Incipiently ulcerated melanomas may be more aggressive than nonulcerated tumors

Key takeaways:

• Tumors with incipient ulceration were thicker than nonulcerated melanomas (2.8 mm vs. 1 mm).
• Patients with nonulcerated vs. incipiently ulcerated tumors had better overall and recurrence-free survival.

Primary melanomas with incipient ulceration may be more aggressive than nonulcerated melanomas, thus warranting a higher-risk pathologic T stage, according to a study.

“There exists a subset of melanomas in which pathologic interpretation of the presence of ulceration is difficult, particularly when some, but not all, of the required diagnostic criteria for true ulceration are fulfilled,” Elizabeth C. Paver, MBBS, of Melanoma Institute Australia at The University of Sydney, and colleagues wrote. “In light of this, assessment of the prognostic implication of incipient ulceration is of potential clinical significance given that the prognosis of these patients is currently uncertain.”

The researchers conducted a case-control study to evaluate the clinicopathological factors of incipiently ulcerated melanoma vs. ulcerated or nonulcerated melanoma and the outcomes of affected patients.

The study consisted of 340 patients (median age, 69 years; 68% men) that were diagnosed with resected primary cutaneous melanoma between 2005 and 2015. Forty incipiently ulcerated melanoma cases were matched with 80 nonulcerated controls and 80 ulcerated controls. Median follow-up was 7.2 years.

Results showed that tumors with incipient ulceration had a greater median Breslow thickness than nonulcerated melanomas (2.8 mm vs. 1 mm; P < .001) but were not as thick as ulcerated melanomas (5.3 mm; P < .001). Similarly, incipiently ulcerated tumors showed a greater median mitotic activity rate than nonulcerated tumors (5 per mm² vs. 1 per mm²; P < .001) but less than ulcerated controls (9 per mm²).

Further, incipiently ulcerated tumors were more likely than nonulcerated tumors to have lymphovascular invasion, positive sentinel nodes and satellite lesions.

Compared with patients with incipient ulceration, those with nonulcerated tumors had significantly better overall survival (HR = 0.49; 95% CI, 0.27-0.88) and recurrence-free survival (HR = 0.37; 95% CI, 0.22-0.64). The recurrence-free survival, however, was significantly worse in ulcerated vs. incipiently ulcerated tumors (HR = 1.67; 95% CI, 1.07-2.6).

“The findings of this retrospective case-control study indicate that the classification of primary melanomas with incipient ulceration as nonulcerated and assigning them a lower-risk pathologic T stage may not be appropriate,” the authors concluded. “Moving forward, pathologists should comment on the presence of incipient ulceration in pathology reports of primary melanomas, so that related data on this feature can continue to be collected.”