AJCC IB Melanoma and Sentinel Node Status
Research type
Research Study
Full title
AJCC IB Melanoma: The Lost Tribe? Evaluating the utility of sentinel node biopsy in AJCC IB melanoma patients in the context of adjuvant systemic therapy
IRAS ID
284808
Contact name
Marc Moncrieff
Contact email
Sponsor organisation
Norfolk & Norwich University Hospital Foundation NHS Trust
Clinicaltrials.gov Identifier
83-05-20, Local R&D
Duration of Study in the UK
1 years, 3 months, 1 days
Research summary
Summary of Research
Melanoma is the fifth most common cancer in the UK and has a disproportionate preponderance to affect patients of a younger age. Nearly half the patients diagnosed with the disease are under 65 years old. Fortunately, the overall prognosis for melanoma is good with the 10 year survival approaching 90%. Accordingly, decisions made about patient's care at the time of diagnosis have important survivorship issues.
The current standard of care for intermediate stage melanoma (AJCC IB) is to offer a sentinel lymph node biopsy as a staging procedure for the early detection of the presence of microscopic spread to the draining lymph nodes. For patients with more advanced stage melanoma (AJCC II), a positive sentinel node biopsy means that the patient has a very high risk of distant recurrence and they should be referred to the Oncologist for consideration of adjuvant systemic therapy. In the case of the AJCC IB patient, with less high-risk melanoma, the chance of having a positive sentinel node is only 10%. Furthermore, if a positive node is detected in the sentinel node biopsy, the risk of recurrence is so low that adjuvant systemic therapy is not indicated in many countries at present, including the UK. Whilst there is some therapeutic benefit from act of removing the sentinel node itself, it is estimated from previous major studies that this benefit is limited to a very small fraction of the entire AJCC IB cohort (~4%).
AJCC IB patients make up ~50% of the entire sentinel node biopsy caseload yet they are the group that have the least to gain. A retrospective review of the data is merited nationally to better stratify patients and streamline resource usage in the post-covid recovery phase. This study has been identified as a priority in the UK melanoma forum.Summary of Results
Purpose: Indications for offering adjuvant systemic therapy for patients with early-stage melanomas with low disease burden sentinel node (SN) micrometastases, namely, American Joint Committee on Cancer (AJCC; eighth edition) stage IIIA disease, are presently controversial. The current study sought to identify high-risk SN-positive AJCC stage IIIA patients who are more likely to derive benefit from adjuvant systemic therapy.
Methods: Patients were recruited from an intercontinental (Australia/Europe/North America) consortium of nine high-volume cancer centers. All were adult patients with pathologic stage pT1b/pT2a primary cutaneous melanomas who underwent SN biopsy between 2005 and 2020. Patient data, primary tumor and SN characteristics, and survival outcomes were analyzed.
Results: Three thousand six hundred seven patients were included. The median follow-up was 34 months. Pairwise disease comparison demonstrated no significant survival difference between N1a and N2a subgroups. Survival analysis identified a SN tumor deposit maximum dimension of 0.3 mm as the optimal cut point for stratifying survival. Five-year disease-specific survival rates were 80.3% and 94.1% for patients with SN metastatic tumor deposits ≥ 0.3 mm and < 0.3 mm, respectively (hazard ratio, 1.26 [1.11 to 1.44]; P < .0001). Similar findings were seen for overall disease-free and distant metastasis-free survival. There were no survival differences between the AJCC IB patients and low-risk (< 0.3 mm) AJCC IIIA patients. The newly identified high-risk (≥ 0.3 mm) subgroup comprised 271 (66.4%) of the AJCC IIIA cohort, whereas only 142 (34.8%) patients had SN tumor deposits > 1 mm in maximum dimension.
Conclusion: Patients with AJCC IIIA melanoma with SN tumor deposits ≥ 0.3 mm in maximum dimension are at higher risk of disease progression and may benefit from adjuvant systemic therapy or enrollment into a clinical trial. Patients with SN deposits < 0.3 mm in maximum dimension can be managed similar to their SN-negative, AJCC IB counterparts, thereby avoiding regular radiological surveillance and more intensive follow-up.
REC name
North East - Tyne & Wear South Research Ethics Committee
REC reference
20/NE/0174
Date of REC Opinion
1 Jul 2020
REC opinion
Further Information Favourable Opinion