International consensus recommendations on key outcome measures for organ preservation after (chemo)radiotherapy in patients with rectal cancer

Abstract

Organ preservation constitutes a paradigm shift in the management of patients with rectal cancer. One of the main reasons for exploring organ preservation strategies is the potential to preserve anorectal function, thus avoiding the need for permanent colostomy and maintaining quality of life (QoL) 1 . Deteriorations in several parameters of bowel function -including urgency, frequency, incontinence and bowel movement clusteringcan occur with variable frequency in patients with rectal cancer who receive low anterior resection after neoadjuvant chemoradiotherapy (CRT). The number of clinical trials examining organ preservation strategies such as nonoperative management (NOM) or local excision (LE) only after CRT in patients with rectal cancer is progressively increasing 1 . Habr-Gama and colleagues were the first to implement a selective NOM approach in patients with resectable rectal cancers with a clinical complete response (cCR) following CRT 2 . Since this initial study,

Targeted Radiotherapy Using Contact X-ray Brachytherapy 50 kV

“…A planned or “intended” [ 18 , 23 ] organ preservation in rectal cancer could be decided or proposed to a patient if, at the time of initial treatment decision, the chance of “success” is estimated close to 80% at 2 or 3 years with good bowel function and acceptable toxicity. Such an approach is a standard strategy for anal squamous cell carcinoma, which is a quite highly radiosensitive cancer (interestingly, this standard was not based on any Phase III trial vs. radical proctectomy with a permanent stoma).…”

Assessment of clinical and pathological complete response after neoadjuvant chemoradiotherapy in rectal adenocarcinoma and its therapeutic implications

“…Because biopsy samples are frequently taken from mucosa and submucosa, the risk of a false-negative pCR is very high. Based on such information, as well as those derived from other studies [ 38 , 39 ], a recent consensus released by experts in RC treatment did not recommend the routinely use of biopsy sampling to establish the pCR due to the risk of false-negative findings and a lack of evidence of value, especially when DRE, endoscopy and MRI criteria for cCR are all fulfilled [ 40 , 41 , 42 ].…”

“…Patients without downstaging at 12 weeks should be immediately referred for RS to ensure oncological safety. The good responders (identified at 12 weeks) should be re-evaluated 4–8 weeks later, recommending rectum-sparing approaches in those who achieved a cCR at that time point [ 40 ]. In patients treated with TNT, the optimal interval between the start of neoadjuvant therapy and the time of cCR assessment is still unclear, especially due to the various durations of different TNT schemes.…”

“…However, an early response evaluation is needed to identify the poor responders that should be referred to RS for oncological safety reasons. For good responders, who might benefit from completing the scheduled TNT, the evaluation of cCR could be done at 4–8 weeks after the end of TNT, but even in these patients close monitoring during the neoadjuvant treatment is mandatory [ 40 ].…”

“…In such patients, the accurate evaluation of cCR is crucial, because alternative strategies consist in LE or WW approach, both of them omitting TME which is still considered the standard approach to RC. A recent international consensus on key outcome measures for organ preservation after (chemo)radiotherapy in patients with RC [ 40 ] has chosen the Amsterdam/Maastricht criteria for defining cCR [ 22 ].…”