Large negative lymph nodes – a surrogate for immune activation in rectal cancer patients?

Many colorectal resections do not meet the minimum of 12 lymph nodes (LNs) recommended by the American Joint Committee on Cancer for accurate staging of colorectal cancer. The aim of this study was to investigate factors affecting the number of the adequate nodal yield in colorectal specimens subject to routine pathological assessment. We have retrospectively analysed the data of 2319 curatively resected colorectal cancer patients in San Raffaele Scientific Institute, Milan, between 1993 and 2017 (1259 colon cancer patients and 675 rectal cancer patients plus 385 rectal cancer patients who underwent neoadjuvant therapy). The factors influencing lymph node retrieval were subjected to uni- and multivariate analyses. Moreover, a survival analysis was carried out to verify the prognostic implications of nodal counts. The mean number of evaluated nodes was 24.08±11.4, 20.34±11.8, and 15.33±9.64 in surgically treated right-sided colon cancer, left-sided colon cancer, and rectal tumors, respectively. More than 12 lymph nodes were reported in surgical specimens in 1094 (86.9%) cases in the colon cohort and in 425 (63%) cases in the rectal cohort, and patients who underwent neoadjuvant chemoradiation were analysed separately. On univariate analysis of the colon cancer group, higher LNs counts were associated with female sex, right colon cancer, emergency surgery, pT3-T4 diseases, higher tumor size, and resected specimen length. On multivariate analysis right colon tumors, larger mean size of tumor, length of specimen, pT3-T4 disease, and female sex were found to significantly affect lymph node retrieval. Colon cancer patients with 12 or more lymph nodes removed had a significantly better long-term survival than those with 11 or fewer nodes (P=0.002, log-rank test). Rectal cancer patients with 12 or more lymph nodes removed approached but did not reach a statistically different survival (P=0.055, log-rank test). Multiple tumor and patients’ factors are associated with lymph node yield, but only the removal of at least 12 lymph nodes will reliably determine lymph node status.

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No Downstaging After Short-Term Preoperative Radiotherapy in Rectal Cancer Patients

Journal of Clinical Oncology ◽

10.1200/jco.2001.19.7.1976 ◽

2001 ◽

Vol 19 (7) ◽

pp. 1976-1984 ◽

Cited By ~ 251

Author(s):

C.A.M. Marijnen ◽

I.D. Nagtegaal ◽

E. Klein Kranenbarg ◽

J. Hermans ◽

C.J.H. van de Velde ◽

...

Keyword(s):

Rectal Cancer ◽

Lymph Nodes ◽

Cancer Patients ◽

Tumor Size ◽

Preoperative Radiotherapy ◽

Multicenter Trial ◽

Short Term ◽

Size Number ◽

Tumor Node Metastasis Stage ◽

Poorly Differentiated

PURPOSE: In retrospective studies, total mesorectal excision (TME) surgery has been demonstrated to result in a reduction in the number of local recurrences of rectal cancer. Reports on improved local control after preoperative, hypofractionated radiotherapy have led to the introduction of a randomized multicenter trial to evaluate the effect of TME surgery with and without preoperative radiotherapy. Treatment with preoperative radiotherapy might have an effect on the pathologic characteristics that determine staging of rectal cancer. We investigated the occurrence of downstaging in rectal cancer patients treated with and without preoperative radiotherapy. PATIENTS AND METHODS: We analyzed the differences in tumor size, number of examined lymph nodes, tumor-node-metastasis stage, and histopathologic features in 1,321 patients entered onto a randomized trial. The trial compared preoperative radiotherapy (5 × 5 Gy) followed by TME surgery with TME surgery alone. Patients who had an interval of more than 10 days between the start of radiotherapy and surgery were excluded from analysis. RESULTS: Differences were observed in tumor size (P < .001) and total number of examined lymph nodes (P < .001). No difference in tumor or node classification was detected. The irradiated group demonstrated more poorly differentiated tumors as well as more mucinous tumors. CONCLUSION: In rectal cancer patients, short-term, preoperative radiotherapy with 5 × 5 Gy does not lead to downstaging if the interval between the start of radiotherapy and surgery does not exceed 10 days.

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