Extramural Venous Invasion in Patients with Locally Advanced Esophageal Cancer: A Reminder to Pathologists to Look Harder

Excerpt

Venous invasion (VI), the infiltration of malignancies into veins, has been described as an important predictor of patient outcome in a variety of tumors, i.e., renal,1 colorectal,2 pancreas,3 and stomach4. In contrast to lymphatic space invasion, which tends to predict lymph node involvement, VI appears to predict distant metastases, particularly to the liver.5 The issue has perhaps been best studied in renal carcinoma, where hilar vein involvement is routinely reported, and in colorectal carcinomas, where papers on the subject date back to the 1930s.6 Extramural VI (EMVI), involving veins in the pericolonic fat in pathological stage T3 colorectal carcinomas, should be identified in at least 30% of cases;7 however, for many years, colorectal carcinoma EMVI was not well reported by pathologists, even those subspecializing in gastrointestinal tract pathology. Although the older College of American Pathologists (CAP) protocol for evaluation of colorectal cancers included a recommendation to look for both EMVI and intramural VI (IMVI), in the synoptic protocols developed in the early 2000s there was only one line item for ‘lymphovascular space invasion’, combining lymphatic space invasion, EMVI and IMVI into one factor, with no allowance for details. For most pathologists, observation of VI when it was clearly obvious on hematoxylin and eosin (H&E)-stained slides would merit a comment on this, however few pathologists would have made any particular extra effort to identify EMVI. Thus, as Quirke and Morris noted in 2007, the reported rate of VI for colorectal carcinoma languished at approximately 10%, rather than 30%.7 Comments such as this led to a renewed interest in better detection of VI. EMVI is now listed as a line item in the most current CAP cancer reporting protocols (see www.​cap.​org/​web/​home/​protocolsandguid​elines/​cancerreportingt​ools) and is a specific item in the UK’s Royal College of Pathologists cancer datasets (see www.​rcpath.​org/​profession/​publications/​cancer-datasets.​html). …