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Thomas et al. Mini-invasive Surg 2018;2:17 I http://dx.doi.org/10.20517/2574-1225.2018.25 Page 3 of 7

In a later study, the accuracy of colonoscopic EUS was assessed in the selection of patients with rectal
neoplasia suitable for local excision by TEM. Patients with premalignant (uT0) lesions or with uT1 tumours
that had favourable histology were offered a TEM. This has been our preferred method of local excision
since 1996. Data were collected prospectively over a six-year period. The preoperative stage predicted by
EUS (uT stage) was compared to the postoperative histopathological stage of the resected specimens (pT
stage). One hundred and fifty-six EUS examinations were evaluated. Sixty-two patients went on to have
TEM whilst the remaining 94 had another form of surgery. Of the 62 patients undergoing TEM, 3 were
over staged on EUS. No patients were understaged, giving an accuracy of 95%. The accuracy of EUS at
[22]
predicting more advanced disease fell to 89%, giving an overall accuracy of 92% . Indeed, we feel that
EUS in our institution is highly accurate at predicting T0/1 vs. T2 disease and we routinely use EUS in
combination with CT and MRI before planning intervention. In addition, the staging of local disease
can be further augmented by colonoscopic EUS guided fine needle aspiration of extra rectal lesions lying
[23]
within or outside of the mesorectum that are demonstrated on cross-sectional imaging .
The need for highly accurate staging for early rectal cancer and early stage disease is highlighted by the
observation that the National Bowel Cancer Screening Programme in the United Kingdom will result in an
increase in the proportion of early stage tumours that are potentially amenable to local excision, although
stage migration has yet to be demonstrated in population-based studies. Local recurrence rates of < 5%
after TEM excision have been reported for pT1 tumours with favourable histology that equate to those
achieved by radical surgery. As local excision offers the possibility of organ preservation and thus improved
quality of life, recent focus has therefore shifted toward the use of neoadjuvant therapy as a means of
downstaging early tumours (cT1-T3a) and sterilizing the mesorectal nodal field before local excision.

TREATMENT STRATEGY
Given the reluctance to administer neoadjuvant radiotherapy in early rectal cancer, there is a lack of data
addressing the oncological outcomes and morbidity profile of this approach. This prompted us to undertake
our systematic review of LE after neoadjuvant therapy to determine oncological outcomes as defined by
[20]
LR and, second, to determine the incidence and nature of postoperative complications . A total of 22
unique studies reporting on 1068 patients were analysed. Pre-treatment T2 and T3 tumours accounted for
46.4% and 30.7% of cases, respectively and LCCRT was administered in all studies, except to a cohort of
64 patients who received SCRT. The pooled cCR based on the staging modalities used in these studies was
45.8% with a pooled pCR 44.2%. At a median follow-up of 54 months, ypT0 tumours had a pooled local
recurrence rate of 4% and a median disease-free survival rate of 95%. This compared favourably to results
achieved with radical surgery in equivalent stage disease. Outcomes for ≥ ypT1 tumours were much worse
[20]
with pooled local recurrence and disease-free survival of 22% and 68%, respectively . Despite the obvious
limitations of study heterogeneity and their retrospective nature, we conclude that local excision should
only be considered as a definitive therapy if a pCR, i.e., ypT0, is obtained in the excision specimen.

The other unresolved issue is whether radiotherapy should be used in an adjuvant setting to improve
outcomes after local excision of early rectal cancer, specifically in pT1 disease with unfavourable histology
and pT2/pT3a disease. It is our current practice to offer local excision alone to patients with pT1 disease
with favourable histology. Where post-operative histology reveals pT1 disease with adverse histological
features or unexpected pT2 disease, we offer completion radical surgery as the standard of care and reserve
adjuvant LCCRT for patients either deemed unfit or who wish to preserve their rectum. Even though much
of the recent work in this field has focussed on the use of neoadjuvant therapy prior to local excision, we
conducted our own systematic review of local excision followed by adjuvant therapy to determine if this
was an acceptable treatment option. In this review, 22 studies described 804 patients who underwent
local excision followed by adjuvant therapy either for unfavourable histology, prohibitive comorbidity or