title: Histologic observations and P-glycoprotein expression in gastric and esophageal adenocarcinomas treated with preoperative chemotherapy.
abstract: To describe histologic changes associated with chemotherapy response, we reviewed biopsy and resection specimens from 52 patients with locally advanced esophageal or gastric adenocarcinoma who were treated with preoperative chemotherapy, followed by resection. P-Glycoprotein expression in the adenocarcinomas was also determined with the use of antibody C219. Significant changes in morphologic appearance of the tumor between prechemotherapy and postchemotherapy samples was noted in 17 tumors (32.7%). The most frequent changes observed in these 17 tumors were a decrease in tumor cellularity and an increase in dense fibrosis in comparison with the prechemotherapy specimen. In signet-ring cell carcinomas, the intracytoplasmic mucin vacuoles were often smaller after chemotherapy, making tumor cells more difficult to identify. Another finding observed in tumors that showed histologic alteration after chemotherapy was the formation of large mucin pools that contained lymphocytes and macrophages. The remaining 35 tumors showed similar histologic features in prechemotherapy and postchemotherapy specimens. P-Glycoprotein was identified in 15 (29.4%) of 51 specimens after chemotherapy. P-Glycoprotein content of the residual tumors did not correlate with stage, degree of differentiation, or clinically determined chemotherapy response. We concluded that chemotherapy-induced changes in morphology were frequent in patients with upper gastrointestinal tract adenocarcinomas treated with preoperative chemotherapy. These changes should be recognized as they may cause difficulties in both gross and histologic evaluation of the extent of tumor in postchemotherapy resection specimens. The response of adenocarcinomas to this chemotherapy protocol does not appear to be linked to P-glycoprotein expression.
authors.affiliation: Department of Pathology, University of Texas M.D. Anderson Cancer Center, Houston.
authors.forename: S S
authors.initials: SS
authors.lastname: Robey-Cafferty
authors.forename: J A
authors.initials: JA
authors.lastname: Ajani
authors.forename: D M
authors.initials: DM
authors.lastname: Ota
authors.forename: J A
authors.initials: JA
authors.lastname: Roth
authors.forename: J M
authors.initials: JM
authors.lastname: Bruner
mesh_terms: D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1; D000230:Adenocarcinoma / Q000188:drug therapy / Q000378:metabolism* / Q000473:pathology; D000368:Aged; D000970:Antineoplastic Agents / Q000627:therapeutic use*; D004938:Esophageal Neoplasms / Q000188:drug therapy / Q000378:metabolism* / Q000473:pathology; D006801:Humans; D007124:Immunoenzyme Techniques; D008562:Membrane Glycoproteins / Q000378:metabolism*; D008875:Middle Aged; D011300:Preoperative Care; D013194:Staining and Labeling; D013274:Stomach Neoplasms / Q000188:drug therapy / Q000378:metabolism* / Q000473:pathology
chemical_list: D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1; D000970:Antineoplastic Agents; D008562:Membrane Glycoproteins