Potentially fatal skin cancers called melanomas are more likely to grow fast
when they’re thicker, symmetrical, elevated, have regular borders or produce
symptoms, a new Australian study found.
“Rapidly growing melanomas can potentially
kill in a matter of weeks,” said lead researcher Dr. Wendy Liu, of the Peter
MacCallum Cancer Center, in East Melbourne.
“They can occur in anyone, not necessarily
those with large numbers of moles and freckles. In fact, they more often occur
in those without large numbers of moles and freckles and elderly men. They are
more often red, rather than brown and black, symmetrical, elevated and
symptomatic,” Liu added.
In the study, Liu’s team investigated the
growth rate of melanoma in 404 patients with invasive melanoma. Patients had
their skin examined, and data about the moles were collected. In addition,
patients were interviewed as soon as possible after
Patients and their families were asked to
recall when they first noticed a spot on their skin from which the melanoma
later developed, and when they noticed the mole had changed or become
The researchers collected data on
demographics, skin cancer risk factors, the characteristics of the tumor and who
first detected the cancer — the patient, a family member or friend, or a
Using this information and the thickness of
the tumor when it was removed, Liu’s group was able to estimate its rate of
The researchers found that about one-third
of all the melanomas grew less than 0.1 millimeters per month, another one-third
grew between 0.1 millimeter and 0.49 millimeters per month, and one-third grew
0.5 millimeters or more per month.
Rapid tumor growth was associated with
tumor thickness, ulceration (formation of a break or sore on the skin),
amelanosis (lack of pigment in the tumor), regular borders, elevation and
Moreover, faster-growing melanomas were
more often found in people 70 and older, in men, and in those with fewer moles
and freckles, the researchers reported.