Four in 10 people who have survived cancer still battle exhaustion, pain or sleep problems – even years after their treatment has ended according to a new nationwide study from the Danish Cancer Institute that found major social differences in who is affected.
Forty-five-year-old Mette smiles when she meets old colleagues at the supermarket. She does not want to be the one who always talks about illness. But inside, she is struggling. Three years after being declared cancer-free, she rarely sleeps more than two hours at a time. Her body aches, and fatigue weighs her down. Even small tasks feel like climbing a mountain. No one can see it in her – and she never imagined that life after cancer could be like this.
For Mette, the late effects are invisible but always there. Similar stories are repeated among thousands of people who have had cancer, and a new study in Denmark has put a number on how many people are struggling with the same problems – and who they are.
The study was led by postdoc Anne Katrine Graudal Levinsen, senior researcher Trille Kjær and professor Susanne Oksbjerg Dalton, all from the Danish Cancer Institute. The results, recently published in Journal of Cancer Survivorship, are based on the largest and most detailed dataset on cancer sequelae in Denmark to date.
Never before have so many people’s own experiences been linked directly to national registries of cancer type, treatment and social conditions.
“What I find is that 42% of former cancer patients reported severe fatigue, pain or sleep problems – and 8% experienced the whole package – exhaustion, pain and sleep problems at the same time,” explains Anne Katrine Graudal Levinsen, emphasising that 8% is a large proportion since a disease is considered a public health problem if it affects at least 1% of the population.
“And these are the three most common late effects. So we need to keep an eye on this, especially when people are affected by several late effects such as fatigue, pain and sleep problems, it becomes a complex health problem – a condition that requires coordinated efforts from several different health professionals. This suggests that more patients need close follow-up and help with their late effects than they are currently offered,” she says.
Denmark’s largest survey of cancer sequelae
To get the full picture, the researchers conducted a nationwide study (SEQUEL) combining questionnaires with information from national registries. This enabled them to collect patients’ own experiences and see them in the context of cancer type, treatment, income, education and other diseases.
“This gives us a nuanced picture of who is severely affected and what characterises those at greatest risk of developing late effects,” says Anne Katrine Graudal Levinsen.
In 2022, the researchers sent questionnaires to 100,000 people older than 40 years who had had cancer. They had survived breast, prostate, lung, colon, rectum, head/neck, skin cancer or lymphoma and had completed treatment at least two years earlier. The questions followed an international tool used by researchers worldwide to measure the quality of life and symptoms of people with cancer. For fatigue, pain and sleep problems, the researchers used fixed thresholds for when symptoms are so severe that they should lead to getting help.
A total of 41,000 people responded, and 42% had at least one of the three symptoms to a severe degree; 21% experienced two symptoms at the same time; and 8% had all three.
What the researchers found – three important points
The researchers drew three main points from the results.
First, late effects strike hardest at those with the fewest resources – short education, low income and living alone. The researchers had long suspected this, and the study confirmed it with figures: people who had a short education were twice as likely to be severely affected by late effects as those with longer education, and the pattern was repeated among people with low incomes. Another important social factor was living alone. Without a network and support, everyday life with fatigue, pain and sleep problems can become even more difficult to cope with.
Second, the problems do not necessarily disappear over time. Even among those who completed treatment 10–12 years before, many still reported severe fatigue, pain or sleep problems. For some, this is not a temporary but a chronic condition that affects everything from working life to social relationships.
Third, the symptoms are often interrelated. Pain can disrupt sleep, poor sleep can exacerbate fatigue, and fatigue can make the pain more debilitating.
“If we only look at one symptom at a time, we might overlook the whole picture,” says Anne Katrine Graudal Levinsen, who notes that this connection makes it particularly important for the healthcare system to offer a more holistic approach – which is not always the case today.
Too little help for life after cancer
Specialised late effects clinics exist, but not in all five administrative regions of Denmark, and the clinics can only accept a few patients. The rest must seek help from general practitioners or municipal services, where late effects are not always a familiar area.
Although the fifth national cancer plan rolled out by the Government of Denmark in autumn 2024 includes measures aimed at earlier and better detection of late effects, Anne Katrine Graudal Levinsen points out that there is still no concrete plan for how the healthcare system will take care of all those needing support.
“Many patients would like help from late effects clinics, but these clinics only have the capacity to take on a fraction of them – the most complex cases. The problem is that the help is simply not enough. Far too many cancer survivors are left alone, not knowing where to turn with their problems,” she says.
New knowledge to ensure better help for cancer survivors
According to the researchers, many of the cancer survivors who participated in the SEQUEL study find that things can be quite quiet after their last check-up at the hospital. They are largely left to fend for themselves with problems that can be both complex and long-lasting.
“Our study only highlights part of the challenge. In addition to fatigue, pain and sleep problems, some also struggle with anxiety, depression and other serious late effects,” adds Anne Katrine Graudal Levinsen.
She further points out that more people are surviving cancer. This means that the number of people who live for many years with the consequences of both cancer and the treatment is increasing.
“That is why we urgently need more knowledge – and, above all, concrete services for the many thousands who continue to live in cancer’s shadow,” she says.
The researchers are now continuing their work to map mental health late effects such as anxiety and depression and investigate which types of treatment trigger which symptoms. The aim is to identify the most vulnerable patients at an early stage and help them cope with the late effects.
For Mette and thousands of others, it is about more than surviving cancer, it is also about the quality of life.
“We need to see the whole patient and take late effects seriously. Because it is not just about surviving – it is about being able to live well afterwards,” concludes Anne Katrine Graudal Levinsen.
