A special report published by the BMJ has found that thousands of melanoma patients around the world are undergoing an expensive and invasive procedure called sentinel node biopsy, despite a lack of clear evidence and concerns that it may do more harm than good.
Although not recommended for routine use in England, it has become the standard care for melanoma patients in a number of countries.
Melanoma is the fifth most common cancer in the UK, affecting one in 60 people. In the US it affects one in 50 people and, of the seven most common cancers, is the only one that is increasing. Sentinel node biopsy was developed in the US in the early 1990s to detect the early spread of cancer cells in melanoma patients. It involves taking a small sample of the lymph node nearest to the melanoma for testing. If cancer cells are found, patients are advised to have surgery to remove some of the surrounding lymph nodes.
In 2006, a trial (known as MSLT-I) published in NEJM found that sentinel node biopsy did not improve overall survival after 5 years, yet the researchers claimed that disease-free survival was significantly higher in the biopsy group. The results proved controversial, but further analyses of the data that would have settled the question of effectiveness have not yet been published.
Meanwhile, large numbers of patients are being exposed to unnecessary and potentially harmful surgery. It is thought that as many as 96% of patients who have sentinel node biopsy will have unnecessary surgery, which carries a risk of complications such as lymphoedema, cellulitis (deep skin infection) and scarring.
In England, guidance states that sentinel node biopsy should be performed only in centres with expertise in the context of clinical trials. Yet data obtained by the BMJ show that at least 19 trusts across England carried out sentinel node biopsy procedures on melanoma patients between 2006 and 2011.
Commenting on the report, BMJ Editor Dr Fiona Godlee, says the evidence that research goes unreported is overwhelming, putting patients at risk and wasting resources. She calls on both industry and academia to clean up their act.