In Korean patients, male sex and Breslow thickness greater than 2.5 mm are the most important prognostic factors for localized melanoma recurrence, according research in Journal of the American Academy of Dermatology.
“In our study, recurrence of localized melanoma showed no relevance to age or presence of ulceration, but was associated with sex,” Yeongjoo Oh, MD, of the department of dermatology, Cutaneous Biology Research Institute at Yonsei University College of Medicine, Seoul, and colleagues wrote.
Medical records were reviewed at a single hospital in the Yonsei University Health System for patients diagnosed with cutaneous malignant melanoma. Eligible patients visited the clinic for more than 6 months after the primary melanoma removal. Sentinel lymph node biopsy was performed in patients with Breslow thickness of at least 1 mm. After complete removal, high-dose adjuvant interferon-alpha was administered to those with stage IIB and IIC when appropriate.
A total 340 patients were included in the analysis and 92 patients (27.1%) were classified with recurrence after primary tumor removal. The mean follow-up period was 46.2 months. Local recurrence was found in 25 patients, regional metastasis in 37 patients and distant metastasis in 18 patients.
The average patient age was 57.94 years and 57.4% were women. The acral area was the most common anatomic site (70.3%), and acral melanoma was the predominant histologic subtype (65.2%).
Among 227 patients evaluated for mitotic rate, the average rate was 1.8/mm2.
Twenty-one patients (29.6%) had BRAF mutation of the 71 evaluated for the mutation.
Sentinel lymph node biopsy was performed in 192 patients, most had greater than 1 mm depth, of which 67 patients (34.9%) showed recurrence, according to researchers.
The majority of recurrences (81.5%) were detected within 3 years from surgery.
Men had a higher recurrence rate than women (P = .03).
The researchers determined that Breslow thickness was related to recurrence rates and recurrence-free survival with 1 mm and 2 mm cutoffs.
Furthermore, “age, tumor location, histologic subtypes, tumor removal surgery type, presence of lymphovascular invasion or tumor infiltrating lymphocytes, and BRAF mutation showed no statistical relationships with recurrence rate or recurrence-free survival,” Oh and colleagues wrote.
In men, depths of 2 mm to 4 mm and greater than 4 mm showed similar recurrence; however, women did not show the same correlation at these depths.
The researchers identified a new criteria for those at high risk of recurrence. Thickness greater than 2.5 mm in men and greater than 4 mm in women was shown to have a higher predictive power in localized melanoma compared with the traditional high-risk groups of stage IIB and IIC, according to researchers.
The retrospective nature of the study along with the methods of surgery, follow-up and high-dose adjuvant interferon-alpha treatment were not controlled and represent limitations. Larger nationwide studies among Asian patients with melanoma are needed to confirm these results.
“Although previous studies investigating risk factors for recurrence of localized melanomas could not prove male sex as a risk factor, we showed that sex was an important risk factor for predicting recurrence, even in localized melanomas,” Oh and colleagues wrote. – by Abigail Sutton
Disclosures: The authors report no relevant financial disclosures.