Gloria Zaffaroni interviewed George Chang ahead of his session on ‘Risk assessment of lateral lymph nodes and therapeutic implications in rectal cancer’ at Virtually Vilnius.
George is Deputy Department Chair of Surgical Oncology and Chief at the Colon and Rectal Surgery Section at The University of Texas MD Anderson Cancer Center, Houston, Texas.
Rectal cancer constitutes a major public health issue. Although the introduction of the total mesorectal excision (TME) improved pathological and oncological outcomes, the treatment of mid and low rectal cancers remains challenging: in fact, this tumor has the tendency to spread to lateral nodes (such as the internal iliac nodes, common iliac nodes, obturator nodes, and external iliac nodes).
Cases of metastases in these nodes reportedly range between 8-25% (depending on the studies) when the lateral lymph node dissection (LLND) has been performed for stage II-III rectal cancer.
Although the treatment strategy recommended by the international guidelines for advanced rectal cancer is neoadjuvant chemoradiotherapy (CRT) and TME, data has recently shown that radiotherapy is associated with substantial long-term functional side effects.
On the other hand, when an LLND is performed, we know from literature that is associated with an increase in complications, such as bleeding and major urinary complications.
In addition, a discrepancy in classification makes this topic more challenging and complicated this: the 8th edition of the AJCC considers the lateral lymph node (LLN) involvement as indicating distant disease status. However, Japanese surgeons still consider the presence of LLN involvement as a local disease.
So globally, the debate continues regarding the best management of patients with suspected LLN.
Gloria Zaffaroni: Considering the importance of detecting lymph node metastases, what do you think is the best way to evaluate lateral lymph nodes?
George Chang: We have made great progress in the management of rectal cancer. Focus on good TME technique and incorporation of multidisciplinary treatment has greatly improved outcomes. However, there are some patients, who despite good TME and appropriate chemoradiotherapy, are at high risk for both local and distant treatment failure. Lymphatic drainage pathways for rectal cancer include ascending along the mesorectum and superior rectal artery as well as laterally along the middle rectal and to the internal iliac/obturator. Advances in high-resolution MRI scans with multi-plane views have helped us to better appreciate the anatomy of rectal cancers and enlargement or other high-risk features within lateral pelvic lymph nodes. Contrast enhanced high resolution CT imaging also facilitates evaluation.
GZ: How can the different classifications impact on the management of rectal cancer? And how can surgeons deal with this?
GC: Historically the debate regarding patients with locally advanced rectal cancers below the peritoneal reflection has been focused on the use of preoperative radiation therapy (in Western countries) or prophylactic lateral pelvic lymph node dissection (in Japan). However, this debate has not adequately distinguished between patients for whom radiation (or dissection) is performed with prophylactic intent (in absence of clinical evidence of disease) or performed with therapeutic intent (when lateral lymph node metastasis is suspected). Regardless of which classification system for rectal cancer is utilised, these are two clinically distinct situations that require distinct solutions.
GZ: What should we look forward to in your presentation?
GC: During this session, I will discuss the current controversies and evidence regarding management of lateral pelvic lymph node metastases from rectal cancer and provide new recommendations for the evaluation and selection of patients for lateral pelvic lymph node dissection following multidisciplinary treatment.
George’s session at ESCP Virtually Vilnius 2020 will take place between 17:10-18:20 on Wednesday 23 September.
