Genomic Assessment of Blood-Derived Circulating Tumor DNA in Patients With Colorectal Cancers: Correlation With Tissue Sequencing, Therapeutic Response, and Survival.

PurposeGenomic alterations in blood-derived circulating tumor DNA (ctDNA) from patients with colorectal cancers were correlated with clinical outcomes.Patients and methodsNext-generation sequencing of ctDNA (54- to 73-gene panel) was performed in 94 patients with colorectal cancer.ResultsMost patients (96%) had metastatic or recurrent disease at the time of blood draw. The median number of nonsynonymous alterations per patient was three (range, zero to 30). The most frequently aberrant genes were TP53 (52.1% of patients), KRAS (34%), and APC (28.7%). Concordance between tissue and blood next-generation sequencing ranged from 63.2% (APC) to 85.5% (BRAF). Altogether, 74 patients (79%) had one or more nonsynonymous alterations, 69 (73%) had one or more potentially actionable alterations, and 61 (65%) had an alteration actionable by a drug approved by the US Food and Drug Administration (on or off label). Lung metastases correlated with improved survival from diagnosis in univariable analysis. ctDNA of 5% or more from blood tests as well as EGFR and ERBB2 (HER2) nonsynonymous alterations correlated with worse survival (but only ERBB2 remained significant in multivariable analysis). No two patients had identical molecular portfolios. Overall, 65% versus 31% of patients treated with matched (n = 17) versus unmatched therapy (n = 18) after ctDNA testing achieved stable disease for 6 months or more, partial response, or complete response (P = .045); progression-free survival, 6.1 versus 2.3 months (P = .08); and survival not reached versus 9.4 months (P = .146; all by multivariable analysis).ConclusionPatients with colorectal cancer have heterogeneous ctDNA profiles, and most harbor potentially actionable ctDNA alterations. Matched therapy yielded higher rates of stable disease for 6 months or more, partial response, or complete response. ctDNA assessment may have clinical utility and merits further investigation

Cetuximab as Second-Line Therapy in Patients with Metastatic Esophageal Adenocarcinoma: A Phase II Southwest Oncology Group Study (S0415)

IntroductionEsophageal adenocarcinomas commonly express the epidermal growth factor receptor. This trial assessed the 6-month overall survival probability in metastatic esophageal cancer patients treated with cetuximab as second-line therapy.MethodsThis was a multicenter, open-label phase II study of single-agent cetuximab for metastatic esophageal adenocarcinoma patients who failed one prior chemotherapy regimen. Adequate organ function and Zubrod performance status of 0 to 2 were required. Patients received cetuximab 400 mg/m2 intravenously (IV) on week 1 and 250 mg/m2 IV weekly thereafter. The primary objective was to determine 6-month overall survival. Secondary end points included progression-free survival, response rate, and toxicity. Tumor tissue was collected for correlative studies.ResultsSixty-three patients were registered, with eight ineligible or never treated. Fifty-five eligible patients (49 men, 6 women; median age = 61.2 years [range, 30.7–88.5]) were enrolled. Twenty patients survived more than 6 months for a 6-month overall survival rate of 36% (95% confidence interval [CI]: 24–50%). The median overall survival was 4.0 months (95% CI: 3.2–5.9). Median progression-free survival was 1.8 months (95% CI: 1.7–1.9). One partial response and two unconfirmed partial responses were observed. Two patients experienced grade 4 fatigue. There was one treatment-related death due to pneumonitis. Germline polymorphisms of epidermal growth factor receptor, epidermal growth factor, interleukin (IL)-8, cyclooxygenase (COX)-2, vascular epidermal growth factor receptor (VEGF), CCND1, neuropilin 1 (NRP1), and K-ras mutational status were not associated with response or survival.ConclusionsThe 6-month overall survival rate of 36% observed on this study failed to meet the primary survival objective. Thus, cetuximab alone cannot be recommended in the second-line treatment of metastatic esophageal cancer