Immune to Disappointment

So many hyped-up cancer "cures" are reported in the media that it's hard to know which – if any – will ever really make a difference. The case of a 52-year-old man who made a complete recovery from late-stage skin cancer, after being injected with billions of cells cloned from his own immune system, is one of those rare occasions when the media's coverage is justified.

It is true that this was only one man among nine to receive the new treatment. All were taking part in a clinical trial to see whether boosting their immune cells would force their cancer into remission. He alone made a remarkable recovery. It could have been a fluke; a lucky consequence of one man's physiology and the particular make-up of his cancer. To prove the treatment is useful, scientists must now conduct much larger trials. Otherwise, there will always be a niggling doubt that this patient was a one-off.

There are other reasons to be cautious. A good deal of immunotherapy research focuses on skin cancer – and for good reason. Around 2% of melanoma patients go into spontaneous remission and rarely need treatment afterwards. Scientists suspect this happens when the patient's immune system suddenly kicks into action, wiping the cancer from the body. If we can learn how this happens, so the thinking goes, we might be able to direct the full force of the immune reaction at other cancers, with a potentially dramatic impact on survival rates.

Sadly, skin cancer is rare in its vulnerability to the body's own defenses. Most cancers are more successful at hiding from the immune system and are able to dampen it down so they are not attacked. And, unlike skin cancers, they do not bristle with such obvious marker proteins, which give immune cells the green light to attack.

This case is remarkable none the less. When infused into a patient, the newly-created immune cells last only 80 days. Yet, in this man, a cancer that had spread to his lung and groin – and was surely close to killing him – was not only wiped out, but failed to reappear in medical scans two years later.

For cancer researchers, there is an urgent need to find out what went right. That could vastly improve scientists' understanding of why our bodies' defenses so often ignore cancer, and whether it might one day be possible to uncloak growing tumors so our immune systems can attack. While this one treatment may make a difference for around a quarter of skin cancer patients, the real breakthrough will be extending it to more stealthy tumors.

Writing alongside the research in the New England Journal of Medicine, Louis Weiner, director of the Lombardi Comprehensive Cancer Center at Georgetown University in Washington DC, notes that 1987 witnessed the beginning of the beginning for immunotherapy. Now, he says, we are at the beginning of the endgame. For him to say that means we are really getting somewhere.