BACKGROUND: @entity5 are composed of subpopulations of cells with heterogeneous characteristics that allow for @entity5 progression and development of treatment resistance. The purpose of this study was to determine if there is heterogeneity in the in vitro chemosensitivity in different invasive sections of a @entity5 . MATERIALS AND METHODS: Chemosensitivity in advanced @entity14 specimens was examined using an @entity855 -based chemotherapy response assay. Four chemotherapeutic agents ( @entity1487 ( @entity1487 ), @entity901 , @entity2600 , and @entity1138 ) were used for chemosensitivity studies. Tumor tissues were obtained from the superficial (mucosa/submucosa) and deep parts (muscle/subserosa/serosa), respectively. Twenty @entity1 who had results for both the superficial and deep parts were evaluated. RESULTS: The chemosensitivity study showed variable cell death rates in both parts of the @entity5 . Regression analysis showed some correlations with @entity1487 and @entity2600 , but not with @entity901 or @entity1138 . With the exception of three @entity1 in whom no drug was recommended, at least one chemotherapeutic drug showed some consistency between the superficial and deep parts of the @entity5 . @entity1138 was the most frequently active agent for the superficial part. In the deep part, @entity901 and @entity1138 were the most active agents. CONCLUSIONS: There may be heterogeneity in the responses to anti-chemotherapeutic agents in advanced @entity14 , according to the depth of invasion. Therefore, in clinical situations, chemosensitivity test specimens should be mixed with various parts of the whole @entity5 in order to obtain representative chemosensitivity and chemoresistance profiles.

In vitro chemosensitivity based on depth of invasion in advanced XXXX using @entity855 -based chemotherapy response assay ( @entity855 -CRA).

@entity901 :: ('MESH:C030110', 'Chemical') :: ['oxaliplatin'] @entity1 :: ('9606', 'Species') :: ['patients'] @entity2600 :: ('MESH:C051890', 'Chemical') :: ['irinotecan'] @entity5 :: ('MESH:D009369', 'Disease') :: ['tumor', 'Tumors', 'single tumor'] @entity1138 :: ('MESH:D016685', 'Chemical') :: ['mitomycin', 'Mitomycin'] @entity1487 :: ('MESH:D005472', 'Chemical') :: ['5-FU', '5-fluorouracil'] @entity14 :: ('MESH:D015179', 'Disease') :: ['colorectal cancer'] @entity855 :: ('MESH:D000255', 'Chemical') :: ['ATP']
@entity14 :: (MESH:D015179,Disease) :: ['colorectal cancer']
