Watch and wait approach in rectal cancer: Current controversies and future directions

Abstract

According to the main international clinical guidelines, the recommended treatment for locally-advanced rectal cancer is neoadjuvant chemoradiotherapy followed by surgery. However, doubts have been raised about the appropriate definition of clinical complete response (cCR) after neoadjuvant therapy and the role of surgery in patients who achieve a cCR. Surgical resection is associated with significant morbidity and decreased quality of life (QoL), which is especially relevant given the favourable prognosis in this patient subset. Accordingly, there has been a growing interest in alternative approaches with less morbidity, including the organ-preserving watch and wait strategy, in which surgery is omitted in patients who have achieved a cCR. These patients are managed with a specific follow-up protocol to ensure adequate cancer control, including the early identification of recurrent disease. However, there are several open questions about this strategy, including patient selection, the clinical and radiological criteria to accurately determine cCR, the duration of neoadjuvant treatment, the role of dose intensification (chemotherapy and/or radiotherapy), optimal follow-up protocols, and the future perspectives of this approach. In the present review, we summarize the available evidence on the watch and wait strategy in this clinical scenario, including ongoing clinical trials, QoL in these patients, and the controversies surrounding this treatment approach.

Molecular and Dynamic Evaluation of Proteins Related to Resistance to Neoadjuvant Treatment with Chemoradiotherapy in Circulating Tumor Cells of Patients with Locally Advanced Rectal Cancer

“…For patients with pCR, especially for tumors of the distal rectum, the WW strategy is quite attractive and safe [ 10 , 41 ]. However, the clinical response presents poor correlation with the pathological response [ 42 , 43 , 44 ]. Therefore, in addition to endoscopy and imaging, new tools are need to more accurately predict response.…”

Radiomics and machine learning applications in rectal cancer: Current update and future perspectives

“…While TME should follow nCRT in patients with LARC, the role of surgery in patients with a complete response to nCRT is currently debated, and a “watch and wait” strategy has been proposed[ 53 ]. Indeed, patients who achieve a pathological complete response (pCR) after nCRT have better long-term outcomes compared with non-pCR patients, and could therefore be managed differently[ 54 ].…”

Re-staging and follow-up of rectal cancer patients with MR imaging when “Watch-and-Wait” is an option: a practical guide

“…Approximately 10–25% of patients with locally-advanced rectal cancer undergoing NAT prior to surgery achieve a pCR [ 4 ], escalating to even higher rates when more intense RT and/or chemotherapy regimens are employed [ 4 ].…”

“…It traditionally applies to all clinically staged T3/T4 and/or N+ tumours, although in the UK and other centres across Europe criteria may be more strict [ 1 , 2 ]. NAT regimens were initially designed with the sole purpose of downsizing/downstaging tumours in order to increase the likelihood of an R0 resection and diminish the risk of local recurrence [ 3 ], but the 10–25% pathologic complete response (pCR) rates have led clinicians to question the utility of radical surgery itself in such cases [ 4 ]. In fact, the real pCR odds may be even higher, given most patients included in reported studies were operated at 6–8 weeks while pCR rates increase significantly when the interval to surgery is lengthened to > 12 weeks post-radiotherapy (RT) [ 5 ].…”

“…In fact, the real pCR odds may be even higher, given most patients included in reported studies were operated at 6–8 weeks while pCR rates increase significantly when the interval to surgery is lengthened to > 12 weeks post-radiotherapy (RT) [ 5 ]. This means that if patients are re-staged and no signs of tumour persistence are present, deferral of surgery may be a reasonable option, and “Watch-and-Wait” (W&W) programs have grown increasingly available and popular during the past almost 20 years [ 4 ]. For willing and able patients, this decision is largely based on re-staging rectal endoscopy and MR imaging assessments [ 6 ].…”