Smoking status associated with melanoma survival

Key takeaways:

• Patients with melanoma who smoke had an increased risk for melanoma-associated death.
• The risk is even greater for those who smoke 20 or more cigarettes a day .

Patients with melanoma who smoke have a higher risk for melanoma-related death, according to a study.

“In past studies, and for decades, there has been no evidence to suggest that smoking increases your chance of developing melanoma. This is in contrast to many other cancer types where we know smoking increases your risk of getting cancer,” Katherine M. Jackson, MD, of the department of surgical oncology at Saint John’s Cancer Institute and the study’s lead author, told Healio.

Jackson and colleagues evaluated a post hoc analysis of data from the randomized multinational Multicenter Selective Lymphadenectomy Trials (MSLT-I and MSLT-II) in this retrospective cohort study of 6,279 patients.

Patients were split into three groups: those who did not undergo sentinel lymph node biopsy (SLNB) in MSLT-1, those who did undergo SLNB in both MSLT-I and MSLT-II who had negative findings, and those in both MSLT-I and MSLT-II who underwent SLNB with tumor-positive nodes.

Patients were categorized as current, former or never smokers based on self-reporting at trial enrollment.

An association with melanoma-related death was found in patients who currently smoked.

A multivariable analysis was performed and found decreased melanoma-specific survival (MSS) associated with current smokers (HR = 1.48; 95% CI, 1.26-1.75), but not former smokers (HR = 1.03; 95% CI, 0.89-1.20).

This was shown most in current smokers in the SLNB-negative group (HR = 1.85; 95% CI, 1.35-2.52).

Current smoking was also an independent prognostic factor for the SLNB-positive group (HR = 1.29; 95% CI, 1.04-1.59) as well as for patients who underwent nodal observation (HR = 1.68; 95% CI, 1.09-2.6).

“While other studies had mixed results regarding melanoma and survival, our results show that smoking is clearly associated with shorter survival in early-stage melanoma patients,” Jackson said.

Melanoma-associated death (MAD) also increased in those who smoked more. When quantified by light (1-9 cigarettes per day), moderate (10-19 cigarettes per day) or heavy smoking ( 20 cigarettes per day), the adjusted risk for MAD increased by approximately 20% for each group. Heavy and moderate smokers had the greatest risk for MAD compared with light smokers or nonsmokers, with the difference between light and heavy being significant (HR = 1.45; 95% CI, 1-2.09). Also, the risk for death due to melanoma was doubled among heavy smokers with SLNB-negative disease (HR = 2.06; 95% CI, 1.36-3.13).

“Heavy smokers with early-stage melanoma (stage I and II) had double the risk of dying from their disease compared to the nonsmokers. That was a striking statistic, especially for an environmental and modifiable factor like smoking,” Jackson said.

The study’s limitations included its retrospective nature, the single time point and self-reported smoking status and the study’s population.

“If you have patients who smoke, you now have evidence to suggest that smoking can worsen their odds of survival, and that quitting could be important event in melanoma,” Jackson said. “And of course, smoking counseling at every encounter is important.”