Dermatology Year in Review: 2013

Hensin Tsao, MD, PhD

In this first presentation at MauiDerm 2014, Dr Tsao, a leader in Dermatology, provides us with an update on the latest hot topics in the field.

Melanoma

Dr Tsao begins with a short case study of a 45 year old man who presents with:

  • SSM- 0.80mm/Clark level IV
  • Mitotic rate: 2 per mm2
  • Lymphovascular invasion
  • Ulcerated
  • TILs present

As a dermatologist, would you recommend a sentinel lymph node biopsy? According to Dr Tsao “there has been a shift in the utilization of sentinel lymph node biopsies.”  Han and colleagues conducted a study with a large data set of patients (N = 5,125) with sentinel lymph node biopsies and found that in patients with thin melanomas, thickness and ulceration are the most predictive features of a positive sentinel lymph node.  This report can be found in the Journal of Clinical Oncology.

Dr Tsao’s key takeaway messages:

  • Among thin melanomas, increasing thickness and ulceration most predictive of positive nodal status
    • Rate is still low (~5%) and survival high (91% positive)
    • MSLT-1 OS: 90% negative vs. 72% positive
    • Among patients with 0.75mm/ulcerated lesions, if knowing the difference between 91% and 98% 5-year survival is important, then SLNB is reasonable

Cellulitis

A recent study from the New England Journal of Medicine looked at the use of penicillin for the prevention of recurrent leg cellulitis. The researchers found that   prophylactic penicillin (250 mg p.o. BID) reduced the risk of cellulitis recurrence by approximately 50 percent. The duration of the benefit; however, is still unknown. Future studies for penicillin-allergic patients and cost effectiveness need to be performed.

Kidney Transplant

A report by Verneuil and colleagues found that in kidney transplant patients, donor kidney cells have been found in squamous cell carcinoma. SCC arising in kidney transplant patients. In another report by Xiao and colleagues, who looked at 69 studies which reported 104 donor transmitted cancers, they found that renal cell cancer, melanoma, and lymphoma were the most common. The cancer was usually diagnosed within one year from transplantation. For most non-renal cancers, cancers are metastatic at the time of diagnosis. Additionally, immunosuppression is stopped in most instances.

What are Dr Tsao’s key takeaway points?

  • Although rare, secondary malignancies from kidney transplants have been reported
    • Provides biologic evidence of secondary metastases
    • Renal cell cancer, melanoma and lung cancers may be most common- could be reporting bias since they may most likely cause death
    • Recent malignancy is an absolute contraindication for organ donation

Remember that a solid metastases can create another metastases from a different host.

Basal Cell Carcinomas (BCCs)

According to a 2013 study by Erits and colleagues, topical imiquimod five times a week for six weeks exhibits the greatest efficacy against BCCs. This was a single-blind, non-inferiority, randomized controlled trial looking at photodynamic therapy (PDT) versus topical imiquimod versus topical fluorouracil for the treatment of superficial basal cell carcinoma. The researchers found that imiquimod appears to be superior to PDT in efficacy but also appears to be associated with more side effects and 5-FU was intermediate in terms of efficacy and side effects. Of note, the limitations of the study include short follow-up times (12 months) and lack of cost-effectiveness analysis.

GNAQ

Shirley and colleagues reported, in the New England Journal of Medicine, that an activating mosaic mutation in GNAQ (R183Q) is associated with anomalous skin and brain tissue in Sturge-Weber Syndrome. Its important to know that the variant is not as biochemically activating as the Q209 mutation observed in ocular melanoma. The R183Q variant occurs in 0.7 percent of the general population as a germline variant. Definitive proof of this mutation requires functional verificaton, e.g. model systems.

Spitz Tumors and Spitzoid Melanomas

Recently, Weisner and colleagues found that kinase fusions are frequent in Spitz tumors and spitzoid melanomas. We know that molecular diagnostics are continuing to advance and the paucity of point mutations that are identified in spitzoid neoplasms could be accounted for by gene translocations. Remember that pediatric tumors may be more susceptible to translocations while adult cancers may reflect accumulation of carcinogen-mediated point mutations. Kinase fusions offer new opportunities for treatment, though the market for metastatic spitzoid melanoma is small.

Urticaria

Let’s consider a 35 year-old woman who has had a three-year history of chronic urticaria. A 2013 study demonstrated that omalizumab reduces