Ex Vivo Intraarterial Methylene Blue Injection Improve Nodal Staging Accuracy in Colorectal Cancer

Nodal staging holds both important prognostic and predictive value at colorectal cancer. Regional lymph nodes are located close to the primary tumor in the mesocolon / mesorectum. Current pathology and oncology standards require a separate examination of at least 12 lymph nodes each case to fulfill staging "accuracy" criteria. In order to reach this number of lymph nodes, a precise surgical technique (total mesorectal excision or complete mesocolic excision), as well as a thorough pathological specimen work-up is needed. The aim of the study is to investigate, if ex vivo intra-arterial methylene blue injection by the surgeon can help improving nodal harvesting effectivity of the pathologist, hence leading to a better staging and hopefully even to a better outcome in the long run. In 2014-2015 two surgical centers randomised resected colorectal specimens in 1:1 ratio to methylene-blue injection arm and control (no injection) arm in a total of 200 consecutive cases. Both pathologic and oncologic treatment were led regardless of the injection, reports were just routinely saved in the routine medical documentation. This retrospective study is designed to recall patient-related, surgery-related factors, as well as pathology reports including nodal staging from the medical databases. The investigators aim to find correlation between methylene blue "staining" and lymph node yield. In addition, the investigators plan to crossmatch methylene blue injection, as a process, with long term survival of the patients.

Sex

All

Minimum age

18 Years

Maximum age

100 Years

Inclusion Criteria:

* Elective operation.
* Colon or rectum resection performed.
* Malignant colorectal condition.
* Curative intent.

Exclusion Criteria:

* Acute surgery performed
* Final histology: benign
* No other pathologic method (apart form Methylene Blue injection) used to improve lymph node yield