A cross-sectional study comparing a blood test for methylated BCAT1 and IKZF1 tumor-derived DNA with CEA for detection of recurrent colorectal cancer
CANCER MEDICINE
Authors: Young, Graeme P.; Pedersen, Susanne K.; Mansfield, Scott; Murray, David H.; Baker, Rohan T.; Rabbitt, Philippa; Byrne, Susan; Bambacas, Libby; Hollington, Paul; Symonds, Erin L.
Abstract
Recurrence will develop in 30-50% of colorectal cancer (CRC) cases despite apparent clearance following treatment. Carcinoembryonic antigen (CEA) is the only guideline-recommended blood test for monitoring cases for recurrence, but its sensitivity and specificity are suboptimal. This observational study compared a novel 2-gene (methylated BCAT1 and IKZF1 DNA) blood test with CEA for detection of recurrent CRC. We conducted a paired comparison of the BCAT1/IKZF1 test with CEA (cut-off 5 ng/mL) in blood from patients in remission after treatment for primary CRC and undergoing surveillance. Blood collected in the 12 months prior to or 3 months after complete investigational assessment of recurrence status were assayed and the results compared by Mc-Nemar's test. Of 397 patients enrolled, 220 underwent satisfactory assessment for recurrence and 122 had blood testing performed within the prescribed period. In 28 cases with recurrent CRC, CEA was positive in 9 (32%; 95% CI 16-52%) compared to 19 (68%; 95% CI 48-84%) positive for methylated BCAT1/IKZF1 (P = 0.002). All samples that were CEA positive were also BCAT1/IKZF1 positive. In 94 patients without clinically detectable recurrence, CEA was positive in 6 (6%, 95% CI 2-13%) and BCAT1/IKZF1 in 12 (13%, 95% CI 7-21%), P = 0.210. The odds ratio of a positive CEA test for recurrence was 6.9 (95% CI 2-22) compared to 14.4 (5-39) for BCAT1/IKZF1. The BCAT1/IKZF1 test was more sensitive for recurrence than CEA and the odds of recurrence given a positive test was twice that of CEA. The BCAT1/IKZF1 test should be further considered for monitoring cases for recurrence.
Refining risk classification in childhood B acute lymphoblastic leukemia: results of DFCI ALL Consortium Protocol 05-001
BLOOD ADVANCES
Authors: Vrooman, Lynda M.; Blonquist, Traci M.; Harris, Marian H.; Stevenson, Kristen E.; Place, Andrew E.; Hunt, Sarah K.; O'Brien, Jane E.; Asselin, Barbara L.; Athale, Uma H.; Clavell, Luis A.; Cole, Peter D.; Kelly, Kara M.; Laverdiere, Caroline; Leclerc, Jean-Marie; Michon, Bruno; Schorin, Marshall A.; Sulis, Maria Luisa; Welch, Jennifer J. G.; Neuberg, Donna S.; Sallan, Stephen E.; Silyerman, Lewis B.
Abstract
Dana-Farber Cancer Institute (DFCI) ALL Consortium Protocol 05-001 tested a new risk stratification system in children and adolescents with newly diagnosed acute lymphoblastic leukemia (ALL). At study entry, B-ALL patients were classified as standard risk (SR) or high risk (HR) based on age, white blood cell (WBC) count, and central nervous system status. After achieving complete remission (CR), patients with high end-induction minimal residual disease (MRD) (>10(-3) by polymerase chain reaction analysis of patient-specific antigen receptor rearrangements) and/or adverse cytogenetics (KMT2A rearrangement or hypodiploidy) were reclassified as very high risk (VHR) and received intensified therapy. IKZF1 deletion status was retrospectively evaluated by multiplex ligation-dependent probe amplification. Between 2005 and 2011, 678 Philadelphia chromosome-negative B-ALL patients aged 1 to 18 years enrolled; 651 achieved CR and 648 received a final risk group. Among all 678 patients, 5-year event-free survival (EFS) was 87% (95% confidence interval [CI], 84-89) and overall survival 93% (95% CI, 90-94). Five-year disease-free survival of SR patients (N = 407) was 94% (95% CI, 91-96), HR (N = 176) was 84% (95% CI, 77-88), and VHR (N = 65) was 79% (95% CI, 67-87). IKZF1 deletion was present in 62 of 385 (16%) assessed patients and was associated with inferior 5-year EFS (63%; 95% CI, 49%-74% vs 88%; 95% CI, 84%-91%; P < .001), and higher 5-year cumulative incidence of relapse, including among those with low MRD (24% vs 8%, P = .001). In multivariable analysis, age >= 15 years, WBC >= 50 x 10(9)/L, IKZF1 deletion, and MRD >= 10(-4) was each associated with inferior outcome. In conclusion, risk-stratified therapy on DFCI 05-001 resulted in favorable outcomes for B-ALL patients, including those with VHR features. IKZF1 deletion was an independent predictor of inferior outcome.