Messina, Jane L.

Importance Contemporary guidelines recommend sentinel lymph node biopsy (SLNB) for patients with melanoma with predicted risk of SLN metastasis greater than 10% and consideration of SLNB when the risk is 5% to 10%. A gene expression profile (GEP)–based test that can accurately identify patients with a low risk of SLN metastasis would refine selection for SLNB. Objective To establish the predictive capability of the combined clinicopathological factors and GEP (CP-GEP) test to identify patients with primary cutaneous melanoma who can safely forgo SLNB and to investigate the prognostic value of CP-GEP regarding the outcome in patients with cutaneous melanoma after a negative SLNB (not reported herein). Design, Setting, and Participants This prognostic study was conducted from September 2021 to June 2024 at 9 academic medical centers with experienced melanoma surgeons. Included were patients with biopsy-proven invasive cutaneous melanoma with T1 to T3 tumors and clinically negative regional LNs. All patients were deemed candidates for SLNB using standard clinical criteria. GEP was performed on formalin-fixed, paraffin-embedded tissue from the primary melanoma biopsy. Analyses were performed from December 2024 to August 2025. Intervention CP-GEP testing to determine risk of having a positive SLNB in patients with T1 to T3 cutaneous melanoma who were considered appropriate candidates for the procedure based on standard clinical parameters. Main Outcomes and Measures CP-GEP results were reported as low risk or high risk; the primary outcome measure was negative predictive value (NPV) in low-risk cases. Analyses included NPV assessment by tumor (T) subcategory, primary site, and age. Results A total of 1761 patients (median [IQR] age, 64 [53-72] years; 997 male [56.6%]) underwent SLNB (310 [17.6%] SLN positive) and had a successful CP-GEP test; GEP was successful in 97.7% of samples. A total of 651 patients (37.0%) were considered low risk by CP-GEP. Among low-risk cases, 46 (7.1%) were SLN positive, and NPV was 92.9% (95% CI, 90.7%-94.8%). High-risk cases had a 23.8% (264 of 1110) SLN-positive rate. The percentage of cases with low-risk CP-GEP declined with increasing T category (T1 = 346 of 507 [68.2%]; T2 = 295 of 897 [32.9%]; T3 = 10 of 357 [2.8%]). CP-GEP results were consistent in discriminating SLN-positive rates across primary sites, histologic subtypes, and mitotic count categories. In 2 large subsets, clinical stage IB (n = 1187) and patients 65 years and older (n = 832), 6.5% (95% CI, 4.6%-8.8%) of low-risk clinical stage IB cases and 6.6% (95% CI, 4.2%-9.7%) of all low-risk cases in patients 65 years and older were SLN positive vs 18.3% (95% CI, 15.3%-21.6%) and 20.3% (95% CI, 16.8%-24.2%) for high-risk cases, respectively. Conclusions and Relevance In this multicenter, prospective, blinded, prognostic study, the CP-GEP test reliably identified patients with melanoma with less than 10% SLN metastasis risk. SLN metastasis rates were approximately 3-fold greater for high-risk vs low-risk CP-GEP cases. In appropriately selected patients, the CP-GEP test may add value for shared patient-surgeon decision-making.

BackgroundThe significance of tumor‐infiltrating lymphocytes (TILs) in melanoma is debated. This article presents a multicenter, retrospective study assessing the predictive and prognostic value of TILs.MethodsThe Sentinel Lymph Node Working Group database was queried from 1993 to 2018 for cases with known TIL data. TILs were categorized as absent or present, which included nonbrisk (NB), brisk (B), and present but unspecified TIL levels. Clinicopathologic factors were correlated with TILs, sentinel lymph node (SLN) status, and melanoma‐specific survival (MSS).ResultsOverall, 3203 patients were included. The median thickness was 1.5 mm, and 469 cases had SLN metastases. TILs were present in 2458 cases (76.7%), with NB, B, and unspecified TILs seen in 1691 (68.8%), 691 (28.1%), and 76 (3.1%), respectively. Multivariable analysis showed that the presence of TILs significantly predicted a negative SLN biopsy (P < .05). The median follow‐up was 25.2 months. MSS was significantly better for cases with TILs than cases without TILs (P < .001). According to multivariable analysis, age, gender, thickness, mitotic rate, ulceration, lymphovascular invasion, and SLN status were significantly prognostic of MSS (all P values < .05). Although TILs were not prognostic of MSS, when multiple imputation was used and the SLN status was excluded, the presence of TILs was significantly prognostic of improved MSS (hazard ratio, 0.78; 95% confidence interval, 0.64‐0.95; P = .0154).ConclusionsTILs are a favorable marker because their presence significantly predicts a negative SLN, and the absence of TILs may be a prognostic marker of worse survival in patients with a positive SLN but not a negative SLN. TILs may also serve as a prognostic marker of survival when the SLN status is not considered.

AbstractBackgroundAppropriate use criteria (AUC) provide patient‐centered physician guidance in test selection. An initial set of AUC was reported by the American Society of Dermatopathology (ASDP) in 2018. AUC reflect evidence collected at single timepoints and may be affected by evolving evidence and experience. The objective of this study was to update and expand AUC for selected tests.MethodsRAND/UCLA (RAND Corporation [Santa Monica, CA]/University of California Los Angeles) methodology used includes the following: (a) literature review; (b) review of previously rated tests and previously employed clinical scenarios; (c) selection of previously rated tests for new ratings; (d) development of new clinical scenarios; (e) selection of additional tests; (f) three rating rounds with feedback and group discussion after rounds 1 and 2.ResultsFor 220 clinical scenarios comprising lymphoproliferative (light chain clonality), melanocytic (comparative genomic hybridization, fluorescence in situ hybridization, reverse transcription polymerase chain reaction, telomerase reverse transcriptase promoter), vascular disorders (MYC), and inflammatory dermatoses (periodic acid‐Schiff, Gömöri methenamine silver), consensus by panel raters was reached in 172 of 220 (78%) scenarios, with 103 of 148 (70%) rated “usually appropriate” or “rarely appropriate” and 45 of 148 (30%), “appropriateness uncertain.” Limitations: The study design only measures appropriateness. Cost, availability, test comparison, and additional clinical considerations are not measured. The possibility that the findings of this study may be influenced by the inherent biases of the dermatopathologists involved in the study cannot be excluded.ConclusionsAUC are reported for selected diagnostic tests in clinical scenarios that occur in dermatopathology practice. Adhering to AUC may reduce inappropriate test utilization and improve healthcare delivery.

AbstractBackground and ObjectivesThe prognostic significance of regression in predicting melanoma recurrences is unknown. We present a large multicenter study correlating regression with recurrence.MethodsThe Sentinel Lymph Node Working Group database was queried from 1993 to 2018 for cases with regression data. Clinicopathologic factors were correlated with overall and first‐site of recurrence and with recurrence‐free survival (RFS).ResultsThere were 4790 patients and the median follow‐up was 39.6 months. Regression and recurrences were seen in 1081 (22.6%) and 773 (16.1%) cases, respectively. First‐site locoregional and distant recurrences were seen in 412 (8.6%) and 352 (7.3%) patients, respectively. Regression was seen in 15.8% and 24.7% of all cases with and without recurrences (p < 0.0001), respectively, while regression was seen in 14.3% and 17.9% of first‐site locoregional and distant recurrent cases, respectively, compared with 23.3% and 22.9% of patients with regression and without first‐site locoregional and distant recurrences, respectively (p = 0.29). On multivariable analysis, after controlling for age, gender, thickness, ulceration, lymphovascular invasion, and sentinel lymph node status, regression significantly predicted improved RFS (p = 0.004) and fewer first‐site regional recurrences (p = 0.017).ConclusionOur data suggest that regression is a favorable prognostic marker in melanoma and predicts significantly better RFS and decreased first‐site regional recurrences.

8025 Background: The Src/Stat 3 pathway has been implicated in the pathogenesis of several malignancies including melanoma. In the current study we evaluated the prevalence of Src and Stat3 activation in human melanoma and the effect of Src inhibitors alone or in combination with chemotherapeutic agents on melanoma cell lines. Methods: Activation of Src was measured by staining for Src-phosphotyrosine 416 (P-Src) and Stat3 by phosphotyrosine 705 Stat3 (P-Stat3). Immunohistochemistry was performed with anti-pStat3-Y705 and anti-pSrc-Y416 antibodies (Cell Signaling, Beverly, MA) on 3 melanoma subtypes. Staining of tumor cells for P-Stat3 was scored by percentage of stained cells as follows: 0 (no staining), 1 (1–25%), 2 (26–50%), 3 (>50%), and intensity 0–3 (0: absent, 1: low, 2: moderate, and 3: high). The sum of these was the composite P-Stat3 score: 0 (0), 1 (1–2), 2 (3–4), and 3 (5–6). P-Src staining was scored by intensity. Melanoma cell lines, A-375, SK-Mel-5 and SK-Mel-28 were exposed to Src inhibitors, SKI-606, PD 180970 and BMS 354825 alone or in combination with standard chemotherapy agents and IC-50 was determined by MTT assay at 24 and 72 hours. Results: 35 biopsies were stained. Median age was 66 years (range 23–90); 60% were women. 48% of all melanoma stained express P-Src; all samples express pStat3. We found a positive correlation between P-Src and P-Stat3 (Spearman coefficient=0.346, p=0.042). 46% stained only for pStat3 and 6% did not stain for either P-Src or P-Stat3. Most positively stained biopsies stained weakly for P-Src and moderately or strongly for pStat3. Src inhibitors inhibited the proliferation of melanoma cell lines; furthermore Src inhibitor treatment synergized with platinum and topoisomerase I inhibitors but not temozolomide. Conclusions: 1) Immunohistochemistry shows variable expression of P-Src and P-Stat3 in human melanoma 2) All tumors staining for P-Src also stain for P-Stat3 and the strength of staining is significantly related. 3) This data may be useful in planning future clinical trials with Src inhibitors in melanoma. [Table: see text] [Table: see text]

AbstractBackgroundCompletion lymph node dissection (CLND) for sentinel lymph node (SLN) disease in melanoma patients is debated. We evaluated the impact of CLND on survival and assessed for predictors of nonsentinel node metastasis (positive CLND).MethodsPositive SLN melanoma patients were retrospectively identified in the Sentinel Lymph Node Working Group database. Clinicopathological factors were correlated with CLND status, overall survival (OS), and melanoma‐specific survival (MSS).ResultsThere were 953 positive SLN patients of whom 831 (87%) had CLND. Positive CLND was seen in 141 (17%) cases and was associated with worse OS and MSS (both P < 0.001). CLND was not performed (No‐CLND) in 122 of 953 positive SLN cases (13%), of whom 100 had follow‐up and 18 (18%) developed a nodal recurrence (NR). No significant differences in OS and MSS were seen comparing CLND with No‐CLND (P = 0.084, P = 0.161, respectively) and comparing positive CLND with No‐CLND NR patients (P = 0.565, P = 0.998, respectively). Gender, primary site, ulceration, and number of positive SLNs were correlated with nonsentinel node metastasis.ConclusionsPerformance of CLND provides prognostic information but is not associated with a survival benefit. Clinical variables can predict a positive CLND in patients who may be at high risk of recurrence.

Abstract: Cellular blue nevomelanocytic lesions (CBNLs) frequently pose diagnostic problems to pathologists, and their biological potential may be difficult to establish. In this study, the authors have analyzed the clinical, histological, and outcome data of 37 cellular blue nevomelanocytic lesions and the molecular characteristics of 4 lesions. The cohort of cases comprised 8 cellular blue nevi (CBNs), 17 atypical cellular blue nevi (ACBNs), and 12 blue-nevus–like melanomas (BNLMs) with a mean follow-up of 5 years. The average age at diagnosis was 25.9 years for patients with ACBN, versus 30.4 years for CBN, and 44.6 years for BNLM. Both CBN and ACBN occurred most frequently on the trunk or extremities, whereas BNLM primarily involved the scalp. Histologically, CBN and ACBN were characterized by a mean diameter of <1 cm, absence of necrosis, low mitotic rate (mean: 1–2 mitotic figures/mm2), little or no infiltrative properties, and usually low-grade cytologic atypia. In contrast, BNLM had a mean diameter of 1.6 cm, necrosis, tissue infiltration, greater mitotic activity (mean: 6 mitotic figures/mm2), and high-grade cytologic atypia. ACBNs often were larger, more densely cellular, exhibited higher mitotic counts, and were cytologically more atypical than CBN. Seven CBN cases with follow-up had a benign clinical course (average follow-up of 4.7 years). Among 6 patients with ACBN who underwent sentinel lymph node (SLN) biopsy, 3 were positive, and a single additional case had 1 positive non-SLN (this patient did not have a SLN biopsy performed). All 14 cases of ACBN with follow-up were alive and without recurrence with mean follow-up of 5 years. Of the 9 melanoma cases with follow-up, 3 patients with SLN and non-SLN involvement died from their disease (average follow-up of 4.8 years). Array comparative genomic hybridization was performed on 2 ACBNs and 1 BNLM: One of the 2 ACBNs showed chromosomal aberrations and 1 BNLM showed multiple chromosomal gains and losses. Multiplex polymerase chain reaction was performed on 1 ACBN, and no mutations were found. From these results, the authors conclude that ACBN occupy an intermediate position within the spectrum of CBN and BNLM, yet many lesions cannot be reliably distinguished from either CBN or BNLM because of overlapping histologic features. However, in general, ACBNs seem to aggregate more closely with CBN in terms of clinical, histological, molecular profile (limited data), and biological behavior.

Purpose Indications for sentinel lymph node biopsy (SLNB) for thin melanoma are continually evolving. We present a large multi-institutional study to determine factors predictive of sentinel lymph node (SLN) metastasis in thin melanoma. Patients and Methods Retrospective review of the Sentinel Lymph Node Working Group database from 1994 to 2012 identified 1,250 patients who had an SLNB and thin melanomas (≤ 1 mm). Clinicopathologic characteristics were correlated with SLN status and outcome. Results SLN metastases were detected in 65 (5.2%) of 1,250 patients. On univariable analysis, rates of Breslow thickness ≥ 0.75 mm, Clark level ≥ IV, ulceration, and absence of regression differed significantly between positive and negative SLN groups (all P < .05). These four variables and mitotic rate were used in multivariable analysis, which demonstrated that Breslow thickness ≥ 0.75 mm (P = .03), Clark level ≥ IV (P = .05), and ulceration (P = .01) significantly predicted SLN metastasis with 6.3%, 7.0%, and 11.6% of the patients with these respective characteristics having SLN disease. Melanomas < 0.75 mm had positive SLN rates of < 5% regardless of Clark level and ulceration status. Median follow-up was 2.6 years. Melanoma-specific survival was significantly worse for patients with positive versus negative SLNs (P = .001). Conclusion Breslow thickness ≥ 0.75 mm, Clark level ≥ IV, and ulceration significantly predict SLN disease in thin melanoma. Most SLN metastases (86.2%) occur in melanomas ≥ 0.75 mm, with 6.3% of these patients having SLN disease, whereas in melanomas < 0.75 mm, SLN metastasis rates are < 5%. By using a 5% metastasis risk threshold, SLNB is indicated for melanomas ≥ 0.75 mm, but further study is needed to define indications for SLNB in melanomas < 0.75 mm.

BACKGROUNDThe management of pediatric melanoma (PM) has largely been extrapolated from adult data. However, the behavior of PM appears to differ from its adult counterparts. Therefore, an international PM registry was created and analyzed.METHODSTwelve institutions contributed deidentified clinicopathologic and outcome data for patients diagnosed with PM from 1953 through 2008.RESULTSOverall survival (OS) data were reported for 365 patients with invasive PM who had adequate follow‐up data. The mean age of the patients was 16 years (range 1 year‐21 years). The 10‐year OS rate, 80.6%, tended to vary by patient age: 100% for those aged birth to 10 years, 69.7% for those aged > 10 years to 15 years, and 79.5% for those aged > 15 years to 20 years (P = .147). Patients with melanomas measuring ≤ 1 mm had a favorable prognosis (10‐year OS rate of 97%), whereas survival was lower but similar for patients with melanomas measuring > 1 mm to 2 mm, > 2 mm to 4 mm, and > 4 mm (70%, 78%, and 80%, respectively; P = .0077). Ulceration and lymph node metastasis were found to be correlated with worse survival (P = .022 and P = .017, respectively). The 10‐year OS rate was 94.1% for patients with American Joint Committee on Cancer stage I disease, 79.6% for those with stage II disease, and 77.1% for patients with stage III disease (P < .001).CONCLUSIONSTumor thickness, ulceration, lymph node status, and stage were found to be significant predictors of survival in patients with PM, similar to adult melanoma. There is a trend toward increased survival in children aged ≤ 10 years versus adolescents aged > 10 years. Further analyses are needed to probe for potential biological and behavioral differences in pediatric versus adult melanoma. Cancer 2013;119:4012–4019. © 2013 American Cancer Society.