Dr Ritesh Goel, Amrita Hospital, Faridabad Pelvic lymph node dissection (PLND) is an integral part of RC & the incidence of LN positivity ranges from 25-40%. (1,2,3) The extent of LND is still debatable, however, the rationale of better oncological safety by clearing wider lymphatic drainage is well accepted. Levels of lymph node dissection have been simplified into three broader categories: Level I: removal of pelvic nodes situated beneath the division point of the common iliac artery, Level II extends to the region reaching the aortic bifurcation and is subdivided into two parts, IIA the upper limit is the point where the ureter intersects with the common iliac artery, and Level IIB the upper limit is the aortic bifurcation and Level III when the dissection extends up to the origin of the inferior mesenteric artery (IMA).(4) (Figure 3) Older studies evaluating the extent of lymph node dissection demonstrated better recurrence-free survival (RFS) in patients undergoing extended lymph node dissection i.e till aortic bifurcation. (5,6,7) However, most of these studies were retrospective. (Table 2) A study comparing super-extended versus extended PLND did not show any further improvement in survival or recurrence outcomes, rather showed an increased risk of complications like lymphocele.(8) A recent comparative trial, the LEA study, comparing extended PLND with standard PLND failed to show an improvement in the RFS, cancer-specific survival and overall survival. Also, there were higher incidences of Clavein grade ≥3 lymphoceles.(9) However, this study had a few major drawbacks. First, the inclusion of T1G3 tumors lead to a negative study and secondly, they performed a super-extended LND resulting in higher complications. Another phase 3 trial, SWOG-1101 also compared extended PLND with standard PLND. It also failed to demonstrate any significant DFS or OS benefit of extended PLND compared to patients undergoing standard PLND. Extended PLND was also associated with greater morbidity and higher peri-operative mortality.(10) Major guidelines outline thee patterns for LND patterns, yet lack uniform consistency. EAU recommends removal of lymph nodes upto the common iliac bifurcation, with the ureter being the medial border, and includes the internal iliac, presacral, obturator fossa, and external iliac nodes.(11) AUA recommends removal of the external and internal iliac and obturator LN at the minimum with >12 lymph nodes being submitted for evaluation.(12) However, NCCN suggests that additional removal of common iliac, lower para-aortic and para-caval might improve overall survival. (13)
Figure 1:Levels of Lymphnode dissection during RC
Table 2: Select studies evaluating role of LND during RC
Author | Type of study | Sample Size | Comparative groups | RFS | OS | CSS |
Abol-Enein et al (5) | Prospective, non-randomized | 400 | I vs III | P = 0.02 | - | - |
Simone et al (6) | Retrospective | 933 | I vs IIa | P < 0.001 | - | P < 0.001 |
Abdi (7) | Retrospective, matched cohort | 210 | I vs IIB | P = 0.005 | P = 0.84 | - |
Zehnder et al (8) | Retrospective | 959 | IIA vs III | P = 0.75 | P = 0.45 | |
Gschwend et al (9) | Prospective, randomised | 401 | I vs III | P = 0.36 |