Differences between right- and left-sided colon cancer in patient characteristics, cancer morphology and histology

Authors


Toru Nawa, Department of Gastroenterology and Hepatology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, 2-5-1 Shikata-cho, Okayama 700-8558, Japan. Email: torunawa@yahoo.co.jp

Abstract

Background and Aim:  Recently, the clinical and biological differences between right- and left-sided colon cancers have been widely debated. However, close analyses of these clinical differences, based on large-scale studies, have been scarcely reported.

Methods:  A total of 3552 consecutive Japanese colorectal cancer cases were examined and the clinical differences between right- and left-sided colon cancer cases were investigated.

Results:  The proportion of right-sided colon cancer was relatively high in patients aged less than 40 years (33%) and more than 80 years (43%). The proportion of right-sided colon cancer in patients aged 40–59 years was relatively low (male 22% and female 29%). In male patients the proportion increased in the 70-79 years age group (30%), while in female patients the proportion increased in the 60-69 years age group (39%). Right-sided colon cancer was more likely to be detected at an advanced stage (T1 stage; left 22%, right 15%) (P < 0.01) with severe symptoms. Polypoid-type early cancer was dominant in the left colon (left 59%; right 40%) (P < 0.01), while the proportion of flat-type early cancer in the right colon was significantly higher than that in the left colon (left 25%; right 44%) (P < 0.01).

Conclusions:  Specific age distribution of right-sided colon cancer was observed and the difference between male and female patients was highlighted. Other clinical features also differed between right- and left-sided colon cancer, suggesting that different mechanisms may be at work during right and left colon carcinogenesis.

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