A new study from Johns Hopkins shows that by sampling oral tissue from patients with a history of head and neck cancer doctors can predict with some accuracy the presence of a recurrence or of another primary tumor (presumably from the oropharynx). I found a couple of things about this report fascinating – first, the oropharyngeal tissue was not obtained by performing blind biopsies, which requires general anesthesia and O.R. time. Rather, the cells were collected by the patients themselves in a simple manner – gargling and spitting, and who doesn’t love to do that, especially while watching a presidential debate? Actually the instructions were to scrape the inside of the mouth with a brush and then after gargling with 20cc of salt water, spit into a specimen container.
The second interesting fact is what the researchers did with the collected cells in order to predict the risk of recurrence.
A specialized form of polymerase chain reaction allows the detection of hypermethylated tumor suppressor genes in the salivary rinse. Hypermethylation prevents transcription of a gene — essentially turning it off — without altering the DNA code.
In this study, the researchers enrolled 211 patients whose median age was 57.8 — mostly men with a history of alcohol and tobacco use. The control group was slightly older — a median age of 61 — but also included mostly men with a history of alcohol and tobacco use.
From the initial set of 21 genes, eight were selected as part of a panel to distinguish salivary rinses from patients and healthy controls, the researchers said. They found that various combinations of three or four genes gave better detection than single genes, including one panel with 35% sensitivity and 90% specificity and a panel with 85% sensitivity and 30% specificity.
If scientists can identify a gene expression profile with both high sensitivity and specificity this test could be useful in following patients after treatment for head and neck cancer, or in screening high-risk groups, and if the test is a simple brush, gargle and spit it can be widely used.
Say, what exactly is a “high-risk group” for the development of head and neck cancer anyway?