Patients suffering from cancer and those treated with chemotherapy may be at 40 per cent increased risk of developing shingles compared with those not having cancer finds a new study. Shingles (herpes zoster) -- marked by painful rashes and skin blisters -- is caused by the varicella zoster virus that causes chickenpox. The virus remains dormant in the body but causes shingles if it reactivates later in life. The study showed that patients with a blood-related cancer had the greatest shingles risk of more than three times compared to people without cancer the Health Day reported. The higher risk among