Introduction
Watch-and-Wait is an increasingly recognized non-surgical management option for rectal cancer patients achieving a clinical complete response (cCR) following neoadjuvant therapy. This approach aims to preserve organ function by avoiding surgery, but necessitates vigilant endoscopic surveillance, to detect local tumor regrowth1 (LTR). The specific endoscopic features associated with regrowth remain incompletely defined.
Aims & Methods
We performed a retrospective analysis of patients monitored under the Watch-and-Wait program at Karolinska University Hospital2, focusing on the endoscopic characteristics of LTR. As of December 2023, 145 patients who met the criteria for clinical complete response (cCR) were included.
The neoadjuvant treatment consisted of chemoradiotherapy (CRT) in 16 patients (11%), short course radiotherapy (SCRT) + chemotherapy in 69 patients (47.6%) and SCRT alone (5 x 5 Gy) in 60 patients (41.4%). The median age of the patients was 66 years (range 29-94), with 61.4% being male. The initial tumor stage was T1/T2 in 42 patients (29%) and T3/T4 in 103 patients (71%). The nodal stage was N0 in 35 patients (24%) and N+ in 110 patients (75.9%). The median follow-up period was 29 months (range 3-102 months).
Patients were monitored with rectal digital exams, flexible endoscopy, CEA measurements, and MRI every 3 months for 2 years, and then every 6 months thereafter. During endoscopy, narrow-band imaging (NBI) and NICE classification3 was utilized.
Results
Out of the 145 patients, 28 (19.3%) experienced LTR as of December 2023. The median time from the completion of radiotherapy to regrowth was 9 months (range 3-20 months). Regrowth was detected intraluminally by endoscopy in 23 patients (82.1%), while in 5 patients (17.9%), regrowth was detected on MRI but was not visible intraluminally.
The most common endoscopic features of regrowth included a NICE 3 pattern (n=16) and contact bleeding (n=16). Additional findings included polypoid tissue (n=13), ulceration (n=10), irregular surface (n=9), fibrin cover (n=9), stenosis (n=6), and submucosal nodules (n=5).
Conclusion
As regrowth occurs in at least one of five patients and most commonly with intraluminal findings, this study highlights the importance of meticulous endoscopic follow-up. Contact bleeding and NICE type 3 lesions observed with narrow-band imaging (NBI) were key endoscopic findings in patients with tumor regrowth, while polypoid lesions were observed in less than 50%. Combining endoscopic assessment with other modalities, such as MRI, is essential, as regrowth may be undetectable endoscopically in a proportion of patients.
References
1. Cerdan-Santacruz C, Vailati BB, Sao Juliao GP, Habr-Gama A, Perez RO. Local tumor regrowth after clinical complete response following neoadjuvant therapy for rectal cancer: what happens when organ preservation falls short. Tech Coloproctol 2023;27(1):1-9. DOI: 10.1007/s10151-022-02654-5.
2. Nilsson PJ, Ahlberg M, Kordnejad S, Holm T, Martling A. Organ preservation following short-course radiotherapy for rectal cancer. BJS Open 2021;5(5). DOI: 10.1093/bjsopen/zrab093.
3. Hamada Y, Tanaka K, Katsurahara M, et al. Utility of the narrow-band imaging international colorectal endoscopic classification for optical diagnosis of colorectal polyp histology in clinical practice: a retrospective study. BMC Gastroenterol 2021;21(1):336. DOI: 10.1186/s12876-021-01898-z.
Disclosure
Stephan Haas (SLH) has received speaker's honoraria from Santax Medico, Tillotts Pharma, Lilly, Mediahuset, and Johnson & Johnson.
