Update on the surgical pathology standards on rectal cancer diagnosis, staging and quality assessment of surgery.

Surgery for rectal cancer continues to develop towards improving local control and overall survival, maintaining quality of life and preserving sphincter, genitourinary and sexual function. The multidisciplinary approach integrated in a team of different specialists ensures an individualised treatment for each patient with rectal cancer. Thus, the role of the pathologist has acquired an important relevance, not only in diagnosis, management and evaluation of the surgical specimen, but also for selection of the best adjuvant treatment. Parameters such as macroscopic quality of the mesorectum, status of the circumferential margin and lymph node harvest are considered basic criteria by current guidelines. Additionally, consistency in reporting based on the histologic classification proposed by the World Health Organization (WHO) is mandatory, along with inclusion into the pathologic report of current criteria for tumour node metastasis (TNM) staging, assessment of response to neoadjuvant chemoradiation therapy and clinically relevant molecular studies. Detection of defects in mismatch repair genes and mutational analysis of specific genes should be included as predictive markers for therapy.