Background/aims: Herpes zoster is associated with immunosuppression, and also has an increased risk of malignancy. The aim of this study is to determine whether patients with Herpes zoster are at a higher risk of occult malignancy and gastrointestinal diseases.
Methodology: We examined 131 of 201 Japanese patients who showed evidence of Herpes zoster in the gastrointestinal tract including the large intestine using gastrointestinal endoscopy, total colonoscopy and CT scanning.
Results: Six of 131 patients (4.6%) with Herpes zoster, who had undergone all three examinations, had malignancies. This rate is significantly higher than the predicted rate (P < 0.05). Five of six patients had gastrointestinal or colon cancer. Previously, 17 of the 201 patients has been surgically treated for cancers (17/201 = 8.5%, predictable rate = 8.9%), eleven of these 17 patients had surgery for gastric cancer, or for colon cancer etc. We also diagnosed three patients to have cancers after an episode of Herpes zoster, out of the 140 patients who we examined as study prospects (3/140 = 2.1%, relative risks = 1.75). No significant increases in the malignant rates were observed before or after the onset of Herpes zoster.
Conclusions: These findings are considered to support the policy to investigate patients with Herpes zoster for the presence of occult malignancies, though the rate of malignancy in such patients before or after episodes of Herpes zoster was not significantly different from that of the predictable rate.