title: Effect of the 12-gene colon cancer assay results on adjuvant treatment recommendations in patients with stage II colon cancer.
abstract: BACKGROUND
  The 12-gene colon cancer Recurrence Score assay is a clinically validated predictor of recurrence risk in stage II colon cancer patients. A survey was performed characterizing the assay's impact on treatment recommendations for these patients.
  
  
  METHODS
  US medical oncologists (n = 346) who ordered the assay for ≥3 stage II colon cancer patients were asked to complete a web-based survey regarding their most recent such patient. Physicians surveyed represented users of the assay within the first 2 years of commercial availability which may include 'early adopters'.
  
  
  RESULTS
  Most of 116 eligible physicians were in community practice (86%), with median 14.5 years' experience (range = 2-40). Mean patient age was 61 years (range = 32-85); 81% had T3 disease, and 38% had comorbidities. Of 76 patients tested for mismatch-repair/microsatellite-instability (MMR/MSI), 13 (17%) were MMR-deficient/MSI-high; 46 (61%) MMR-proficient/MSI-low; and 17 (22%) unknown. Most patients (84%) had ≥12 nodes examined. Median Recurrence Score result was 20 (range = 1-77). Before assay, treatment recommendations were specified for 92 (79%) patients, with no recommendation for 24 (21%). Of the 92 with pre-assay recommendations, chemotherapy was planned for 52 (57%) and observation for 40 (43%); the assay changed recommendations for 27 (29%). Treatment intensity decreased for 18 (67%) and increased for nine (33%) patients; it was more likely to decrease for lower Recurrence Score values and increase for higher values (p < 0.001).
  
  
  CONCLUSIONS
  For stage II colon cancer patients receiving Recurrence Score testing, 29% of treatment recommendations were changed. Use of the assay may lead to reductions in treatment intensity. Study limitations include retrospective design, data gathering during the first 2 years of assay availability only, and potential non-representativeness of respondents.
authors.affiliation: Ocala Oncology , Ocala, FL , USA.
authors.forename: T
authors.initials: T
authors.lastname: Cartwright
authors.forename: C
authors.initials: C
authors.lastname: Chao
authors.forename: M
authors.initials: M
authors.lastname: Lee
authors.forename: M
authors.initials: M
authors.lastname: Lopatin
authors.forename: T
authors.initials: T
authors.lastname: Bentley
authors.forename: M
authors.initials: M
authors.lastname: Broder
authors.forename: E
authors.initials: E
authors.lastname: Chang
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use; D017024:Chemotherapy, Adjuvant; D003110:Colonic Neoplasms / Q000188:drug therapy* / Q000235:genetics*; D053843:DNA Mismatch Repair / Q000235:genetics; D005260:Female; D005820:Genetic Testing; D006801:Humans; D008297:Male; D053842:Microsatellite Instability; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000188:drug therapy; D009367:Neoplasm Staging; D017410:Practice Guidelines as Topic; D010818:Practice Patterns, Physicians'; D012189:Retrospective Studies; D011795:Surveys and Questionnaires