretofore-undescribed mechanistic role of MASTL in key oncogenic signaling pathway/s to regulate colon cancer progression and chemo-resistance that would tremendously help to overcome drug resistance in colon cancer treatment.

Test-retest reliability of freesurfer measurements within and between sites: Effects of visual approval process.

In the last decade, many studies have used automated processes to analyze magnetic resonance imaging (MRI) data such as cortical thickness, which is one indicator of neuronal health. Due to the convenience of image processing software (e.g., FreeSurfer), standard practice is to rely on automated results without performing visual inspection of intermediate processing. In this work, structural MRIs of 40 healthy controls who were scanned twice were used to determine the test-retest reliability of FreeSurfer-derived cortical measures in four groups of subjects-those 25 that passed visual inspection (approved), those 15 that failed visual inspection (disapproved), a combined group, and a subset of 10 subjects (Travel) whose test and retest scans occurred at different sites. Test-retest correlation (TRC), intraclass correlation coefficient (ICC), and percent difference (PD) were used to measure the reliability in the Destrieux and Desikan-Killiany (DK) atlases. In the approved subjects, reliability of cortical thickness/surface area/volume (DK atlas only) were: TRC (0.82/0.88/0.88), ICC (0.81/0.87/0.88), PD (0.86/1.19/1.39), which represent a significant improvement over these measures when disapproved subjects are included. Travel subjects' results show that cortical thickness reliability is more sensitive to site differences than the cortical surface area and volume. To determine the effect of visual inspection on sample size required for studies of MRI-derived cortical thickness, the number of subjects required to show group differences was calculated. Significant differences observed across imaging sites, between visually approved/disapproved subjects, and across regions with different sizes suggest that these measures should be used with caution.