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Shi, Qian

0000-0002-4640-8832

Mayo Clinic

Mayo Clinic

Citations 126

Microsatellite Instability in Patients With Stage III Colon Cancer Receiving Fluoropyrimidine With or Without Oxaliplatin: An ACCENT Pooled Analysis of 12 Adjuvant Trials
Cohen, Romain , Taı̈eb, Julien , Fiskum, Jack, Yothers, Greg , Goldberg, Richard M. , Yoshino, Takayuki , Alberts, Steven R. , Allegra, Carmen J. , Gramont, Aimery de , Seitz, J. F., Haller, Daniel G. , Erlichman, Charles , Zaniboni, Alberto , Shi, Qian , Goldberg, Richard M , Alberts, Steven R , O'Connell, Michael, Lonardi, Sara , Sinicrope, Frank A , André, Thierry , Shi, Qian , Yoshino, Takayuki , Yothers, Greg , Taieb, Julien , Cohen, Romain , O’Connell, Michael J. , Wolmark, Norman , Lonardi, Sara , Kerr, Rachel , Grothey, Axel , Sinicrope, Frank A. , André, Thierry

Journal of Clinical Oncology | December 23, 2020 | Volume: 39 | Issue: 6 | Pages: 642-651

10.1200/jco.20.01600 Get It

PURPOSE: In patients with stage III colon cancer (CC) whose tumors demonstrate microsatellite instability (MSI), the efficacy of adjuvant fluoropyrimidine (FP) with or without oxaliplatin has not been clearly demonstrated and the prognostic value of MSI remains uncertain. MATERIALS AND METHODS: Individual patient data from the ACCENT database were used to evaluate the effect of FP with or without oxaliplatin on disease-free survival (DFS) and overall survival (OS) among patients with MSI stage III CC and the prognostic value of MSI in patients treated with FP plus oxaliplatin, by stratified Cox models adjusted for demographic and clinicopathological factors. RESULTS: MSI status was available for 5,457 patients (609 MSI, 11.2%; 4848 microsatellite stable [MSS], 88.8%) from 12 randomized clinical trials (RCTs). Oxaliplatin significantly improved OS of MSI patients from the two RCTs testing FP with or without oxaliplatin (n = 185; adjusted hazard ratio [aHR] = 0.52, 95% CI, 0.28 to 0.93). Among the 4,250 patients treated with FP plus oxaliplatin (461 MSI and 3789 MSS), MSI was associated with better OS in the N1 group compared with MSS (aHR = 0.66; 95% CI, 0.46 to 0.95) but similar survival in the N2 population (aHR = 1.13; 95% CI, 0.86 to 1.48; P interaction = .029). The main independent prognosticators of MSI patients treated with FP plus oxaliplatin were T stage (aHR = 2.09; 95% CI, 1.29 to 3.38) and N stage (aHR = 3.57; 95% CI, 2.32 to 5.48). Similar results were observed for DFS in all analyses. CONCLUSION: Adding oxaliplatin to FP improves OS and DFS in patients with MSI stage III CC. Compared with MSS, MSI patients experienced better outcomes in the N1 group but similar survival in the N2 group.
Genetic Predictors of Severe Skin Toxicity in Patients with Stage III Colon Cancer Treated with Cetuximab: NCCTG N0147 (Alliance)
Labadie, Julia , Hua, Xinwei , Harrison, Tabitha A. , Banbury, Barbara L. , Huyghe, Jeroen R. , Sun, Wei , Shi, Qian , Yothers, Greg , Sinicrope, Frank A. , Goldberg, Richard M. , George, Thomas J. , Phipps, Amanda I. , Peters, Ulrike , Sinicrope, Frank A , Goldberg, Richard M , George, Thomas J , Cohen, Stacey A , Sun, Wei , Harrison, Tabitha A , Shi, Qian , Yothers, Greg , Alberts, Steven R. , Penney, Kathryn , Cohen, Stacey A. , Chan, Andrew T. , Newcomb, Polly A.

Cancer Epidemiology, Biomarkers & Prevention | November 17, 2020 | Volume: 30 | Issue: 2 | Pages: 404-411

10.1158/1055-9965.epi-20-1274 Get It

Abstract Background: Cetuximab, an EGFR inhibitor used to treat multiple cancer types, including colon cancer, causes severe skin toxicity in 5%–20% of patients, leading to decreased quality of life and treatment delays. Our understanding of which patients have an increased risk of severe toxicities is limited. We conducted a genome-wide association study to identify germline variants predictive of cetuximab-induced severe skin toxicity. Methods: Our study included 1,209 patients with stage III colon cancer randomized to receive cetuximab plus 5-fluorouracil and oxaliplatin as part of the NCCTG N0147 (Alliance) clinical trial. Skin toxicity outcomes were collected using the Common Toxicity Criteria for Adverse Events version 3.0. We performed genotyping, evaluating approximately 10 million genetic variants. We used logistic regression to evaluate the association of each genetic variant and severe (grade ≥ 3) skin toxicity, adjusting for age, sex, and genetic ancestry. Genome-wide significance was defined as P < 5 × 10−8. Results: Participants were predominantly middle-aged white men; 20% (n = 243) experienced severe skin toxicity. Two genetic variants in the retinoic acid receptor alpha (RARA) gene were significantly associated with severe skin toxicity [OR, 3.93; 95% confidence interval (CI), 2.47–6.25; P < 7.8 × 10−9]. Functional annotations indicate these variants are in the RARA promoter. Additional significantly associated variants were identified in chromosome 2 intergenic regions. Conclusions: Identified variants could represent a potential target for risk stratification of patients with colon cancer receiving cetuximab. Impact: Retinoids have shown promise in the treatment of cetuximab-induced skin toxicity, so follow-up work could evaluate whether individuals with the RARA variant would benefit from retinoid therapy.
Adverse event load, onset, and maximum grade: A novel method of reporting adverse events in cancer clinical trials
Lopes, Guilherme S. , Tournigand, Christophe , Olswold, Curtis L., Cohen, Romain , Kempf, Emmanuelle , Goldberg, Richard M. , Hurwitz, Herbert I. , Fuchs, Charles S. , Gramont, Aimery de , Shi, Qian , Shi, Qian , Cohen, Romain , Lopes, Guilherme S , Saltz, Leonard B.

Clinical Trials | October 1, 2020 | Volume: 18 | Issue: 1 | Pages: 51-60

10.1177/1740774520959313 Get It

Background Current adverse event reporting practices do not document longitudinal characteristics of adverse effects, and alternative methods are not easily interpretable and have not been employed by clinical trials. Introducing time parameters in the evaluation of safety that are comprehensive yet easily interpretable could allow for a better understanding of treatment quality. In this study, we developed and applied a novel adverse event reporting method based on longitudinal adverse event changes to aid describing, summarizing, and presenting adverse event profile. We termed it the “Adverse Event Load, Onset, and Maximum Grade” method. Methods We developed two adverse event summary metrics to complement the traditional maximum grade report. Onset time indicates the time period in which the maximum grade for a specific adverse event occurred and was defined as “early” (i.e. maximum grade happened for the first time before 6 weeks) or “late” (i.e. after the 6 th week). Adverse event load indicates the overall severity of a specific adverse event over the entire treatment. Higher adverse event load indicates a worse overall experience. These metrics can be calculated for adverse events with different maximum grades, in treatments with planned changes (e.g. dosage changes), using data sets with different number of adverse event data points between treatments (e.g. treatments with longer cycle lengths may have less adverse event data points) and on data sets with different adverse event data availability (e.g. cycle basis and patient-outcome reports). We tested the utility of this method using individual patient data from two major backbone therapies (“Irinotecan” and “Oxaliplatin”) from the N9741 trial available in the Fondation ARCAD database ( fondationarcad.org ). We investigated profiles of diarrhea, neutropenia/leukopenia, and nausea/vomiting. Results Our method provided additional information compared to traditional adverse event reports. For example, for nausea/vomiting, while patients in Irinotecan had a higher risk of experiencing maximum grade 3–4 (15.6% vs 7.6%, respectively; p < 0.001), patients in both groups experienced similar severity over time (adverse effect load = 0.102 and 0.096, respectively; p = 0.26), suggesting that patients in Oxaliplatin experienced a lower-grade but more persistent nausea/vomiting. For neutropenia/leukopenia, more patients in Irinotecan experienced their maximum grade for the first time early in the treatment compared to patients in Oxaliplatin (67.9% vs 41.7%; p < 0.001), regardless of maximum grade. Longitudinal information can help compare treatments or guide clinicians on choosing appropriate interventions for low-grade but persistent adverse event or early adverse event onset. Conclusion We developed an adverse event reporting method that provides clinically relevant information about treatment toxicity by incorporating two longitudinal adverse event metrics to the traditional maximum grade approach. Future research should establish clinical benchmarks for metrics included in this adverse event reporting method.
Sex and Adverse Events of Adjuvant Chemotherapy in Colon Cancer: An Analysis of 34 640 Patients in the ACCENT Database
Wagner, Dorothea , André, Thierry , Dixon, Jesse G. , Haller, Daniel G. , Allegra, Carmen J. , Gramont, Aimery de , VanCutsem, Eric, George, Thomas J. , Twelves, Christopher , Taı̈eb, Julien , Blanke, Charles D. , Francini, Edoardo , Yothers, Greg , Seitz, Jean François, Marsoni, Silvia , Goldberg, Richard M. , Shi, Qian , George, Thomas J , André, Thierry , Shi, Qian , Yothers, Greg , Taieb, Julien , Marsoni, Silvia , Dixon, Jesse G , Grothey, Axel , Wolmark, Norman , Alberts, Steven R. , O’Connell, Michael J. , Saltz, Leonard B. , Kerr, Rachel

JNCI: Journal of the National Cancer Institute | August 19, 2020 | Volume: 113 | Issue: 4 | Pages: 400-407

10.1093/jnci/djaa124 Get It

Abstract Background Adjuvant chemotherapy is a standard treatment option for patients with stage III and high-risk stage II colon cancer. Sex is one of several factors responsible for the wide inter-patient variability in drug responses. Amalgamated data on the effect of sex on the toxicity of current standard adjuvant treatment for colorectal cancer are missing. Methods The objective of our study was to compare incidence and severity of major toxicities of fluoropyrimidine- (5FU or capecitabine) based adjuvant chemotherapy, with or without oxaliplatin, between male and female patients after curative surgery for colon cancer. Adult patients enrolled in 27 relevant randomized trials included in the ACCENT (Adjuvant Colon Cancer End Points) database, a large, multi-group, international data repository containing individual patient data, were included. Comparisons were conducted using logistic regression models (stratified by study and treatment arm) within each type of adjuvant chemotherapy (5FU, FOLFOX, capecitabine, CAPOX, and FOLFIRI). The following major toxicities were compared (grade III or IV and grade I-IV, according to National Cancer Institute Common Terminology Criteria [NCI-CTC] criteria, regardless of attribution): nausea, vomiting, nausea or vomiting, stomatitis, diarrhea, leukopenia, neutropenia, thrombocytopenia, anemia, and neuropathy (in patients treated with oxaliplatin). Results Data from 34 640 patients were analyzed. Statistically significant and clinically relevant differences in the occurrence of grade III or IV nonhematological {especially nausea (5FU: odds ratio [OR] = 2.33, 95% confidence interval [CI] = 1.90 to 2.87, P &lt; .001; FOLFOX: OR = 2.34, 95% CI = 1.76 to 3.11, P &lt; .001), vomiting (5FU: OR = 2.38, 95% CI = 1.86 to 3.04, P &lt; .001; FOLFOX: OR = 2.00, 95% CI = 1.50 to 2.66, P &lt; .001; CAPOX: OR = 2.32, 95% CI = 1.55 to 3.46, P &lt; .001), and diarrhea (5FU: OR = 1.35, 95% CI = 1.21 to 1.51, P &lt; .001; FOLFOX: OR = 1.60, 95% CI = 1.35 to 1.90, P &lt; .001; FOLFIRI: OR = 1.57, 95% CI = 1.25 to 1.97, P &lt; .001)} as well as hematological toxicities (neutropenia [5FU: OR = 1.55, 95% CI = 1.37 to 1.76, P &lt; .001; FOLFOX: OR = 1.96, 95% CI = 1.71 to 2.25, P &lt; .001; FOLFIRI: OR = 2.01, 95% CI = 1.66 to 2.43, P &lt; .001; capecitabine: OR = 4.07, 95% CI = 1.84 to 8.99, P &lt; .001] and leukopenia [5FU: OR = 1.74, 95% CI = 1.40 to 2.17, P &lt; .001; FOLFIRI: OR = 1.75, 95% CI = 1.28 to 2.40, P &lt; .001]) were observed, with women being consistently at increased risk. Conclusions Our analysis confirms that women with colon cancer receiving adjuvant fluoropyrimidine-based chemotherapy are at increased risk of toxicity. Given the known sex differences in fluoropyrimidine pharmacokinetics, sex-specific dosing of fluoropyrimidines warrants further investigation.
Immunotherapy for Early Stage Colorectal Cancer: A Glance into the Future
Cohen, Romain , Shi, Qian , André, Thierry , André, Thierry , Shi, Qian , Cohen, Romain

Cancers | July 22, 2020 | Volume: 12 | Issue: 7 | Pages: 1990

10.3390/cancers12071990 Get It

Immune checkpoint inhibitors (ICI) have reshaped therapeutic strategies for cancer patients. The development of ICI for early stage colorectal cancer is accompanied by specific challenges: (i) the selection of patients who are likely to benefit from these treatments, i.e., patients with tumors harboring predictive factors of efficacy of ICI, such as microsatellite instability and/or mismatch repair deficiency (MSI/dMMR), or other potential parameters (increased T cell infiltration using Immunoscore® or others, high tumor mutational burden, POLE mutation), (ii) the selection of patients at risk of disease recurrence (poor prognostic features), and (iii) the choice of an accurate clinical trial methodological framework. In this review, we will discuss the ins and outs of clinical research of ICI for early stage MSI/dMMR CC patients in adjuvant and neoadjuvant settings. We will then summarize data that might support the development of ICI in localized colorectal cancer beyond MSI/dMMR.
International prognostic indices in diffuse large B-cell lymphoma: a comparison of IPI, R-IPI, and NCCN-IPI
Ruppert, Amy S. , Dixon, Jesse G. , Salles, Gilles , Wall, Anna, Cunningham, David , Poeschel, Viola, Tilly, Hervé , Ghesquières, Hervé , Ziepert, Marita , Flament, Jocelyne, Flowers, Christopher R. , Shi, Qian , Schmitz, Norbert , Shi, Qian , Salles, Gilles A , Cunningham, David , Dixon, Jesse G , Haïoun, Corinne

Blood | March 31, 2020 | Volume: 135 | Issue: 23 | Pages: 2041-2048

10.1182/blood.2019002729 Get It

Abstract Great heterogeneity in survival exists for patients newly diagnosed with diffuse large B-cell lymphoma (DLBCL). Three scoring systems incorporating simple clinical parameters (age, lactate dehydrogenase, number/sites of involvement, stage, performance status) are widely used: the International Prognostic Index (IPI), revised IPI (R-IPI), and National Comprehensive Cancer Network IPI (NCCN-IPI). We evaluated 2124 DLBCL patients treated from 1998 to 2009 with frontline rituximab plus cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP; or variant) across 7 multicenter randomized clinical trials to determine which scoring system best discriminates overall survival (OS). Median age was 63 years, and 56% of patients were male. Five-year OS estimates ranged from 54% to 88%, from 61% to 93%, and from 49% to 92% using the IPI, R-IPI, and NCCN-IPI, respectively. The NCCN-IPI had the greatest absolute difference in OS estimates between the highest- and lowest-risk groups and best discriminated OS (concordance index = 0.632 vs 0.626 [IPI] vs 0.590 [R-IPI]). For each given IPI risk category, NCCN-IPI risk categories were significantly associated with OS (P ≤ .01); the reverse was not true, and the IPI did not provide additional significant prognostic information within all NCCN-IPI risk categories. Collectively, the NCCN-IPI outperformed the IPI and R-IPI. Patients with low-risk NCCN-IPI had favorable survival outcomes with little room for further improvement. In the rituximab era, none of the clinical risk scores identified a patient subgroup with long-term survival clearly &lt;50%. Integrating molecular features of the tumor and microenvironment into the NCCN-IPI or IPI might better characterize a high-risk group for which novel treatment approaches are most needed.
Contribution of Immunoscore and Molecular Features to Survival Prediction in Stage III Colon Cancer
Sinicrope, Frank A. , Shi, Qian , Hermitte, Fabienne , Mlecnik, Bernhard , Benson, Al B. , Goldberg, Richard M. , Kahlenberg, Morton S., Nair, Suresh , Shields, Anthony F. , Smyrk, Thomas C. , Mlecnik, Bernhard , Goldberg, Richard M , Shields, Anthony F , Alberts, Steven R , Sinicrope, Frank A , Shi, Qian , Zemla, Tyler , Gill, Sharlene , Galon, Jérôme , Alberts, Steven R.

JNCI Cancer Spectrum | March 24, 2020 | Volume: 4 | Issue: 3 | Pages: No page available

10.1093/jncics/pkaa023 Get It

Abstract Background The American Joint Committee on Cancer staging and other prognostic tools fail to account for stage-independent variability in outcome. We developed a prognostic classifier adding Immunoscore to clinicopathological and molecular features in patients with stage III colon cancer. Methods Patient (n = 559) data from the FOLFOX arm of adjuvant trial NCCTG N0147 were used to construct Cox models for predicting disease-free survival (DFS). Variables included age, sex, T stage, positive lymph nodes (+LNs), N stage, performance status, histologic grade, sidedness, KRAS/BRAF, mismatch repair, and Immunoscore (CD3+, CD8+ T-cell densities). After determining optimal functional form (continuous or categorical) and within Cox models, backward selection was performed to analyze all variables as candidate predictors. All statistical tests were two-sided. Results Poorer DFS was found for tumors that were T4 vs T3 (hazard ratio [HR] = 1.76, 95% confidence interval [CI] = 1.19 to 2.60; P = .004), right- vs left-sided (HR = 1.52, 95% CI = 1.14 to 2.04; P = .005), BRAF V600E (HR = 1.74, 95% CI = 1.26 to 2.40; P &lt; .001), mutant KRAS (HR = 1.66, 95% CI = 1.08 to 2.55; P = .02), and low vs high Immunoscore (HR = 1.69, 95% CI = 1.22 to 2.33; P = .001) (all P &lt; .02). Increasing numbers of +LNs and lower continuous Immunoscore were associated with poorer DFS that achieved significance (both Ps&lt; .0001). After number of +LNs, T stage, and BRAF/KRAS, Immunoscore was the most informative predictor of DFS shown multivariately. Among T1–3 N1 tumors, Immunoscore was the only variable associated with DFS that achieved statistical significance. A nomogram was generated to determine the likelihood of being recurrence-free at 3 years. Conclusions The Immunoscore can enhance the accuracy of survival prediction among patients with stage III colon cancer.
Threshold Change in CEA as a Predictor of Non-Progression to First-Line Systemic Therapy in Metastatic Colorectal Cancer Patients With Elevated CEA
Gulhati, Pat , Yin, Jun , Pederson, Levi , Schmoll, Hans‐Joachim , Hoff, Paulo M. , Douillard, Jean‐Yves , Hecht, J. Randolph, Tournigand, Christophe , Tebbut, Niall, Chibaudel, Benoist , Gramont, Aimery de , Shi, Qian , Overman, Michael J. , Shi, Qian , Schmoll, Hans-Joachim , Chibaudel, Benoist

JNCI: Journal of the National Cancer Institute | March 16, 2020 | Volume: 112 | Issue: 11 | Pages: 1127-1136

10.1093/jnci/djaa020 Get It

Abstract Background Carcinoembryonic antigen (CEA) levels are used in conjunction with imaging to monitor response to systemic therapy in metastatic colorectal cancer (mCRC). We sought to identify a threshold for CEA change from baseline to predict progressive disease (PD) in mCRC patients receiving first-line therapy. Methods Patients from trials collected in the ARCAD database were included if baseline CEA was at least 10 ng/mL and repeat CEA was available within 14 days of first restaging scan. Optimal cutoffs for CEA change were identified by receiver operating characteristic analysis. Prediction performance of cutoffs was evaluated by sensitivity, specificity, and negative predictive value. Analyses were conducted by treatment class: chemotherapy alone, chemotherapy with anti-VEGF antibody, and chemotherapy with anti-EGFR antibody. Results A total of 2643 mCRC patients treated with systemic therapy were included. Median percent change of CEA from baseline to first restaging for patients with complete response, partial response, or stable disease (non-PD) and PD was −53.1% and +23.6% for chemotherapy alone (n = 957) and −71.7% and −45.3% for chemotherapy with anti-VEGF antibody (n = 1355). The optimal area under the curve cutoff for differentiating PD from non-PD on first restaging was −7.5% for chemotherapy alone and −62.0% for chemotherapy with anti-VEGF antibody; chemotherapy alone, adjusted odds ratio = 6.51 (95% CI = 3.31 to 12.83, P &lt; .001), chemotherapy with anti-VEGF antibody, adjusted odds ratio = 3.45 (95% CI = 1.93 to 6.18, P &lt; .001). A 99% negative predictive value clinical cutoff for prediction of non-PD would avoid CT scan at first restaging in 21.0% of chemotherapy alone and 16.2% of chemotherapy with anti-VEGF antibody–treated patients. Among patients with stable disease on first restaging, those with decreased CEA from baseline had statistically significantly improved progression-free and overall survival. Conclusions Change in CEA from baseline to first restaging can accurately predict non-progression and correlates with long-term outcomes in patients receiving systemic chemotherapy.
Developing an FHIR-Based Computational Pipeline for Automatic Population of Case Report Forms for Colorectal Cancer Clinical Trials Using Electronic Health Records
Zong, Nansu , Stone, Daniel J. , Yu, Yue , Shi, Qian , Jiang, Guoqian , Sharma, Deepak K, Shi, Qian , Wen, Andrew , Sharma, Deepak , Wang, Chen , Liu, Hongfang

JCO Clinical Cancer Informatics | March 5, 2020 | Volume: No volume available | Issue: 4 | Pages: 201-209

10.1200/cci.19.00116 Get It

PURPOSE The Fast Healthcare Interoperability Resources (FHIR) is emerging as a next-generation standards framework developed by HL7 for exchanging electronic health care data. The modeling capability of FHIR in standardizing cancer data has been gaining increasing attention by the cancer research informatics community. However, few studies have been conducted to examine the capability of FHIR in electronic data capture (EDC) applications for effective cancer clinical trials. The objective of this study was to design, develop, and evaluate an FHIR-based method that enables the automation of the case report forms (CRFs) population for cancer clinical trials using real-world electronic health records (EHRs). MATERIALS AND METHODS We developed an FHIR-based computational pipeline of EDC with a case study for modeling colorectal cancer trials. We first leveraged an existing FHIR-based cancer profile to represent EHR data of patients with colorectal cancer, and then we used the FHIR Questionnaire and QuestionnaireResponse resources to represent the CRFs and their data population. To test the accuracy of and overall quality of the computational pipeline, we used synoptic reports of 287 Mayo Clinic patients with colorectal cancer from 2013 to 2019 with standard measures of precision, recall, and F1 score. RESULTS Using the computational pipeline, a total of 1,037 synoptic reports were successfully converted as the instances of the FHIR-based cancer profile. The average accuracy for converting all data elements (excluding tumor perforation) of the cancer profile was 0.99, using 200 randomly selected records. The average F1 score for populating nine questions of the CRFs in a real-world colorectal cancer trial was 0.95, using 100 randomly selected records. CONCLUSION We demonstrated that it is feasible to populate CRFs with EHR data in an automated manner with satisfactory performance. The outcome of the study provides helpful insight into future directions in implementing FHIR-based EDC applications for modern cancer clinical trials.
Clinical Outcomes in Patients With Colon Cancer With Microsatellite Instability of Sporadic or Familial Origin Treated With Adjuvant FOLFOX With or Without Cetuximab: A Pooled Analysis of the PETACC8 and N0147 Trials
Shi, Qian , Taı̈eb, Julien , Meyers, Jeffrey P., Smyrk, Thomas C. , Julié, Catherine , Zawadi, Ayman, Mini, Enrico , Goldberg, Richard M. , Folprecht, Gunnar , Laethem, Jean‐Luc Van , Malicot, Karine Le , Laurent‐Puig, Pierre , Zaanan, Aziz , Shi, Qian , Taieb, Julien , Laurent-Puig, Pierre , Alberts, Steven R. , Tabernero, Josep , Sargent, Daniel J. , Sinicrope, Frank A.

JCO Precision Oncology | February 26, 2020 | Volume: No volume available | Issue: 4 | Pages: 116-127

10.1200/po.19.00237 Get It

PURPOSE The microsatellite instability (MSI) or deficient mismatch repair (dMMR) phenotype is usually regarded as a single biologic entity, given the absence of comparative analyses regarding prognosis and response to chemotherapy between sporadic and familial dMMR cancers. PATIENTS AND METHODS Patients with stage III colon cancers were randomly assigned to FOLFOX (leucovorin, fluorouracil, and oxaliplatin) with or without cetuximab in 2 large adjuvant phase III trials (N = 5,577). Among patients with MSI and KRAS exon 2 wild-type (WT) tumors, the prognostic and predictive impacts of sporadic versus familial dMMR cancers and BRAF V600E mutational status were determined. Multivariable Cox proportional hazards models were used to assess disease-free survival (DFS) by treatment arm, adjusting for age, sex, tumor grade, Eastern Cooperative Oncology Group performance status, pT/pN stage, and primary tumor location. RESULTS Among patients with MSI status with complete data for dMMR mechanism analysis (n = 354), 255 (72%) had sporadic ( BRAF mutation and/or MLH1 methylation) and 99 (28%) had familial tumors ( BRAF WT and unmethylated MLH1 or loss of MSH2/MSH6/PMS2 protein expression). A large proportion of dMMR sporadic tumors were mutated for BRAF (n = 200). In patients treated with FOLFOX, DFS did not differ statistically by dMMR mechanism, whereas in patients treated with FOLFOX plus cetuximab, those with sporadic tumors had worse DFS than those with familial cancers (multivariable hazard ratio, 2.69; 95% CI, 1.02 to 7.08; P = .04). Considering the predictive utility, the interaction between treatment and dMMR mechanism was significant ( P = .03). Furthermore, a nonsignificant trend toward a deleterious effect of adding cetuximab to FOLFOX was observed in patients with BRAF-mutant but not BRAF WT tumors. CONCLUSION The addition of cetuximab to adjuvant FOLFOX was associated with shorter DFS in patients with sporadic dMMR colon cancer. Additional studies are needed to validate these results in metastatic disease.