Haematological Malignancies on the Island of Sardinia, 1974-1993: A Geographical Study

We studied the geographical distribution of all cases of HM that were diagnosed among residents of Sardinia during the 20-year period from 1974 to 1993. Cases, grouped into three categories (lymphoproliferative diseases, myeloproliferative diseases, and total haematological malignancies), were assigned to the 356 municipalities of the island according to the reported residence of each patient. In each municipality, the relative risk (RR) of diagnosis was calculated for the three disease groups, for females, for males, and for the total population. The RR of diagnosis of HM was significantly different from 1 (p<0.05) for a limited number of estimates (5.4%), with almost as many instances of elevated RR as of reduced RR. Interested municipalities (87) were distributed unevenly across Sardinia. Nevertheless, we did observe the following: 1) Municipalities with increased risk were mostly situated in central and northern Sardinia, especially for lymphoproliferative diseases in females; 2) One municipality in north-central Sardinia featured numerous estimates of elevated RR; 3) A group of municipalities near the east coast of the island had 1-5 estimates of reduced RR, particularly for lymphoproliferative diseases in females; 4) Only a few municipalities located in areas harbouring potentially polluting activities exhibited increased RRs. Observed differences in RR, if not due to chance, might be linked to unknown environmental or genetic factors.