[Retrospective analysis of colorectal carcinomas reveals potential for improvement of diagnostic quality]

The histopathological work-up of colorectal cancer is of critical importance for prognosis and therapy. Therefore we retrospectively analyzed all colorectal carcinomas diagnosed at our institution from January 2002 through March 2003.

735 of a total of 777 carcinomas could be followed up. These tumors comprised 74 polypectomy specimens, 32 transanal microscopic surgery specimens, 322 surgical resection specimens analyzed at our own institution (subgroup A) and 263 surgical resection specimens that had been worked up at other pathological institutions (subgroup B) after the diagnosis of carcinoma had been established in our own institution in biopsies. 44 tumors were not treated locally until the end of the study. Quantitative quality parameters were analyzed statistically using Fisher's exact test.

Between subgroups A and B significant differences were found within 1. the proportion of specimens with less than 12 lymph nodes examined (11 vs. 25 %), 2. for the detection of an R1 situation despite macroscopic R0 resection (9 vs. 1 %), 3. the proportion of early colonic cancers (9 vs. 4 %), 4. of mucinous adenocarcinomas (19 vs. 4 %), 5. of lymphatic (48 vs. 23 %) and venous invasion (25 vs. 8 %), 6. the frequency of a macroscopic description of mesorectum quality (85 vs. 14 %). In 7 of 32 surgically treated patients with a high-risk carcinoma originally found within a polypectomy specimen, residual tumor was detected in the surgical resection specimen (at the polypectomy site and/or in regional lymph nodes).

Due to retrospective analysis of colorectal cancer specimens we were able to identify potential for improvement of diagnostic quality. Furthermore our data underline the importance of an oncological resection, if a high risk carcinoma has been detected within a polypectomy specimen.