Recently, however, researchers, including Hayday, have found an unexpected ally in their battle against autoimmune disease: cancer. It is an unexpected link, but a promising one, as Hayday explains. “In the past five years, there has been a revolution in the way we treat some cancers – by using immunological techniques,” he told the Observer. “These have had unprecedented positive results against metastatic melanomas and non-small-cell lung carcinoma. By giving patients drugs, we have been able to turn up their immune systems so they successfully mount attacks against these cancers. We have armed their immune systems and made them active.”
It is one of the most important developments in the battle against cancer this century. But side-effects have recently emerged. “There are around 140 patients undergoing immunotherapy for their cancer at Guy’s hospital in London, where I do my clinical research,” says Hayday. “Our cancer drugs boost our patients’ immune systems to help them kill off their tumours. But of course, that is the same sort of thing that happens in people with rheumatoid arthritis and diabetes: something triggers their immune systems so that they become overactive and souped-up.
“As a result, some of the cancer patients – happily, not too many – who are being treated with immunotherapies are beginning to develop rheumatoid arthritis and type I diabetes. By boosting their immune systems,” Hayday said, “we have exacerbated any tendency for these people to have had these conditions and we are beginning to see the occasional case arising among our cancer patients.”
