Clinical utility of Oncotype DX in early stage colon cancer.

Abstract

e15076 Background: With the advent of colon cancer screening, patients with early stage colon cancer will be more common in our clinics. The evidence supporting the absolute benefit of chemotherapy in resected Stage II and (to a lesser extent) Stage IIIA disease is poor. Not all patients benefit from chemotherapy and toxicity is a problem. There is a need for validated biomarkers to assess individual patient recurrence risk and discriminate absolute treatment benefit. Several studies have validated the role of the OncotypeDX testing in Stage II/IIIA disease. Our objective is to characterize whether this test impacted oncologists’ decisions in treating patients with Stage II/IIIA in the adjuvant setting. Methods: :The Onco typeDX assay is a multi-gene reverse-transcriptase-polymerase-chain-reaction test that analyses the expression of 12 genes involved in key biologic pathways in colon cancer. Stage II and Stage IIIA colon cancers were studied in affiliated hospitals of our region in southwest Ireland. All data collected is prospective and each colon cancer was assigned a recurrence risk score. Oncologists were blinded to this score and the decision to prescribe adjuvant chemotherapy was recorded. After un-blinding the score, a second decision was recorded and comparisons made. Results: :From August 2015 to September 2016, 70 patients have been recruited with M: F of 2:1. Median age at diagnosis was 65 years. Most patients (80%) had stage II disease, 11 of whom had mismatch repair loss on IHC. OncotypeDX testing has been carried out and reported for 59 patients (85%), MMR intact. Recurrence scores: < 30 in 46 patients (77.9%), 30-40 in 10 patients, and > 40 in 3 patients. The treatment plan was altered in 16 patients (27%), of whom 12 patients (20%) received none or less intense chemotherapy. Conclusions: We have shown that the decision to prescribe adjuvant chemotherapy was changed in 27% of patients. This test has helped to define patients with low scores, where chemotherapy-related toxicity is a concern especially in older patients. Absolute benefit of adjuvant chemotherapy versus the risk of toxicity should be discussed. . Hospital managers may be interested in cost savings due to a reduction in chemotherapy use.

Current Achievements and Applications of Transcriptomics in Personalized Cancer Medicine

“…The similar assays are being tested in prognosis of colon cancer. The twin test of Oncotype DX ® used in breast cancer – 12-gene Oncotype DX ® Colon Cancer Assay identifies the tumors with high risk of recurrence and helps to determine the necessity of implementation of adjuvant systemic therapy [ 182 , 183 , 184 ]. In the study of Aziz et.…”

Adjuvant Therapy for Stages II and III Colon Cancer: Risk Stratification, Treatment Duration, and Future Directions

“…The data from the National Surgical Adjuvant Breast and Bowel Project C-07 study suggest that genomic profiling using the Oncotype dx assay (Genomic Health, Redwood City, CA, U.S.A.) might improve risk prognostication in high-risk resected stage ii and iii colon cancers 39 . A recent study demonstrated that Oncotype dx results altered the decision about adjuvant chemotherapy use in 27% of patients with stages ii and iiia-b crcs and that its results might be applicable in decision-making for adjuvant therapy in elderly patients 40 .…”