Is it possible that we can increase the lymph node number in cases with rectum tumor receiving neoadjuvant therapy?

Though the recommended sampled lymph node number in colorectal carcinomas is at least 12, due to shrinkage after preoperative neoadjuvant chemoradiotherapy (NCRT), it can be difficult to attain that number.

Our aim is to increase the lymph node number by applying alcohol fixation on the formalin-fixed resection materials of the patients that received or not received neoadjuvant therapy and to evaluate the changes in staging due to obtained lymph nodes.

Non-randomized controlled trial.

Lymph node dissection was performed in the resection materials with rectum tumor which were formalin- and afterwards, alcohol-fixed. The number of lymph nodes obtained by both of the methods and status of metastasis were evaluated statistically.

Of the total 76 rectal tumors, 57 had and 19 had not received NCRT. The number of lymph node was adequate in 89.5% cases with no NCRT and in 63.2% cases with NCRT. While no change was observed after the alcohol fixation in the cases fulfilling adequacy criterion among those with no NCRT (p = 1.000), the adequacy rate increased from 63.2% to 87.7% in those with NCRT (p < 0.001). Although statistically insignificant, there was a change in pN stage in eight cases. In three of them, the stage varied from pN0 to pN1c, and in five cases, from pN1a to pN1b.

Using solutions as alcohol during fixation might facilitate the identification of metastatic lymph nodes, might change the stage of the disease and therefore, might affect the patient-based therapy.