LOSS OF HETEROZYGOSITY AT CHROMOSOME-11 IN BREAST-CANCER - ASSOCIATION OF PROGNOSTIC FACTORS WITH GENETIC ALTERATIONS

We examined DNA from 116 female and four male breast cancer patients f or loss of heterozygosity (LOH). DNA was analysed by polymerase chain reaction using ten microsatellite markers on chromosome ii. Three dist inct regions of LOH were identified: 11p15.5, 11q13 and 11q22-qter wit h a LOH frequency of 19, 23 and 37-43% respectively. The marker D11S96 9 showing the highest frequency of LOH (43%) is located at the 11q24.1 -q25 region. No previous molecular genetic studies have shown frequent LOH at the region telomeric to q23 on chromosome 11. Southern analysi s revealed that LOH at 11q13 was due to amplification, whereas LOH at 11q22-qter was due to deletion. LOH at 11p15.5 was associated with pau city of hormone receptor proteins, high S-phase and positive node stat us. An association was found between LOH at 11q13 and positive node st atus. LOH at the 11q22-qter region correlated with a high S-phase frac tion. A significant association was found between LOH at 11p15 and chr omosome regions 17q21 (the BRCAl region) and 3p.