For patients recently diagnosed with melanoma, one of the first hurdles is to find out whether the melanoma cells have spread. To do this, clinicians will biopsy the first lymph node (known as the “sentinel” node) to see if melanoma cells are present, indicating that this spread has occurred.  If it has, it greatly increases the likelihood that it has spread further. This information, in turn, helps determine the patient’s best treatment plan. 

A team led by Dr Alexander Varey from Western Sydney Local Health District and Associate Professor Serigne Lo from Melanoma Institute Australia (MIA), developed the calculator based on research funded by Sydney Health Partners and published today in the Journal of Clinical Oncology.

The research found the calculator has the potential to better identify melanoma patients who are most likely to benefit from a sentinel node biopsy, as well as those least likely to benefit.

‘For us, one of the big questions was, can we better predict which patients will be at significant risk of having their cancer spread to their lymph nodes?’ said Dr Varey.  ‘That’s what this calculator aims to do.

‘The calculator takes into account five pieces of basic information about the melanoma and the patient’s age to determine the patient’s individual risk of the cancer having spread to their lymph nodes.

‘This means that patients deemed at low risk of disease spread can potentially avoid having a sentinel node biopsy, which sometimes has complications and usually requires a general anaesthetic.’

Current treatment guidelines recommend that if a patient has a tumour with particular characteristics – mainly tumours that are slightly thicker or ulcerated – then removal and examination of the sentinel node should be considered. However, these guidelines are not tailored to individual patients and don’t account for important information, including the age of the patient. Younger age is known to be one of the most important risk factors for melanoma spreading to lymph nodes.

The research team used established international calculators as a starting point, tailoring them to Australian demographics using patient data from Melanoma Institute Australia’s extensive database, built up over a 50-year period. The team then built a new calculator to include additional patient parameters that increased its reliability. The team showed it provided considerably more accurate predictions than were previously available. 

The calculator has been trialed at sites including Royal Prince Alfred, Royal North Shore and Westmead Hospitals with enthusiastic responses from clinicians and their patients.

‘The calculator enables clinicians to have better informed discussions with their patients based on each individual’s percentage risk, rather than a few simplistic criteria that only approximate the risk of disease spread to the lymph nodes,’ said MIA Co-Medical Directors, Professors Richard Scolyer and Georgina Long.

‘The main benefit of the calculator is likely to be for those deemed to be at low risk of disease spread, who can safely forgo a sentinel node biopsy. This is of benefit particularly to older patients who are less likely to have melanoma spread to their lymph nodes, but who are at increased risk of complications from extra surgery and general anaesthesia.’ 

Avoiding unnecessary procedures is good for patients, clinicians and health services.

The Sentinel Node Biopsy Risk Calculator is available for clinician use here.