Re: Sentinel node biopsy for melanoma: unnecessary treatment?
I have enjoyed the discussion regarding whether SLNB is a treatment or a test. Increasingly it is viewed as just a test. This is different to discussions 10 and 15 years ago when we hoped SLNB would prolong life for melanoma patients. Reality bit when the MSLT1 data failed to show a 5 year survival advantage (1). Now we talk of a test that allows our patients a more accurate prediction of their prospects of beating their cancer.
We counsel our patients regarding the option of the SLNB test. We advise the lack of demonstrated survival benefit. We advise that if the test is positive that we have no clear adjunctive treatment to offer that has thus far been shown to prolong life. We explain that we remain unsure even whether to proceed to remove the remaining nodes, (while hoping MSLT 2 data might answer this question for us). We explain the test is actually an operation and had a complication rate of 10% in the MSLT 1 trial (2). We also explain the operation is expensive and not always accurate (3).
When I was a junior doctor I was taught that the fundamental purpose of a medical test is that it should help direct intervention. This is the case whenever we order a bacterial culture, a cholesterol level or a skin biopsy. One hospital made juniors tick a box confirming, “Future management of our patient is predicated on this test” before we signed a request form. SLNB ‘tests’ this boundary.
Adverse events following SLNB are not always transient and minor. Patients can suffer anaphylaxis, be left with permanent nerve damage or suffer lymphoedema (4). When I see patients so disabled by SLNB I am reminded of the importance of counselling all patients in detail of the pros and cons of the SLNB test.
We hope for our future melanoma patients that when the 10 year MSLT 1 data is published that a survival benefit in the intervention group will be demonstrated. Then we could start talking of SLNB as a treatment again. It is imperative that this full data be in the public domain as soon as possible.
1. Morton DL, Thompson JF, Cochran AJ, Mozzillo N, Elashoff R, Essner R, et al. Sentinel-node biopsy or nodal observation in melanoma. The New England journal of medicine. 2006 Sep 28;355(13):1307-17.
2. Morton DL, Cochran AJ, Thompson JF, Elashoff R, Essner R, Glass EC, et al. Sentinel node biopsy for early-stage melanoma: accuracy and morbidity in MSLT-I, an international multicenter trial. Annals of surgery. 2005 Sep;242(3):302-11;
3. Scoggins CR, Martin RC, Ross MI, Edwards MJ, Reintgen DS, Urist MM, et al. Factors associated with false-negative sentinel lymph node biopsy in melanoma patients. Annals of surgical oncology. 2010 Mar;17(3):709-17.
4. Wilke, L. G., et al. (2006). "Surgical complications associated with sentinel lymph node biopsy: results from a prospective international cooperative group trial." Ann Surg Oncol 13(4): 491-500.