Tag: 13/9/24

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Does Giving Lifestyle Advice Really Work?

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Photo by Cottonbro on Pexels

Healthcare professionals are increasingly giving advice to patients on how to improve their health, but there is often a lack of scientific evidence if this advice is actually beneficial. This is according to a study from the University of Gothenburg, which also guides towards more effective recommendations.

The researchers do not criticise the content of the advice – after all, it is good if people lose weight, stop smoking, eat a better diet or exercise more. But there is no evidence that patients actually do change their lifestyle after receiving this advice from healthcare professionals.

“There is often a lack of research showing that counselling patients is effective. It is likely that the advice rarely actually helps people,” says study lead author Minna Johansson, Associate Professor at Sahlgrenska Academy at the University of Gothenburg and General Practitioner at Herrestad’s Healthcare Center in Uddevalla.

Few pieces of advice are well-founded

The study, published in the Annals of Internal Medicine, was conducted by an international team of researchers. They have previously analysed medical recommendations from the National Institute for Health and Care Excellence (NICE) in the UK. This organisation is behind 379 recommendations of advice and interventions that healthcare professionals should give to patients, with the aim of changing their lifestyle.
 
In only 3% of cases there were scientific studies showing that the advice has positive effects in practice. A further 13% of this advice had some evidence, but with low certainty. The researchers also reviewed additional guidelines from other influential institutions around the world and found that these often overestimate the positive impact of the advice and rarely take disadvantages into account.
 
“Trying to improve public health by giving lifestyle advice to one person at a time is both expensive and ineffective. Resources would probably be better spent on community-based interventions that make it easier for all of us to live healthy lives,” says Minna Johansson, who also believes the advice could increase stigmatisation for people with, eg, obesity.

Showing the way forward

Today’s healthcare professionals would not be able to give all the advice recommended while maintaining other care. The researchers’ calculations show that in the UK, for example, five times as many nurses would need to be hired, compared to current levels, to cope with the task.
 
The study also presents a new guideline to help policy makers and guideline authors consider the pros and cons of the intervention in a structured way before deciding whether or not to recommend it.
 
Victor Montori, Professor of Medicine at the Mayo Clinic in the United States is a co-author of the study:
“The guideline consists of a number of key questions, which show how to adequately evaluate the likelihood that the lifestyle intervention will lead to positive effects or not,” says Victor Montori.

Source: University of Gothenburg

Categories : Cancer Metabolic DisordersTags : Leave a comment

The Outcomes of Cancer Therapies and BMI Have a Complex Relationship

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Risk of mortality during cancer treatment in relation to BMI. For non-small cell lung cancer treatment, immunotherapy seems to pose less risk for persons under a certain BMI, while conventional chemotherapy appears optimal for persons who might be overweight or obese. Credit: Osaka Metropolitan University

While being overweight increases the risk of developing lifestyle-related diseases, there is a phenomenon known as the obesity paradox where a decreased risk of death has been seen during cancer therapy. However, that paradox might not hold true for all cancer therapies, an Osaka Metropolitan University team reports in JAMA Network Open, a publication of the American Medical Association.

Led by graduate student Mr Yasutaka Ihara and Professor Ayumi Shintani of the Graduate School of Medicine’s Department of Medical Statistics, the team used a Japanese administrative claims database of more than 500 000 lung cancer patients and examined the relation between body mass index (BMI) and the risk of mortality during immunotherapy and conventional chemotherapy.

Focusing only on patients with advanced non-small cell lung cancer, the team found that the higher the BMI, the lower the risk of mortality when undergoing both immunotherapy and chemotherapy, though it does a U-turn around a BMI of 24. Patients with a BMI under 28 showed lower risk of mortality when undergoing immunotherapy compared to conventional chemotherapy, but for those at or over that figure, the risk increases with immunotherapy while it continues to get lower with chemotherapy.

“Immunotherapy might not always be the optimal treatment method for obese patients with advanced non-small cell lung cancer, so the use of conventional chemotherapy should also be considered,” Mr. Ihara stated. “In addition to BMI, age, hormones, and gut microbiota have been reported as factors that influence the effectiveness of immunotherapy. Evaluation of whether immunotherapy or conventional chemotherapy improves survival in the presence of these factors is expected to contribute to the development of precision medicine.”

Source: Osaka Metropolitan University

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How Cancer Reprograms Immune Cells to Join the Enemy

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Squamous cancer cell being attacked by cytotoxic T cells. Image by National Cancer Institute on Unsplash

Cancer has been described as “a wound that does not heal,” implying that the immune system is unable to wipe out invading tumour cells. A new discovery reported in PNAS confirms that a key molecule can reprogram immune cells into turncoats that promote cancer growth.

Studying the behaviour of these “pro-tumour” immune cells is important because they could be targets for therapies that block their harmful activity, said Minsoo Kim, PhD, corresponding author of the study and a research leader at the Wilmot Cancer Institute.

Kim led a team of scientists investigating the dynamic interactions that occur between cells in the tumor environment, and the underlying factors that cause the harmful transformation of immune cells from good to bad.

They found that PAF (platelet-activating factor) is the key molecule that controls the destiny of the immune cells. PAF not only recruits cancer-promoting cells, but it also suppresses the immune system’s ability to fight back. In addition, they found that multiple cancers rely on the same PAF signals.

“This is what could be most significant,” said Kim. “Because if we find a treatment that could interfere with PAF, it could potentially apply to many types of cancer.”

Much of the team’s work focused on pancreatic cancer cells. It is one of the most deadly cancers, with a five-year survival rate of about 12%, and is notoriously hard to treat because pancreatic tumours are surrounded by a toxic stew of proteins and other tissues that protect the cancer from the immune system’s natural role to attack invaders. They also studied breast, ovarian, colorectal, and lung cancer cells, using advanced 3D imaging technology to watch the behaviour of immune cells as they swarmed to the cancerous region.

Source: University of Rochester Medical Center

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Antibiotic Usage can Damage the Intestine’s Protective Mucus Layer

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Source: CC0

Researchers at Umeå University and Tartu University have found that a history of repeated antibiotic use causes defects in the normally protective mucus barrier of the gut, due to antibiotic-driven alterations in the microbiota. In a further study in a different collaboration, the researchers found a bacteria-independent mechanism through which antibiotics can damage the mucus barrier directly.

The results have been published in the scientific journals Gut Microbes and Science Advances.

“Together, these two studies suggest that antibiotics can damage the mucus layer through at least two independent mechanisms, and that they may have long-lasting effects through an altered gut bacteria. This further supports the notion that antibiotics should be administered in a responsible manner,” says Björn Schröder, Docent in Infection Biology in the Department of Molecular Biology at Umeå University.

Previous research has shown the consequences of short-term antibiotic treatments on the intestinal environment, but it is less clear how repeated antibiotic use in past years can affect our guts.

To address this question, Björn Schröder and his group at Umeå University teamed up with a research group at Tartu University in Estonia, who have built a deeply characterised cohort of individuals that provided stool samples and health records.

The researchers selected individuals who had taken at least five courses of antibiotics in the past, but not within six months before the stool collection, and compared their microbiota composition to individuals who had not taken any antibiotics within the last 10 years.

“The analysis revealed changes to the gut bacteria composition, even though the antibiotics were taken a long time ago. These results indicate that repeated antibiotic use has a lasting effect on gut bacteria composition that can persist at least months after the last treatment,” says Kertu-Liis Krigul, PhD student at Tartu University.

After transplantation of the human microbiota into mice and using specialised methods to analyse the mucus function in the gut, the researchers found that the function of the mucus layer was disrupted in mice transplanted with bacteria from humans with a history of repeated antibiotic use. Expansion of the mucus was reduced, and the mucus layer became penetrable, allowing bacteria to move closer to the intestinal lining.

“Looking at the bacteria present in the gut in more detail, we could see that bacteria known to feed on the mucus layer were present at higher levels in these mice. This further supports a role for the gut bacteria in determining how well the mucus barrier can function,” says Rachel Feeney, PhD student at the Department of Molecular Biology at Umeå University.

A separate study carried out in another international collaboration, further showed that antibiotics can also directly disrupt the mucus barrier in a gut bacteria-independent manner.

By giving the antibiotic vancomycin to normal and ‘bacteria-free’ mice, the researchers were able to show that this antibiotic can act directly on the mucus barrier, independent of the gut bacteria. Complementary experiments on intestinal tissue were carried out at Umeå University and showed that the antibiotic could disrupt the mucus expansion within a few minutes of application.

Source: Umeå University

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How, When and Where: Sex Matters in Melanoma Development

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Melanoma rates differ consistently between men and women in terms of the ages at which melanomas occur and the locations on the body where they occur. Over time, melanoma rates have increased in both men and women, but the trends differ by body site. A new study in the Journal of Investigative Dermatology, published by Elsevier, presents the findings from a large-scale, long-term melanoma data analysis investigating incidence trends by age, sex, and anatomic site.

Lead investigator David C. Whiteman, MBBS, PhD, Cancer Control Group, QIMR Berghofer Medical Research Institute, and Faculty of Medicine, The University of Queensland, Brisbane, Australia, explains, “There has been a general observation in numerous populations that melanomas appear to arise at different rates in men and women. We decided to investigate this observation rigorously and assess whether these differences have been constant through time or across generations by using large-scale data from population registries to investigate long-term melanoma trends in men and women.”

The research team analysed more than 40 years of melanoma data from Queensland, Australia, the USA, and Scotland. These three populations were chosen because historically they have had high (Queensland), moderate (USA), and low (Scotland) rates of melanoma. Over time, the rates of melanoma increased in all three populations, especially among women. In women in all populations, melanomas arise most commonly on the limbs, whereas in men, melanomas arise most commonly on the trunk and head and neck. In both sexes, there has been a steady increase in melanomas on the head and neck with increasing age.

Researchers found that in virtually all investigated populations, women experience higher rates of melanoma than men in early life (up to age ~45 years), but men develop melanomas at higher rates than women later in life (from ages ≥ 65 years). Furthermore, these sex-specific trends reflect complex patterns of incidence across body sites that vary consistently with age. Thus, in early life, women experience higher rates of lower limb melanomas than men, which persists into older ages. Also, on the upper limbs, women experience substantially higher rates than men from young ages until middle age (45–64 years), after which men experience higher rates. In contrast, on the head and neck and the trunk, melanomas occur at higher incidence in men than in women early in life. On all body sites, the rate at which melanoma incidence rises with age is much more rapid for men than for women.

The study confirms that men and women experience melanoma in different ways. While this is most likely driven by different patterns of sun exposure between men and women, there appear to be inherent differences in the ways in which melanomas develop at different body sites in women compared with men. Understanding the underlying biological differences could provide important clues about the etiology of this enigmatic cancer.

Source: Elsevier