AS REPORTED IN the Journal of Clinical Oncology by Sandra L. Wong, MD, of Dartmouth-Hitchcock Medical Center, and colleagues, ASCO and the Society of Surgical Oncology (SSO) have issued an update to the ASCO/SSO clinical practice guideline on sentinel lymph node biopsy and management of regional lymph nodes in melanoma.1 The previous version of the guideline was published in 2012.
Sandra L. Wong, MD
Gary H. Lyman, MD
For the update, an ASCO/SSO expert panel performed a systematic review of the literature on sentinel lymph node biopsy and completion lymph node dissection after a positive sentinel node in patients with melanoma. The update was informed by nine new observational studies, two systematic reviews, an updated randomized controlled trial of sentinel lymph node biopsy, and two randomized controlled trials of completion lymph node dissection after positive sentinel lymph node biopsy. The expert panel was co-chaired by Dr. Wong and Gary H. Lyman, MD, of Fred Hutchinson Cancer Research Center, Seattle.
The primary guideline questions follow: What are the indications for sentinel lymph node biopsy? What is the role of completion lymph node dissection? Key recommendations are summarized/reproduced here; the type of recommendation, quality of evidence, and strength of recommendation are shown in brackets. It should be noted that Breslow thickness categories are defined according to the American Joint Committee on Cancer staging system 8th edition.2
Key Recommendations
THIN MELANOMAS: Routine sentinel lymph node biopsy is not recommended for patients with melanomas that are T1a (nonulcerated lesions < 0.8 mm Breslow thickness). Sentinel lymph node biopsy may be considered for T1b patients (0.8–1.0 mm Breslow thickness or < 0.8 mm Breslow thickness with ulceration), after a thorough discussion with the patient of the potential benefits and risks of harm associated with the procedure. [Type = evidence-based, potential benefits outweigh risks of harm; quality of evidence = low to intermediate; strength of recommendation = moderate].
Intermediate-thickness melanomas: Sentinel lymph node biopsy is recommended for patients with melanomas that are T2 or T3 (Breslow thickness > 1.0–4.0 mm). [Type = evidence-based, potential benefits outweigh risks of harm; quality of evidence = intermediate; strength of recommendation = moderate].
Thick melanomas: Sentinel lymph node biopsy may be recommended for patients with melanomas that are T4 (> 4.0 mm Breslow thickness), after a thorough discussion with the patient of the potential benefits and risks of harm associated with the procedure. [Type = evidence-based, potential benefits outweigh risks of harm; quality of evidence = low to intermediate; strength of recommendation = moderate].
In the case of a positive SLN biopsy, either completion lymph node dissection or careful observation may be offered to patients with low-risk micrometastatic disease, with due consideration of clinicopathologic factors. For higher-risk patients, careful observation may be offered only after a thorough discussion with patients about the potential risks and benefits of foregoing completion lymph node dissection. [Type = evidence-based, potential benefits outweigh risks of harm; quality of evidence = intermediate to high; strength of recommendation = strong].
“Routine sentinel lymph node biopsy is not recommended for patients with melanomas that are T1a (nonulcerated lesions < 0.8 mm Breslow thickness).”— Sandra L. Wong, MD, and colleagues
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The guideline update includes qualifying statements regarding the use of completion lymph node dissection vs careful observation, as below:
Key evidence for this recommendation comes from the Multicenter Selective Lymphadenectomy II (MSLT-II) and German Dermatologic Oncology Cooperative Group (DeCOG-SLT) randomized controlled trials.3,4 In both trials, the authors reported no difference in melanoma-specific survival between the completion lymph node dissection and close observation groups. The incidence of lymphedema was significantly higher in the completion lymph node dissection group in the MSLT-II trial. The percentage of patients with sentinel node metastases that were < 1.01 mm (micrometastases) in these two trials was 66%.
High-risk features of the sentinel lymph node can be defined on the basis of the exclusion criteria of MSLT-II, such as extracapsular spread/extension, concomitant microsatellitosis of the primary tumor, more than three involved nodes, more than two involved nodal basins, and immunosuppression of the patient. Lower-risk features may be defined as no characteristics defined as high risk but should also take into account other clinicopathologic features, after thorough discussion with the patient.
Both MSLT-II and DeCOG-SLT were conducted in patient populations in which the observation group received frequent follow-up evaluations, including the use of serial nodal ultrasound. Consequently, results from these trials may have limited applicability in settings where patients are unable to undergo frequent follow-up evaluations or in those who receive treatment at institutions that are not able to perform high-quality nodal ultrasonography.
Additional information is available at www.asco.org/melanomaguidelines. ■
DISCLOSURE: For full disclosures of the authors, visit www.jco.ascopubs.org.
REFERENCES
1. Wong SL, Faries MB, Kennedy EB, et al: Sentinel lymph node biopsy and management of regional lymph nodes in melanoma: American Society of Clinical Oncology and Society of Surgical Oncology clinical practice guideline update. J Clin Oncol 36:399-413, 2018.
2. Gershenwald JE, Scolyer RA, Hess KR, et al: Melanoma staging: Evidence-based changes in the American Joint Committee on Cancer eighth edition cancer staging manual. CA Cancer J Clin 67:472-492, 2017.
3. Leiter U, Stadler R, Mauch C, et al: Complete lymph node dissection versus no dissection in patients with sentinel lymph node biopsy positive melanoma (DeCOG-SLT): A multicentre, randomised, phase 3 trial. Lancet Oncol 17:757- 767, 2016.
4. Faries MB, Thompson JF, Cochran AJ, et al: Completion dissection or observation for sentinel-node metastasis in melanoma. N Engl J Med 376:2211-2222, 2017.
