The past 25 years have brought enormous advances in cancer treatment. Chemotherapy has been joined by targeted therapies and immunotherapy, while treatment decisions are increasingly guided by molecular changes found in tumour cells. This can make therapy more effective and less damaging to healthy tissue, and some advanced cancers can now be controlled for many years. In the United States, the five-year relative survival rate for all cancers combined is now 70%, compared with 49% in the mid-1970s.
“At the beginning of this century, systemic cancer treatment was essentially limited to chemotherapy and, in some cancers, hormone therapy, which then played a much smaller role. Chemotherapy kills all dividing cells. Cancer cells have that characteristic, but healthy bodies also contain dividing reproductive, blood-forming and epithelial cells. That is where the toxicity and major limitations of chemotherapy came from, because doses could not be increased safely,” Prof. Jacek Jassem, head of the Department and Clinic of Oncology and Radiotherapy at the Medical University of Gdańsk, told Newseria.
Chemotherapy remains an important part of oncology, but it is no longer the only foundation of systemic treatment. Combining it with targeted drugs, immunotherapy or other methods has significantly broadened treatment options. According to the American Cancer Society’s “Cancer Statistics, 2026”, particularly strong improvements have been recorded in cancers that until recently had very poor prognoses. Between the mid-1990s and 2015–2021, five-year relative survival increased from 32% to 62% for multiple myeloma, from 7% to 22% for liver cancer and from 15% to 28% for lung cancer.
Results for advanced disease have also improved. Across all cancers diagnosed at a metastatic stage, five-year relative survival doubled from 17% in the mid-1990s to 35% among patients diagnosed in 2015–2021. The report’s authors link this improvement both to better treatment and to earlier detection.
“Other treatment methods developed mainly because we learned the molecular profiles of many cancers. First came the human genome atlas, then an atlas of molecular changes associated with cancer. It turned out that many tumours are driven by specific molecular abnormalities that underlie their development. If we block the relevant pathways, the cancer stops growing. This began the era of targeted therapies, which strike the tumour’s Achilles heel while having only a marginal effect on healthy cells. We achieved what generations of oncologists had dreamed about: attacking the cancer while damaging healthy cells to a much smaller extent,” Prof. Jassem said.
Chronic myeloid leukaemia is one example of the effectiveness of targeted therapy. According to the American Cancer Society, five-year relative survival increased from 22% in the mid-1970s to 70% among patients diagnosed in 2015–2021. The improvement is attributed mainly to tyrosine kinase inhibitors, which allow most patients to live almost as long as people in the general population.
“What happened in the 21st century, and was recognised with a Nobel Prize, was the development of immunotherapy. It does not act directly on the tumour. Instead, it releases the mechanisms that allow our T lymphocytes to work at full strength. These cells are the immune system’s main weapon against cancer. Restoring the full power of an immune system that tumour cells had been suppressing produced spectacular improvements in treatment results,” the oncologist said.
Immunotherapy first produced breakthrough results in advanced melanoma. In the United States, melanoma mortality fell by a combined 17.9% between 2013 and 2016. The reversal of the previous upward trend coincided with the wider use of immunotherapy and molecularly targeted treatment.
“Suddenly it became clear that in metastatic melanoma, where most patients once died within a year, long-term survival was possible. Some people now live for years with controlled cancer much like healthy people and eventually die from another cause. Metastatic melanoma became a chronic disease. Then came non-small-cell lung cancer and a range of other malignancies. The progress is broad, and today there are relatively few cancers in which immunotherapy has no role,” Prof. Jassem said.
The development of molecular diagnostics has also made it possible to use the same medicine in different cancers if they share the same molecular abnormality.
“We can test whether a particular molecular disorder is present in a tumour. If we find it, we can use a medicine targeted specifically at that abnormality. Tumour-agnostic therapies are becoming increasingly common because we have learned so much more about cancer and know what to look for,” he explained.
