AUTHOR=Haanappel Anouck , Kroon Hidde M. , Schaap Dennis P. , Bedrikovetski Sergei , Dudi-Venkata Nagendra N. , Lee Hong X. , Thomas Michelle L. , Liu Jianliang , van der Valk Maxime J. M. , Rutten Harm J. T. , Beets Geerard L. , Kusters Miranda , Sammour Tarik 

TITLE=Lateral Lymph Node Metastases in Locally Advanced Low Rectal Cancers May Not Be Treated Effectively With Neoadjuvant (Chemo)Radiotherapy Only

JOURNAL=Frontiers in Oncology

VOLUME=9

YEAR=2019

URL=https://www.frontiersin.org/journals/oncology/articles/10.3389/fonc.2019.01355

DOI=10.3389/fonc.2019.01355

ISSN=2234-943X

ABSTRACT=<p><bold>Background:</bold> In the West, pre-treatment abnormal lateral lymph nodes (LLN+) in patients with a low locally advanced rectal cancer (AJCC Stage III), are treated with neoadjuvant (chemo)radiotherapy (nCRT), without a lateral lymph node dissection (LLND). It has been suggested, however, that LLN+ patients have higher local recurrence (LR) rates than similarly staged patients with abnormal mesorectal lymph nodes only (LLN−), but no comparative data exist. Therefore, we conducted this international multi-center study in the Netherlands and Australia of Stage III rectal cancer patients with either LLN+ or LLN− to compare oncological outcomes from both groups.</p><p><bold>Materials and Methods:</bold> Patients with Stage III low rectal cancer with (LLN+ group) or without (LLN− group) abnormal lateral lymph nodes on pre-treatment MRI were included. Patients underwent nCRT followed by rectal resection surgery with curative intent between 2009 and 2016 with a minimum follow-up of 2-years. No patient had a LLND. Propensity score matching corrected differences in baseline characteristics.</p><p><bold>Results:</bold> Two hundred twenty-three patients could be included: 125 in the LLN+ group and 98 in the LLN− group. Between groups, there were significant differences in cT-stage and in the rate of adjuvant chemotherapy administered. Propensity score matching resulted in 54 patients in each group, with equal baseline characteristics. The 5-year LR rate in the LLN+ group was 11 vs. 2% in the LLN− group (<italic>P</italic> = 0.06) and disease-free survival (DFS) was 64 vs. 76%, respectively (<italic>P</italic> = 0.09). Five-year overall survival was similar between groups (73 vs. 80%, respectively; <italic>P</italic> = 0.90).</p><p><bold>Conclusions:</bold> In Western patients with Stage III low rectal cancer, there is a trend toward worse LR rate and DFS rates in LLN+ patients compared to similarly staged LLN− patients. These results suggest that LLN+ patients may currently not be treated optimally with nCRT alone, and the addition of LLND requires further consideration.</p>