Potential pathological understaging of pT3 rectal cancer with less than 26 lymph nodes recovered: a prospective study based on a resampling of 50 rectal specimens

Abstract

The aim of the paper was to establish if the 12 lymph nodes recommended by tumor-node-metastasis (TNM) system are sufficient for a correct staging of rectal cancer. For this purpose, we first compared the mean number of lymph nodes recovered in the same surgical specimen at the routine sampling and at a resampling performed by a second expert gastrointestinal pathologist. The study was performed on 50 cases of pT2N0 and pT3N0 rectal cancers, with a minimum number of 12 lymph nodes recovered at first sampling, histologically negative for metastases. Resampling retrieved a variable number (1 to 24) of nodes missed at first sampling. The final pN0 status was maintained in pT2 patients, whereas in 18.7% of pT3 patients, metastatic lymph nodes were detected if the mean number of lymph nodes increased from 17.8 to 26.8 after the second sampling. Interestingly, all pN1 patients had only a single metastatic lymph node measuring less than 4.9 mm. As we have shown that most (five out of six) missed metastatic lymph nodes were detected in specimens in which a maximum number of 19 lymph nodes had been originally recovered, we strongly suggest a resampling of pT3N0 rectal specimens if less than 20 lymph nodes have been recovered.

Comments on the reporting of lymph nodes and tumour budding in the checklist of colorectal carcinoma

“…In a large series of colorectal cancers reported by Goldstein [1], about 30% of pT3N+ patients had a single metastatic lymph node, and the percentage of specimens with one lymph-node metastasis increased from 41.62 to 80.36% when the number of lymph nodes increased from 11-15 to more than 21, respectively. Notably, in our study, we obtained similar results, as all restaged pT3N+ patients had only a single metastatic lymph node, which was found in specimens in which a minimum number of 19 lymph nodes had been originally detected [2]. Accordingly, we propose that at least 20 lymph nodes should be recovered as an acceptable mean number in a series of colorectal cancer dissections.…”

“…There is no general consensus about this number if other authors, recently reporting colorectal cancer guidelines, propose a mean number of 15-18 lymph nodes [6]. Recently, we have published in Virchows Archiv a paper showing that in pT3 rectal cancer, 12-15 lymph nodes are insufficient for a correct staging [2]. In that prospective study, we first showed that if the mean number of lymph nodes recovered increased from 17.8 to 26.8, after a second sampling of the same surgically resected specimens, metastases were detected in 18.7% of patients that had been originally understaged [2].…”

“…In that prospective study, we first showed that if the mean number of lymph nodes recovered increased from 17.8 to 26.8, after a second sampling of the same surgically resected specimens, metastases were detected in 18.7% of patients that had been originally understaged [2]. Our results are in line with those previously obtained by other authors showing that most lymph-node metastases (about 80-90% of cases) of colorectal cancer are detected if about 26-30 lymph nodes are recovered [2]. Jass et al do not provide any comment about the possibility that some patients with colorectal cancer have only a single metastatic lymph node.…”

“…Recently, we have published in Virchows Archiv a paper showing that in pT3 rectal cancer, 12-15 lymph nodes are insufficient for a correct staging [2]. In that prospective study, we first showed that if the mean number of lymph nodes recovered increased from 17.8 to 26.8, after a second sampling of the same surgically resected specimens, metastases were detected in 18.7% of patients that had been originally understaged [2]. Our results are in line with those previously obtained by other authors showing that most lymph-node metastases (about 80-90% of cases) of colorectal cancer are detected if about 26-30 lymph nodes are recovered [2].…”

Pelvic Lymphedema in Rectal Cancer

“…Lymphadenectomy is the most important prognostic factor in pelvic malignancies, a finding that has substantially changed surgical approaches from a "quantitative" premise to a more "qualitative" nature giving priority to the psycho-physical integrity of cancer patients by limiting the surgical intervention (Breyer et al, 2008;Mills et al, 2006;Desnoo & Faithfull 2006;Greco et al, 2006). However, despite progress made by the conservative surgical approach for rectal cancer, the development of functional abnormalities in patients undergoing conservative surgery has become more evident (Ortiz & Armendariz, 1996).…”