Pathogenetic implications of DNA nondiploidy in colorectal cancers.
OBJECTIVE
Several studies propose that proximal and distal colorectal cancers have a different pathogenesis. We tested the hypothesis using flow cytometric DNA analysis.


METHODS
DNA analysis was performed in 719 patients with colorectal cancer. In addition, histopathologic data were re-evaluated in a blinded fashion by a single pathologist.


RESULTS
Distal tumors were more often nondiploid than were proximal tumors (61 vs. 49 percent; P = 0.015). Compared with the proximal tumor, distal tumors were smaller (P = 0.0001) and had less desmoplastic reaction (39 vs. 53 percent; P = 0.0001). Tumor location had no significant associations with the remaining parameters, including mucin production, perineural invasion, blood/lymphatic vessel invasion, lymphocytic infiltration, histologic grade, tumor stage, gross appearance, age, and gender.


CONCLUSIONS
The unequal distribution of ploidy suggests distinct pathogenetic mechanisms at proximal and distal sites.
Changchien
C R
CR
Division of Colon and Rectal Surgery, Chang Gung Memorial Hospital, Taipei, Taiwan.
Wang
J Y
JY
Tang
R
R
Ho
Y S
YS
D015179:Colorectal Neoplasms / Q000235:genetics* / Q000473:pathology; D004273:DNA, Neoplasm / Q000235:genetics*; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D008297:Male; D008875:Middle Aged; D011003:Ploidies; D012189:Retrospective Studies
D004273:DNA, Neoplasm