Apart from the notable exceptions of stomach and cervical cancers, other forms of the disease have shown dramatic increases over the last four decades. The US appears to be worst affected with overall rates of the disease increasing by 43 per cent, according to official figures.
Incidence is increasing in a broad range of cancers at all ages including: childhood leukaemia and brain cancer, non-Hodgkin's lymphona, melanoma, multiple myeloma, colon, bladder, prostate, testicular and breast. Lung cancer incidence has increased by over 260 per cent. Cigarette smoking is a prime culprit although one in four lung cancers is not linked to the habit.
Breast cancer has shown a disturbing trend. American women are now three times more likely to develop the disease than their great-grandmothers. The US has one of the highest breast cancer rates in the world, along with Canada and northern European countries. Irish women, both North and South, show high levels of the disease comparable to those in Britain and higher than those of France, Germany and Italy. Breast cancer has been correlated with increasing levels of industrialisation and environmental contamination. Japan, a country with a traditionally low rate of breast cancer, has over the last two decades shown the greatest increases for the disease. Some researchers point to the concurrent rapid industrialisation of the country and the heavier use of agro-chemicals.
Israel is another country with notoriously high levels of the disease which has also been associated with intensive use of agro-chemicals there. Of major interest is the finding that breast cancer rates dropped immediately when the Israeli authorities in 1978 banned three pesticides known to accumulate in breast cancer tissue.
In this context, high Irish levels of breast cancer seem contradictory given the country's "green and clean" image. However, given the island's high rainfall and prevailing wind and sea currents, it is possible that environmental contamination could originate outside the island.