AACR, Author Interviews, Biomarkers, Chemotherapy, Colon Cancer, MD Anderson / 10.11.2015
Plasma cfDNA Can Monitor Response To Metastatic Colon Cancer Treatment
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Dr. Morris[/caption]
MedicalResearch.com Interview with:
Van K. Morris, M.D.
Assistant Professor, GI Medical Oncology
University of Texas – M.D. Anderson Cancer Center
Houston, TX 77030
Medical Research: What is the background for this study? What are the main findings?
Dr. Van K Morris: BRAF V600E mutations are associated with poor clinical outcomes for patients with metastatic colorectal cancer. Patients were enrolled in a phase I clinical trial with the BRAF inhibitor vemurafenib, the anti-EGFR antibody cetuximab, and irinotecan. Blood samples were collected every two weeks with each dose, and plasma was analyzed for changes in the fraction of mutant BRAF V600E allele relative to wild-type BRAF allele with time. Trends in circulating free DNA (cfDNA) changes were compared with radiographic changes by RECIST 1.1 criteria to examine this technique as a marker for response to therapy.
For patients who had a response radiographically, drastic reductions in the BRAF V600E allele fraction were observed even after two weeks of starting therapy, well before the first restaging scan. Patients who did not have responses radiographically had less dramatic changes relative to baseline in the BRAF V600E allele fraction. This technique analyzing cfDNA from plasma was validated using two different approaches – digital droplet PCR and next-generation sequencing by Guardant Health. Sequencing of cfDNA was also compared in pretreatment and post-progression samples, and novel mutations in MEK1 and GNAS were observed uniquely in post-progression samples.
Dr. Morris[/caption]
MedicalResearch.com Interview with:
Van K. Morris, M.D.
Assistant Professor, GI Medical Oncology
University of Texas – M.D. Anderson Cancer Center
Houston, TX 77030
Medical Research: What is the background for this study? What are the main findings?
Dr. Van K Morris: BRAF V600E mutations are associated with poor clinical outcomes for patients with metastatic colorectal cancer. Patients were enrolled in a phase I clinical trial with the BRAF inhibitor vemurafenib, the anti-EGFR antibody cetuximab, and irinotecan. Blood samples were collected every two weeks with each dose, and plasma was analyzed for changes in the fraction of mutant BRAF V600E allele relative to wild-type BRAF allele with time. Trends in circulating free DNA (cfDNA) changes were compared with radiographic changes by RECIST 1.1 criteria to examine this technique as a marker for response to therapy.
For patients who had a response radiographically, drastic reductions in the BRAF V600E allele fraction were observed even after two weeks of starting therapy, well before the first restaging scan. Patients who did not have responses radiographically had less dramatic changes relative to baseline in the BRAF V600E allele fraction. This technique analyzing cfDNA from plasma was validated using two different approaches – digital droplet PCR and next-generation sequencing by Guardant Health. Sequencing of cfDNA was also compared in pretreatment and post-progression samples, and novel mutations in MEK1 and GNAS were observed uniquely in post-progression samples.


Dr. Cooper[/caption]
MedicalResearch.com Interview with:
Lauren Cooper, MD
Fellow in Cardiovascular Diseases
Duke University Medical Center
Duke Clinical Research Institute
Medical Research: What is the background for this study? What are the main findings?
Dr. Cooper: Heart failure guidelines recommend routine monitoring of serum potassium and renal function in patients treated with a mineralocorticoid receptor antagonist (MRA). Specific monitoring recommendations include: within 2-3 days of initiation of the drug, again at 7 days, monthly for at least 3 months, then every 3 months thereafter. However, no large studies had evaluated compliance with these safety recommendations in routine clinical practice. Using Medicare claims data from 2011, we evaluated monitoring of serum creatinine and potassium levels among patients with heart failure initiated on an MRA.
After MRA initiation, rates of guideline-recommended laboratory monitoring of creatinine and potassium were low. Of 10,443 Medicare beneficiaries included in this study, 91.6% received pre-initiation testing; however, only 13.3% received appropriate testing in the first 10 days after drug initiation and 29.9% received appropriate testing in the first 3 months. Only 7.2% of patients received guideline-recommended laboratory monitoring both before and after MRA initiation. Chronic kidney disease was associated with a greater likelihood of appropriate testing (relative risk, 1.83; 95% CI, 1.58-2.13), as was concomitant diuretic use (relative risk, 1.78; 95% CI, 1.44-2.21).
MedicalResearch.com Interview with:
Dr. Priscilla Kaliopi Brastianos MD
Instructor, Medicine, Harvard Medical School
Assistant Physician in Medicine
Hematology/Oncology, Massachusetts General Hospital
Medical Research: What is the background for this study? What are the main findings?
Response: Craniopharyngiomas are rare brain tumors that can cause serious problems because of their location near critical structures in the brain, such as optic and other cranial nerves, the pituitary gland and the hypothalamus. Not only does the growing tumor compromise neurological and hormonal functions by impinging on these structures, but treatment by surgical removal or radiation therapy can produce the same symptoms by damaging adjacent tissues. In addition, since the tumor adheres to these nearby critical structures, complete removal is difficult, which can lead rapid recurrence. Medical therapies have not been effective for craniopharyngiomas, namely because we did not understand the molecular underpinnings of these tumors. Last year, we performed genomic characterization of craniopharyngiomas, with the goal to identify potential therapeutic targets. We were surprised to find that nearly all papillary craniopharyngiomas have BRAF mutations, which are the same mutations that have been found in 
















