The results of new cancer drugs trials have been hailed as spectacular, with one expert claiming the potential for a cure for the disease is "definitely there".
Immunotherapy, which uses the body's immune system to attack cancerous cells, proved so effective that in one British-led trial, more than half of patients with advanced melanoma saw tumours shrink or brought under control, according to researchers.
The trials, a number of which have been presented at the American Society of Clinical Oncology's annual conference in Chicago, could herald a "new era" for cancer treatments.
Professor Roy Herbst, chief of medical oncology at Yale Cancer Centre, described some of the findings as "spectacular", and said immunotherapy could replace chemotherapy as the standard cancer treatment within the next five years, according to reports.
He told reporters: "I think we are seeing a paradigm shift in the way oncology is being treated.
"The potential for long-term survival, effective cure, is definitely there."
Professor Peter Johnson, director of medical oncology at Cancer Research UK, said: "The evidence suggests we are at the beginning of a whole new era for cancer treatments."
An international trial involving 945 patients with advanced melanoma saw them treated with two drugs - ipilimumab and nivolumab.
Researchers found the treatments stopped cancer advancing for almost a year in 58% of cases, with tumours stable or shrinking for an average of 11.5 months.
This compared to 19% of cases for just ipilimumab, with tumours stable or shrinking for an average of 2.5 months, according to the research, which was published in the New England Journal of Medicine.
:: New Treatments: Q&A
Dr Alan Worsley, Cancer Research UK's senior science information officer, said the findings suggest combining immunotherapy treatments could hit advanced melanoma with a "powerful one-two punch".
He said: "Together these drugs could release the brakes on the immune system while blocking cancer's ability to hide from it."
However, Dr Worsley did sound a note of caution.
He said: "But combining these treatments also increases the likelihood of potentially quite severe side effects.
"Identifying which patients are most likely to benefit will be key to bringing our best weapons to bear against the disease."