4.1. Patients and Tissue Specimens for mRNA Analysis

Primary tumor specimens were retrieved from 32 CC patients (13 men and 19 women, median age 72 years, range 43–86 years) after surgery. None of the patients received treatment before surgery. Twelve patients were in stage I (T1-2N0M0), 10 patients were in stage II (T3-4N0M0), eight patients were in stage III (anyTN1-2M0), and two patients were in stage IV (anyTanyNM1). Primary tumor stage distribution (pT1-pT4) was 2, 10, 10, and 10, respectively. The tumor samples, approximately 0.5 × 0.5 × 0.5 cm in size, were collected immediately after resection, snap-frozen, and stored at −70 °C until undergoing RNA extraction. Normal colon samples retrieved from the proximal or distal resection margin of CC tumors were also collected from 30 patients (13 women and 17 men, median age 72 years, range 57–85 years) and treated the same way.

Lymph nodes were from 121 CC patients (median age 70 years, range 41–88 years, 66 women and 55 men). Seventy-three lymph nodes were from 23 patients in stage I, 190 lymph nodes were from 52 patients in stage II, 88 lymph nodes were from 37 patients in stage III, and 31 lymph nodes were from nine patients in stage IV. Twenty-two lymph nodes were H&E(+) and 360 lymph nodes were H&E(−). Control lymph nodes were from 13 patients (median age 23 years, range 9–32 years: three women and 10 men). Eleven patients had ulcerative colitis, one had Crohn’s disease and one had lipoma. In total, 459 lymph nodes were investigated in this analysis.