Australia has one of the highest skin cancer rates globally, with nearly 19,000 Australians diagnosed with invasive melanoma – the most lethal type of skin cancer – each year.

While advanced melanoma can be fatal, it is highly treatable when detected early.

But Australian clinical practice guidelines and health authorities do not recommend screening for melanoma in the general population.

Given our reputation as the skin cancer capital of the world, why isn’t there a national screening program? Australia currently screens for breast, cervical and bowel cancer and will begin lung cancer screening in 2025.

It turns out the question of whether to screen everyone for melanoma and other skin cancers is complex. Here’s why.

The current approach

On top of the 19,000 invasive melanoma diagnoses each year, around 28,000 people are diagnosed with in-situ melanoma.

In-situ melanoma refers to a very early stage melanoma where the cancerous cells are confined to the outer layer of the skin (the epidermis).

Instead of a blanket screening program, Australia promotes skin protection, skin awareness and regular skin checks (at least annually) for those at high risk.

About one in three Australian adults have had a clinical skin check within the past year.

Why not just do skin checks for everyone?

The goal of screening is to find disease early, before symptoms appear, which helps save lives and reduce morbidity.

But there are a couple of reasons a national screening program is not yet in place.

We need to ask:

1. Does it save lives?

Many researchers would argue this is the goal of universal screening. But while universal skin cancer screening would likely lead to more melanoma diagnoses, this might not necessarily save lives. It could result in indolent (slow-growing) cancers being diagnosed that might have never caused harm. This is known as “overdiagnosis”.

Screening will pick up some cancers people could have safely lived with, if they didn’t know about them. The difficulty is in recognising which cancers are slow-growing and can be safely left alone.

Receiving a diagnosis causes stress and is more likely to lead to additional medical procedures (such as surgeries), which carry their own risks.

2. Is it value for money?

Implementing a nationwide screening program involves significant investment and resources. Its value to the health system would need to be calculated, to ensure this is the best use of resources.

Narrower targets for better results

Instead of screening everyone, targeting high-risk groups has shown better results. This focuses efforts where they’re needed most. Risk factors for skin cancer include fair skin, red hair, a history of sunburns, many moles and/or a family history.

Research has shown the public would be mostly accepting of a risk-tailored approach to screening for melanoma.

There are moves underway to establish a national targeted skin cancer screening program in Australia, with the government recently pledging $10.3 million to help tackle “the most common cancer in our sunburnt country, skin cancer” by focusing on those at greater risk.

Currently, Australian clinical practice guidelines recommend doctors properly evaluate all patients for their future risk of melanoma.

Looking with new technological eyes

Technological advances are improving the accuracy of skin cancer diagnosis and risk assessment.

For example, researchers are investigating 3D total body skin imaging to monitor changes to spots and moles over time.

Artificial intelligence (AI) algorithms can analyse images of skin lesions, and support doctors’ decision making.

Genetic testing can now identify risk markers for more personalised screening.

And telehealth has made remote consultations possible, increasing access to specialists, particularly in rural areas.

Check yourself – 4 things to look for

Skin cancer can affect all skin types, so it’s a good idea to become familiar with your own skin. The Skin Cancer College Australasia has introduced a guide called SCAN your skin, which tells people to look for skin spots or areas that are:

1. sore (scaly, itchy, bleeding, tender) and don’t heal within six weeks

2. changing in size, shape, colour or texture

3. abnormal for you and look different or feel different, or stand out when compared to your other spots and moles

4. new and have appeared on your skin recently. Any new moles or spots should be checked, especially if you are over 40.

If something seems different, make an appointment with your doctor.

You can self-assess your melanoma risk online via the Melanoma Institute Australia or QIMR Berghofer Medical Research Institute.

H. Peter Soyer, Professor of Dermatology, The University of Queensland; Anne Cust, Professor of Cancer Epidemiology, The Daffodil Centre and Melanoma Institute Australia, University of Sydney; Caitlin Horsham, Research Manager, The University of Queensland, and Monika Janda, Professor in Behavioural Science, The University of Queensland

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

Fourteen years ago, the older drug cousin of semaglutide (Ozempic and Wegovy) came onto the market. The drug, liraglutide, is sold under the brand names Victoza and Saxenda.

Patents for Victoza and Saxenda have now expried. So other drug companies are working to develop “generic” versions. These are likely be a fraction of current cost, which is around A$400 a month.

So how does liraglutide compare with semaglutide?

How do these drugs work?

Liraglutide was not originally developed as a weight-loss treatment. Like semaglutide (Ozempic), it originally treated type 2 diabetes.

The class of drugs liraglutide and semaglutide belong to are known as GLP-1 mimetics, meaning they mimic the natural hormone GLP-1. This hormone is released from your small intestines in response to food and acts in several ways to improve the way your body handles glucose (sugar).

How do they stop hunger?

Liraglutide acts in several regions of the unconscious part of your brain, specifically the hypothalamus, which controls metabolism, and parts of the brain stem responsible for communicating your body’s nutrient status to the hypothalamus.

Its actions here appear to reduce hunger in two different ways. First, it helps you to feel full earlier, making smaller meals more satisfying. Second, it alters your “motivational salience” towards food, meaning it reduces the amount of food you seek out.

Liraglutide’s original formulation, designed to treat type 2 diabetes, was marketed as Victoza. Its ability to cause weight loss was evident soon after it entered the market.

Shortly after, a stronger formulation, called Saxenda, was released, which was intended for weight loss in people with obesity.

How much weight can you lose with liraglutide?

People respond differently and will lose different amounts of weight. But here, we’ll note the average weight loss users can expect. Some will lose more (sometimes much more), others will lose less, and a small proportion won’t respond.

The first GLP-1 mimicking drug was exenatide (Bayetta). It’s still available for treating type 2 diabetes, but there are currently no generics. Exenatide does provide some weight loss, but this is quite modest, typically around 3-5% of body weight.

For liraglutide, those using the drug to treat obesity will use the stronger one (Saxenda), which typically gives about 10% weight loss.

Semaglutide, with the stronger formulation called Wegovy, typically results in 15% weight loss.

The newest GLP-1 mimicking drug on the market, tirzepatide (Mounjaro for type 2 diabetes and Zepbound for weight loss), results in weight loss of around 25% of body weight.

What happens when you stop taking them?

Despite the effectiveness of these medications in helping with weight loss, they do not appear to change people’s weight set-point.

So in many cases, when people stop taking them, they experience a rebound toward their original weight.

What is the dose and how often do you need to take it?

Liraglutide (Victoza) for type 2 diabetes is exactly the same drug as Saxenda for weight loss, but Saxenda is a higher dose.

Although the target for each formulation is the same (the GLP-1 receptor), for glucose control in type 2 diabetes, liraglutide has to (mainly) reach the pancreas.

But to achieve weight loss, it has to reach parts of the brain. This means crossing the blood-brain barrier – and not all of it makes it, meaning more has to be taken.

All the current formulations of GLP-1 mimicking drug are injectables. This won’t change when liraglutide generics hit the market.

However, they differ in how frequently they need to be injected. Liraglutide is a once-daily injection, whereas semaglutide and tirzepatide are once-weekly. (That makes semaglutide and tirzepatide much more attractive, but we won’t see semaglutide as a generic until 2033.)

What are the side effects?

Because all these medicines have the same target in the body, they mostly have the same side effects.

The most common are a range of gastrointestinal upsets including nausea, vomiting, bloating, constipation and diarrhoea. These occur, in part, because these medications slow the movement of food out of the stomach, but are generally managed by increasing the dose slowly.

Recent clinical data suggests the slowing in emptying of the stomach can be problematic for some people, and may increase the risk of of food entering the lungs during operations, so it is important to let your doctor know if you are taking any of these drugs.

Because these are injectables, they can also lead to injection-site reactions.

During clinical trials, there were some reports of thyroid disease and pancreatitis (inflammation of the pancreas). However, it is not clear that these can be attributed to GLP-1 mimicking drugs.

In animals, GLP-1 mimicking drugs drugs have been found to negatively alter the growth of the embryo. There is currently no controlled clinical trial data on their use during pregnancy, but based on animal data, these medicines should not be used during pregnancy.

Who can use them?

The GLP-1 mimicking drugs for weight loss (Wegovy, Saxenda, Zepbound/Mounjaro) are approved for use by people with obesity and are meant to only be used in conjunction with diet and exercise.

These drugs must be prescribed by a doctor and for obesity are not covered by the Pharmaceutical Benefits Scheme, which is one of the reasons why they are expensive. But in time, generic versions of liraglutide are likely to be more affordable.

Sebastian Furness, ARC Future Fellow, School of Biomedical Sciences, The University of Queensland

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