Certain Autoimmune Skin Diseases Linked to Better Cancer Prognosis

Individuals with pre-existing autoimmune skin diseases (ASDs) had disproportionately better survival outcomes after antineoplastic treatment for cancer, a large population-based study in Taiwan found.

Over a mean follow-up of 566 days, all-cause mortality rates significantly favored those with ASDs compared with non-ASD peers (23.10 vs 25.99 per 100 person-years, adjusted HR 0.94, 95% CI 0.92-0.96), according to Li-Ting Kao, PhD, of the National Defense Medical Center in Taipei City, Taiwan, and colleagues.

The difference was also apparent for cancer-specific mortality (subdistribution HR 0.94, 95% CI 0.92-0.96).

“The survival advantage was particularly evident in patients with alopecia areata and Sjögren’s syndrome, and remained consistent across cancer stages, anticancer treatment regimens, and most comorbidity subgroups,” study authors noted in JAMA Dermatology.

The study adds an important layer to how we understand the intersection between chronic inflammation and oncologic prognosis, commented Danilo Del Campo, MD, of the Chicago Skin Clinic. “Given what we know about the immune system’s role in both skin disease and cancer biology, this connection is biologically plausible,” he said.

“Cancer attempts to evade the immune system, so patients with an ‘overactive’ immune system, such as those with ASD, have the benefit of a higher likelihood that their immune system can battle their cancer, as demonstrated by this study,” explained Steven Daveluy, MD, of Wayne State Dermatology in Dearborn, Michigan, who wasn’t involved with the research.

“The authors saw a similar pattern for rheumatoid arthritis, confirming that it’s the autoimmune nature of the diseases that confers a survival benefit,” Daveluy told MedPage Today. “We know that patients treated with immune checkpoint inhibitors for their cancer, which stimulate an immune response, have better prognosis when they develop immune-mediated diseases, including skin disease.”

“That’s the silver lining that we share with patients who develop these side effects during cancer treatment: we have to deal with the symptoms of these side effects, but it means your medication will work better against your cancer,” according to him.

He cautioned that some of the skin conditions in the present study (e.g., psoriasis, hidradenitis suppurativa, vitiligo, alopecia areata, and lichen planus) can be better classified as autoinflammatory.

“Now we can also provide some reassurance to patients with pre-existing inflammatory skin diseases that they are likely to have better outcomes as well. We wouldn’t wish an inflammatory skin disease on anyone, but it’s nice to know that if you have the unfortunate luck of developing cancer, maybe your skin disease can turn from a burden to a blessing,” Daveluy concluded.

For their observational study, Kao and colleagues probed Taiwan’s National Health Insurance database for patients with cancer who received antineoplastic medications, specifically immune checkpoint inhibitors, monoclonal antibodies, protein kinase inhibitors, and chemotherapy treatments from 2019 to 2021.

There were nearly 200,000 individuals identified for the analysis, split between the ASD group (mean age 64 years, 57.6% women) and non-ASD group (mean age 62.8 years, 46.9% women).

Inverse probability of treatment weighting and propensity score matching created comparable groups for analysis.

The ASD subtypes linked with significantly lower mortality rates after cancer treatment were:

• Alopecia areata (adjusted HR 0.83, 95% CI 0.77-0.90)
• Sjögren’s syndrome (adjusted HR 0.89, 95% CI 0.86-0.92)
• Vitiligo (adjusted HR 0.89, 95% CI 0.80-0.99)
• Psoriasis (adjusted HR 0.97, 95% CI 0.93-1.00)

Meanwhile, no significant survival difference could be detected for lupus erythema, lichen planus, bullous, sclerosis, morphea, hidradenitis, or dermatomyositis.

The researchers acknowledged study limitations including the absence of information on ASD severity and the potential of residual confounding (e.g., lifestyle factors, genetic predisposition, and environmental exposures).

“The study’s large sample size and stratified analysis by cancer type add credibility, particularly with the consistent signal seen in breast and prostate cancers. Of course, this is observational data, and there are many potential confounders to consider. But the signal is certainly worth exploring further,” said Del Campo.

“The field of immunology truly sits at the crossroads of dermatology, and it is clear that this connection continues to deepen as we learn more,” he said. “While this may not be practice-changing at the moment, it’s a meaningful reminder of the value of multidisciplinary care and the importance of staying tuned in to emerging evidence.”