However, the effect is most likely multi factorial and there are other factors which are also important, but the exact role and individual effect of the components is difficult to measure. There are many factors influencing the final node count. Most often quoted is the patient’s age (6), also the experience of the surgeon and the pathologist (7); but there is also INCB024360 chemical structure important to consider

the anatomical location and previous treatment modalities. The anatomical distribution Inhibitors,research,lifescience,medical and the extent of the excision will limit the number of potentially recoverable lymph nodes; in theory and with diligent practice, up to 87 lymph nodes achievable (4) from a total colectomy specimen. However, we need to note that most of theses nodes are in the sub-2 mm category. This

degree of dissection and retrieval is Inhibitors,research,lifescience,medical usually beyond the possibilities and resources of a busy pathology department. The most important factors in the lymph node count equation are: the patient (age, BMI, individual differences), the surgeon (the experience seems to the one which counts most), the specimen Inhibitors,research,lifescience,medical type (total colectomies yield significantly more nodes than segmental colectomy), the pathologist (diligence and experience). There are factors which are difficult to influence, but there are some which are possible to do so – that’s where our assessment comes in. But how precise should we be – i.e. how much is enough? When we look at the optimal lymph node count to get accurate stage information for all stages, it seems that 15 lymph nodes seem to be safest option to cover all angles and include all stages. At our department (University Hospital with approximately 400 colorectal cancer Inhibitors,research,lifescience,medical resections/ year) we found in an audit of one year whole section caseload that if we had at least 16 lymph nodes found, no staging information needed changing – and we were able to reliably differentiate between N1 and N2 stages – any additional Inhibitors,research,lifescience,medical node harvested did not improve accuracy. It the days of hard economic driving

forces, an optimal number of lymph nodes need to be found. However, as a pathologist I will always look for the maximum number of recoverable nodes in any specimen – it is important not to stop at 16. When we look for the lymph nodes – it is quite straightforward that one seeks the lymph nodes between the tumour and the feeding vessels (please note: lymph node collecting areas follow the ways of arterial distribution, not the veins – venous system confluences secondly in the portal vein/liver). It is important that we need to look around the tumour, and make sure we looked this area carefully – nodes collected around splenic flexure in an extended right hemicolectomy for a caecal cancer are not likely to contain metastatic disease and will not going to influence the treatment. Several major series suggest that we need at least. 12-14 nodes to get sufficient prognostic information.