Nicholas Hornstein, Assistant Professor at Northwell Health, shared a post on XÂ about a recent article by Koji Ando et al. published in Annals of Surgery:
“Jaw-dropping ctDNA data in rectal cancer thanks to the GALAXY study (the gift that keeps on giving)
This prospective cohort from Japan looked at stage II–III rectal cancer treated with upfront surgery, no neoadjuvant therapy. It gives us one of the cleanest looks yet at postoperative ctDNA and who actually benefits from adjuvant chemo.
 In the MRD window (2–10 weeks postop):
- 14% ctDNA positive → very high recurrence risk (HR ~10)
- 86% ctDNA negative → excellent outcomes with or without adjuvant therapy
The key finding:
Among ctDNA-negative patients, adjuvant chemotherapy did not show a statistically significant DFS benefit (HR 0.59, p = 0.21), 2 year DFS 86.1% vs 84.2%. The direction favors treatment, but the study didn’t demonstrate benefit with very wide confidence intervals due to low numbers of ctDNA + patients (35). The HR implies improvement, but the curves overlap…
In contrast, ctDNA-positive patients clearly benefited from adjuvant chemo (HR 0.28).
Serial testing mattered. Patients who remained ctDNA negative did extremely well, while those who converted to positive had a sharp rise in recurrence risk.
Takeaway:
This strongly questions the value of adjuvant chemotherapy in ctDNA negative rectal patients after upfront surgery irrespective of stage.
Looking forward to discussing at GI26 (and why ctDNA still isn’t in NCCN CRC guidelines).”
Title: Molecular Residual Disease and Recurrence in Rectal Cancer Patients Undergoing Upfront Surgery
A Prospective Cohort Study
Authors: Koji Ando, Atsushi Hamabe, Yoshiaki Nakamura, Jun Watanabe, Keiji Hirata, Kozo Kataoka, Masaaki Miyo, Kentaro Kato, Naoya Akazawa, Yoshinori Kagawa, Mitsuru Yokota, Kentaro Yamazaki, Saori Mishima, Hiroki Yukami, Daisuke Kotani, Hideaki Bando, George Laliotis, Shruti Sharma, Charuta C. Palsuledesai, Matthew Rabinowitz, Adham Jurdi, Minetta C. Liu, Alexey Aleshin, Hiroya Taniguchi, Ichiro Takemasa, Takeshi Kato, Takayuki Yoshino, Eiji Oki
Read the Full Article on Annals of SurgeryÂ
More posts featuring Nicholas Hornstein.
