Association between allergies and cancer: do allergies offer protection from cancer?

According a comprehensive literature review, individuals with any type of allergy have a decreased risk for cancer (compared with the general population), including:

• glioma
• colorectal cancer
• cancer of the larynx
• non-Hodgkin lymphoma
• cancer of the esophagus
• oral cancer
• pancreatic cancer
• stomach cancer
• uterine body cancer

However, an increased risk for the following cancers was observed among those with allergies:

• bladder cancer
• lymphoma
• myeloma
• prostate cancer

Further research is needed to verify these results and to determine why such associations may exist.

References:

The association between allergies and cancer: what is currently known? Merrill RM, Isakson RT, Beck RE. Ann Allergy Asthma Immunol. 2007 Aug;99(2):102-16; quiz 117-9, 150.
Relationship between Allergy and Cancer: enhanced immunosurveillance might prevent cancer http://goo.gl/uq9mC

Related reading:

Allergo-Oncology. Prof. Erika Jensen-Jarolim, MD, head of the Department of Pathophysiology at the Center of Physiology, Pathophysiology and Immunology, Medical University of Vienna.

Are cancer and allergy mutually exclusive?: Myths and difficulties. JACI News Beyond Our Pages, 2010.

Patients with atopic dermatitis were at 1.5 times greater risk of getting cancer in a large UK study of 4.5 million people. The cancers included lymphoma, melanoma, and non-melanoma skin cancer. http://bit.ly/bGjdpO
Can allergies prevent tumors? Can antihistamines increase risk? CNN - Probably not. Most pts with allergies take anthistamines.

Assessment of Type of Allergy and Antihistamine Use in the Development of Glioma http://goo.gl/105HQ
The nascent field of AllergoOncology  http://goo.gl/tUZ32