Cancer Rates Rise Across Generations, SpaceX Private Spacewalk Delayed

Scientists sound alarm over new surge in cancers, private spacewalk postponed

By Rachel Feltman and Kelso Harper and Fonda Mwangi

Rachel Feltman: Happy Monday, listeners. Let’s kick off the first full week of August by catching up on some science news. For Scientific American’s Science Quickly, I’m Rachel Feltman.

Last Wednesday, researchers at the American Cancer Society published a study suggesting that for a number of cancers, rates of cases are increasing from one generation to the next. They found that for eight of the 34 cancers studied, incidence rates increased in every five-year interval observed from 1920 to 1990. In other words, the cohort born in 1965 had higher rates than the cohort born in 1960, but lower rates than the cohort born in 1970, and so on. For nine of the other cancers, while rates had been declining for a time, they began to rise again in younger cohorts. The researchers stressed that they do not yet have a conclusive explanation for this trend. While headlines often point to sedentary lifestyles and excess weight as the main culprits, particularly for the recent rise in colorectal cancers among young people, some experts have sounded the alarm that these factors alone cannot explain the increase.

But we did get some good news on that front. Last Monday, the Food and Drug Administration approved a new blood test for colorectal cancer. Guardant Health’s test, called Shield, was previously available as a diagnostic tool for doctors, with a price tag of nearly $900. Shield isn’t a replacement for colonoscopies, which are essential for spotting — and even removing — polyps that can lead to colon cancer, as well as detecting the cancer itself. Research suggests that the noninvasive blood test is 83 percent effective at detecting colorectal cancer, but it works best in the later stages of the disease. Still, since colonoscopies are notoriously time-consuming due to the need for bowel prep — which is often a bit unpleasant — there’s hope that this blood test will fill in some of the gaps in screening.

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Another recent cancer study has highlighted the increasingly clear importance of a healthy microbiome. Scientists have found that certain oral bacteria appear to provide some benefits to people with head and neck cancers, leading to better outcomes. The researchers also found that the type of bacteria in question, a common oral resident called Fusobacterium, could completely kill some cancer cells in a petri dish.

In a completely different health news story, let’s turn to cat poop. Most people have probably heard of it Toxoplasma gondii, The protozoan parasite that causes toxoplasmosis reproduces in the digestive tracts of cats and infects other mammals through contact with their feces. Humans can also catch it by eating raw or undercooked meat. The parasite is known to make infected rodents lose their fear of cats and increase the risk of miscarriage in pregnant women. Last week, researchers published a new study suggesting that the parasite could be used for positive purposes. In a nutshell, the scientists exploited the microbe’s ability to cross the blood-brain barrier, which is notoriously tricky when it comes to delivering drugs. The research is still in its early stages, but it appears that Toxoplasma gondii It might be possible to design a device that could deliver therapeutic proteins to the brain. Scientists have had some success using rodent models.

Now let’s move on to bird flu. Listen, there’s a lot of health stuff this week! I don’t know what to tell you, it’s just the news.

Last week, the Centers for Disease Control and Prevention (CDC) announced a $5 million initiative to vaccinate farm workers against seasonal flu. While the vaccine doesn’t target H5N1, one of the viruses that causes bird flu, it does reduce the risk of catching common human flu strains. The idea is to minimize the risk that people will get the flu at the same time as the H5N1 strain, which is more common in humans. When viruses coexist inside a human host, they have the opportunity to exchange genetic material. That could lead to a new strain of bird flu that can jump from one person to another. Only half the U.S. population tends to get vaccinated against seasonal flu, so this kind of intervention could make a real difference. Still, some argue that the U.S. should also vaccinate farm workers against H5N1, as the Finnish government reportedly plans to do. But CDC officials say they are still weighing the pros and cons.

Okay, that’s enough for us. Let’s enjoy some junk food.

SpaceX is about to send billionaire entrepreneur Jared Isaacman on the first-ever private spacewalk, but not as well as both parties had hoped. Funded by Isaacman, the Polaris Dawn mission was originally scheduled to launch aboard SpaceX’s Crew Dragon spacecraft in 2022, and the company recently said that liftoff could happen as early as last Wednesday. In a press conference on July 26, SpaceX pushed back the launch to mid- to late August. Hopefully, everyone involved is diving into a pool of money Scrooge-style to make themselves feel better.

Finally, we are used to hearing about the discovery of new planets, new species, etc. But what about new… wood? Scientists say they have found exactly that. Typically, when we talk about types of wood, we are making a distinction between hardwood and softwood. This is not necessarily a reference to the actual density of the wood. Hardwoods typically come from trees that have flowers and seasonal changes in their leaves. Softwoods typically come from conifers.

In a new study, scientists examined the two surviving species of the Liriodendron The researchers studied tulip tree species, such as the tulip tree and the Chinese tulip tree, and found wood that didn’t fit the pattern. This “intermediate wood” structure could explain why these trees grow so fast and are so effective at capturing carbon. Understanding this mechanism could help scientists select the best trees for carbon sequestration, and perhaps even engineer plants that are better suited to the task.

That’s it for this week’s news roundup. We’ll be back on Wednesday with some more science news to sink your teeth into. And don’t forget to tune in on Friday for the final episode of our ongoing Fascination mini-series, which focuses on the craziest types of archaeological research.

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Science in brief is produced by me, Rachel Feltman, with Fonda Mwangi, Kelso Harper, Madison Goldberg, and Jeff DelViscio. Shayna Posses and Aaron Shattuck fact-check our show. Our background music was composed by Dominic Smith. Subscribe to American scientist for more up-to-date and in-depth scientific news.

For American scientist, This is Rachel Feltman. Have a great week!