In a recent study titled “IL28B Polymorphism Cannot Predict Response to Interferon Alpha Treatment in Patients with Melanoma”, published in PlosOne, a team of researchers led by Dr. Katharina Grabmeier-Pfistershammer, Medical University of Vienna, has found that in melanoma patients treated with interferon alpha, IL28B polymorphism is not associated with progression-free or overall survival.
Recent studies have reported that a particular single nucleotide polymorphism (SNP), rs12979860, in the IL28B gene could be a strong predictor of response to interferon alpha therapy in patients suffering from chronic hepatitis C infection. However, other than viral hepatitis, not much is known on the function of IL28B polymorphism in interferon therapy of other malignancies.
In melanoma patients, adjuvant interferon alpha treatment usually lasts for 18 months and is associated with toxic side effects such as liver, heart and bone marrow toxicity. Due to its long time-course and adverse toxicity, a predictive marker of therapy response would be of extreme clinical use and would avoid unnecessary therapy costs.
To address this unmet medical need, the research team designed a monocentric retrospective study that included 106 patients who had histologically proven melanoma stage IB, II or III and adjuvant low-dose or high dose interferon alpha therapy. In addition, the team gathered patients’ history, clinical and histological data, including age, sex, type and location of melanoma, clinical stage at diagnoses, and disease progression under interferon therapy, disease-free survival and overall survival.
Patient’s genomic DNA was isolated and amplified using real time polymerase chain reaction (PCR) to look for the rs12979860 SNP.
The results showed that 58.5 % of patients had the IL28B polymorphism, whereas 41.5% did not. Throughout the observation period (roughly 6 years), the team saw that, overall, disease progression occurred in 34% of patients. Among them, those carrying an rs12979860 SNP had a 27.4% ratio of disease progression, versus 43.2% of those who did not. Importantly, this ratio was higher in patients who were given high dose interferon therapy.
It has become increasingly important to identify risk factors to be able to personalize health care to specific patient’s needs and different genotypes.
This study found that, contrary to typical predictors such as tumor thickness and clinical stage, IL28B polymorphism is not related with progression-free or overall survival in patients with melanoma treated with interferon alpha.