Role of radiation therapy in neoadjuvant era in patients with locally advanced rectal cancer

Surgery remains the primary determinant of cure in patients with localized rectal cancer, and total mesorectal excision is now widely accepted as standard of care. The widespread implementation of neoadjuvant short-course radiotherapy (RT) or long-course chemoradiotherapy (CRT) has reduced local recurrence rates from 25% to 40% to less than 10%; Preoperative RT in resectable rectal cancer has a number of potential advantages, most importantly reducing local recurrence, and down-staging effect. In this article making a comprehensive literature review searching the reliable medical data bases of PubMed and Cochrane we present all available information on the role of radiation therapy alone or in combination with chemotherapy in preoperative setting of rectal cancer. Data reported show that in locally advanced rectal cancer the addition of radiation therapy or CRT pre surgically has significantly improved sphincter prevention surgery. Moreover, the addition of chemotherapy to radiation therapy in preoperative setting has significantly improved pathologic complete response rate and loco-regional control rate without improvement in sphincter preserving surgery. Finally, the results of recently published randomized trials have shown a significant improvement of pre- vs postoperative CRT on local control; however, there was no effect on overall survival.

Role of radiotherapy for resectable rectal cancer

SUMMARY The role of radiation therapy in the treatment of resectable rectal cancer is better defined than at any point in history; however, as technology improves, increasing treatment options can lead to better patient care when used appropriately with adequate training. Understanding the risk factors for local recurrence can assist in delivering individualized treatment options. Technological improvements such as intensity-modulated radiation therapy have the potential to decrease toxicity, but without adequate training, highly conformal treatment can result in undertreating or missing critical areas. This review will provide an overview of treatment and standard treatment options for resectable rectal cancer, as well as an update on the state of radiation therapy as it relates to rectal cancer and the use of intensity-modulated radiation therapy.

Multimodal treatment strategies for locally advanced rectal cancer

This review outlines the important multimodal treatment issues associated with locally advanced rectal cancer. Changes to chemotherapy and radiation schema, as well as modern surgical approaches, have led to a revolution in the management of this disease but the morbidity and mortality remains high. Adequate treatment is dependent on precise preoperative staging modalities. Advances in staging via endorectal ultrasound, computed tomography, MRI and PET have improved pretreatment triage and management. Important prognostic factors and their impact for this disease are under investigation. Here we discuss the different treatment options including modern tumor-related surgical approaches, neoadjuvant as well as adjuvant therapies. Further clinical progress will largely depend on the broader implementation of multidisciplinary treatment strategies following the principles of evidence-based medicine.

Toward the non-surgical management of locally advanced rectal cancer

Neoadjuvant short-course radiotherapy and long-course chemoradiation (CRT) reduce local recurrence rates when compared to surgery alone and remain widely accepted as standard of care for patients with locally advanced rectal cancer. However, surgery is not without complications and a non-surgical approach in carefully selected patients warrants evaluation. A pathological complete response to CRT is associated with a significant improvement in survival and it has been suggested that a longer time interval between the completion of CRT and surgery increases tumor downstaging. Intensification of neoadjuvant treatment regimens to increase tumor downstaging has been evaluated in a number of clinical trials and more recently the introduction of neoadjuvant chemotherapy prior to CRT has demonstrated high rates of radiological tumor regression. Careful selection of patients using high-resolution MRI may allow a non-surgical approach in a subgroup of patients achieving a complete response to neoadjuvant therapies after an adequate time period. Clearly this needs prospective evaluation within a clinical trial setting, incorporating modern imaging techniques, and tissue biomarkers to allow accurate prediction and assessment of response.

Radiation in rectal cancer: what are the options and if/when can it be avoided?

Treatment of rectal cancer has improved greatly over recent decades. This review looks at the pivotal trials in the development of the current standard of therapy as well as new directions for more individualized therapy for rectal cancer. Rates of local recurrence and overall survival (OS) for surgery alone have improved with the use of (neo)adjuvant 5-fluorouracil (5-FU)-based chemoradiation. New surgical techniques have improved outcomes, but preoperative radiotherapy still confers an additional benefit. Despite benefits in the metastatic setting, the addition of oxaliplatin to 5-FU and radiotherapy has not shown improved outcomes, although it increased toxicity. Preoperative therapy also allows for the identification of predictive and prognostic markers for response to treatment, which has great potential to individualize treatment. Currently, the search for validated biomarkers and the refinement of risk stratification are the focus of ongoing study. Tailored therapy may include modification of the pelvic radiotherapy field, nonoperative therapy, or avoidance of radiotherapy.