La radiothérapie des cancers du rectum : stratégie thérapeutique et perspective

Bowel function after anterior rectal resection for cancer: short and long-term prospective evaluation with low anterior rectal syndrome (LARS) score in a cohort of Cameroonian patients

Introduction

bowel dysfunction is the most common and disabling complication after anterior rectal resection (ARR) for cancer. We aimed to evaluate these complications in a cohort of Cameroonian patients, using the low anterior rectal syndrome (LARS) score.

Methods

we conducted a descriptive and analytical cross-sectional study, in two university hospitals of Yaoundé (Cameroon). Prospectively, we collected the records of all patients aged at least 18 years who had an ARR indicated for rectal cancer from January 2015 to March 2018. Alive patients among them were subsequently received in consultation at 1 and 3 years after surgery, for short and long-term assessment of their digestive function using the LARS score.

Results

during the study period, 28 patients underwent anterior rectal resection for rectal cancers. Short-term bowel function was evaluated in 23 patients. Their mean age was 48.42 ± 12.2 years and 14 were males. LARS was present in 10 of them (43.47%) and classified as "minor" in the majority of cases (n=6). The commonest bowel dysfunction at this term was splitting of stool (56.53%). Long-term digestive function was evaluated in 11 patients; LARS was found in 3 of them (27,27%) and classified as minor in all cases. Perfect continence was significantly improved (p=0.003) in the long term compared to the short-term status. Continence (p=0.049) and urgency (p=0.048) were better in patients who had a low colorectal anastomosis compared to those who had a colo supra-anal anastomosis.

Conclusion

after ARR for cancer, there is a high prevalence of LARS in the short term with an improvement in the long term.

[Place of radiotherapy in the treatment of rectal cancer in the elderly]

Rectal cancer is a common disease of the elderly. Current treatment recommendations are established for young subjects in good general health condition, without taking into account the frailty, comorbidities and polymedications inherent in patients over 75 years old. For locally advanced lower and middle rectal cancers (T3, T4 or N+), these are based on variations of regimens including neoadjuvant chemoradiotherapy, surgery of the rectum with total removal of the mesorectum, and a possibility of adjuvant chemotherapy. This restrictive treatment presents a problem of compliance and is not without adverse effects. Treatment by short exclusive radiotherapy or chemoradiotherapy with close monitoring according to the Watch and Wait strategy can be proposed to fragile patients not eligible for surgery, even if there is a non-negligible risk of recurrence.

[Preoperative intensity-modulated radiotherapy of rectal cancers: Relevance and modalities]

Preoperative radiotherapy boosted by chemotherapy is a recommended treatment in locally advanced rectal cancers. This treatment is delivered by three dimensional conformal irradiation, which is usually well tolerated but can induce potential toxicity such as rectitis, cystitis and hematologic adverse effects. Intensity-modulated radiotherapy, widely available nowadays, allows optimization of volume covering and sparing of organs at risk such as bladder and bone marrow. This review presents relevant clinical situations and requirements for a beneficial and safe preoperative irradiation of rectal cancers by intensity-modulated technique. This technique is compared to three-dimensional conformal radiotherapy.

[Follow-up after rectal cancer treatment]

Along with the surgeon, the gastroenterologist and the general practitioner, the radiation oncologist is involved in the follow-up of patients with rectal cancer treated by radiation. Post-treatment follow-up is recommended by major professional expert groups and consists of clinical examination, monitoring of carcinoembryonic antigen, colonoscopy and computed tomography of the abdomen and pelvis. Three recent large phase III randomized trials demonstrated a lack of survival benefit from intensive follow-up strategies in comparison with minimal follow-up. However, a follow-up program is not only important for the detection of an early disease relapse but it can be also used for the identification and the management of long-term toxicity and sequalae related to rectal cancer treatment.

[Anal canal cancer: In the era of intensity-modulated radiotherapy, outstanding issues]

Intensity-modulated radiotherapy makes possible to optimize the irradiation and spare normal tissues. The toxicity remains important with concomitant chemotherapy often associated. The improvement of MRI and PET-CT define more precisely the target volumes, which need a higher dose, but necessitates to respect the rules of contouring. The treatment is uniform whatever the stage but should be individualized based on clinical stage and tumor response. New paradigms concern biology, staging, volumes and doses, fractionation and combined treatments.