People with more than one primary melanoma are 39% more likely to die than those who have only one primary melanoma, according to a study that researchers claim settles a controversy.

Opposing reports of the effect on survival of having more than one primary melanoma may be because of the use of inappropriate statistical methods, Australian researchers say.

Their meta-analysis of just four studies, using ‘correct’ statistical methods, shows that, over the same time period, people with more than one primary melanoma are 39% more likely to die than those with only one.

Until now, studies have produced widely differing estimates of the effect of having two primaries, with some even suggesting that having two or more primary melanomas is protective, while other research shows that survival was reduced.