Leukaemia Areas?

Press, Volume CVI, Issue 31139, 16 August 1966, Page 3

Leukaemia Areas?

(N Z. Press Association) DUNEDIN, August 15. In certain areas of New Zealand there may be special factors with the capacity of increasing the incidence of leukaemia, Dr. F. W. Gunz, the hematologist at Christchurch Hospital, suggests in studies on the incidence and possible causes of leukaemia in New Zealand.

Dr. Gunz reported on his work to the New Zealand symposium on geographical hematology which opened in Dunedin today. Results obtained from 350.000 computer calculations confirmed the impressions gained from a “naked-eye” look at the statistics. “Geographically there seemed to be a definitely irregular distribution of cases. But to interpret the significance of such events is a diffi-

cult matter. We found aggregations both in space and time.” This is what some of the studies revealed: In a town of 2000 the only ’ two cases of childhood leukaemia in 10 years occurred during the same month in children aged one who lived within 800 yards of each other. In a surburban area two boys aged two who lived on opposite sides of the street developed acute leukaemia within a year of each other. In a thinly-populated country area of about 50 square miles four cases of childhood leukaemia occurred within two years. This was 10 times more than expected.

In another country area 11 cases, both childhood and adults were found, some close together An incidence of 30 times more than expected over 11 years was found in a country area of 1000 people. There were five acute leukaemias in children up to 16 —three of them in the same year—as well as two forms of anaemia.

“All these aggregations may of course be pure chance. The trouble is that so little is known about the distribution of leukaemia over a wider area and the significance of any deviations from regularity.

“It now seems necessary to make a much closer examination of the suspect areas and in particular to determine if anything suggests any peculiar characteristics of the disease in one or more of these areas.” Another factor noted by Dr. Gunz was that among firstdegree relatives of 590 leukaemia patients, the disease was four times more common than in a control group. “This of course need not have been caused by genetic factors, for close relatives tend to live in closely similar environments, and environmental factors can cause disease including presumably leukaemia.” It was found multiple cases were especially common where chronic lymphocytic leukaemia was involved. “In a second survey we concentrated on this type and found even more first-degree relatives with the disease. At this stage it seems that siblings of such patients have nearly eight times the chance of getting leukaemia as members of the general population.”