Cancer risk in Northern Ireland lower than the Republic of Ireland

People in Northern Ireland have a lower risk of developing some cancers than those living in the Republic of Ireland, according to the All-Ireland Cancer Atlas - a collaborative publication by the Northern Ireland Cancer Registry at Queen's University Belfast and the National Cancer Registry in Cork.

The first ever All-Ireland Cancer Atlas analysed 18 types of cancer by electoral division over a 12-year period.

Those cancers which were significantly higher for both sexes in the Republic of Ireland were:

• Non-melanoma skin cancer
• Melanoma
• Leukaemia
• Bladder
• Pancreas
• Brain/central nervous system cancers

For men, the risk of prostate cancer was higher in the Republic of Ireland and, for women, cancer of the oesophagus and cervix were higher.

Lung cancer, however, was higher in Northern Ireland compared with the Republic.

The following cancers were higher for women in Northern Ireland:

• Uterus
• Non-Hodgkin's lymphoma
• Head and neck cancers

The Atlas also found that the following cancers were more common in areas of higher unemployment and/or lower levels of degree attainment across the island.

• Lung
• Stomach
• Head and neck
• Cervical cancers

The following cancers were lower in areas of higher unemployment and/or lower levels of degree attainment:

• Non melanoma skin cancer
• Female breast cancer
• Prostate cancer
• Melanoma

Other findings include:

• Stomach cancer rates were higher in a band running from Dublin to Donegal, excluding the north-east, but including Belfast.
• There was no statistically significant difference in female breast cancer risk between the Republic of Ireland and Northern Ireland.
• The risk of diagnosis of prostate cancer was 29 per cent lower in Northern Ireland. Men in areas with the highest educational attainment had the highest risk.
• The risk of head and neck cancer was greater, by 21 per cent, for women in Northern Ireland compared to the Republic of Ireland but there was no statistically significant difference for men.

Commenting on the findings in the Atlas, Dr Anna Gavin, Director of the Northern Ireland Cancer Registry, said: "Mapping the incidence of cancer geographically in Ireland is hugely important in our quest to understand factors that increase cancer rates and also to provide appropriate treatment and cancer services.

"While it is generally accepted that geographic variations in cancer risk are predominantly the result of factors such as tobacco smoking, alcohol drinking, obesity, diet and sexual behaviour there are also a number of findings which we cannot explain yet including the band of increased stomach cancer incidence from Donegal to Dublin. The launch of the first All-Ireland Cancer Atlas today will enable us to further identify different contributing factors to cancer in Ireland."

Dr Harry Comber, Director of the National Cancer Registry, said: "The Atlas shows major variations, sometimes more than two-fold, in the risk of several cancers, across the island. Understanding the reasons for this geographical variation, and taking appropriate action, would reduce the cancer burden significantly in Ireland. Areas with unexplained higher than average risk should now be studied in detail and a comprehensive programme of research into already known determinants of cancer risk in Ireland is needed to inform cancer control."