Study Links Cancer with Increased Shingles Risk

Understanding Varicella-Zoster Virus (VZV)

A recent study examined the relationship between cancer and the risk of shingles among Australian adults. The Varicella-zoster virus (VZV), part of the herpes virus family, causes chickenpox, a highly contagious illness primarily affecting children. Characterized by itchy blisters, chickenpox can spread the virus. Notably, recovering from chickenpox does not guarantee future immunity, as the virus can remain dormant in the nervous system for many years. If reactivated, it leads to shingles.

Shingles: Symptoms and Severity

Shingles manifests as a painful rash, with symptoms that can vary significantly in severity. While some individuals experience mild symptoms that resolve quickly, others may suffer from extensive lesions that last for weeks.

Immune System Weakness and Shingles Risk

The reactivation of VZV is fairly common, yet challenging to quantify, as it can occur without noticeable symptoms. The exact mechanisms behind the virus’s reactivation remain unclear, but it is believed that a weakened immune system increases the risk. Cancer and its treatments can compromise immune function, raising the likelihood of shingles. Evidence suggests that cancer patients, particularly those undergoing chemotherapy, are at a heightened risk, although the specific contributions of cancer and its treatments to this risk are not well understood.

Research Findings on Cancer and Shingles

The study in question, published in the Journal of Infectious Diseases, involved nearly 250,000 adults from New South Wales, Australia. Researchers tracked health changes, including cancer diagnoses, over a nine-year period to assess shingles risk relative to cancer type and treatment.

Increased Risk Among Blood Cancer Patients

Results indicated that individuals diagnosed with cancer had a 40% increased risk of developing shingles compared to those without cancer. The risk was particularly pronounced among patients with blood cancers, such as leukemia, who were more susceptible during the two years prior to diagnosis and even more so in the year following. The immune system may already be impacted by blood cancers, making viral infections more likely; the onset of chemotherapy further exacerbates this risk.

Limitations of the Study

One limitation of the study is the inability to isolate the specific impact of chemotherapy on shingles risk among blood cancer patients, as nearly all of them underwent this treatment, precluding comparisons with a non-chemotherapy group. Conversely, in organ cancer patients, researchers could assess that chemotherapy increased shingles risk compared to those who did not receive such treatment.

Importance of Understanding Shingles Risk Factors

This extensive study highlights that individuals with blood cancers, as well as those with organ cancers undergoing chemotherapy, face an elevated risk of shingles. These patients not only have higher chances of developing the disease but are also more likely to experience complications.

Preventive Measures and Future Strategies

The use of preventive antiviral medications is recommended for blood cancer patients receiving chemotherapy, although guidelines for organ cancer patients are less defined. A new shingles vaccine, proven safe for individuals with compromised immune systems, offers promising potential for preventing this disease in cancer patients. The findings of this study lay the groundwork for future prevention strategies.

References

1. Qian, J., Heywood, A. E., Karki, S., Banks, E., Macartney, K., Chantrill, L., & Liu, B. (2018). Risk of Herpes Zoster Prior to and Following Cancer Diagnosis and Treatment: A Population-Based Prospective Cohort Study. The Journal of Infectious Diseases.
2. Yawn, B. P., & Gilden, D. (2013). The global epidemiology of herpes zoster. Neurology, 81(10), 928–930.
3. Kennedy, P. G. E., & Gershon, A. A. (2018). Clinical Features of Varicella-Zoster Virus Infection. Viruses, 10(11), 609.