Response to chemotherapy (irinotecan plus 5-fluorouracil) in colorectal carcinoma can be predicted by tumour DNA content.
OBJECTIVE
The aim of this study was to identify markers that might predict response to chemotherapy. Postoperative chemotherapy improves the outcome in stage III colon cancer and is widely accepted as a standard therapy, but there are currently no reliable predictors to identify and select patients that will benefit.


METHODS
Using DNA image cytometry, the DNA content was determined from the isolated nuclei of 56 primary colorectal carcinomas of patients who received chemotherapy (either irinotecan or irinotecan plus 5-fluorouracil and folinic acid) for advanced disease. Response to chemotherapy could be reliably evaluated in 53 patients.


RESULTS
The modal DNA content (ploidy status) of the tumour correlated with the observed response to chemotherapy (p = 0.01). An objective response was observed in 56% of patients whose tumour histograms displayed tetraploid, peri-tetraploid or multiploid patterns of peaks, compared with 19% in patients with diploid, peri-diploid or aneuploid peaks. Notably, 86% (6/7) of patients whose tumours displayed a multiploid peak pattern showed an objective response and 1 patient had stable disease.


CONCLUSIONS
This study suggests that modal DNA content can be used to predict a patient's response to chemotherapy in advanced colorectal carcinoma. This may help in identifying patients who will benefit most from therapy for advanced colorectal cancer.
Bendardaf
R
R
Department of Oncology and Radiotherapy, Turku University Central Hospital, Turku, Finland.
Lamlum
H
H
Ristamäki
R
R
Algars
A
A
Collan
Y
Y
Pyrhönen
S
S
D000328:Adult; D000368:Aged; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000494:pharmacology*; D014408:Biomarkers, Tumor / Q000032:analysis*; D002166:Camptothecin / Q000031:analogs & derivatives* / Q000494:pharmacology; D015179:Colorectal Neoplasms / Q000188:drug therapy* / Q000235:genetics* / Q000601:surgery; D004273:DNA, Neoplasm / Q000032:analysis* / Q000187:drug effects*; D005260:Female; D005472:Fluorouracil / Q000494:pharmacology; D006801:Humans; D000077146:Irinotecan; D002955:Leucovorin / Q000494:pharmacology; D008297:Male; D008875:Middle Aged; D011003:Ploidies; D011237:Predictive Value of Tests; D016896:Treatment Outcome
D014408:Biomarkers, Tumor; D004273:DNA, Neoplasm; D000077146:Irinotecan; D002955:Leucovorin; D005472:Fluorouracil; D002166:Camptothecin