Selective use of radiation for locally advanced rectal cancer: one size does not fit all

Abstract

INTRODUCTION The last three decades have seen several major advances in the multidisciplinary management of locally advanced rectal cancer (LARC). Although rectal cancer management varies globally, the standard of care for clinical stage II/III rectal cancer in North America remains chemoradiation followed by total mesorectal excision and adjuvant therapy. EVIDENCE ACQUISITION In this review we evaluate the evidence for neoadjuvant therapy in LARC and the variety of treatment options available. EVIDENCE SYNTHESIS We identify heterogeneity of outcomes in stage II/III rectal cancer, leading to the potential for overtreatment. The PROSPECT trial is a multi-centre, international effort to determine whether a selective approach to provision of radiotherapy in stage II/ III LARC is a viable treatment option. Unlike many other studies, the aim of PROSPECT is to reduce treatment rather than increase the intensity of preoperative therapy. CONCLUSION LARC is a heterogeneous disease with varying risk of relapse. Studies are underway to attempt to individualise care to avoid overtreatment while maintaining excellent oncologic outcomes.

Durvalumab (MEDI 4736) in combination with extended neoadjuvant regimens in rectal cancer: a study protocol of a randomised phase II trial (PRIME-RT)

“…Although MMR deficiency is only detected in a minority of patients with LARC, the neoadjuvant setting provides an opportunity to evaluate this treatment in both MMR proficient, as well as MMR deficient LARC. Specifically, DNA damaging treatments used in the neoadjuvant setting such as radiotherapy [ 25 ] and chemotherapy [ 26 , 27 ] induce cellular damage and the resulting antigen exposure can incite lymphocytic responses. In this respect, radiotherapy and chemotherapy may ‘prime’ the tumour microenvironment, and when used in combination with immunotherapy may enhance this host anticancer immune response.…”

Modern Concepts on the Role of Hypoxia in the Development of Tumor Radioresistance

“…Более половины пациентов со злокачественными новообразованиями получают лучевую терапию (ЛТ) в монорежиме, в сочетании с хирургическим вмешательством и/или химиотерапией. Облучение и химиотерапия широко используются как один из этапов комбинированного лечения, а также как методы паллиативной терапии при первично неоперабельных или диссеминированных злокачественных новообразованиях (ЗНО) [1][2][3]. При ряде локализаций ЛТ, не уступая хирургическому методу в эффективности, является более функциональным и косметически щадящим методом.…”