Neoadjuvant radiotherapy for rectal cancer management

Abstract

Thirty per cent of all colorectal tumours develop in the rectum. The location of the rectum within the bony pelvis and its proximity to vital structures presents significant therapeutic challenges when considering neoadjuvant options and surgical interventions. Most patients with early rectal cancer can be adequately managed by surgery alone. However, a significant proportion of patients with rectal cancer present with locally advanced disease and will potentially benefit from down staging prior to surgery. Neoadjuvant therapy involves a variety of options including radiotherapy, chemotherapy used alone or in combination. Neoadjuvant radiotherapy in rectal cancer has been shown to be effective in reducing tumour burden in advance of curative surgery. The gold standard surgical rectal cancer management aims to achieve surgical removal of the tumour and all draining lymph nodes, within an intact mesorectal package, in order to minimise local recurrence. It is critically important that all rectal cancer cases are discussed at a multidisciplinary meeting represented by all relevant specialties. Pre-operative staging including CT thorax, abdomen, pelvis to assess for distal disease and magnetic resonance imaging to assess local involvement is essential. Staging radiology and MDT discussion are integral in identifying patients who require neoadjuvant radiotherapy. While Neoadjuvant radiotherapy is potentially beneficial it may also result in morbidity and thus should be reserved for those patients who are at a high risk of local failure, which includes patients with nodal involvement, extramural venous invasion and threatened circumferential margin. The aim of this review is to discuss the role of neoadjuvant radiotherapy in the management of rectal cancer.

Intersphincteric Resection for Low Rectal Cancer: A Review of Anatomy and Surgical Techniques, Oncologic and Functional Outcomes and the Role of Robotics

“…The recorded local recurrence rate of 5.6% after 2 years is in range with published literature. 72,73,74 Publications on robotic ISR with significant patient numbers or follow-up periods is lacking in the literature. Kim et al 75 published a long-term retrospective study on robotic ISR patients, reporting 5-year cumulative rates of LR, OS and DFS of 2.5%, 86.7% and 80.7%, respectively.…”

MicroRNAs in Rectal Cancer: Functional Significance and Promising Therapeutic Value

“…Colorectal cancer (CRC) is the third most commonly diagnosed malignancy and the second leading cause of cancer-related deaths in the world, with approximately 1.8 million new cases and 900,000 deaths annually [1]. Rectal carcinoma represents approximately 30% of all colorectal tumors and is defined as tumors arising within 15 cm of the anal verge [2]. Both environmental and genetic factors play a major role in the pathogenesis of rectal cancer [3].…”

“…A significant proportion of patients with locally advanced disease (LARC) will potentially benefit from downsizing or downstaging tumors with a clinical stage T3 or T4 prior to total mesorectal excision (TME). Therefore, neoadjuvant 5-fluorouracil (5-FU)-based chemoradiotherapy represents the current standard treatment in this subgroup of patients [2]. The response to chemoradiotherapy (CRT) varies widely, from complete responses to complete resistance.…”

“…In 15-20% of cases, a complete response to radiotherapy is observed and patients can potentially avoid surgery and associated morbidities [7,10]. While these results are promising, there are a significant number of patients that will not benefit from CRT and will endure the side effects secondary to radiation exposure, including an increased risk of anorectal and genitourinary dysfunction, which negatively impacts their quality of life, and excessive tissue oedema, leading to the cancellation or postponement of surgical plans [2]. Notably, there is a current lack of well-established biomarkers for predicting responses to neoadjuvant CRT in LARC patients and all patients receive the same therapy [11].…”

The apparent diffusion coefficient is a useful biomarker in predicting treatment response in patients with locally advanced rectal cancer

“…In Mexico, it represents the third leading cause of new cases of cancer and cancer-related deaths in both men and women ( 1 ). The standard of care to manage locally advanced rectal cancer (LARC; stage II–III) consists of neoadjuvant chemoradiation therapy (nCRT) and total mesorectal excision (TME), followed by adjuvant chemotherapy ( 2 ). After nCRT, most LARCs demonstrate variable degrees of tumor response, including pathologic complete remission, in 4%–31% of patients.…”