Frequent Allelic Loss at 6q26-27 in Breast Carcinomas of the Solid-tubular Histologic Type

To characterize the effect that inactivation of a putative tumor suppressor gene on 6q appears to have on breast carcinogenesis, we examined loss of heterozygosity in 528 primary breast carcinomas with a polymorphic marker located at 6q26-27, a frequent target region of allelic loss in ovarian and breast cancers. Ofthe 56 informative tumors of the solid-tubular type, 29(52&precnt;)showed allelic lossat 6q26-27;however, only 10 of 42 papillotubular carcinomas(23%)and 34 of 86 scirrhous carcinomas(39%)showed allelic loss(p = 0.0215). These results are consistent with reported alterations at 6q26-27 in serous and mucinous types of ovariancancers, in that they suggest that inactivation of one or more genes in that region may affect carcinogenic mechanisms in a histologic type-specific manner in neoplasms of the female reproductive organs.