How would urine-based mutational screening be of continued benefit in treating this patient?
BERZ:We have identified circulating tumor DNA fragments in the serum. Recently, we have identified that those tumor DNA fragments also are filtrated into the urine, where we identify them in a higher concentration than we see them in the serum in the first place.
BONOMI:This is important for patients who have a low tumor burden and where their circulating tumor DNA may be particularly low. In those patients, you might have a fairly high concentration of DNA in the urine and, utilizing a liquid biopsy, will be able to perform the genomic analyses.
BERZ:The identification of those molecular changes like the T790M mutation allows the primary identification of a mutation in the urine and the appropriate treatment can be selected. It also allows an easy way to establish a molecular response if we identify the mutational burden at a certain level in the urine initially. This way, medical professionals can expose the patient to the appropriate treatment who would very much expect this mutational burden in the urine to decline very soon after therapy.
BONOMI:I think liquid biopsies will be particular useful in providing care for patients. We believe that looking at the circulating DNA might give a better indication of what is actually going on in that tumor.
The other part of liquid biopsies is looking at serum protein panels, which may be something very important to tell us what's going on in the patient. The tumors aren't existing in a vacuum. They are interacting with inflammatory cells and immune cells. Possibly a serum DNA signature along with a serum protein signature may be something that is useful in taking care of patients in the coming years.
Naoko T. is a 74-year-old retired high school teacher originally from Nagoya, Japan. She currently lives in San Diego, California and enjoys tennis and traveling with her husband.
In November 2014, after several months of stable disease, the patient returns for follow-up visit with worsening back pain, and her CT scan is consistent with progression of metastatic lesions.
At this point, the patient declined further treatment, and by March 2015, she returned with worsening dyspnea and declining performance status