Volume 471 Number 7339 pp409-542 24 March 2011
Special Supplement: Cancer
Vaccines: Know your enemy
23 March 2011
Vaccines are arguably our greatest medical achievement. But to what extent can they help prevent cancer?
[Initial article language]
Cancer operates like a well-disguised saboteur. Occasionally it slips up by displaying unusual proteins, tripping immunological surveillance systems that are checking for abnormal growth. For decades now, scientists have tried to exploit this vulnerability with therapeutic vaccines — injections of tumour-associated proteins that essentially hang a ‘Wanted’ poster, helping immune cells recognize and kill cancer cells.
After a string of expensive and dispiriting defeats, therapeutic cancer vaccines recently registered their first big win. In April 2010, the US Food and Drug Administration (FDA) approved Provenge (sipuleucel-T) — a mixture of a patient’s own cells incubated with a protein expressed by 95% of prostate tumours. This was not an unequivocal victory, however. “On average, patients live about four months longer,” says Martin Kast, a cancer vaccine specialist at the Norris Comprehensive Cancer Center at the University of Southern California (USC) in Los Angeles. “It certainly measures up to many chemotherapeutics, but there’s still a long way to go.”