A blood test may one day replace invasive tissue biopsies as a pain-free way to confirm lung cancer and guide treatment, new research suggests.

According to investigators, the test is as effective as a tissue biopsy in diagnosing advanced non-small cell lung cancer, by far the leading form of the leading cancer killer.

A convincing argument

The so-called “liquid biopsy” can also quickly identify tumour gene mutations that match targeted drug therapies — potentially boosting patient survival.

The new findings present “a convincing argument for use of the liquid biopsy as a first option for molecular testing in advanced non-small cell lung cancer,” said lead researcher Dr Vassiliki Papadimitrakopoulou. She’s professor of thoracic head and neck medical oncology at the University of Texas MD Anderson Cancer Center.

As the Houston team explained, if a CT scan suggests lung cancer, patients are typically asked to undergo a surgical tissue biopsy. It’s an expensive, invasive procedure that comes with risks and inconvenience to patients.

Seeking a way around these procedures, numerous companies have been developing blood-based diagnostic tests for lung cancer. The new study focuses on one such test, called Guardant360, developed by Guardant Health, the company that funded the new study.

Blood tests like Guardant360 rely on traces of tumour DNA in blood for clues to the presence of lung cancer and the best way to treat it.

In addition to the higher accuracy found in the new study, the researchers reported that the results of the blood test can be turned around sooner than those of a tissue biopsy.

Higher response rates

While results for a standard biopsy took 15 days to process, results of the liquid biopsy took just nine days, on average, the study found.

That means treatment could begin sooner, with potentially better outcomes, the researchers said.

Speedier genetic analysis of the tumour is crucial, the investigators explained, because 30% of lung cancers can now be successfully treated with new gene-targeted medicines. These drugs tend to have higher response rates than standard chemotherapy.

For the study, Papadimitrakopoulou and her colleagues used Guardant360 to identify mutant genes in the blood of nearly 300 patients.

Specifically, the tests were focused on seven “biomarkers” in blood samples — tumour-specific gene mutations that can help identify subtypes of lung cancer.

The Guardant360 test also looked for one biomarker — called KRAS — that helps predict a cancer patient’s prognosis, the research team said.

The blood test seemed to outperform standard tissue biopsy. While the standard surgical biopsy found at least one marker predictive of lung cancer in 60 patients, the blood test spotted it in 89 patients, the findings showed.

Study limitations

Drugs that target many of these lung tumour gene mutations are already approved by the US Food and Drug Administration, the researchers noted.

Among the more than 190 patients who did not show the presence of one of the seven genetic tumour biomarkers, testing was often still able to spot the KRAS prognostic biomarker, the study team said.

Again, the blood test beat tissue biopsy in this regard: The Guardant360 test spotted the KRAS biomarker in 92 patients, compared with 24 patients who underwent standard biopsy.

Still, the new study was limited in two ways. First, Guardant360 results weren’t compared to the results of the very latest gene-based surgical biopsy analyses. And secondly, the results apply only to the Guardant360 test — not to other liquid biopsies already out there.

One lung cancer specialist was still heartened by the results, however.

“For years, we have been doing surgical biopsies, but over the last few years there’s been a recognition that this is more a ‘molecular disease’, governed by [gene] mutations,” said Dr Richard Lazzaro, chief of thoracic surgery at Lenox Hill Hospital in New York City.

It’s also been known that cancer cells can shed their DNA into the blood, he said.

A better therapeutical paradigm

“If you can make diagnosis and treating decisions and save time, that’s outstanding for patient care,” Lazzaro said.

Effective treatment, delivered sooner after diagnosis, should improve survival, he added.

Already, liquid biopsies are often being used in tandem with surgical biopsies, Lazzaro noted.

However, “perhaps one day they will replace a surgical biopsy and may become a better therapeutical paradigm,” he said.

The results of the study are to be presented at the American Association for Cancer Research meeting, in Atlanta. Findings presented at medical meetings are typically considered preliminary until published in a peer-reviewed journal.

According to the American Cancer Society, lung cancer remains the number one cancer killer in the United States, with nearly 143 000 deaths expected in 2019.

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Did you hear what happened when Bill Gates walked into a bar? Everybody there immediately became millionaires – on average.

That joke about a very rich man is an old one among statisticians. So why did Peter Smibert use it to explain a revolution in biology?

‘Mushed-up average’

Because it shows averages can be misleading. And Smibert, of the New York Genome Center, says that includes when scientists are trying to understand the basic unit of life, the cell.

Until recently, trying to study key traits of cells from people and other animals often meant analysing bulk samples of tissue, producing a mushed-up average of results from many cell types. It was like trying to learn about a banana by studying a strawberry-blueberry-orange-banana smoothie.

In recent years, however, scientists have developed techniques that let them directly study the DNA codes, the activity of genes and other traits of individual cells. The approach has become widely adopted, revealing details about the body that couldn’t be shown before. And it has opened the door to pursuing an audacious goal: listing every cell type in the human body.

“Single-cell analysis is crucial for a comprehensive understanding of our biology and health,” Dr Francis Collins, the director of the National Institutes of Health, declared recently.

In fact, the journal Science named the techniques that allow single-cell tracking of gene activity over time in developing organisms and organs as its “breakthrough of the year” for 2018. Its announcement declared, “The single-cell revolution is just starting.”

Even complicated animals like us are really just massive communities of cells, each taking on a particular role and working with its neighbours. An average adult human has 37 trillion or so of them, and they’re surprisingly varied: the inner lining of the colon, for example, has more than 50 kinds of cells.

A slew of discoveries

It was just five years ago that methods for decoding of DNA and its chemical cousin RNA from individual cells became broadly accessible, according to the journal Nature Methods. New techniques are still being developed to pry more and more secrets out of individual cells.

The single-cell approach is leading to a slew of discoveries. In just the past year, for example:

• Scientists closely tracked gene activity within fish and frog embryos, a step toward the longstanding goal of understanding how a single fertilised egg can produce an animal. One study compiled results from more than 92 000 zebrafish embryonic cells.
• Other researchers revealed details of the physical connection between pregnant women and the foetus, giving potential clues for understanding some causes of stillbirth.
• A study found a pattern of gene activity in some melanoma cells that let them resist immunotherapy, the practice of unleashing the body’s immune system on cancer. That might lead to finding a way to render those cells vulnerable.

And a pair of other studies may affect research into cystic fibrosis, the genetic disease that causes lung infections and limits breathing ability. Scientists have long known that the disease stems from a faulty version of protein called CFTR. The studies identified a type of rare cell in the airway that makes large amounts of CFTR, surpassing earlier but only dimly understood indications that such cells existed.

The discovery offers great potential for guiding the development of new treatments, said Dr William Skach, senior vice president of research affairs for the Cystic Fibrosis Foundation. Single-cell techniques will be important in studying them further for coming up with new therapies, he said. (Two co-authors of one paper are from the foundation).

At the MD Anderson Cancer Center of the University of Texas, Nicholas Navin uses single-cell DNA studies to reveal different patterns of mutations in various cells of a single tumour. That lets him reconstruct when and where those mutations appeared as the tumour evolved from benign cells. And he can identify cells that contain combinations of mutations that make them the most lethal.

Someday, such research should indicate what treatments to use for particular patients, or which patients have the highest risk of the disease progressing, he says. It might also allow doctors to check how well their treatments are working against a cancer over time. A decade or two from now, it might let doctors detect cancers very early by picking up and analysing the DNA of rare cells in blood tests, he says.

Thousands of genetic variants

Meanwhile, the ability to produce single-cell results for hundreds of thousands of cells at a time has opened the door to a huge effort to catalogue every cell type in the human body. More than 1 000 scientists from 57 countries have joined the Human Cell Atlas Consortium, which estimates it will eventually profile at least 10 billion cells found in both healthy and sick people.

Why do this? It’s a natural follow to the big project that catalogued all the human genes, says co-organizer Aviv Regev, a biology professor at the Massachusetts Institute of Technology and researcher at the Broad Institute of MIT and Harvard. (Her salary is paid by the Howard Hughes Medical Institute, which also supports The Associated Press Health & Science Department.)

The gene map led to identifying thousands of genetic variants that raise or lower the risk of many diseases. But to turn that into therapies, scientists have to know in which cells those variants act, she said. And to run down those cells in the human body, “we have to map all of them”.

Some cells are rarer than others, but these can be just as critical for a functioning body as their more plentiful neighbours, she said.

She hopes for a first draft of the cell atlas in about five years, focused on certain organs and tissues of the body. To finish the job might take about a decade, she figures. Regev won’t hazard a guess about how many cell types will be found for the entire human body.

“This is not going to cure all disease immediately,” she said, but “it is a critical stepping stone.”

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Headed out on vacation? Beware of heart attack: It’s the leading cause of natural death among travellers.

If you have heart attack symptoms on the road, getting immediate medical care can improve your odds of long-term survival, according to a study presented at a meeting of the European Society of Cardiology, in Malaga, Spain.

Prompt treatment

“If you are traveling and experience heart attack symptoms — such as pain in the chest, throat, neck, back, stomach or shoulders — that lasts for more than 15 minutes, call an ambulance without delay,” study author Dr Ryota Nishio said in a society news release.

“Our study shows that long-term outcomes after a heart attack while travelling can be good if you get prompt treatment,” added Nishio, who works in the cardiology department at Juntendo University Shizuoka Hospital in Izunokuni, Japan.

For the study, the researchers examined data on more than 2 500 patients who had a heart attack and rapid treatment with a stent (percutaneous coronary intervention, PCI) between 1999 and 2015 at the hospital. It’s located on the Izu Peninsula, a popular tourist destination near Mount Fuji, and a regional centre for PCI.

Patients who were travelling tended to be younger than other patients, and had a higher prevalence of heart attacks due to a blockage in a major artery to the heart, the investigators found.

Preventive medication

The researchers followed the patients for up to 16 years, comparing death rates among different groups. The median follow-up period was 5.3 years — meaning half were tracked longer, half for less time.

During the follow-up period, local patients had a much higher rate of death from all causes (25%) than travellers (17%), mainly due to cancer. But the two groups had similar rates of death from heart-related causes.

“It is important that, when you are over the immediate emergency phase, and return home, you see your doctor to find out how you can reduce your risk of a second event by improving your lifestyle and potentially taking preventive medication,” Nishio said.

Research presented at meetings should be viewed as preliminary until published in a peer-reviewed journal.

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