LAUSR

Rectal cancer is the most common subsite and comprises over a quarter of all colorectal cancers in Australia. The incidence is decreasing in those older than 50, coinciding with the success of screening programs, however, there is an increasing incidence in patients under 50. For optimal care, rectal cancer requires multidisciplinary management and ongoing follow-up and surveillance. This can be challenging in regional and rural areas. Evolving changes in management with total neoadjuvant therapy and the emerging practice of ‘watch-and-wait’ can add to this complexity. Rectal cancer treatment typically involves surgical excision. This may be via a transanal approach if superficial (T0-T1), however higher stage disease requires enbloc mesorectal excision. In low rectal cancers, an abdominoperineal resection is often required to achieve oncological clearance. For locoregionally advanced rectal cancers with threatened margins, neoadjuvant long-course chemoradiotherapy (ChemoRT) or short-course radiotherapy alone in select cases, is typically utilized prior to surgery. This may downstage the tumour to allow complete oncological resection and sphincter preserving surgery. A proportion of cases have complete disappearance of the cancer after neoadjuvant treatments. This is termed a complete response (CR) and is resulting in the emerging practice of a watch-and-wait approach, sparing surgery unless there is recurrence. The treatment approach with ChemoRT has markedly improved local control of locally advanced rectal cancer, decreasing local recurrence rates from 25% to 5%. Chemotherapy has traditionally been used in an adjuvant setting. However, given 35% of patient’s relapse by 5 years with distant metastases, chemotherapy is now typically used in a neoadjuvant setting instead, in addition to ChemoRT. This is termed total neoadjuvant therapy (TNT). This is showing excellent results with complete pathological response (pCR) rates of 29.9% using TNT versus 15.5% with the traditional approach. It has also shown improvements in reducing metastasis and improving disease-free and overall survival. The optimal sequencing and timing of the various modalities used continue to be refined. The challenges of providing care in regional centres are manifold. The 5-year observed survival of all cancer types decreases with increasing remoteness, from 63% in major cities to 55% in very remote areas. This is consistent for colorectal cancer with regional, rural and remote areas experiencing worse survival outcomes and less optimal care. This is likely due to geographic variations in demographics, but also service accessibility and provider factors. There are longer surgical wait times, less provision of chemotherapy for stage 3 colon cancer and less utilization of radiotherapy for rectal cancer. The difficulty in attracting and retaining specialists is well-known, with frequent staffing shortages and often rapid turnover of clinicians. This can delay or prevent the use of trimodality therapy and can affect provision of critical surveillance procedures such as endoscopy. It heightens the risk of patients being lost to follow up without robust handover and clinical databases. MRI and PET imaging may require long distance travel and patients face longer wait times and higher out-of-pocket costs, further contributing to poorer outcomes. Posttreatment surveillance is critical in rectal cancer and can allow the detection of recurrence while the disease remains salvageable in addition to detection of metachronous disease. The risk of local regrowth in those that have pCR is approximately 25%, necessitating intensive surveillance if watch-and-wait is undertaken. There is no clear consensus on the optimal surveillance structure for these patients. One recommendation has been made for threemonthly MRI and endoscopy for 2 years, four-monthly in the third year and six-monthly in years four and five. The feasibility of this intensive follow up in regional and rural centres, given the difficulties described above, has not yet been established and may prove problematic for many centres and their patients. With the use of TNT, more patients are becoming candidates for watch-and-wait. Data is revealing it is a viable alternative to surgery in strictly selected patients with robust and timely follow-up to allow curative salvage surgery in those that experience regrowth. Its use will no doubt be increasingly implemented. The risk of curable disease becoming incurable must be at the forefront of clinician’s minds when considered. Centres must be certain they can meet the requirements in terms of service provision and be rigorous in patient selection and shared decision-making before offering it. They must also have robust record keeping and follow-up protocols. A guideline has not yet been incorporated into the Australian cancer council colorectal cancer clinical practice guidelines. It should be established to help centres, particularly regional and rural, ensure patients can gain the benefits of this novel approach without causing inadvertent harm.