Association of symptoms of colon cancer patients with tumor location and TNM tumor stage

Objective. Colon cancer is the second most common cause of cancer death in Iceland and accounts for 8% of malignancies. We related information on symptoms of colon cancer patients with information on tumor location and pTNM-stage. Material and methods. The study is retrospective and population-based. Information on all patients diagnosed with colon cancer in Iceland in 1995-2004 was obtained. Information on symptoms of patients and blood hemoglobin was collected from patients' files. The pathological parameters were derived from a previously performed study. Results. A total of 768 patients (422 males, 346 females) participated in this study. Median age was 73 years. Nearly 60% had anemia at the time of diagnosis, 53% had visible blood in stools, and 65% had changes in bowel habits. Around 84% had visible blood in stools and/or anemia. Of those with right-sided tumors, 75% had anemia and were more likely to be diagnosed incidentally (40%) than those with leftsided tumors (20%). Left-sided tumors were associated with blood in stools (68% compared to 41%, p < 0.05) and changes in bowel habits (74% compared to 57%, p < 0.05). Multivariate analysis indicated that blood in stools was strongly associated with a lower TNM-stage (OR = 0.75, p < 0.05). Anemia was strongly associated with a higher TNM-stage (OR = 1.84, p < 0.05). Conclusion. Right-sided tumors were associated with anemia and incidental diagnosis; left-sided tumors were associated with visible blood in stools and changes in bowel habits. Visible blood in stools was significantly associated with lower TNM-stage, whereas abdominal pain, general and acute symptoms were associated with higher TNM-stage.