title: Deletion mapping of chromosome 1 in early onset and late onset breast tumors--a comparative study in eastern India.
abstract: Younger women exhibit more aggressive pathologic features of breast cancer (BC) compared to their older counterparts. Young age has been shown to be an independent predictor of adverse prognosis. These findings have raised the question of whether these differences are also present at the genetic level. Twenty-five early onset (age < or = 40 years) tumors including 4 bilateral tumors, and 26 late onset (>40 years) breast tumors, including 2 bilateral tumors, were examined for loss of heterozygosity (LOH) at chromosome 1 using 11 polymorphic microsatellite markers. A comparative study revealed high frequencies of LOH in chr. 1p36 (61%), 1p31.3 (40%), 1p21.3 (50%) and 1q22-23.2 (56%) in a younger group, and chr. 1p36 (46%), 1p34.2 (48%), and 1q22-23.2 (52%) in an older group. These differences in LOH frequency in these two age groups were significant for chr. 1p21.3 (p = 0.025) only. These data suggest that the deletion pattern in early onset breast tumors is not fully identical to late onset breast tumors. Similar differential deletion patterns of LOH in the 5 highly deleted regions were seen in premenopausal and postmenopausal groups. An association was seen between LOH at chr. 1p34.2 and chr. 1q22-23.2 and higher grade of the tumors in older women. Among the highly deleted regions, the deletion at chr. 1p36 was found to occur early in both groups because of common allelic loss in the bilateral tumors.
authors.affiliation: Department of Oncogene Regulation, Chittaranjan National Cancer Institute, 37, S. P. Mukherjee Road, Kolkata-00026, India.
authors.forename: Neelanjana
authors.initials: N
authors.lastname: Chunder
authors.forename: Syamsundar
authors.initials: S
authors.lastname: Mandal
authors.forename: Debasis
authors.initials: D
authors.lastname: Basu
authors.forename: Anup
authors.initials: A
authors.lastname: Roy
authors.forename: Susanta
authors.initials: S
authors.lastname: Roychoudhury
authors.forename: Chinmay Kumar
authors.initials: CK
authors.lastname: Panda
mesh_terms: D000328:Adult; D017668:Age of Onset; D000368:Aged; D001943:Breast Neoplasms / Q000235:genetics*; D002874:Chromosome Mapping; D002878:Chromosomes, Human, Pair 1 / Q000235:genetics*; D005260:Female; D006801:Humans; D007194:India / Q000453:epidemiology; D019656:Loss of Heterozygosity / Q000235:genetics*; D018895:Microsatellite Repeats; D008875:Middle Aged; D017698:Postmenopause; D017697:Premenopause