A new study shows promising long-term survival trends overall with regard to 23 solid cancers in the Nordic countries of Sweden, Denmark, Finland, and Norway.
The 5-year survival rate reached between 50% and 100% in 17 cancers, and it topped 90% for five. Although 5-year survival remained below 50% for six cancers, survival still markedly improved over the 50-year study period.
In about half of cancer types, the percentage of patients who survived for 5 years more than doubled since the early 1970s.
Still, metastatic cancer remains tough to cure, which highlights "the importance of early diagnosis and prevention, and the need for new therapies with curative potential, such as immunotherapy," lead author Kari Hemminki, MD, PhD, with Charles University in Prague, Czech Republic, and colleagues write.
The report was published online late last month in the International Journal of Cancer.
To track cancer survival trends, Hemminki and colleagues used the NORDCAN database to analyze long-term survival data regarding 23 solid cancers in Sweden, Denmark, Finland, and Norway between 1970 and 2019.
The authors categorized the survival results into four groups. Group 1 included cancers for which survival has historically been good, such as melanoma as well as breast, endometrial and thyroid cancers — survival was over 50% from 1970–1974. Group 2 encompassed cancers in which survival consistently improved by at least 20% over 5-year increments across the entire study period. Group 3 focused on similar survival improvements that occurred over a narrower time window. And group 4 included cancers with the worse survival outcomes — less than 20% improvement over 5-year increments.
Cancers in groups 1 and 2, which included stomach, colon, rectum, and kidney cancers, were characterized by consistent survival improvements, owing to multiple developments in therapy, diagnosis, and patient care.
The trends varied slightly by cancer type. In female breast cancer, for instance, the increase in survival has been constant over the 50-year period. In melanoma, however, the data showed a lag phase in survival between 1995 and 2005, with clear improvement in more recent years. The improvement may be due to the development of MAPKinase (BRAF/MEK) inhibitors and immune checkpoint inhibitors.
Notably, kidney cancer, categorized in group 2, showed the best improvement in survival among the 23 solid cancers studied — survival rates doubled over the 50-year period in Sweden and tripled in Denmark. The survival gain was particularly favorable after 2000.
Cancers in group 3, which included oral, oropharyngeal, testicular, and prostate cancers, showed periodic improvements in survival, owing to novel therapies or more favorable presentation (testis and prostate cancer) or etiology (oropharynx cancer).
Group 4 included cancers in which survival has historically been poor, such as lung, esophageal, liver, pancreatic, bladder, and cervical cancers. Among these most fatal cancers, survival in stomach cancer was most favorable — going from a 12% to 14% relative 5-year survival rate in 1970–1974 to about 27% in men and 35% in women in 2015–2019. Pancreatic cancer was associated with the worst survival — a 2.5% relative 5-year survival rate in 1970–1974 to about 15% by 2015–2019.
Survival in esophageal cancer was only slightly better compared with pancreatic cancer. Lung cancer survival started to increase around 2000 and had doubled by 2019. Survival gains in cervical and vulvar cancers were modest over the 50-year period, which, the authors note, "remains a puzzle," given that cervical cancer screening started in Finland and Sweden in the 1970s and in Denmark and Norway in the1990s.
But overall, "one positive message emerging from these analyses is that even in the six most fatal cancers survival markedly improved in the last decades," the authors write.
Where the US Cancer Stats Stand
How do these survival trends compare to those in the United States?
Earlier this month, the American Cancer Society (ACS) released the latest cancer statistics.
The data showed a promising 33% decline in overall cancer mortality since 1991, which equated to an estimated 3.8 million cancer deaths averted.
Regarding different cancer types, the good news was the "astounding" 65% drop in the incidence of cervical cancer among women in their early 20s, the first cohort to have access to the human papillomavirus vaccine, ACS Chief Executive Officer Karen E. Knudsen, MBA, PhD, said.
The bad news, however, was a "concerning" 3% annual increase in prostate cancer incidence from 2014–2019, driven by an increase in the diagnosis of advanced disease, following two decades of declining incidence, Knudsen noted.
Although it is difficult to compare the two analyses directly, the ACS data also demonstrate overall progress in cancer survival over time, which was "particularly evident in the rapid declines in mortality (approximately 2% annually during 2016 through 2020) for leukemia, melanoma, and kidney cancer," the ACS authors write.
The study was supported by the European Union's Horizon 2020 research and innovation program, the Swedish Research Council, the Jane and Aatos Erkko Foundation, and others. One co-author is a shareholder in Targovax ASA and is an employee and shareholder in TILT Biotherapeutics Ltd.
Int J Cancer. Published online December 26, 2022. Full text
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Cite this: Promising Cancer Survival Trends Seen in Nordic Countries - Medscape - Jan 26, 2023.