Cancer specialists have given new hope to the 13,000 people in the UK who each year are diagnosed with melanoma, a cancer that starts in the skin.
Melanoma is one of the most lethal cancers: until now sufferers have had a poor prognosis, often dying within months of being diagnosed.
Less than a quarter of those diagnosed with melanoma survive for more than 12 months; 2,200 sufferers die every year and the number developing melanoma is rising, partly due to the increasing number of people who enjoy foreign holidays.
Now Professor Peter Johnson, chief clinician at Cancer Research UK, says researchers have found new ways of using drugs that turn the body's natural defences against tumours. He is hopeful the breakthrough might lead to treatments for other forms of cancer.
The treatment works by combining two drugs, ipilimumab (ipi) and anti-PD1s, which are still in clinical trials but which appear to break down cancer cell defences. When combined, doctors say they can effectively "reboot" a patient's immune system.
One in six patients receiving the treatment are already being saved using the new treatment, and Professor Alexander Eggermont of the Institut Gustave Roussy in France believes this figure could rise to 50% within five to 10 years. Eggermont claims the new treatment might be used to treat other cancers, including kidney and lung cancer.
Melanoma - which is diagnosed in two people aged 15 to 24 each day in the UK - is notoriously difficult to treat because by the time symptoms become noticeable the cancer has often spread.
Currently the Cancer Research UK website describes melanoma as incurable, stating only: "Treatments are available that can shrink the melanoma or stop it growing. It may be possible to control it for quite a while."
Cancer researchers have always been notoriously cautious about using what they call the "C word" - for "cure". Yet when speaking about this latest breakthrough, some scientists are beginning to use that very word.
For now, though, families hoping to leave the sunscreen at home shouldn't get too excited - experts stress that when it comes to melanoma, prevention is still very much a safer bet.