Clinical Chemistry Podcast

Metastatic or recurrent cancers are a common cause of death among cancer patients.  Genomic investigations of cancer over the past 10 years have led to tremendous advancement in the understanding of the underlying biology and in the development of targeted treatment options.  Much of the discovery has been focused on primary treatment-naive cancers, since biological specimens for genomic analysis are more abundant in these cases that are available from patients with metastatic cancers. The lack of specimens has provided a significant obstacle in the genomic study of metastatic cancers.  Therefore, a recent study by Dr. Dan Robinson and colleagues reported in the journal Nature has raised excitement.  The investigators performed integrative analysis of DNA and RNA data for 500 metastatic lesions obtained from cancer patients with over 30 different primary cancer diagnoses to derive several types of molecular characterizations.  Though further studies are needed, applying these approaches to individual patients

Surgery is a common form of treatment in patients with solid tumors.  Depending on the cancer, surgery may be used to remove cancer that is contained within a specific area, to debulk a tumor, or to ease symptoms caused by a tumor.  In each case, it is critical to distinguish cancerous from noncancerous tissue during the operation. Today, pathologists perform rapid microscopic investigations of biopsied tissue and make the diagnosis.  In the future, this may be conducted using mass spectrometry based measurements.  Ambient ionization mass spectrometry methods make localized molecular level chemical analysis of tissue samples possible at atmospheric pressure and without prior sample purification and pre-treatment.  Over the past decades, scientific advances have extended the role of these methods from the research laboratory to the operating room.  The April 2018 issue of Clinical Chemistry includes a commentary on the different technologies and their potential in cancer diagnosis.

Cardiac troponin measured with newer generations of analytically highly sensitive assays have been investigated in accelerated discharge protocols on the assumption that they have an improved ability to detect and quantify cardiomyocyte injury more quickly than previous generation’s assays. In the May 2018 issue of Clinical Chemistry, Dr. Jaimi Greenslade from the Royal Brisbane and Women’s Hospital in Herston, Australia, and her colleagues investigated a high sensitivity cardiac troponin I assay to see if a single test threshold can safely rule out acute MI.

Amniocentesis is a common procedure usually performed to collect cells from the fetus to allow testing for abnormal chromosomes.  Cells from the amniotic fluid are collected through centrifugation, cultured, and after about two weeks, analyzed by fluorescent in situ hybridization, or FISH, or with a microarray to detect abnormal chromosome copy number changes or large chromosomal structural rearrangements.  These tests have become the gold standard for detecting Down Syndrome and several other serious birth defects because they have a low false positive rate.  However, they are unable to detect the majority of birth defects.Amniocentesis is a common procedure usually performed to collect cells from the fetus to allow testing for abnormal chromosomes.  Cells from the amniotic fluid are collected through centrifugation, cultured, and after about two weeks, analyzed by fluorescent in situ hybridization, or FISH, or with a microarray to detect abnormal chromosome copy number changes or large chromosomal structura

High-density lipoprotein, or HDL, cholesterol is often referred to as the “good” cholesterol due to its involvement in transport of cholesterol from peripheral tissues back to the liver during reverse cholesterol transport.  However, some studies have demonstrated that the size and composition of HTL particles may influence the mechanism and capacity for this cholesterol efflux and other possible protective activities.  So, some researchers believe that measurement of HTL particles, size, and composition may provide an indication of HTL protective activity. The March 2018 issue of Clinical Chemistry published a report comparing five different procedures for HDL particle measurement.  In the same issue an editorial by Dr. Jeffrey Meeusen appeared titled “Comparing Measures of HDL: On the Right Path with the Wrong Map.”

Data on biological variation can be used in many ways, most notably for the diagnosis and monitoring of disease and also for setting analytical performance specifications.  In 2014, after the first strategic conference of the European Federation of Clinical Chemistry and Laboratory Medicine, a task force was established to develop criteria for evaluation of the literature on biological variation. A report from this group appears in the March 2018 issue of Clinical Chemistry.