Skin Cancer Review

A review of recent news, research, and treatment related to skin cancer.

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One Diuretic Therapy Linked to Skin Cancer Risk 

High hydrochlorothiazide (Microzide) use was associated with an increased risk of Merkel cell carcinoma (MCC) and malignant adnexal skin tumors (MAST), according to the findings of a recent study published in the Journal of the American Academy of Dermatology. 

In the study, researchers identified patients with MCC or MAST from the Danish nationwide health registries from 2004 to 2015 and matched the cases with cancer-free population controls. They calculated estimated odds ratios (ORs) to determine the risk of developing cancer based on cumulative hydrochlorothiazide exposure.

The adjusted OR for high use of hydrochlorothiazide was 2.3 for MCC (95% CI, 1.1-4.8) and 3.6 for MAST (95% CI, 1.9-7.0). The ORs for MCC and MAST increased to 3.3 (95% CI, 1.3-8.3) and 5.6 (95% CI, 2.4-13.3), respectively, for the highest use of hydrochlorothiazide. 

While the researchers found no increased risk of tumors in analyses of drugs with indications similar to hydrochlorothiazide, they found furosemide use was associated with a tendency toward increased MCC risk (OR 1.9; 95% CI, 0.9-4.0). A study limitation was the limited data available on sun exposure. 

Reference

Pedersen SA, Schmidt SAJ, Hölmich LR, Friis S, Pottegård A, Gaist D. Hydrochlorothiazide use and risk of Merkel cell carcinoma and malignant adnexal skin tumors: A nationwide case-control study [published online June 15, 2018]. J Am Acad Dermatol. doi:10.1016/j.jaad.2018.06.014

Location of cSCC on Lip Linked to Recurrence and Mortality Risk 

Cutaneous squamous cell carcinoma (cSCC) on the vermilion lip was associated with an increased risk for metastasis and disease-specific mortality compared to the cutaneous lip, according to the findings of a recent study published in JAMA Dermatology

The retrospective cohort study included 303 participants with 310 primary cSCCs on the lip diagnosed between 2000 and 2015 at 2 academic tertiary care centers (median age 68 years, 50.5% were men). A total of 138 cSCCs were on the cutaneous lip and 172 were on the vermilion lip. The development of local recurrence, nodal metastasis, distant metastasis, disease-specific death, and all-cause death were assessed as the main outcomes. 

Local recurrence for the vermilion location was 6.4% compared with 2.9% for cutaneous location. Nodal metastasis, distant metastasis, disease-specific death, and all-cause death for vermilion location were 7.6%, 0.6%, 3.5%, and 26.7%, respectively, compared with 1.5%, 0.7%, 2.9%, and 29% among cutaneous cSCCs. Additionally, the difference for nodal metastasis was found to be statistically significant and multivariable analysis showed that nodal metastasis was associated with vermilion lip location and invasion beyond fat with a subhazard ratio of 4.4 (95% CI, 1.3-14.9).

“The risk of nodal metastasis is 5-fold greater for cSCCs on the vermilion lip compared with those on the cutaneous lip. Squamous cell carcinomas of the cutaneous lip have a nodal metastasis risk similar to cSCCs in general (1.5%),” the researchers concluded. “Thus, vermilion involvement appears responsible for the increased risk associated with cSCC of lip. Vermilion involvement may merit radiologic nodal staging and inclusion in future tumor staging since it was independently associated with higher-risk cSCC of the lip region.” 

Reference

Wang DM, Kraft S, Rohani P, et al. Association of nodal metastasis and mortality with vermilion vs cutaneous lip location in cutaneous squamous cell carcinoma of the lip. JAMA Dermatol. 2018;154(6):701-707.

Negative Margins Are Poor Predictors of Residual BCC

A recent study found that negative margins in basal cell carcinoma (BCC) biopsies are poor predictors of residual disease.

While pathology reports often contain comments on positive or negative margins of BCC biopsies with only 1%-2% of the margins evaluated, the negative predictive value (NPV) of these margins on the presence of residual BCC is not known. 

To determine the NPV of biopsy margin status on the absence of residual BCC, the researchers collected 143 BCC biopsies with negative margin readings that had subsequent excisions from their institutions’ archives. The excision blocks were sectioned at 150-μm intervals until exhausted to determine a read as negative for residual BCC.

A total of 34 biopsies were found to have residual BCC in the corresponding excision, with a NPV of 76%, and the residual histologic subtype was superficial in 31 of these cases. A limitation of this study was that the sectioning technique did not evaluate 100% of the excision specimens.

“We recommend clinicians treat these lesions, and that pathologists who comment on margin status of BCC biopsies consider adding a caveat to reflect these findings,” the researchers concluded. 

Reference

Willardson HB, Lombardo J, Raines M, et al. Predictive value of basal cell carcinoma biopsies with negative margins: a retrospective cohort study. J Am Acad Dermatol. 2018;79(1) 42-46.