A rise in the rates of certain cancers linked to obesity is a cause for concern for the future, the body responsible for keeping records of the disease said today.
The number of new cancer cases in Ireland grew by 3 per cent each year between 1994 and 2005, but the risk of dying from the disease continues to fall, latest figures show. However, cancers of the kidney, breast and uterus, all linked to obesity, are rapidly increasing.
According to the National Cancer Registry Ireland (NCRI) report published today, the overall increase in cancer cases is mostly due to the ageing and growing population.
"When we allow for these factors the risk to an individual of developing cancer is increasing very little," the NCRI said.
NCRI
"The picture is even more positive for cancer deaths; these have remained more or less the same since 1994, and the risk of dying of cancer is falling by 1.5 per cent per year."
Despite the overall trends, the risk of developing some cancers continues to increase, the NCRI said.
For men, these include prostate cancer, with a 7 per cent annual increase in risk, kidney cancer (4 per cent), melanoma (4 per cent) and lymphoma (2 per cent).
For women, the higher risks relate to kidney cancer (up 4 per cent), cancer of the uterus (2 per cent), breast (2 per cent) and lung (2 per cent).
The risk of dying from most cancers is falling, but for melanoma of the skin, cancer of the kidney (in men) and cancer of the rectum the risks are increasing.
In a statement, the NCRI said there is "no single explanation" for these trends. It expressed concern, in particular, about the continuing upward trend in lung cancer in women, which it said is due to smoking.
"Equally worrying are the trends in melanoma of the skin, which is related to sun exposure. It is striking that a number of these cancers (those of the kidney, breast and uterus) have all been linked to overweight and obesity, which are rapidly increasing in Ireland. This gives concern for the future, if the trends in weight gain continue," the NCRI said.
The rapid increase in prostate cancer is almost certainly due to many small and slow-growing cancers being picked up by the PSA blood test, which is being increasingly used.
The NCRI said most of these cancers would not have affected the man during his lifetime and would have gone undiagnosed had he not had the blood test.
"Given that the death rate from prostate cancer is falling, it is very unlikely that there is any real increase in the underlying risk of this cancer."
Cancer risk appears to be quite evenly spread throughout the country, the NCRI said.
"The report confirms earlier impressions of higher risk for many cancers in Dublin, and to a lesser extent in Cork. However, none of the geographical differences observed were major."
The body said it is working on a more detailed analysis of the relationship between area of residence and cancer risk, which it hopes to publish later this year.
For almost all cancers, the number of patients having chemotherapy and radiotherapy to treat the disease increased. Between the period 1995-1998 and 1999-2003 there was a 27 per cent increase in those having chemotherapy and a 24 per cent ncrease in radiotherapy.
"These increases were most notable for cancers of the stomach, oesophagus and pancreas and seem to signal a more active and positive approach to the treatment of these cancers, which have a relatively poor outlook," the NCRI said.