A study in Australia examined patient and tumor characteristics of melanomas for higher mitotic rates (a marker of tumor cell growth) in an effort to increase earlier detection of this aggressive cancer in patients.

Prognosis and survival in patients with melanoma has been connected to the tumor characteristic known as mitotic rate, which is a measure of cell division. However, the literature is scarce regarding the clinical presentation of high-mitotic rate melanoma, which could help in identifying those patients at risk for poor prognosis.

This study, led by Sarah Shen, MBBS, BMedSci, of Alfred Hospital, in Victoria, Australia, included 1,441 patients with 1,500 primary invasive melanomas from a clinic in a public hospital in Australia.  Of the 1,500 melanomas, 813 (54%) occurred in men and 687 manifested in women.

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The study found that melanomas with higher mitotic rates were more likely to occur on the head and neck, be rapidly growing lesions (2 mm or more per month), more often present as amelanotic (without pigmentation), more often found on older men (70 years or older), and more often found on those with a history of solar keratosis caused by sun damage. A history of blistering sunburns and family history of melanoma were associated with lower mitotic rate activity. The study was published in JAMA Dermatology (2014; doi:10.1001/jamadermatol.2014.635).

“The results from this single-center study merit replication elsewhere to confirm generalizability and to further explore the potential implications for detection and treatment of at-risk patients, who in this study were found to have a distinct phenotypic and historical profile. Mitotically active melanomas were more often seen in older men with chronic solar field damage,” the authors stated. “These tumors have a predilection for the head and neck and can present with nodular structure and amelanosis. Such atypical clinical features may pose a challenge to timely detection; thus a high index of suspicion is warranted when the patient reports a history of morphologic change and rapid growth.”

“Clinicians have no guidelines by which to estimate clinically which suspect lesions might have a high mitotic rate, and therefore pose more of a threat, and which might have a low mitotic rate and ultimately behave less aggressively. The study by Shen and colleagues addresses this deficiency in knowledge and elucidates the clinical characteristics of rapidly growing tumors,” wrote Samuel J. Balin, MD, PhD, of the University of California, Los Angeles, and Raymond L. Barnhill, MD, MSc, of the University of California, Los Angeles Medical Center, in a related editorial, also published in JAMA Dermatology (2014; doi:10.1001/jamadermatol.2014.924).

The editorial concluded that, “Shen [and colleagues] provide clinicians with more data and ultimately another tool to factor into their clinical decision-making process. By understanding the clinical characteristics of more rapidly growing tumors, clinicians can better guide their own screening and treatment decisions and better counsel patients, from diagnosis through treatment, and ultimately to prognosis.”