The management of low rectal cancer varies significantly around the world, with different surgical strategies endorsed by regional guidelines. Specifically, adding extended lymphadenectomy to the standard total mesorectal excision (TME) is more commonly practiced in Asian countries, while Western countries generally favor TME alone for treating rectal cancer.

In Western countries, total mesorectal excision (TME) is the preferred method for treating advanced tumors classified up to stages cT2c/T3a/b and is regarded as the optimal choice due to its effectiveness in reducing the risk of local recurrence [1]. To further reduce this risk, neoadjuvant radiotherapy (nRT) has been implemented for locally advanced rectal cancers, alongside surgical treatment. Notably, patients who do not receive neoadjuvant radiotherapy continue to face a risk of local recurrence along the pelvic sidewall [2]. This approach is based on the belief among Western surgeons that the risk of local recurrence is largely determined by the surgical clearance of the circumferential resection margin [3]. nRT is strongly believed to provide adequate surgical clearance and secure the circumferential margins [4].

In contrast, Eastern surgeons consider nRT + TME insufficient to mitigate the risk of local recurrence, which is primarily attributed to the metastasis of cancer cells to lymph nodes near the internal iliac artery, originating from the middle rectal artery. Therefore, in Japan, lateral lymphadenectomy is currently recommended for patients whose tumors are located below the peritoneal reflection and have invaded beyond the muscularis propria [5].

Extended pelvic lymph node dissection (EPLND), when first introduced, was associated with increased risks of urinary and sexual dysfunction.

According to the Japanese classification, EPLND usually includes dissection of the aortic bifurcation area, common iliac area, internal iliac areas proximal and distal to superior vescical artery, obturator area, and external iliac area [6].

However, the development of nerve-sparing techniques has enabled the preservation of various degrees of the autonomic nervous system in the pelvis [7]. Additionally, this procedure involves lengthy operation times and significant blood loss. These factors contribute to Western surgeons’ reluctance to perform EPLND [8]. Nevertheless, the combination of TME and nRT also carries long-term risks. Fecal incontinence is a significant side effect associated with these treatments [9].

Therefore, since the debate is still open, and the two approaches are both considered valuable, with this umbrella review we aim to select the best therapeutic standard, to establish a universal approach to rectal cancer treatment. The main objective is to compare the outcomes of TME alone with those of TME combined with EPLND, with a specific focus on the use of neoadjuvant radiotherapy, and to compare the results in terms of local recurrence, overall survival, and complications related to surgery.