Rectal cancer forms in the tissues of the rectum. The most common symptoms are rectal bleeding, pain and feeling like there is a lump in or around the anus. Less common symptoms include itching and changes to bowel habits. The likelihood of developing rectal cancer rises sharply with age, or if there is a familial genetic predisposition. For many people with the condition, the cancer is asymptomatic and detected through the national bowel cancer screening programme.
Management of rectal cancer depends on the cancer stage and individual patient factors. Surgery has traditionally been the gold standard for early-stage rectal cancer, but radiotherapy or chemoradiotherapy with a 'watch and wait' approach is increasingly used. Advanced tumours are usually treated with surgery, such as transanal excision, endoscopic submucosal dissection or total mesorectal excision. If surgery is not suitable or the person chooses not to have it, chemoradiotherapy may be used to shrink the tumour. NICE's guideline on colorectal cancer recommends preoperative radiotherapy or chemoradiotherapy for rectal cancer of stages cT1 to T2, cN1 to N2, M0 or cT3 to T4, any cN, and M0. Radiotherapeutic options include external beam radiation therapy (EBRT) or brachytherapy, in which radioactive material is placed inside or near the tumour.
Organ-preserving techniques and procedures have been increasingly adopted because they offer improvements in quality of life and reduce the risks and complications associated with surgery. So, they have become preferred by people with rectal cancer who do not wish to have surgery. One alternative to surgery, EBRT, is associated with a range of side effects, including skin discomfort, because it is an external application of radiation. When used with EBRT, low-energy contact X-ray brachytherapy (CXB) may provide a more targeted, organ-preserving option for local control by focusing radiation directly to the tumour without substantially increasing toxicity. Low-energy CXB may be particularly beneficial for some people, such as older people with comorbidities for whom surgery may not be an option because the risk is unacceptably high.
NICE did a rapid review of the published literature on the efficacy and safety of this procedure. This comprised a comprehensive literature search and detailed review of the evidence from 13 sources, which was discussed by the committee. The evidence included 1 systematic review and meta-analysis, 2 randomised controlled trials and 10 observational studies, and is presented in the summary of key evidence section in the interventional procedures overview. Other relevant literature is in the appendix of the overview. Several different devices were used in the studies informing this guidance. All delivered a beam of 50‑kV X-rays.
The professional experts and the committee considered the key efficacy outcomes to be:
quality of life
organ preservation
avoiding a permanent stoma
clinical response
survival
recurrence.
The professional experts and the committee considered the key safety outcomes to be:
proctitis
rectal bleeding
mortality
dermatitis.
Fifty-one commentaries from people who have had low-energy CXB, or their carers, were available. The committee highlighted the lived experience of people who have had this procedure, with every respondent stating that they would recommend it to other people with rectal cancer.
The committee noted that small polyps should be removed endoscopically as a first-line treatment, and that people with only small polyps would not be eligible for this procedure.
One of the clinical experts explained the opposing risk profiles of low-energy CXB and surgery. Low-energy CXB is less invasive but has a higher risk of local recurrence, while surgery offers more definitive control but has higher upfront risks such as surgical complications and long-term side effects.
The committee noted that providing a less-invasive treatment option for rectal cancer may encourage people to use screening services.
The committee noted that people who have larger tumours (larger than 3 cm) that have reduced in size after neoadjuvant treatment and have limited nodal involvement may become eligible for this procedure.
The committee emphasised the importance of organ preservation (the rectum and surrounding structures) provided by low-energy CXB and its impact on quality-of-life outcomes.
The committee noted that regular ongoing surveillance is needed for people who have this procedure, with repeat imaging and endoscopies recommended for 5 years after the procedure.
The committee was informed that the device applicator is only suitable for tumours of 3 cm or less.
The prevalence of rectal cancer is strongly related to age, with 75% of cases occurring in people aged 50 or over. Incidence rates for colorectal cancer are lower in Asian and Black ethnic groups, and in people of mixed or multiple ethnicities, compared with the White ethnic group, in England.
People from ethnic minority backgrounds are less likely to use screening services. This may lead to a delay in diagnosis and treatment.
People from ethnic minority backgrounds may have higher prevalence of stoma rejection.
The committee noted that there are only a few centres in the UK that specialise in managing rectal cancer and performing low-energy CXB. So, people living further from these centres may not have access to this procedure.