The number of invasive skin cancer cases continues to climb among Victorians aged 55 and over, sparking calls by researchers for a targeted awareness campaign.

The research, published in the Medical Journal of Australia, has also revealed a drop in rates of invasive melanoma for Victorians under 55, which it attributes to decades of public health campaigns targeted at the young.

The study, which used data from 1985 to 2015 from the Victorian Cancer Registry, showed the rate of invasive melanoma had overall slowed significantly for men and plateaued for women since the mid 1990s.

For Victorians aged 55 and over, the number of deadly skin cancer cases rose by 5.8 per cent each year until 1996, when the rate slowed and incidences of the disease rose by 1.6 per cent per year.

In contrast, annual decreases of 1.4 per cent for men and 1.9 per cent for women under 55 years old were recorded since the mid 1990s.

The study, published on Monday, said lower incidences of invasive cancer could indicate the diagnosis of more melanomas while they were still in the top layer of the skin.

"These results attest to the effectiveness of skin cancer prevention campaigns since the early 1980s ... (which) also promote early detection," the researchers wrote.

The findings presented an opportunity to take skin cancer campaigns in a new direction, said the researchers from the University of Sydney, Royal North Shore Hospital and Peter MacCallum Cancer Centre.

"To complement the skin cancer prevention messages that are largely directed to the young, public awareness campaigns could specifically target older people and men."

The research showed more women under 50 were diagnosed with invasive melanoma, but from age 50 the incidence was higher for men.

The location of tumours varied greatly between the sexes, with 40 per cent of tumours in men found on the trunk while in women 32 per cent were found on upper limbs and 31 per cent on lower limbs.

Men were also more likely to develop tumours on their scalp and neck, where tumours are more likely to be thick.

The different skin cancer locations may be a result of men sporting shorter hair cuts and women wearing clothes exposing their limbs, the researchers said.

"The higher rates of thicker tumours in older people show the importance of early detection in these patients, and this should be the focus of public awareness campaigns," the researchers said.