Volume 202 - Issue 2
Sentinel lymph node biopsy for melanoma: an important risk-stratification tool
Authors: Samuel S Zagarella, Michael Sladden, Catalin Popescu and Michael Bigby
Med J Aust 2015; 202 (2): 78. || doi: 10.5694/mja14.01569
Published online: 2 February 2015
Published online: 2 February 2015
The benefits of sentinel lymph node biopsy are unproven
To the Editor: The article by Gyorki and Henderson1 is misleading and inaccurate. The stated primary outcome of the Multicenter Selective Lymphadenectomy Trial-1 (MSLT-1) was:
To determine whether wide excision of the primary with intraoperative lymphatic mapping (LM) followed by selective lymphadenectomy will effectively prolong overall survival compared to wide excision of the primary melanoma alone.2
It was prolongation of overall survival, and not disease-specific survival as the authors state.1
The MSLT-1 final report3 is an example of selective reporting bias, and failed to prove its primary outcome. The conclusions based on the post-hoc analysis are unreliable, and should never be used to guide management decisions, yet the MSLT-1 trial reporting focused almost exclusively on these results.
The other claimed benefit by the authors of MSLT-1, disease-free survival, is an illusion and has been rejected on several grounds, lead-time bias being a chief one.4
Lymph node status may not be the strongest predictor of survival for patients with intermediate thickness melanoma. Indeed, combining clinicopathological features (thickness, mitotic count, ulceration, vessel invasion, site, age and sex) better predicts relapse and survival in melanoma than sentinel lymph node biopsy (SLNB) status alone.5
We thus question the prerequisite for SLNB to be performed for patients to enter drug trials.
High-resolution ultrasound can already detect lymph node deposits of 2 mm, and this technique will improve. We reject any assertion that SLNB should be the “standard of care”, as any benefits are unproven.
In conclusion, subjecting patients to a surgical procedure, with the risk of morbidity, for no clearly demonstrated benefit is questionable.
Competing interests
No relevant disclosures.
References
- Gyorki DE, Henderson MA. Sentinel lymph node biopsy for melanoma: an important risk-stratification tool. Med J Aust 2014; 201: 442-444. _Ref408830041
- ClinicalTrials.gov. A service of the U.S. National Institutes of Health. Multicenter Selective Lymphadenectomy Trial (MSLT). http://clinicaltrials.gov/ct2/show/NCT00275496?term=NCT00275496&rank=1 (accessed Nov 2014).
- Morton DL, Thompson JF, Cochran AJ, et al. Final trial report of sentinel-node biopsy versus nodal observation in melanoma. N Engl J Med 2014; 370: 599-609. _Ref408830082
- Sladden M, Zagarella S, Popescu C, Bigby M. No survival benefit for melanoma patients undergoing sentinel lymph node biopsy: critical appraisal of the multicenter selective lymphadenectomy trial-1 final report. Br J Dermatol 2015. In press. _Ref408830084
- Mitra A, Conway C, Walker C, et al. Melanoma sentinel node biopsy and prediction models for relapse and overall survival. Br J Cancer 2010; 103: 1229-1236. _Ref408830085