Lung cancer cases are increasing in people who have never smoked, especially in women, a new study by the World Health Organization’s cancer agency has found.

The findings, published in The Lancet Respiratory Medicine, reveal that lung adenocarcinoma, the most common type of lung cancer among non-smokers, accounts for nearly 60% of lung cancer cases in women compared to 45% in men.

About 2.5 million new lung cancer cases were diagnosed worldwide in 2022 – an increase of 300,000 since 2020. The study suggests that environmental factors, particularly air pollution, along with genetic predisposition and immune responses, may be driving this rise in non-smoking-related lung cancer.

One of the most significant risk factors for lung cancer in non-smokers is genetic mutations, especially mutations in the EGFR gene. This gene provides instructions for producing a protein on the surface of cells involved in growth and division.

Mutations in this gene drive uncontrolled cell division and tumour growth. They are found in 50% of lung adenocarcinomas in non-smoking Asian women and 19% in non-smoking western women – compared with 10–20% in non-smoking men.

Advances in genetic testing have made it easier to detect these mutations. However, rising exposure to air pollution, which is known to trigger EGFR mutations – may also be contributing to their increasing prevalence.

Other genetic changes that drive tumour growth include mutations in the genes ALK and ROS1, which are found in about 5% of lung cancer cases in non-smokers. These mutations are more often seen in younger non-smoking women, particularly in Asia. Thankfully, improved screening programmes, especially in east Asian countries, have helped detect these mutations more frequently.

Mutations in TP53, a crucial tumour-suppressing gene, also appear to be more commonly found in non-smoking women than in men. This gene prevents cells from becoming cancerous, and its mutation leads to out-of-control cell growth. The hormone oestrogen can interact with TP53 mutations, making lung cancer more likely to develop in women over time.

Another gene that is worth mentioning is KRAS. Mutations in this gene are usually associated with smoking-related lung cancer, however, they are increasingly being found in non-smokers – particularly women.

Recent studies suggest that exposure to tiny particles in the air, or PM2.5 (so-called because they are 2.5 micrometres or smaller) may be responsible for these mutations in non-smoker women.

Since PM2.5 levels continue to rise in many towns and cities, exposure to these particles could be another factor not only in lung cancer but also in other types of cancers in women.

In addition to genetic predisposition, hormone fluctuations may influence tumour growth in women. Oestrogen receptors are found in lung tissue, and experimental studies suggest that oestrogen promotes tumour growth. Studies have shown.) that women who receive hormone-replacement therapy (HRT), have a lower risk of lung cancer compared with women not on HRT, suggesting that natural oestrogen cycles may provide some level of protection.

Chronic inflammation

Beyond genetics and hormones, chronic inflammation could also explain why lung cancer is rising among non-smoking women.

Women are more likely to develop autoimmune diseases than men, and problems with the immune system can play a role in cancer. Persistent inflammation can cause repeated damage to tissues, leading to changes in DNA and promote abnormal cell growth, all of which raise the risk of cancer.

Women with autoimmune diseases like rheumatoid arthritis and lupus have a higher chance of getting lung cancer, possibly because of long-lasting inflammation in the lungs. Inflammatory molecules – like interleukin-6 and tumour necrosis factor-alpha – can exacerbate the cancer by helping tumour cells survive and spread.

Autoimmune diseases have been increasing globally, probably because of environmental changes, changes in diet and shifts in gut microbiomes (the constellation of microorganisms that live in our guts and play an important role in our health). Because women are disproportionately affected by autoimmune conditions, they may be more vulnerable to chronic inflammation-driven cancer.

As life expectancy increases, more women are accumulating years of immune system activation, leading to a higher risk of developing inflammation-related lung cancer. In addition, things like pollution, household chemicals and work-related exposures can make immune system problems worse, increasing the risk of cancer even more.

Air pollution has long been recognised as a significant factor in lung cancer risk, but emerging evidence suggests that women may be particularly vulnerable. Studies show that women’s lung anatomy and function make them more susceptible to the harmful effects of pollutants. Women’s lungs are smaller than men’s, with narrower airways, which might cause more fine particles, like PM2.5, to get trapped in their lungs.

Additionally, oestrogen has been shown to amplify inflammatory responses when exposed to pollutants, potentially making lung tissue more prone to damage that can lead to lung cancer.

Women are more exposed to air pollution than men, but in a different way. While men often face pollution from factory work, women spend more time indoors where toxic fumes from cooking and heating are more common.

Air pollution in the home, especially from things like wood, coal and kerosene, can raise the risk of lung cancer. Women working in places such as textile factories, beauty salons and hospitals are also more exposed to harmful chemicals that can damage the lungs. In rapidly growing cities, women are often in areas with high traffic and factory pollution.

More significant

Women are biologically more likely than men to develop certain genetic mutations that increase the risk of lung cancer. However, factors like rising pollution, changes in hormone levels, immune system imbalances and longer life expectancy are making these risks even more significant.

Recent research suggests that HPV, a virus, may also contribute to lung cancer in women, underscoring the need for further study and preventative measures.

Understanding the roles of immune, hormonal, genetic and viral factors is key to spotting lung cancer early, creating more effective treatments and developing better ways to prevent it.

Pinar Uysal-Onganer, Reader in Molecular Biology, University of Westminster

This article is republished from The Conversation under a Creative Commons license. Read the original article.

The mere mention of Leonardo da Vinci evokes genius. We know him as a polymath whose interests spanned astronomy, geology, hydrology, engineering and physics. As a painter, his Mona Lisa and Last Supper are considered works of mastery.

Yet one great achievement that frequently goes unrecognised is his studies of human anatomy. More than 500 years after his death, it’s time this changed.

Leonardo is thought to have been born on April 15 1452 in Anchiano, a small hamlet near the town of Vinci, close to Florence. His mother was a 16-year-old peasant girl called Caterina di Meo Lippi, and his father was Ser Piero da Vinci, a 26-year-old notary.

Being illegitimate, the young Leonardo was only permitted an elementary education in reading, writing and arithmetic. He was also barred from becoming a notary, but this worked out to his advantage. Instead of being constrained by life as an officiate, he was free to be creative and explore the world of nature, satisfying his insatiable appetite for knowledge.

The human anatomy became one of his great interests. This was seeded during his time as an apprentice in Andrea del Verrocchio’s bottega (studio) in Florence, where studying the human form was crucial for achieving realistic depictions.

Creating detailed anatomical drawings required precise sketching skills and the ability to accurately depict the structures being studied. As Leonardo’s fascination grew, he would delve deeper into anatomy as a discipline.

Pioneers

This traces back to the 2nd-century Greek physician Galen of Pergamum, whose anatomical descriptions were mostly based on insights he had gained through dissecting animals and studying wounded gladiators. However, he did no human dissections – they were illegal during his time – and many of his extrapolations from animal to human anatomy were wrong.

It wasn’t until the 14th century that anatomy and medical science advanced thanks to the start of systematic human cadaver dissections. The physician Mondino de Liuzzi, who practised the first public dissections of human cadavers at the University of Bologna, published the first modern anatomical text, Anathomia Corporis Humani, in 1316.

The text was mostly descriptive in nature, like that of Galen, lacking drawings to illustrate anatomy. Subsequent texts on the subject during the 14th and early 15th centuries did contain drawings, but these were basic and unrealistic.

Leonardo advanced this discipline through his remarkable observational skills, knowledge of perspective and, most notably, his outstanding drawing abilities. His anatomical sketches were unlike anything seen before. For example, his sketches of the muscles of the arms and human skull are comparable to illustrations in today’s medical anatomy texts.

According to Leonardo’s biographer, Giorgio Vasari, the artist “was one of the first who, with Galen’s teachings, began to bring honour to medical studies and to shed real light upon anatomy, which had until that time been shrouded in the deepest shadows of ignorance”.

Leonardo was the first to depict a detailed study of the human spine, showing its natural curvature and correctly numbered vertebrae. He drew and described nearly all the bones and muscles of the body in beautiful detail, as well as investigating their biomechanics.

His studies on the heart combined both experimentation and observation. Using an ox’s heart to understand blood flow though the aortic valves, Leonardo poured molten wax into the surrounding cavities to make a wax cast, from which a glass model of the heart was made. He then pumped water mixed with grass seeds through this model to visualise the flow pattern. From this experiment, he concluded that the vortex-like flow of blood through the aortic valves was responsible for closing them during each heartbeat.

Over 450 years later, in 1968, scientists used dyes and radiography methods to observe this blood flow and prove that Leonardo was correct. A study in 2014 using MRI (magnetic resonance imaging) also demonstrated that he had provided a strikingly precise depiction of these vortex-like flows.

Shortcomings

Leonardo may have dissected around 30 human corpses during his lifetime. Most took place at the Santa Maria Nuova hospital in Florence, and later at the Santo Spirito hospital in Rome. The fact he didn’t have more human cadavers to study probably helps to explain why he also got things wrong.

In addition, Leonardo was very influenced by Galen, through his readings of both Mondino de Liuzzi and the Persian writer Avicenna (c980-1037), while also dissecting animals such as dogs, cattle and horses to fill in human anatomical gaps.

This approach is evident in his study of the male and female reproductive system, as I found when carrying out a detailed review of his work in this area. Misconceptions included the presence of three channels in the penis for semen, urine and “animal spirit”. The prostate gland is also missing in all his sketches of the male reproductive system. Meanwhile, he made the uterus spherical (derived from cow dissections), and similarly misrepresented the fallopian tubes and ovaries.

Even then, Leonardo still got a lot right. He correctly depicts the position of the foetus in the uterus, and the umbilical cord anatomy. He also correctly argued that penile erections were caused by blood engorgement and not by air or “vital spirits” flowing into the penis, as suggested by Galen.

Where he got things wrong, Leonardo’s shifting focus may also have played a part. His restlessness, disorganised notes and unfinished work suggest ADHD (attention deficit hyperactivity disorder). Equally, this may also explain his boundless curiosity and incredible creativity.

Despite his shortcomings, Leonardo’s anatomical studies were centuries ahead of their time, rivalling modern standards. His work in this area might have been more appreciated had he published it in a book: he had planned one, and is said to have been collaborating with the Renaissance physician and professor, Marc’Antonio della Torre.

Unfortunately, this was cut short with Marc’Antonio’s death in 1511. Leonardo died in 1519 at the age of 67, and while his gifts to the world have received endless attention, his important contributions to anatomy remain overshadowed, and deserve greater recognition.

Michael Carroll, Reader / Associate Professor in Reproductive Science, Manchester Metropolitan University

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Have you ever asked someone how their day was, or been chatting casually with a friend, only to have them tell you a horrific story that has left you feeling distressed or emotionally exhausted yourself?

This is called “trauma dumping”. It’s when someone shares something traumatic or distressing without checking in first if the person they’re talking to has the capacity or willingness to take on that information.

Trauma dumping is not new, and you’ve probably experienced it (or inadvertently done it yourself) at some stage in your life.

But now, with the rise of social media platforms such as TikTok, the risk of experiencing trauma dumping has increased exponentially.

People often turn to TikTok for support or validation. And because TikTok’s algorithm is based on attention, it’s not uncommon for highly emotional stories to gather traction and go viral.

My colleagues and I wanted to understand more about trauma dumping on TikTok. In a recent study, we found people often share their trauma on TikTok. And this is usually done without a trigger warning.

TikTok and mental health

It’s estimated around 75% of the population have experienced a traumatic event at some point in their lives. This could include exposure to abuse or neglect in childhood, violence, natural disasters, the death of a loved one, or any other event which is unexpected, distressing, and causes long-term impacts on physical or mental health.

TikTok can be an important source of support and validation, especially for young people who have faced trauma, and who may not have sufficient support offline.

Previous research has shown TikTok provides a platform for talking about things like body image concerns, seeking support and information about gender and sexual diversity, and tackling stigma.

But while TikTok can be a great place for community, support and validation, at the same time it can be a hotbed for trauma dumping.

Importantly, sharing trauma on social media runs the risk of exposing other users to vicarious traumatisation, which is when a person is traumatised by someone else’s trauma.

Vicarious trauma is most common in people who work in “frontline” jobs, such as paramedics or therapists, who deal with trauma regularly. However, anyone can be at risk. Factors including personal experiences, personality traits (such as empathy), support systems and coping strategies all play a role in whether someone might experience vicarious trauma.

In our study, we set out to explore the top videos on TikTok with one or more of five hashtags related to trauma: #traumatok, #trauma, #traumatized, #traumatic and #traumabond.

We looked the most viewed 50 videos from each hashtag. At the time we carried out our analysis in December 2022, these 250 videos had a total of 296.6 million likes, 2.3 million comments and 4.6 million shares.

#TraumaTok

We found the majority of videos (about 67%) were from people sharing their trauma. In many cases severe trauma was discussed, including child maltreatment, violence and death.

Our study also showed some videos (about 22%) were from people who claimed to be “experts” in trauma. They were using the platform to speak about the symptoms and treatment for trauma-related mental health conditions.

Worryingly, most “experts” (84%) did not disclose their credentials. And only a small proportion (2%) said they were licensed psychologists, counsellors or medical professionals (who are trained to provide evidence-based treatment or advice for mental health).

The remaining videos were either more general mental health content with a mix of hashtags such as “anxiety” and “depression”, or were meant to be humorous, using memes or jokes about trauma.

One of the most concerning things we found in our study was that only 3.7% of videos had some form of trigger warning. A trigger warning, often a verbal statement by the creator, text within the video or a caption, is meant to alert the audience that potentially distressing content is discussed in the video.

One of the limitations of our study was that we didn’t look at users’ experiences of viewing these videos. We also didn’t explore discourse on the app, such as comments and video replies.

We can’t say for sure what it’s like for people, especially young people or people with lived experience of trauma, to watch and interact with these videos. Exploring this should be a focus for future research.

Trigger warnings are important

None of this is to say that sharing stories, even traumatic ones, should never happen. In fact, we know support from others is essential for healing from trauma. This can be facilitated, among other avenues, through sharing stories on social media.

But to make this safer for everyone, TikTok should encourage trigger warnings, and creators should use them on videos where trauma is shared. This can give users the option to “opt out” and scroll on if they think they might not have the capacity to listen at that time.

For people consuming videos on TikTok and other platforms, it’s important to be wary of misinformation and think critically about the information they see, seeking further advice from other sources.

If you feel distressed by content you see on social media, seek support from a health-care professional.

If this article has raised issues for you, or if you’re concerned about someone you know, call Lifeline on 13 11 14.

Alix Woolard, Senior Research Fellow, The Kids Research Institute Australia

This article is republished from The Conversation under a Creative Commons license. Read the original article.