All the world’s a stage.

Top Line: Is there a difference between N1 and M1a lymph node metastatic prostate cancer?

The Study: You’d hope so or why do we distinguish between them? The first confusing thing is that common iliac nodes are usually considered M1a (aka non-regional lymph node) disease, even though consensus guidelines include the common iliac vessels in elective nodal volumes. Second, it seems arbitrary to draw a line where the external and internal iliac vessels converge and say visible disease above it doesn’t merit curative therapy. This retrospective look at 130 men receiving definitive radiation to the prostate and pelvis with long-course androgen deprivation therapy asked if there was any difference in outcomes between those with nodal disease below (n=87) or above (n=43) the bifurcation of the common iliacs. Nodes >1 cm at time of simulation received a simultaneous integrated boost to 60-66 Gy in 25 fractions. As expected, most men had grade group 4-5 disease (65%) and/or cT3 disease (75%). Also to no real surprise, at 5 years, rates of survival free from biochemical failure (77% without versus 70% with common iliac nodal disease), distant metastasis (87% versus 79%), and overall survival (93% versus 90%) were similar. Analogous to cervical cancer staging moving paraaortic disease from stage IV to IIIC in the era of IMRT where it can all feasibly be included in definitive treatment, perhaps we should consider doing the same in prostate cancer.

TBL: Patients treated with definitive radiation and long-term ADT for N1 and M1a nodal disease appear to have similar outcomes. | Chopade, Int J Radiat Oncol Biol Phys 2022