Geographic heterogeneity of neoplasia‐associated chromosome aberrations

Abstract

Using a database comprising 13,266 cytogenetically abnormal neoplasms, the geographic heterogeneity of neoplasia associated chromosomal abnormalities was investigated by comparing the frequencies of characteristic aberrations in consec utive series of patients with the same diagnosis. Significant frequency differences between geographic areas were found for the aberrations +8, i(17q), +19, and an additional Ph¹ chromosome in chronic myeloid leukemia (CML); ‐5, 5q‐, and +8 in acute nonlymphocytic leukemia (ANLL); t(8;21) in ANLL‐M2; t(15;17) in ANLL‐M3; 5q‐ and ‐7 in myelodysplastic syndromes (MDS); t(9;22) and +21 in acute lymphocytic leukemia (ALL); t(14;18) in follicular lymphoma; ‐8 and ‐22/22q‐ in menin gioma; and structural abnormalities of 12q in pleomorphic adenoma of the salivary glands (PAS). No geographic incidence variation was detected for ‐7 and +21 in ANLL; +8 in MDS; 6q‐ and +8 in ALL; + 12 in chronic lymphocytic leukemia; 6q‐in non‐Hodgkin's lymphoma (NHL); t(8; 14) in Burkitt's lymphoma; t( 11;22) in Swing's sarcoma; i( 12p) in germ cell tumors; I p‐in neuroblastoma; structural abnormalities of 3q, 8q, and 9p in PAS; or 3p‐ in renal cell carcinoma. Intraregional frequency similarities between cytogenetically identical abnormalities in related tumor types were also analyzed. No significant correla tions were found regarding the incidence of 5q‐ in ANLL and MDS, 6q‐ in ALL and NHL, ‐7 in ANLL and MDS, +8 in ANLL and CML, +8 in ANLL and MDS, +8 in ALL and ANLL, or +21 in ALL and ANLL. The findings indicate that some geographic heterogeneity of tumor‐associated aberrations exists both in hematologic neoplasms and in solid tumors. This could be due to genetic factors, although at present no evidence supports this explanation, or to environmental factors, which have been shown to influence the chromosome pattern in some tumor types. It is also possible that both factors are of importance but in different stages of tumorigenesis. Primary and secondary abnormalities may originate through different mechanisms; e.g., environmental factors might be mainly involved in the genesis of primary anomalies, whereas constitutional factors might be more important for the secondary.