Colon Recurrence Score Result, MMR Status, and T-Stage
The QUASAR study demonstrated that, in addition to Colon Recurrence Score result, other variables significantly related to risk of recurrence were T4 versus T3 stage, and MMR deficient versus proficient. The prognostic information provided by the Colon Recurrence Score result will have the greatest utility when used as a complement to T-stage, and MMR status, specifically for patients who have T3, MMR-proficient, Stage II disease.
MMR Testing for Recurrence Risk Assessment
Genomic Health® is pleased to announce the expansion of its Oncotype DX® Colon Recurrence Score offering to include immunohistochemistry (IHC) testing to assess mismatch repair (MMR) status for Stage II colon cancer recurrence risk*. Health care providers are now able to order Oncotype DX Colon Recurrence Score and MMR at the same time in a convenient one-step process by selecting the Sequential Assay option on the Oncotype DX Colon Recurrence Score requisition form. Results from the recently published QUASAR validation study strongly support a paradigm in which the Oncotype DX Colon Recurrence Score result, MMR status, and T-stage are used to determine recurrence risk for individual patients with Stage II colon cancer. The QUASAR study results, which are highly consistent with several other published studies, demonstrate that MMR testing is clinically useful for identifying the ~15% of Stage II patients with MMR-Deficient (MMR-D) tumor biology who have low recurrence risk. MMR testing also enables the identification of the patients with T3 MMR-Proficient (MMR-P) tumors, standard risk patients constituting the majority (~70%) of Stage II colon cancer in whom the Colon Recurrence Score result provides valuable recurrence risk discrimination not available with conventional clinical and pathologic factors. When you select the Sequential Assay option, if your patient’s MMR status is MMR-D which is associated with a low risk of recurrence, Oncotype DX Colon Recurrence Score will not be run. The Oncotype DX Colon Recurrence Score will only be tested on your T3 MMR-P patients. With MMR status and the Colon Recurrence Score result for the individual Stage II colon cancer patient, you will have a more complete picture of each patient’s unique tumor biology and important information needed to make a more informed, individualized treatment plan following surgery.
T-Stage and Outcome
T-Stage and Outcome in Stage II Colon Cancer – SEER database 1991-2000
- T-Stage has been recognized as an important prognostic factor for Stage II colon cancer
- In 119,363 colon cancer patients from the SEER database, the 5-year risk of death was 15.3% in patients with T3 disease as compared to 27.8% for those with T4 tumors
- Patients with T3 disease have a risk of death similar to the overall Stage II colon cancer population (15.3% versus 17% respectively)
- The unmet need remains with the 83% of Stage II colon cancer patients with T3 tumors, who are known to be a heterogeneous population with a wide range of individual risk but as a group are currently considered to be standard risk. This proportion of T3 tumors in SEER is consistent with the 85% found in both the QUASAR study and multivariate QUASAR analysis.
Next: Individualized Risk Assessment