Younger @entity1 exhibit more aggressive pathologic features of @entity0 ( @entity0 ) 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) @entity5 including 4 @entity5 , and 26 late onset (>40 years) @entity0 , including 2 @entity5 , 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 @entity0 is not fully identical to late onset @entity0 . 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 @entity5 in older @entity1 . 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 @entity5 .

Deletion mapping of chromosome 1 in early onset and late onset XXXX --a comparative study in eastern India.

@entity1 :: ('9606', 'Species') :: ['women'] @entity5 :: ('MESH:D009369', 'Disease') :: ['bilateral tumors', 'tumors'] @entity0 :: ('MESH:D001943', 'Disease') :: ['breast cancer', 'breast tumors', 'BC']
@entity0 :: (MESH:D001943,Disease) :: ['breast tumors']
