Pre-operative chemoradiotherapy in locally advanced rectal cancer

Mortality risk analysis following routine vs selective defunctioning stoma formation after total mesorectal excision for rectal cancer

OBJECTIVE

To answer the question whether a defunctioning stoma (DS) should be constructed routinely after total mesorectal excision or whether it could be used selectively to ensure patient safety.

METHOD

A PubMed search was performed. All randomized trials on the role of a DS were included. Also, observational articles published between January 1997 and August 2007 were reviewed. Sensitivity analysis of the mortality risk was performed.

RESULTS

The clinical anastamotic leak (CAL) rate was 17% in 358 patients from four randomized trials and 9.6% in 4059 patients from 39 observational studies. The CAL rate increased significantly from 9.6% with DS to 24.4% without DS in four randomized trials, and from 7.9% with DS to 13.2% without DS in 17 observational studies. The re-operation rate as a result of anastomotic leakage was lower in patients with DS than in patients without DS in both study types. Leak-related mortality was not significantly different: 7.2% with vs 7.7% without DS in observational studies, and 0% with vs 4.6% without DS in randomized trials. Sensitivity analysis indicated that a selective DS strategy is acceptable if the CAL rate without DS is less than 16.6% with a CAL-related mortality of no more than 4.6%.

CONCLUSION

The results of this review support the routine construction of a protective stoma. However, selective use of a DS is justified from a patient safety point of view if the CAL-rate and its related mortality are limited. Each unit should audit its performance.

Evaluation of a protocol-based management of rectal cancer

INTRODUCTION

The management of rectal cancer is multidisciplinary. We have devised and implemented a standardized protocol. This study was designed to evaluate the protocol and identify areas for improvement.

METHODS

All patients with a diagnosis of rectal cancer were staged preoperatively. Magnetic resonance imaging and computed tomography were used to predict whether surgical resection would be complete (RO) or involved (R1/2). Data were collected on preoperative adjuvant therapy, surgical procedure, and subsequent pathologic stage, including circumferential resection margin status.

RESULTS

Between January 2000 and October 2002, 163 patients were studied (107 male; median age, 70 (range, 60-77) years). One hundred and fifty seven patients underwent surgical excision for rectal cancer of whom 155 were discussed in the multidisciplinary meeting. One hundred seventeen patients (75 percent) had pelvic magnetic resonance scan and staging computed tomography of chest and abdomen, whereas 38 had computed tomography only. Seventy-seven tumors were predicted as R0 and 78 as likely R1/2. In the predicted RO group, 50 had surgery alone, 25 had short-course radiotherapy, and 2 had chemoradiotherapy. Twelve patients (15.5 percent) had involved circumferential resection margin on the histologic specimen. In the predicted R1/2 group (n = 78), 40 patients received chemoradiotherapy, 11 had short-course radiotherapy, and 27 had surgery alone. Thirty patients (38.4 percent) had involved circumferential resection margin. Circumferential margin involvement was seen in 11 of 40 patients (27.5 percent) who received chemoradiotherapy, 6 of 11 patients (54.5 percent) who received short-course preoperative radiotherapy, and 13 of 27 patients (48.1 percent) who had surgery alone.

CONCLUSIONS

Protocol-driven management of rectal cancer within the context of a multidisciplinary team has been demonstrated to work. Regular audit allows for modification and improvement of the protocol as newer management strategies evolve.

Tumour regression grading in the evaluation of tumour response after different preoperative radiotherapy treatments for rectal carcinoma

BACKGROUND AND AIMS

Preoperative radiotherapy (PRT) for rectal carcinoma has been shown to cause tumour regression and increase local control and patient survival. The aim of this study was to examine the usefulness of tumour regression grading (TRG) in quantifying the effect of PRT.

METHODS

Depending on the tumour stage (uT), as defined by preoperative endorectal ultrasound (ERUS), fixity and distance from the anal verge, 126 patients with rectal cancer underwent either surgery alone, or received short-course 25-Gy radiotherapy or long-course 50-Gy radiotherapy combined with 5-fluorouracil (5-FU) before surgery. TRG in each group was assessed and compared with the downstaging, defined as a change in preoperative uT stage and pathologic stage (pT).

RESULTS

Complete response (no residual tumour, TRG 1) was seen in 7% of the patients (3/44) and total or major regression (TRG 1-3) in 73% of the patients (32/44) treated with 50-Gy chemoradiation. Of those treated with 25-Gy PRT, 21% (9/42) showed major tumour regression. Of the patients who underwent ERUS and PRT, 32% (26/83) were downstaged when comparing uT with pT, but 53% (14/26) of the downstaged tumours showed no response by TRG. In comparison, 50% (28/57) of the tumours with no downstaging showed a marked response by TRG (p=0.05).

CONCLUSIONS

Tumour regression grading offers detailed information of the effect of PRT and shows that tumour regression is more marked after long-term chemoradiation than after short-course radiotherapy (p=0.02). In contrast, T-stage downstaging was similar in both groups and did not correlate with the TRG results (p=0.05).

Chemoradiation instead of surgery to treat mid and low rectal tumors: is it safe?

BACKGROUND

The main treatment for rectal carcinoma is surgery. Preoperative chemoradiation (CRT) is advocated to reduce local recurrence and improve resection of mid and low tethered rectal tumors.

METHODS

Fifty-two patients with mid or low rectal tumors underwent CRT (external beam radiation plus 5-fluorouracil plus folinic acid). Patients who had low rectal tumors with complete response (CR) were not submitted to surgical treatment. All other patients were submitted to surgery, independently of the response. Mean follow-up was 32.1 months.

RESULTS

Five-year overall survival was 60.5%. Clinical evaluation after CRT showed CR in 10 cases (19.2%), all low tumors; incomplete response (>50%) in 21 (40.4%); and no response (<50%) in 19 (36.6%). Among the 10 cases with CR, 8 presented with local recurrence within 3.7 to 8.8 months. Two patients were not submitted to surgery and are still alive without cancer after 37 and 58 months. Thirty-nine patients had radical surgery. Seven had local recurrences after CRT plus surgery (17.9%). Overall survival was negatively affected by lymph node metastases (P =.017) and perineural invasion (P =.026).

CONCLUSIONS

Exclusive CRT approach is not safe to treat patients with low infiltrative rectal carcinoma.

Can p53 alterations be used to predict tumour response to pre-operative chemo-radiotherapy in locally advanced rectal cancer?

PURPOSE

To examine whether p53 tumour suppressor gene alterations can be used to predict tumour response to pre-operative chemo-radiation in locally advanced rectal cancer in terms of reduction in tumour size and local failure.

METHODS

p53 alterations were studied in pre-treatment biopsy specimens of rectal carcinomas from 48 patients by immunohistochemistry (IHC) and polymerase chain reaction/single strand conformation polymorphism (PCR-SSCP) gene mutation analysis. Pre-operative pelvic radiotherapy was delivered with four fields, 45 Gy to the ICRU point in 25 fractions over 5 weeks. A radio-sensitising dose of 5-fluorouracil (500 mg/m(2)) was delivered concurrently for 6 days of the 5-week schedule (days 1, 2, 3 and days 22, 23 and 24). Total meso-rectal excision was planned 4 to 6 weeks from completion of pre-operative treatment. Response to therapy was assessed by macroscopic measurement of the surgical specimen by a pathologist who was unaware of the pre-treatment tumour size or of the p53 status.

RESULTS

IHC evidence of p53 protein accumulation was found in 40% of tumours, p53 gene mutation in 35% and p53 alteration (either or both changes) in 46%. The average reduction in tumour size was 53% in the group with 'wild-type' p53 (IHC-/SSCP-) and 63% in the group with altered p53 (either IHC+ or SSCP+; P=0.18). No significant differences in tumour size reduction or local failure were observed in the groups with p53 overexpression or p53 mutation compared with normal.

CONCLUSIONS

p53 alteration detected by IHC or SSCP analysis is not a clinically useful predictor of local response to pre-operative adjuvant therapy in advanced rectal carcinoma.