British Medical Journal letter

Anthony Dixon letter - Is SLNB in melanoma a test or a treatment? - BMJ - February 2013

I have enjoyed the discussion regarding whether SLNB is a treatment or a test. Ten years ago we hoped SLNB ‘treatment’ would prolong life for melanoma patients. Then the MSLT1 data failed to show a 5 year survival advantage (1) . Now we talk of the SLNB ‘test’ that allows patients a more accurate survival prediction.

We counsel our patients regarding the option of the SLNB test. We advise the lack of demonstrated survival benefit. We advise that we have no clear life prolonging treatment to offer if the test is positive. We explain that we remain unsure even whether to remove the remaining nodes, (whilst 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) .

As a junior doctor I was taught first do no harm and that the fundamental purpose of a medical test is to direct intervention, such as when ordering 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’ these boundaries.

SLNB adverse events include anaphylaxis, permanent nerve damage and lymphoedema (4) . When I see patients so disabled by SLNB I am reminded of the importance of detailing the pros and cons of the SLNB test to new melanoma patients.

We hope for future melanoma patients that when the 10 year MSLT 1 data is published 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 promptly published.

Anthony J. Dixon PhD MB BS MAOCD FACRRM

Australasian College of Cutaneous Oncology

66 Roslyn Rd, Belmont, Victoria, 3216, Australia

References

  1.  Morton DL, Thompson JF, Cochran AJ, Mozzillo N, Elashoff R, Essner R, et al. Sentinel-node biopsy or nodal observation in melanoma. N Engl J Med. 2006; 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. Ann Surg. 2005; 242(3): 302-11; discussion 11-3.
  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. Ann Surg Oncol. 2010; 17(3): 709-17.
  4. Wilke LG, McCall LM, Posther KE, Whitworth PW, Reintgen DS, Leitch AM, et al. Surgical complications associated with sentinel lymph node biopsy: results from a prospective international cooperative group trial. Ann Surg Oncol. 2006; 13(4): 491-500.