Smoking raises risk of death in early-stage melanoma

Smokers who have received a diagnosis of early-stage melanoma are at increased risk of death, according to a study.

For the study, researchers conducted a a post hoc analysis of data from the first and second Multicenter Selective Lymphadenectomy Trials (MSLT-I and MSLT-II). The population comprised adults with clinical stages I or II melanoma with a Breslow thickness of at least 1.00 mm or Clark level IV to V and available standard prognostic and smoking data.

The primary outcome was melanoma-specific survival in relation to smoking status (current, former, or never) and according to the findings of sentinel lymph node biopsy (SLNB). The median follow-up duration was 110.0 months in MSLT-I and 67.6 months in MSLT-II (median 78.4 months).

A total of 6,279 patients (mean age 52.7 years, 57.9 percent men) were included in the analysis. Most patients (43.7 percent) had their tumour located at an extremity, with the mean Breslow thickness being 2.44 mm.

Of the patients, 17.2 percent were current smokers, 27.0 percent were former smokers, and 55.9 percent were never smokers. Current smokers were more likely to be of male sex and younger age, had thicker tumours, tumour ulceration, and SLNB positivity.

Multivariable analysis showed that compared with never smoking, current smoking was associated with an elevated risk of melanoma-associated death (hazard ratio [HR], 1.48, 95 percent confidence interval [CI], 1.26–1.75; p<0.001). Former smoking showed no such association.

The risk of melanoma-specific mortality associated with current smoking was pronounced for patients with SLNB-negative melanoma (HR, 1.85, 95 percent CI, 1.35–2.52; p<0.001) but was also significantly elevated for those with SLNB-positive melanoma (HR, 1.29, 95 percent CI, 1.04–1.59; p=0.02) and nodal observation (HR, 1.68, 95 percent CI, 1.09–2.61; p=0.02).

Notably, smoking at least 20 cigarettes daily was associated with a twofold increase in the risk of death due to melanoma among patients with SLNB-negative disease (HR, 2.06, 95 percent CI, 1.36–3.13; p<0.001).