Topographical and Chronological Analysis of Thin Cutaneous Melanoma's Progressions: A Multicentric Study

Long-term outcomes and patterns of recurrence in patients with thin melanoma and a negative sentinel lymph node biopsy: a single-center experience

The majority of patients diagnosed with melanoma have thin melanomas (≤1 mm). Data on the rate and pattern of recurrence after a negative sentinel lymph node biopsy (SLNB) are sparse. We retrospectively searched our institutional database and retrieved the records of patients with thin melanomas who underwent an SLNB with negative results. We analyzed patterns of recurrence, time to recurrence, and mode of diagnosis. Thirteen of the 198 patients with thin melanomas and negative SLNB results had tumor recurrence (6.5%): two local in transit (15.4%), three regional (21.3%), and eight distant (61.5%). Distant recurrences tended to occur later than local or regional ones [median disease-free survival = 50 months (95% confidence interval: 36.1-63.9) vs. 34 and 15 months (95% confidence interval: 5.4-24.6), P = 0.005, respectively]. The percentage of patients with tumor thickness ≥0.8 mm was higher among those who sustained recurrence (84.6 vs. 64.9% for no recurrence, P = 0.04). The majority of patients with recurrence were not being followed up when diagnosed (69%), and they are presented because of clinical symptoms. Patients with recurrence had lower survival compared with those without recurrence (median: 118 months vs. ongoing survival, P < 0.001, respectively). Melanoma recurrence in patients with thin melanomas and negative SLNBs is rare, tends to be distant, and negatively affects prognosis. Recurrence tends to occur in patients with melanoma thickness ≥0.8 mm. Further studies are needed to identify patients with high recurrence risk and determine optimal follow-up protocols.

Diagnostic and prognostic risk factors analysis for distant metastasis in melanoma: a population-based study

BACKGROUND

We aimed to develop tools that could predict the occurrence of distant metastases in melanoma and its prognosis based on clinical and pathological characteristics.

MATERIALS AND METHODS

We obtained data from the Surveillance, Epidemiology, and End Results (SEER) database of melanoma patients diagnosed between 2010 and 2019. Logistic analyses were performed to identify independent risk factors associated with distant metastasis. Additionally, multivariate Cox analyses were conducted to determine independent prognostic factors for patients with distant metastasis. Two nomograms were established and evaluated with the receiver operating characteristic (ROC) curves, calibration curves, and decision curve analysis (DCA). Furthermore, we performed a retrospective analysis of melanoma with distant metastasis from our institute between March 2018 and June 2022.

RESULTS

Of the total 19 396 melanoma patients, 352 (1.8%) had distant metastases at the time of diagnosis. The following clinical and pathological characteristics were identified as independent risk factors for distant metastasis in melanoma: N stage, tumor size, ulceration, mitosis, primary tumor site, and pathological subtype. Furthermore, tumor size, pathological subtype, and radiotherapy were identified as independent prognostic factors. The results of the training and validation cohorts' ROC curves, calibration, DCA, and Kaplan-Meier survival curves demonstrate the effectiveness of the two nomograms. The retrospective study results from our center supported the results from the SEER database.

CONCLUSION

The clinical and pathological characteristics of melanoma can predict a patient's risk of metastasis and prognosis, and the two nomograms are expected to be effective tools to guide therapy decisions.