Prognostic role of microsatellites in melanoma and implications in the American Joint Committee on Cancer classification system: A cohort study

BACKGROUND

There is limited information on microsatellite survival outcomes in patients with melanoma.

OBJECTIVE

To evaluate survival outcomes in patients with microsatellites, assess their role within stage III stratification of the American Joint Committee on Cancer classification, and assess the results of sentinel lymph node biopsies in patients with microsatellites.

METHODS

A retrospective bicenter cohort study from 1998 to 2019 included patients with a diagnosis of invasive cutaneous melanoma.

RESULTS

Of a total of 5216 patients, 108 (2.1%) had microsatellites at initial staging. Survival analysis showed that microsatellites were an independent risk factor with decreased overall survival (OS), melanoma-specific survival (MSS), and disease-free survival, with hazard ratios of 1.57, 1.76, and 1.76, respectively. Stratified analysis in patients with stage III melanoma showed a 5-year OS of 35% (95% CI, 17.3%-73.4%) and a MSS of 45% (95% CI, 23.1-87.5) for patients with stage IIIB melanoma with microsatellites.

LIMITATIONS

Retrospective design of the study.

CONCLUSION

Microsatellites were associated with other adverse melanoma prognostic factors. A multivariate Cox regression analysis showed that they are an independent risk factor for worse OS, MSS, and disease-free survival. Patients with stage IIIB melanoma with microsatellites had worse OS and MSS, whereas patients with stage IIIC melanoma had worse OS but not MSS.

Introduction of a pilot program to measure and improve the clinical care of melanoma patients in the Lower Silesian Voivodeship in Poland: a report of 20 months experience

BACKGROUND

In recent years, benchmarking and assessment methods to improve the quality of care have become increasingly important. Such approaches allow for a uniform assessment, comparisons between centers or over time, and the identification of weaknesses. In this study, the results of a 20-month pilot program to assess, monitor and improve the quality of care in melanoma patients primarily treated surgically are presented.

METHODS

The pilot program started in May 2020 at the Lower Silesian Oncology, Pulmonology and Hematology Center (LSOPHC) in Wroclaw, Poland (Lower Silesian Voivodeship, southwestern province of Poland with a population of 2,9 million). The program involved the introduction of a synoptic histopathological protocol, medical coordinators, and a set of measures to assess oncological care. In total, 11 Skin Cancer Unit (SCU) measures were introduced to analyze clinical outcomes, diagnostic quality, and duration. Data from 352 patients covered by the program were analyzed. In addition, the completeness of diagnostics from external sites was compared to our own results. Furthermore, the timeliness of the initial diagnostic tests and in-depth diagnostics were assessed and compared to the timeliness before implementation of the pilot program.

RESULTS

The introduced measures assessed the mortality related to oncological treatment, the rate of complications, advanced stages of melanoma, the completeness and duration of diagnostics, the involved nodes after lymphadenectomy, and melanoma screening. During the study period, the timeliness of the initial diagnostics was maintained at 87.8%, and the timeliness of the in-depth diagnostics at 89.5%. Compared to a similar period before the program, these values were 36.1% and 67.5%, respectively.

CONCLUSION

The introduced measures seem to be effective and practical tools for benchmarking clinical and diagnostic aspects. They also allowed for a sensitive assessment of individual issues and indicated sensitive points. Furthermore, the actions undertaken in this pilot program allowed for a shortening of the duration of diagnostics.

Is the presence of tumor-infiltrating lymphocytes predictive of outcomes in patients with melanoma?

BACKGROUND

The 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.

METHODS

The 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).

RESULTS

Overall, 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).

CONCLUSIONS

TILs 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.

Surveillance of Sentinel Node-Positive Melanoma Patients with Reasons for Exclusion from MSLT-II: Multi-Institutional Propensity Score Matched Analysis

BACKGROUND

In sentinel lymph node (SLN)-positive melanoma, two randomized trials demonstrated equivalent melanoma-specific survival with nodal surveillance vs completion lymph node dissection (CLND). Patients with microsatellites, extranodal extension (ENE) in the SLN, or >3 positive SLNs constitute a high-risk group largely excluded from the randomized trials, for whom appropriate management remains unknown.

STUDY DESIGN

SLN-positive patients with any of the three high-risk features were identified from an international cohort. CLND patients were matched 1:1 with surveillance patients using propensity scores. Risk of any-site recurrence, SLN-basin-only recurrence, and melanoma-specific mortality were compared.

RESULTS

Among 1,154 SLN-positive patients, 166 had ENE, microsatellites, and/or >3 positive SLN. At 18.5 months median follow-up, 49% had recurrence (vs 26% in patients without high-risk features, p < 0.01). Among high-risk patients, 52 (31%) underwent CLND and 114 (69%) received surveillance. Fifty-one CLND patients were matched to 51 surveillance patients. The matched cohort was balanced on tumor, nodal, and adjuvant treatment factors. There were no significant differences in any-site recurrence (CLND 49%, surveillance 45%, p = 0.99), SLN-basin-only recurrence (CLND 6%, surveillance 14%, p = 0.20), or melanoma-specific mortality (CLND 14%, surveillance 12%, p = 0.86).

CONCLUSIONS

SLN-positive patients with microsatellites, ENE, or >3 positive SLN constitute a high-risk group with a 2-fold greater recurrence risk. For those managed with nodal surveillance, SLN-basin recurrences were more frequent, but all-site recurrence and melanoma-specific mortality were comparable to patients treated with CLND. Most recurrences were outside the SLN-basin, supporting use of nodal surveillance for SLN-positive patients with microsatellites, ENE, and/or >3 positive SLN.

Re-evaluation of Sentinel Lymph Node Biopsy for Melanoma

OPINION STATEMENT

The vast majority of patients newly diagnosed with melanoma present with clinically localized disease, and sentinel lymph node biopsy (SLNB) is a standard of care in the management of these patients, particularly in intermediate thickness cases, in order to provide important prognostic data. However, SLNB also has an important role in the management of patients with other subtypes of melanoma such as thick melanomas, certain thin melanomas, and specific histologic variants of melanoma such as desmoplastic melanoma. Furthermore, there have been technical advances in the SLNB technique, such as the development of newer radiotracers and use of SPECT/CT, and there is some data to suggest performing a SLNB may be therapeutic. Finally, the management of patients with a positive sentinel lymph node (SLN) has undergone dramatic changes over the past several years based on the results of recent important clinical trials. Treatment options for patients with SLN metastases now include surveillance, completion lymph node dissection, and adjuvant therapy with checkpoint inhibitors and targeted therapy. SLNB continues to play a crucial role in the management of patients with melanoma, allowing for risk stratification, potential regional disease control, and further treatment options for patients with a positive SLN.

Sentinel Lymph Node Biopsy Is Prognostic in Thickest Melanoma Cases and Should Be Performed for Thick Melanomas

BACKGROUND

Sentinel lymph node biopsy (SLNB) is recommended for intermediate thickness melanoma, but for thick melanoma, guidelines are less definitive about the use of SLNB in this population. We present a study on thick melanoma evaluating for prognostic factors.

PATIENTS AND METHODS

The Sentinel Lymph Node Working Group database was queried for thick (> 4 mm) melanoma cases that had a SLNB from 1993 to 2018. Clinicopathologic characteristics were correlated with SLN status and melanoma-specific survival (MSS).

RESULTS

There were 1235 patients. Median follow-up was 28 months. Median thickness was 5.9 mm, with 956, 175, and 104 cases presenting thickness > 4-8, > 8-12, and > 12 mm, respectively. SLN metastases were seen in 439 of 1235 (35.5%) cases and in 33.9%, 40.6%, and 42.3% of melanomas > 4-8, > 8-12, and > 12 mm, respectively. In each thickness group, MSS was significantly worse for SLN-positive compared with SLN-negative cases (all P < 0.005). Multivariable analysis showed that SLN metastasis, male gender, increasing thickness, lymphovascular invasion, and microsatellitosis significantly predicted worse MSS for melanomas > 4-8 mm, with SLN metastasis showing the greatest risk (HR 2.17, 95% CI 1.64-2.87, P < 0.0001). For melanomas > 8 mm, only SLN metastasis significantly predicted MSS (> 8-12 mm: HR 3.93, 95% CI 2.00-7.73, P < 0.0001; > 12 mm: HR 3.58, 95% CI 1.56-8.22, p < 0.0027).

CONCLUSIONS

Thick melanoma patients with SLN metastasis have significantly worse MSS compared with SLN-negative patients, even in the thickest cases, and SLN status is the most powerful and/or only predictor of MSS. Given these results, SLNB shows important prognostic value in this population and is indicated for clinically localized thick melanoma.

Effect of delay between nuclear medicine scanning and sentinel node biopsy on outcome in patients with cutaneous melanoma

BACKGROUND

Sentinel lymph node biopsy (SLNB) is an important staging tool for the management of melanoma. A multicentre study was done to validate previous findings that the timing of lymphoscintigraphy influences the accuracy of SLNB and patient outcomes, particularly survival.

METHODS

Data were reviewed on patients undergoing SLNB for melanoma at three centres in the UK and Sweden, examining the effect of timing of SLNB after nuclear medicine scanning. Kaplan-Meier survival analysis was used to assess overall (OS), disease-specific (DSS) and progression-free (PFS) survival, stratified by timing of lymphoscintigraphy. Independent risk factors for survival were identified by Cox multivariable regression analysis.

RESULTS

A total of 2270 patients were identified. Median follow-up was 56 months. Univariable analysis showed a 4·2 per cent absolute and 35·5 per cent relative benefit in DSS (hazard ratio 1·36, 95 per cent c.i. 1·05 to 1·74; P = 0·018) for 863 patients whose SLNB was performed up to 12 h after lymphoscintigraphy compared with 1407 patients who had surgery after more than 12 h. There were similar OS and PFS benefits (P = 0·036 and P = 0·022 respectively). Multivariable analysis identified timing of lymphoscintigraphy as an independent predictor of OS (P = 0·017) and DSS (P = 0·030). There was an excess of nodal recurrences as first site of recurrence in the group with delayed surgery (4·5 versus 2·5 per cent; P = 0·008).

CONCLUSION

Delaying SLNB beyond 12 h after lymphoscintigraphy with ⁹⁹ Tc-labelled nanocolloid has a significant negative survival impact in patients with melanoma.

Pathology of Melanoma

Melanoma is an aggressive malignancy arising from melanocytes in the skin and rarely in extracutaneous sites. The understanding of pathology of melanoma has evolved over the years, with the initial classifications based on the clinical and microscopic features to the current use of immunohistochemistry and genetic sequencing. The depth of invasion and lymph node metastasis are still the most important prognostic features of melanoma. Other important prognostic features include ulceration, lymphovascular invasion, mitosis, and tumor-infiltrating lymphocytes. This article reviews the pathology of melanoma and its precursor lesions, along with the recent advances in pathologic diagnosis of melanoma.