[Characteristics of colon cancer diagnosed in patients taking aspirin or warfarin].
OBJECTIVE
Warfarin and aspirin are commonly used to prevent cardiovascular diseases. Aspirin was recently found to have chemopreventive effects on colon cancer and polyps by inhibiting cyclooxygenase-2. Therefore, we evaluated whether the symptoms of bleeding related with aspirin or warfarin could be a clue in early detection of colon cancer. We also assessed the effect of aspirin on the development of synchronous polyps.


METHODS
A total of forty-one and 16 patients diagnosed as colon cancer, taking aspirin or warfarin respectively were enrolled. In addition, 171 patients with colon cancers were age and gender matched as a control group. We investigated the difference of clinical features and laboratory findings among three groups.


RESULTS
The incidence of bleeding was 81.3% (warfarin), 53.7% (aspirin), 40.4% (control). Among three groups, location and size of cancer, number of lymph nodes involvement and stages were not different, but the number of patients in Duke stage D in warfarin group (n=1, 6.3%) were less than that of the control (n=44, 25.7%) (p=0.049). The extent of circumferential involvement by cancer was lower in aspirin group (67%) than in the control group (80%) (p=0.035). The percentage of patients with synchronous polyps and mean number of synchronous polyps in aspirin group (34.1%, 0.68, respectively) was lower than that of control group (53.6%, 1.69, respectively) (p=0.029, 0.008, respectively).


CONCLUSIONS
Bleeding related with aspirin or warfarin usage had no effect on the early diagnosis of colon cancer. However, lower incidence of Duke stage D in warfarin group might be related to anti-metastatic effect of warfarin. In addition, aspirin may have a role in suppressing the development of synchronous polyps.
Shin
Sung Jae
SJ
Department of Internal Medicine and Institute of Gastroenterology, Yonsei University College of Medicine, Seoul, Korea.
Kim
Byung Chang
BC
Park
Sooyoung
S
Kim
Sungai
S
Kim
Tae Il
TI
Kim
Won Ho
WH
D000368:Aged; D000925:Anticoagulants / Q000009:adverse effects / Q000627:therapeutic use; D001241:Aspirin / Q000009:adverse effects / Q000627:therapeutic use*; D002318:Cardiovascular Diseases / Q000517:prevention & control; D003110:Colonic Neoplasms / Q000175:diagnosis* / Q000473:pathology; D005260:Female; D006471:Gastrointestinal Hemorrhage / Q000139:chemically induced; D006801:Humans; D008297:Male; D008875:Middle Aged; D010975:Platelet Aggregation Inhibitors / Q000009:adverse effects / Q000627:therapeutic use*; D014859:Warfarin / Q000009:adverse effects / Q000627:therapeutic use*
D000925:Anticoagulants; D010975:Platelet Aggregation Inhibitors; D014859:Warfarin; D001241:Aspirin