Prospective multicenter study of the impact of oncotype DX colon cancer assay results on treatment recommendations in stage II colon cancer patients.
The Oncotype DX colon cancer assay is a clinically validated predictor of recurrence risk in stage II colon cancer patients. This prospective study evaluated the impact of recurrence score (RS) results on physician recommendations regarding adjuvant chemotherapy in T3, mismatch repair-proficient (MMR-P) stage II colon cancer patients. Patients and Methods. Stage IIA colon cancer patients were enrolled in 17 centers. Patient tumor specimens were assessed by the RS test (quantitative reverse transcription-polymerase chain reaction) and mismatch repair (immunohistochemistry). For each patient, the physician's recommended postoperative treatment plan of observation, fluoropyrimidine monotherapy, or combination therapy with oxaliplatin was recorded before and after the RS and mismatch repair results were provided. Results. Of 221 enrolled patients, 141 patients had T3 MMR-P tumors and were eligible for the primary analysis. Treatment recommendations changed for 63 (45%; 95% confidence interval: 36%-53%) of these 141 T3 MMR-P patients, with intensity decreasing for 47 (33%) and increasing for 16 (11%). Recommendations for chemotherapy decreased from 73 patients (52%) to 42 (30%), following review of RS results by physician and patient. Increased treatment intensity was more often observed at higher RS values, and decreased intensity was observed at lower values (p = .011). Conclusion. Compared with traditional clinicopathological assessment, incorporation of the RS result into clinical decision making was associated with treatment recommendation changes for 45% of T3 MMR-P stage II colon cancer patients in this prospective multicenter study. Use of the RS assay may lead to overall reduction in adjuvant chemotherapy use in this subgroup of stage II colon cancer patients.
Mayo Clinic, Rochester, Minnesota, USA, Medical Oncology and Hematology Associates, Des Moines, Iowa, USA; Genomic Health, Inc., Redwood City, California, USA; Alegent Bergan Mercy Cancer Center, Omaha, Nebraska, USA; Cancer Center of Kansas, Wichita, Kansas, USA; Toledo Clinic, Toledo, Ohio, USA; Columbus Oncology Associates, Columbus, Ohio, USA; Mayo Clinic, Jacksonville, Florida, USA; Sanford Hospital, Sioux Falls, South Dakota, USA.
Geetika
G
Srivastava
Lindsay A
LA
Renfro
Robert J
RJ
Behrens
Margarita
M
Lopatin
Calvin
C
Chao
Gamini S
GS
Soori
Shaker R
SR
Dakhil
Rex B
RB
Mowat
J Philip
JP
Kuebler
George
G
Kim
Miroslaw
M
Mazurczak
Mark
M
Lee
Steven R
SR
Alberts
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000970:Antineoplastic Agents / Q000627:therapeutic use; D024221:Antineoplastic Protocols; D001681:Biological Assay; D014408:Biomarkers, Tumor / Q000235:genetics; D017024:Chemotherapy, Adjuvant / Q000706:statistics & numerical data; D003110:Colonic Neoplasms / Q000175:diagnosis / Q000628:therapy*; D003657:Decision Making; D003661:Decision Support Techniques; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local; D009944:Organoplatinum Compounds / Q000627:therapeutic use; D000077150:Oxaliplatin; D011446:Prospective Studies; D020133:Reverse Transcriptase Polymerase Chain Reaction
D000970:Antineoplastic Agents; D014408:Biomarkers, Tumor; D009944:Organoplatinum Compounds; D000077150:Oxaliplatin
Adjuvant; Chemotherapy; Colon cancer; Decision analysis; Risk assessment