After pre-operative RT, as shown, tumour is often reduced in size, is downstaged or even shrinks and sometimes also disappears and therefore may facilitate conservative surgery. Data from the literature are not conclusive with respect to how often a planned abdominoperineal resection can be converted to a sphincter-saving surgery after pre-operative radiochemotherapy. It depends also on the specialisation of the surgeon, techniques used in colo-anal anastomoses, intersphincteric resections and the length of distal margin judged as adequate (2 cm, 1 cm). There is still controversy about the place of downsizing neoadjuvant therapy and the true long-term functional outcome.
Nowadays, abdominoperineal excision seems to be performed for oncological reasons if cancer invades the anal sphincter and when R0 cannot be otherwise obtained, making sphincter-saving surgery the standard procedure for low rectal cancer .
Experiences of radiochemotherapy without surgery also exist in the literature, with contrasting results. Nakagawa et al.  did not operate on 10 patients after complete clinical response to chemora-diotherapy for middle and low rectal cancer. Eight patients presented local recurrence within 3.7 and 8.8 months, requiring salvage surgery. Two patients were disease free after 37 and 58 months. An exclusive medical non-surgical approach seemed unsafe for rectal cancer.
Other Authors  conclude that a complete clinical response after neoadjuvant chemotherapy is associated with an excellent outcome in terms of five-year overall and disease-free survival also without surgery (respectively 100% and 92%). Surgery may in this context only increase the morbidity and mortality rates and negatively influence quality of life with the creation of a temporary or definitive stoma.
Some Authors have performed local excision after chemoradiation with apparently good results, especially initially after patient's refusal of abdominoperineal resection or associated severe comorbidity. Local control and survival in selected patients (T3N0 with complete response to neoadjuvant therapy) are reported to be similar to those obtained after chemoradiation combined with surgery (TME). Bonnen et al.  collected data results from 5 different institutions concerning local full thickness excision or observation after a good response to neoadjuvant chemotherapy. Only two of them, both with incomplete histological response, developed pelvic recur rence at follow-up. They claim a prospective randomised trail comparing T3N0 patients with complete clinical response to radiochemotherapy with those submitted to radical surgery. Criticism can be aimed at this approach because it may leave residual disease in the rectal mesentery and nodes.
More accurate imaging modalities such as the use of endorectal coil MRI and PET should be of help as it can demonstrate sufficient sensitivity in the detection of neoplastic deposits in mesorectum.
Was this article helpful?