Impact of biopsy on the accuracy of endorectal ultrasound staging of rectal tumors

[Transanal Tumor Resection: Indication, Surgical Technique and Management of Complications]

Transanal resection procedures are special operations for the minimally invasive treatment of rectal tumours. Apart from benign tumours, this procedure is suitable for the excision of low-risk T1 rectal carcinomas, if these can be completely removed (R0 resection). With stringent patient selection, very good oncological results are achieved. Various international trials are currently evaluating whether local resection procedures are oncologically sufficient if there is a complete or near complete response after neoadjuvant radio-/chemotherapy. Numerous studies have shown that the functional results and the postoperative quality of life after local resection are excellent, especially considering the well-known functional deficits of alternative operations, such as low anterior or abdominoperineal resection.Severe complications are very rare. Most complications, such as urinary retention or subfebrile temperatures, are minor in nature. Suture line dehiscences are usually clinically unremarkable. Major complications comprise significant haemorrhage and the opening of the peritoneal cavity. The latter must be recognized intraoperatively and can usually be managed by primary suture. Infection, abscess formation, rectovaginal fistula, injury of the prostate or even urethra are extremely rare complications.

Preoperative Diagnostic Uncertainty in T2-T3 Rectal Adenomas and T1-T2 Adenocarcinomas and a Therapeutic Dilemma: Transanal Endoscopic Surgery, or Total Mesorectal Excision?

BACKGROUND

Endorectal ultrasound and rectal magnetic resonance are sometimes unable to differentiate between stages T2 and T3 in rectal adenomas that are possible adenocarcinomas, or between stages T1 and T2 in rectal adenocarcinomas. These cases of diagnostic uncertainty raise a therapeutic dilemma: transanal endoscopic surgery (TES) or total mesorectal excision (TME)?

METHODS

An observational study of a cohort of 803 patients who underwent TES from 2004 to 2021. Patients operated on for adenoma (group I) and low-grade T1 adenocarcinoma (group II) were included. The variables related to uncertain diagnosis, and to the definitive pathological diagnosis of adenocarcinoma stage higher than T1, were analyzed.

RESULTS

A total of 638 patients were included. Group I comprised 529 patients, 113 (21.4%) with uncertain diagnosis. Seventeen (15%) eventually had a pathological diagnosis of adenocarcinoma higher than T1. However, the variable diagnostic uncertainty was a risk factor for adenocarcinoma above T1 (OR 2.3, 95% CI 1.1-4.7). Group II included 109 patients, eight with uncertain diagnosis (7.3%). Two patients presented a definitive pathological diagnosis of adenocarcinoma above T1.

CONCLUSIONS

On the strength of these data, we recommend TES as the initial indication in cases of diagnostic uncertainty. Multicenter studies with larger samples for both groups should now be performed to further assess this strategy of initiating treatment with TES.

[Impact of endoscopy and endosonography on local staging of rectal carcinoma]

For rectal carcinoma the decision between primary resection, neoadjuvant therapy and local excision depends on an accurate local staging. Local staging includes digital examination, rigid rectoscopy and endorectal ultrasound (EUS). The rectal digitation allows clinical staging according to the mobility of the tumor in relation to the rectal mucosa or the rectal wall. The rigid rectoscopy determines the aboral distance of the tumor from the dentate line or the anal verge. The endorectal ultrasound determines the pre-therapeutic UICC stage on the basis of evaluating the pretherapeutic T and N categories. Results of EUS should be discussed on the background of neoadjuvant therapy including response evaluation and in comparison with the results of magnetic resonance imaging. In addition, there is only little information available concerning evaluation of the circumferential resection margin by EUS. Technical improvements, such as the 3D-EUS, might be appropriate in the future to provide enhancement of EUS staging of rectal tumors.

The concurrence of histologically positive resection margins and sessile morphology is an important risk factor for lymph node metastasis after complete endoscopic removal of malignant colorectal polyps

INTRODUCTION

The optimal procedure to be followed after colonoscopic polypectomy of malignant colorectal polyps with nontumour-free resection margins at histology is a matter of controversy. While some authors recommend merely local or segmental follow-up resection, others favour an oncological resection.

PATIENTS AND METHODS

One hundred five patients, each with a single malignant polyp, were investigated. Patients with a macroscopically evident malignant polyp and those in whom the endoscopist reported incomplete polypectomy were excluded from the study.

RESULTS

Postpolypectomy morbidity was 4%, and postoperative was 14%. In only 39 cases were the resection margins adjudged to be tumour-free. Histology following subsequent surgery or the follow-up examinations revealed a local recurrence or residual carcinoma at the polypectomy site in only three (2.8%) cases and lymph node metastasis in eight (7.6%) cases. Five patients had remnant adenoma at the polypectomy site. Of the high-risk factors, histological incomplete removal (n = 66, p = 0.04, odds ratio (OR) 10.2) and lymph vessel infiltration (n = 7, p = 0.02, OR 9.2) revealed a significant correlation with lymph node metastasis, but not with remnant tumour. In the case of sessile polyp, the assessment of histological incomplete removal was highly significantly correlated with lymph node metastasis (n = 55, p = 0.007, OR 18.1).

CONCLUSIONS

Polypectomy artefacts appear to be responsible for the discrepancy between histology and the tumour remnants actually present. On the other hand, histologically incompletely removed sessile malignant polyps represent an appreciably higher risk for lymph node metastasis. Such cases should, therefore, be submitted to further oncological resection.

Prospective phase II study of preoperative short-course radiotherapy for rectal cancer with twice daily fractions of 2.9 Gy to a total dose of 29 Gy--long-term results

Background

To evaluate clinical outcome after preoperative short-course radiotherapy for rectal cancer with twice daily fractions of 2.9 Gy to a total dose of 29 Gy and adjuvant chemotherapy for pathological stage UICC ≥ II.

Methods

118 patients (median age 64 years; male : female ratio 2.5 : 1) with pathological proven rectal cancer (clinical stage II 50%, III 41.5%, IV 8.5%) were treated preoperatively with twice daily radiotherapy of 2.9 Gy single fraction dose to a total dose of 29 Gy; surgery was performed immediately in the following week with total mesorectal excision (TME). Adjuvant 5-FU based chemotherapy was planned for pathological stage UICC ≥ II.

Results

After low anterior resection (70%) and abdominoperineal resection (30%), pathology showed stage UICC I (27.1%), II (25.4%), III (37.3%) and IV (9.3%). Perioperative mortality was 3.4% and perioperative complications were observed in 22.8% of the patients. Adjuvant chemotherapy was given in 75.3% of patients with pathological stage UICC ≥ II. After median follow-up of 46 months, five-year overall survival was 67%, cancer-specific survival 76%, local control 92% and freedom from systemic progression 75%. Late toxicity > grade II was observed in 11% of the patients.

Conclusions

Preoperative short-course radiotherapy, total mesorectal excision and adjuvant chemotherapy for pathological stage UICC ≥ II achieved excellent local control and favorable survival.

Endosonographic staging of lower intestinal malignancy

The use of EUS in the assessment of rectal pathology is well established. The accurate staging of lower intestinal tumours predicts prognosis and guides the planning of individual patient treatment. Increased experience and the development of high resolution three-dimensional EUS has lead to the greater accuracy of rectal staging with EUS of rectal tumours now considered the gold standard showing T stage accuracy that ranges from 75% to 95%, with N stage accuracy ranging from 65% to 80%. The use of EUS in the staging of colonic pathology, however, is not so well established though advances in miniprobe EUS has improved the assessment of colonic tumours. EUS is also of benefit in the assessment of anal pathology though here, accurate correlation with histology has not been firmly established.

Ultrasound staging of rectal cancer

Endorectal ultrasound (ERUS) is a primary imaging technique in the preoperative evaluation of patients with rectal adenocarcinoma. The purpose of this report is to review ultrasound staging with emphasis on technique and potential pitfalls. The role of ultrasound in multimodality staging and surveillance is also explored. An awareness of inherent imaging challenges and implications may optimize staging accuracy and resultant management of rectal cancer patients.