Number of lymph nodes after neoadjuvant therapy for rectal cancer: How many are needed?

Neoadjuvant chemoradiation is the standard treatment for advanced rectal tumor, providing better local control of disease and potentially increasing sphincter preservation surgery. Neoadjuvant radiation may affect the number of lymph nodes harvested after resection or alter their prognostic value. Over the past 10 years, standards for lymph node harvests in colorectal cancer have been proposed. Several studies have recommend examination of at least 12 lymph nodes (LNs) in the specimen and this number is now used as a reflection of surgical quality. Nevertheless, recent reports have identified significantly decreased LN harvests in patients treated with neoadjuvant radiation. And preoperative chemoradiation has a significant effect on the number of nodes harvested in rectal specimens and this should be considered in staging of the tumor. In the near future, the total number of nodes will be less important than specific biologic markers in detecting high-risk patients and improving their prognosis with adjuvant therapy tailored.