Preoperative radiation therapy for patients with T2-T3 carcinoma of the middle-to-lower rectum

Systematic review and meta-analysis of the accuracy of MRI and endorectal ultrasound in the restaging and response assessment of rectal cancer following neoadjuvant therapy

AIM

Restaging imaging by MRI or endorectal ultrasound (ERUS) following neoadjuvant chemoradiotherapy is not routinely performed, but the assessment of response is becoming increasingly important to facilitate individualization of management.

METHOD

A search of the MEDLINE and Scopus databases was performed for studies that evaluated the accuracy of restaging of rectal cancer following neoadjuvant chemoradiotherapy with MRI or ERUS against the histopathological outcome. A systematic review of selected studies was performed. The methodological quality of studies that qualified for meta-analysis was critically assessed to identify studies suitable for inclusion in the meta-analysis.

RESULTS

Sixty-three articles were included in the systematic review. Twelve restaging MRI studies and 18 restaging ERUS studies were eligible for meta-analysis of T-stage restaging accuracy. Overall, ERUS T-stage restaging accuracy (mean [95% CI]: 65% [56-72%]) was nonsignificantly higher than MRI T-stage accuracy (52% [44-59%]). Restaging MRI is accurate at excluding circumferential resection margin involvement. Restaging MRI and ERUS were equivalent for prediction of nodal status: the accuracy of both investigations was 72% with over-staging and under-staging occurring in 10-15%.

CONCLUSION

The heterogeneity amongst restaging studies is high, limiting conclusive findings regarding their accuracies. The accuracy of restaging imaging is different for different pathological T stages and highest for T3 tumours. Morphological assessment of T- or N-stage by MRI or ERUS is currently not accurate or consistent enough for clinical application. Restaging MRI appears to have a role in excluding circumferential resection margin involvement.

Detection of morphologic alterations in rectal carcinoma following preoperative radiochemotherapy based on multiphoton microscopy imaging

BACKGROUND

Preoperative radiochemotherapy improves outcomes in patients with locally advanced rectal carcinoma, and has been used increasingly in patient management. However, there is a strong clinical need to assess tumor response to neoadjuvant treatment, and a non-invasive technique that allows the precise identification of morphologic changes in tumors would be of considerable clinical interest.

METHODS

In this study, we used multiphoton microscopy (MPM) to detect morphologic alterations in rectal adenocarcinomas in patients treated with preoperative radiochemotherapy.

RESULTS

MPM was able to identify histopathologic alterations in rectal cancer following preoperative radiochemotherapy, and allowed the qualitative assessment of treatment efficacy and feasibility in relation to dose or strategy.

CONCLUSION

These findings may provide the groundwork for evaluating tumor response to neoadjuvant treatment, thus allowing the tailoring of effective treatment doses and strategies.

Local excision after neoadjuvant chemoradiation therapy in advanced rectal cancer: a national multicenter analysis

BACKGROUND

The aim of the current study was to evaluate the clinical availability of local excision (LE) for advanced rectal cancer without lymph node metastasis after neoadjuvant chemoradiation therapy (nCRT) in Korea.

METHODS

From June 2000 to October 2009, 40 patients with cT2-3N0M0 rectal cancer underwent nCRT followed by LE according to a retrospective multicenter analysis.

RESULTS

Of the 40 patients, 22 were men and 18 were women. Eighteen patients were cT2, and 22 patients were cT3. The median follow-up duration was 38 months. Three patients (7.5%) had morbidity after LE. Four patients (10%) had recurrence (local recurrence [1 patient] and systemic metastasis [3 patients]). The 3-year disease-free survival rate was 85.9%. Only pCR was a recurrence-related prognostic factor (P = .040).

CONCLUSIONS

Although the current study was not a randomized controlled study, LE after nCRT in T2-3N0 rectal cancer patients appears to be a safe and effective treatment, especially in pCR patients.

Acceptance of a 5-mm distal bowel resection margin for rectal cancer: is it safe?

AIM

Acceptance of a short distal bowel margin results in a higher rate of anterior resection but may compromise oncological safety. This study aimed to evaluate the safety of a 5-mm distal margin.

METHOD

A retrospective analysis was carried out of 412 consecutive patients with rectal cancer treated with anterior resection with a negative circumferential resection margin. Radiotherapy was given to 63% of patients with an advanced tumour. The median follow up was 75 months.

RESULTS

Fewer patients in the group with a distal margin of ≤ 5 mm had a tumour with an advanced pT stage compared to patients in the group with a distal margin of > 5 mm (P = 0.033). Two patients were converted to abdominoperineal resection because of a positive 'doughnut', leaving 410 patients, in whom 5.4% (95% CI, 0-11.3%) of the group with a distal margin of ≤ 5 mm had local recurrence at 5 years compared with 4.2% (95% CI, 2.1-6.3%) of the group with a distal margin of > 5 mm (P = 0.726). The corresponding figures for the 5-year overall survival were 82.4% (95% CI, 72.6-92.2%) vs 76.3% (95% CI, 71.8-80.8%) (P = 0.581). All four anastomotic recurrences occurred in the group with a distal margin of > 5 mm.

CONCLUSION

A distal margin of ≤ 5 mm did not compromise oncological safety in patients undergoing preoperative radiation for an advanced rectal cancer.

[Surgical treatment of cancer at the beginning of the third millenium--based on the 2004 Krompecher Memorial Lecture of the Society of Hungarian Oncologists]

The author presents a historical overview of cancer surgery of the last century. At the last quarter of the century the main characteristic of this process has been the significant extension of surgical radicality. Three new surgical methods appeared and have been routinely used at the Surgical Clinic of the Szeged University School, to increase surgical radicality, to improve survival rate without impairing the postoperative quality of life. 1.) Subtotal colectomy (STC) involves an extended resection of the colon over the splenic flexure. In a period of 8 years a total of 72 STCs were performed for the treatment of large bowel obstructions or symptomatic stenosis caused by cancer of the left colon. STC offers: a) one stage treatment for colonic obstruction in emergency surgery, b.) removal of the tumor with sufficient oncological radicality, c.) primary reconstruction of the digestive tract, with a safe ileocolic anastomosis even in emergency cases. Based on a study about postoperative quality of life of STC operated patients, it proved to be normal. 2.) The author reports a total of 108 middle and low third rectal cancer cases operated on by total mesorectal excision (TME) by the method of Heald. The oncological basis of this procedure is the horizontal regional metastatization of rectal cancer. The author succeeded in 60% of cases to perform an anterior resection with preservation of the anal sphincter, and to decrease the early (within two years after surgery) local recurrence rate from 14.5% to 6.4%, compared to the group of patients operated on by traditional technic. 3.) A total of 154 patients with locally advanced - stage IV - colorectal cancer underwent extended surgery of multivisceral resections as a treatment of cancer process involving adjacent abdominal organs. Surgery was performed to treat advanced cancer of the colon in 112 cases and the one of the rectum in 42 cases. The mortality rate was 7% in the colon cancer group, and 12% in the group of rectal cancer patients. In their tumor-free postoperative period 90% of colon cancer patients and 95% of rectal cancer patients had an improved quality of life. The 5 years survival rate was 40% in the colon group and 22% in the rectal cancer group. In the group of patients having more than 3 simultaneously tumorous organs, in spite of the multiple organ resections, no 5 years survival has been recorded.

Transanal endoscopic microsurgery for the treatment of selected patients with distal rectal cancer: 15 years experience

BACKGROUND

Local therapy for early rectal cancer is a valid alternative to the classical radical operation, which has a higher morbidity and mortality rate. The use of high-dose preoperative radiation appears to enhance the options for sphincter-saving surgery even for T2-T3 rectal cancer patients with effective local control. The authors report their experience with transanal endoscopic microsurgery (TEM) used to manage selected cases of distal rectal cancer without evidence of nodal or distant metastasis (N0-M0).

METHODS

The study enrolled 196 patients with rectal cancer (51 T1, 84 T2, and 61 T3). All the patients staged preoperatively as T2 and T3 underwent preoperative high-dose radiotherapy, and since 1997, patients younger than 70 years in good general condition also have undergone preoperative chemotherapy.

RESULTS

Minor complications were observed in 17 patients (8.6%) and major complications in only 3 patients (1.5%). The definitive histology was 33 pT0 (17%), 73 pT1 (37%), 66 pT2 (34%), and 24 pT3 (12%). Eight patients (5 pT2 and 3 pT3) experienced local recurrence (4.1%). The rectal cancer-specific survival rate at the end of the follow-up period was 100% for pT1, 90% for pT2, and 77% for pT3 patients.

CONCLUSIONS

Patients with T1 cancer and favorable histologic features may undergo local excision alone, whereas those with T2 and T3 rectal cancer require preoperative radiochemotherapy. The results in the authors' experience after TEM appear not to be substantially different in terms of local recurrence and survival rate from those described for conventional surgery.

Imaging and management of rectal cancer

Local staging and management of rectal cancer has evolved during the past decade. Imaging modalities used for staging rectal cancer include CT, endoscopic ultrasound, pelvic phased-array coil MRI, endorectal MRI, and PET. Each modality has its strengths and limitations. Evidence supports the use of both endoscopic ultrasound and CT in staging rectal cancer. MRI is the only reliable tool for determining the status of the circumferential resection margin, which is important for the assessment of the risk of local recurrence.

A prospective randomized study with a 5-year minimum follow-up evaluation of transanal endoscopic microsurgery versus laparoscopic total mesorectal excision after neoadjuvant therapy

BACKGROUND

This study aimed to compare the oncologic results for local excision via transanal endoscopic microsurgery (TEM) and those for laparoscopic resection (LR) via total mesorectal excision in the treatment of T(2) N(0), G(1-2 )rectal cancer after neoadjuvant therapy with both treatments, incorporating a 5-year minimum follow-up period.

METHODS

The study enrolled 70 patients whose malignancy was staged at admission as T(2) N(0), G(1-2 )rectal cancer located within 6 cm of the anal verge with a tumor diameter less than 3 cm. Of these patients, 35 were randomized to TEM and 35 to LR. The patients in both groups previously had undergone high-dose radiotherapy (5,040 cGy in 28 fractions over 5 weeks) combined with continuous infusion of 5-flurouracil (200 mg/m(2)/day).

RESULTS

The median follow-up period was 84 months (range, 72-96 months). Two local recurrences (5.7%) were observed after TEM and 1 (2.8%) after LR. Distant metastases (2.8%) occurred in one case each after TEM and LR. The probability of survival for rectal cancer was 94% for TEM and 94% for LR.

CONCLUSIONS

The study shows similar results between the two treatments in terms of local recurrences, distant metastases, and probability of survival for rectal cancer.

A prospective randomized study with a 5-year minimum follow-up evaluation of transanal endoscopic microsurgery versus laparoscopic total mesorectal excision after neoadjuvant therapy

BACKGROUND

This study aimed to compare the oncologic results for local excision via transanal endoscopic microsurgery (TEM) and those for laparoscopic resection (LR) via total mesorectal excision in the treatment of T(2) N(0), G(1-2 )rectal cancer after neoadjuvant therapy with both treatments, incorporating a 5-year minimum follow-up period.

METHODS

The study enrolled 70 patients whose malignancy was staged at admission as T(2) N(0), G(1-2 )rectal cancer located within 6 cm of the anal verge with a tumor diameter less than 3 cm. Of these patients, 35 were randomized to TEM and 35 to LR. The patients in both groups previously had undergone high-dose radiotherapy (5,040 cGy in 28 fractions over 5 weeks) combined with continuous infusion of 5-flurouracil (200 mg/m(2)/day).

RESULTS

The median follow-up period was 84 months (range, 72-96 months). Two local recurrences (5.7%) were observed after TEM and 1 (2.8%) after LR. Distant metastases (2.8%) occurred in one case each after TEM and LR. The probability of survival for rectal cancer was 94% for TEM and 94% for LR.

CONCLUSIONS

The study shows similar results between the two treatments in terms of local recurrences, distant metastases, and probability of survival for rectal cancer.

Early rectal cancer: definition and management

BACKGROUND

Local excision of rectal cancer is an alternative to radical resection but today its role surrounding the management of patients with early stage rectal cancer (T1-T2-N0) represents an important surgical issue.

AIM

To analyze the results of 135 patients with early stage low rectal cancer treated with local excision by transanal endoscopic microsurgery and in the case of T2 also by neoadjuvant therapy.

STUDY DESIGN

135 patients with T1-T2-N0-M0 rectal cancer were enrolled in the study. Staging according to the definitive histological findings was as follows: pT0 in 24 patients (17.8%), pT1 in 66 patients (48.8%) and pT2 in 45 patients (33.4%).

RESULTS

Minor complications were observed in 12 patients (8.8%) whereas major complications were seen only in 2 patients (1.5%). At a median follow-up of 78 (36-125) months, local recurrences occurred in 4 patients and distal metastasis in 2 patients (all patients were staged preoperatively T2). Disease-free survival rates in T1 and T2 patients were 100 and 93% respectively at the end of follow-up.

CONCLUSIONS

With respect to local recurrence and survival rate, the long-term results of early stage rectal cancer in patients treated with transanal endoscopic microsurgery were similar to those reported in the literature after conventional surgery (total mesorectal excision).

Association between pathologic response in metastatic lymph nodes after preoperative chemoradiotherapy and risk of distant metastases in rectal cancer: An analysis of outcomes in a randomized trial

PURPOSE

To compare 5 x 5 Gy preoperative radiotherapy with immediate surgery vs. preoperative chemoradiotherapy (50.4 Gy, 5-fluorouracil, leucovorin) with delayed surgery in a randomized trial for cT3-T4 low-lying rectal cancer. Despite the downstaging effect of chemoradiotherapy, similar long-term outcomes were observed in both groups.

METHODS

The Cox model was used to evaluate the prognostic value of ypTN ("yp" denotes that pathologic classification was performed after initial multimodality therapy) categories and the surgical margin status in 291 patients.

RESULTS

Disease-free survival (DFS) (hazard ratio [HR] 1.05, 95% confidence interval [CI], 0.73-1.51), distant metastases (HR, 1.17; 95% CI, 0.77-1.78), and local control (HR, 1.45; 95% CI, 0.74-2.84) were similar in both arms. The ypN status was the only independent prognostic factor for DFS (p < 0.001). An interaction (p = 0.016) between N stage and the assigned treatment was demonstrated. For ypN-negative patients, DFS was similar in both arms (HR, 0.83, 95% CI, 0.47-1.48); however, for ypN-positive patients, DFS was worse in the chemoradiotherapy arm (HR, 1.73; 95% CI, 1.07-2.77). The 4-year (median follow-up) DFS rate in N-positive patients was 51% in the 5 x 5-Gy arm vs. 25% in the chemoradiotherapy arm. The corresponding 4-year rates for the incidence of local recurrence and distant metastases were 14% vs. 27% (HR, 1.95; 95% CI, 0.78-4.86) and 38% vs. 68% (HR, 2.05; 95% CI, 1.21-3.48).

CONCLUSION

N-positive disease after chemoradiotherapy indicates radiochemoresistance. N-positive disease after 5 x 5 Gy RT includes both radiosensitive and radioresistant tumors, because the interval between radiotherapy and surgery was too short for radiosensitive cancer to undergo necrosis. Thus, the greater risk of distant metastases recorded in the chemoradiotherapy arm suggests that radiochemoresistance of nodal metastases from rectal cancer is associated with a high potential for developing distant metastases.

Does rectal cancer shrinkage induced by preoperative radio(chemo)therapy increase the likelihood of anterior resection? A systematic review of randomised trials

BACKGROUND AND PURPOSE

According to common conviction rectal tumour shrinkage after preoperative radio(chemo)therapy increases the likelihood of anterior resection (AR). In order to verify this belief, we performed a systematic review of randomised trials.

PATIENTS AND METHODS

We identified 10 randomised trials encompassing altogether 4596 patients in whom preoperative radio(chemo)therapy resulted in tumour shrinkage in the experimental arm as compared to the control arm.

RESULTS

Tumour shrinkage observed in the experimental groups did not result in a statistically significant higher ARs rate in any study when we performed an analysis of all the randomised cases. Subgroups of patients considered to be candidates for abdominoperineal resection before randomisation were identified in three trials. A statistically significantly higher rate of ARs was demonstrated in the experimental arm of the CAO/ARO/AIO 94 study. However, in that study, sphincter preservation was a secondary endpoint and some features of the trial may bias the estimation of the effect. The benefit of sphincter preservation was not confirmed by subgroup analyses performed in the Lyon R90-01 study and in the Polish study, which were originally designed to evaluate the sphincter preservation issue.

CONCLUSION

The body of evidence gathered from randomised trials does not support the concept of a beneficial effect of preoperative radiotherapy on the ARs rate.

Serum CEA as a predictor for the response to preoperative chemoradiation in rectal cancer

BACKGROUND AND OBJECTIVES

Recent data suggest that good responders to preoperative chemoradiation (CRT) have a favorable prognosis in rectal cancer patients. The aim of this study was to investigate the predictive value of serum carcinoembryonic antigen (CEA) levels for the tumor response to preoperative CRT in rectal cancer patients.

METHODS

The study comprised 141 rectal adenocarcinoma patients who underwent preoperative radiotherapy with 5-fluorouracil (FU) based chemotherapy, followed by radical surgery. The staging workup was consisted of endorectal ultrasound, abdominopelvic computed tomography scan, or magnetic resonance imaging. The outcome parameters were cancer-specific survival and disease-free survival. Pre-CRT clinicopathologic features, including age, gender, location of the tumor, clinical tumor (cT) classification, clinical nodal (cN) classification, and serum CEA levels were investigated as possible predictors for the response to preoperative CRT.

RESULTS

Pathologic complete or near complete responses (good responders, GR) occurred in 26 (19%) patients, while partial or no response (poor responders, PR) occurred in the remaining 115 (81%) patients. GR showed better cancer-specific survival (P = 0.028) and disease-free survival rates (P = 0.011) than PR. Univariate analysis revealed that positive cN and elevated (>5 ng/ml) pre-CRT serum CEA levels are associated with poor tumor response to preoperative CRT. Using logistic regression analysis, elevated pre-CRT serum CEA levels were the only significant predictor for the poor response to CRT (Odd ratio = 2.876, 95% confidence interval = 1.04-7.46, P = 0.041).

CONCLUSIONS

Our data suggest that elevated pre-CRT serum CEA levels are associated with poor tumor response to CRT. Therefore, pre-CRT serum CEA levels provide useful information about tumor response to preoperative CRT in rectal cancer patients.

Impact of colloid response on survival after preoperative radiotherapy in locally advanced rectal carcinoma

Neoadjuvant therapy for rectal carcinoma modifies morphology and natural history of the tumor. Colloid response defined by predominant colloid changes with or without residual tumor cells is a form of tumor response whose impact on survival is unknown. This study evaluated influence of tumor histologic response, especially of colloid response, on survival in patients treated by long-course preoperative radiotherapy for rectal cancer. In 200 patients with uT3-T4 or N1 rectal carcinomas, influence of type of surgery, dose of radiotherapy, residual tumor size, surface tumor aspect, tumor response (downstaging vs. colloid or no response), tumor grade, vascular and neural invasion, circumferential margin, and postoperative chemotherapy on 5-year overall and disease-free survival were studied by univariate and multivariate analyses. A colloid response was observed in 20% of the cases. Tumor response, circumferential margin, and vascular invasion were independently associated with the disease-free survival. Patients with downstaging had a better disease-free survival than patients without response (80% vs. 54%), whereas those with colloid response had an intermediate survival (64%). After colloid response, the rate of recurrence was similar to patients with downstaging for local recurrence (0%-3%) and to those with no response for distant recurrence (28%). After preoperative radiotherapy for rectal cancer, survival and type of recurrence are influenced by the tumor response. The intermediate natural history of patients with colloid response suggests taking colloid response into account in postoperative tumor staging to optimize adjuvant therapy.

Does rectal wall tumor eradication with preoperative chemoradiation permit a change in the operative strategy?

PURPOSE

Preoperative chemoradiation may downstage locally advanced rectal cancer and, in some cases, with no residual tumor. The management of complete response is controversial and recent data suggest that radical surgery may be avoided in selected cases. Transanal excision of the scar may determine the rectal wall response to chemoradiation. This study was designed to assess whether the absence of tumor in the bowel wall corresponds to the absence of tumor in the mesorectum, known as true complete response.

METHODS

A retrospective review of the medical records of patients who underwent preoperative chemoradiation for advanced mid (6-11 cm from the anal verge) and low (from the dentate line to 5 cm from the anal verge) rectal cancer (uT2-uT3) followed by radical surgery with total mesorectal excision was undertaken. Patients in whom the pathology specimen showed no residual tumor in the rectal wall (yT0, "y" signifies pathologic staging in postradiation patients) were assessed for tumoral involvement of the mesorectum.

RESULTS

A total of 109 patients underwent preoperative, high-dose radiation therapy (94 percent with 5-fluorouracil chemosensitization), followed by radical surgery for advanced rectal cancer. Preoperatively, 47 patients were clinically assessed to have potentially complete response. After radical rectal resection, pathology did not reveal any residual tumor within the rectal wall (yT0) in 17 patients. In two (12 percent) of these patients, the mesorectum was found to be positive for malignancy: one had positive lymph nodes that harbored cancer; one had tumor deposits in the mesorectal tissue.

CONCLUSIONS

Compete rectal wall tumor eradication does not necessarily imply complete response, because the mesorectum may harbor tumor cells. Thus, caution should be exercised when considering the avoidance of radical surgery. Reliable imaging methods and clinical predictors for favorable outcome are important to allow less radical approaches in the future.

The value of endosonographic rectal carcinoma staging in routine diagnostics: a 10-year analysis

BACKGROUND

Endosonography is currently the gold standard for the local staging of rectal carcinoma, but its accuracy varies from 62% to 91%. This study aimed to determine the accuracy of endosonography, to evaluate the interobserver variability, and to compare the performance of the 7.5-MHz and the 10-MHz ultrasound scanners.

METHODS

Between 1990 and 2000, 458 patients with rectal cancer were included in the study. All the patients had undergone rectal endosonography with a 7.5-MHz scan (period 1: 1990-1996) or a 10-MHz scan (period 2: 1997-2000). Endosonographic staging was compared with pathologic staging.

RESULTS

The overall rate for correctly classified patients was 69% with respect to the T category and 68% with respect to the N category. There was no difference between the two scanners. In terms of accuracy, the T3 category tumors were the most (86%) and the T4 tumors the least (36%) accurately classified. Overstaging of tumors (19%) was much more frequent than understaging (12%). A high interobserver variability of 61% to 77% was noted. For pT1 tumors, the 10-MHz scan was almost two times more accurate than the 7.5-MHz scan (71% vs 36%).

CONCLUSIONS

The accuracy of endosonographic staging of rectal carcinoma very much depends on the T category. A high-resolution scanner and an experienced examiner can help to ensure that endosonography remains an important tool in the staging process of patients with rectal carcinoma, especially early carcinoma.

Preoperative hyperfractionated radiotherapy for locally advanced rectal cancers: a phase I-II trial

PURPOSE

To assess the toxicity, pathologic response rates, type of surgery, and oncologic results in a prospective Phase I-II trial using pure hyperfractionated radiotherapy (RT) preoperatively in locally advanced rectal cancer.

METHODS AND MATERIALS

Between September 1997 and April 2000, 50 patients with T3-T4 or N1 rectal cancers were treated preoperatively with 50 Gy (45 Gy to the pelvis and a 5-Gy tumor boost) in 40 fractions of 1.25 Gy during 4 weeks. The pretreatment tumor stage as determined by CT and endorectal ultrasonography (80% of patients) included 1 Stage T2 (2%), 45 T3 (90%), and 4 T4 (8%). Nodal involvement (N1) was documented in 26 patients (52%). Surgery was performed at a median interval of 45 days (range 26-114 days) after RT completion. Seventeen patients who presented with pT4 or pN1 and/or pM1 received 5-fluorouracil-based chemotherapy postoperatively.

RESULTS

All patients completed the RT schedule as planned. Severe acute toxicities included two Grade 3 skin reactions (4%) that did not require a break. The other acute toxicities were Grade 2 or less (skin, diarrhea, urinary, rectal tenesmus, and fatigue). A complete pathologic response was observed in 7 patients (14%), and microscopic residual cancer was found in 10 (20%). Of the 20 patients presenting with tumor located < or = 6 cm from the anal verge, sphincter-saving surgery was performed in 14 (70%). At 3 years, the actuarial locoregional control rate was 90.5%, and the disease-free survival rate was 74.6%. At a median follow-up of 32 months, 4 patients (8%) presented with severe late complications (Grade 3-4) that might have been RT related (one rectovaginal fistula, two chronic perineal fistulas, and one bilateral ureteral stenosis).

CONCLUSION

In locally advanced rectal cancer, preoperative hyperfractionated RT to a total dose of 50 Gy is feasible, with acceptable acute and late toxicity and an objective downstaging effect. In view of these results, this schedule might be used as a basis for additional investigation regarding RT dose escalation or the addition of concomitant chemotherapy.

Conformal preoperative endorectal brachytherapy treatment for locally advanced rectal cancer: early results of a phase I/II study

PURPOSE

Downstaging rectal carcinoma by preoperative radiotherapy decreases local recurrence, and recent phase II studies suggest that, in the lower one-third lesions, sphincter-preserving surgery can be considered. The purpose of the current study was to assess the efficacy and the toxicity of endorectal high dose-rate brachytherapy as a preoperative downstaging treatment modality.

METHODS

Patients with newly diagnosed invasive rectal adenocarcinoma, T2 to very early T4, operable tumors were eligible. A dose of 26 Gy was given over four consecutive daily treatments of 6.5 Gy prescribed at the tumor radial margin using endorectal brachytherapy with high dose-rate delivery system. Surgery as planned initially was done four to eight weeks later to allow for tumor downstaging. Patients found to have pathologic positive nodes received postoperative external beam (45 Gy/25 fractions) to the pelvis and systemic 5-fluorouracil-leucovorin chemotherapy.

RESULTS

Forty-nine patients entered the study. Tumors were in the lower one-third in 24 patients, middle one-third in 22, and upper one-third in 3. With preoperative endorectal ultrasound and magnetic resonance imaging, the clinical staging of the tumors was: 3 T2, 42 T3, 4 T4, and 16 N1-2. Acute toxicity related to brachytherapy was limited to a moderate proctitis (Radiation Therapy Oncology Group acute toxicity scoring system, Grade 2) in all patients, with two patients with tumors extending into the anal canal having Grade 3 dermatitis. Forty-seven patients underwent surgery. Two patients refused their operation based on a normal endoscopic rectal ultrasound after treatment. A complete clinical response was obtained in 32 of 47 (68 percent) patients with 32 percent pathologically pT0N0-1, and 36 percent had only residual microfoci of carcinoma. The surgical approaches did not yield more complications than expected.

CONCLUSION

Preoperative high dose-rate endorectal brachytherapy seems to be safe, because acute toxicity was mainly local, with moderate proctitis (Grade 2) and occasional dermatitis (Grade 3) for very low tumors. Finally, this modality, by providing high rate of tumor downstaging and downsizing especially for patients with lesions in the lower one-third of the rectum, represents a definite potential for sphincter-preserving surgery for investigation in future studies.

Efficacy of preoperative radiation therapy for resectable rectal adenocarcinoma when combined with oral tegafur-uracil modulated with leucovorin: results from a phase II study

PURPOSE

The aim of this study was to evaluate the efficacy of preoperative radiation therapy for resectable rectal adenocarcinoma (T3-T4) when delivered in combination with chemotherapy (oral tegafur-uracil modulated with leucovorin).

METHODS

Thirty-eight patients (23 males; mean age, 62 years.) with histologically proven rectal adenocarcinoma with primary tumor clinical classification T3-T4 (resectable) and N0 or N1-N2, according to TNM staging system, took part in the present clinical trial. After tumor and metastasis resectability confirmation, radiation therapy was administered by delivering a dose of 45 Gy in 25 fractions for 5 weeks. Chemotherapy treatment was initiated on the same day as radiotherapy and consisted of intravenous infusion of 6S-steroisomer of leucovorin 250 mg/m /day in 2 hours on Day 1, followed by oral 350 or 300 mg/m /day of tegafur (a 5-fluorouracil prodrug) plus uracil on Days 1 to 14 divided into 2 daily doses, and oral 6S-steroisomer of leucovorin 7.5 mg/12 hours on Days 2 to 14, with a total of 102 courses of neoadjuvant chemotherapy (, mean of 2.7 courses per patient). Six additional courses of tegafur-uracil were given postoperatively to all 38 patients but 1 who refused.

RESULTS

As a result of preoperative chemoradiation treatment, 4 (10.5 percent) complete responses, 20 (52.6 percent) partial responses, and 14 (36.8 percent) patients with disease stabilization were observed. No patients had preoperative disease progression. Histologically proven downstaging was observed in 23 (60 percent) patients. On initial evaluation, only 39 percent of patients were considered as being good candidates for sphincter-preserving surgery; however, on preoperative chemoradiation completion this figure increased up to 60 percent. For the 23 patients eventually undergoing sphincter-preserving surgery, postoperative sphincter function assessment showed excellent function in 15 (65 percent) patients, good in 5 (22 percent), fair in 2 (9 percent), and poor in 1(4 percent). With a median follow-up of 37 (range, 10-62) months, local failure was found in 3 (8 percent) patients and distant failure in 2 (5 percent). Three-year actuarial disease-free survival and 3-year overall survival rates were 83 and 90 percent, respectively. Local control rate was 92 percent. Toxicity and postoperative complication rates were reasonable.

CONCLUSIONS

Our neoadjuvant radiation therapy protocol is efficient for the preoperative treatment of resectable rectal adenocarcinoma when combined with chemotherapy (oral tegafur-uracil modulated with leucovorin). this protocol needs to be tested in a phase-III clinical trial with a larger sample size.

Preoperative chemoradiation in patients with resectable rectal cancer: results on tumor response

BACKGROUND

There is no consensus about the role of preoperative radiotherapy (RT) and chemotherapy (CT) in patients with resectable cancer of the distal rectum. This study analyzed the local clinical and pathologic response in patients receiving preoperative RT/CT for rectal cancer.

METHODS

Thirty-two consecutive patients with a palpable adenocarcinoma of the rectum received preoperative RT (45 Gy in 25 fractions over 5 weeks) plus continuous chemotherapy with doxifluridine and leucovorin or 5-fluorouracil by continuous intravenous infusion during RT. Surgery was performed 8 weeks later. The Wilcoxon and chi(2) tests were used for data analysis.

RESULTS

Twelve patients had mild gastrointestinal toxicity, only one of whom required interruption of therapy. The tumor shrank to 57.8% of its original size, and at the echoendoscopy (u) there was a 58.7% decrease of the maximum diameter (P <.001). Downstaging from uT3 and uT2 to <uT3 and <uT2, respectively, occurred in 41.6% of patients (P =.0020). Total and major regression of the tumor at the histopathologic examination occurred in 12.5% and 50% of patients.

CONCLUSIONS

Local response to preoperative RT/CT was highly satisfactory and allowed conservative surgery in 81% of patients. Optimization of the combined therapy could achieve even better results.

Healing of experimental colonic anastomoses: effects of combined preoperative high-dose radiotherapy and intraperitoneal 5-fluorouracil

To study the effects of preoperative radiochemotherapy (RCT) on the healing of colonic anastomosis, the rectosigmoid colon in male Wistar rats was irradiated up to an end dose of 41.6 Gy (RT) or sham-irradiated (SR). During the last 5 days of the irradiation schedule, 5-fluorouracil (5-FU) was administered intraperitoneally in either a high dose (20 mg/kg, chemotherapy-high dose [CH]) or a low dose (10 mg/kg, chemotherapy-low dose [CL]). Animals were randomly arranged into six groups: group I, control (SR + saline intraperitoneally); group II, RT only; group III, SR + CL; group IV, RT + CL; group V, SR + CH; group VI, RT + CH. Four days after RCT, a side-to-side anastomosis was constructed between the irradiated rectosigmoid and the nonirradiated caecum. Animals were killed 10 days postoperatively. No significant differences were found in the anastomotic bursting pressure or the bursting wall tension. In group VI, mitoses were less (P < 0.01) and mucosal ulceration was more (P = 0.03) pronounced compared to group I. Sclerotic arteries were seen in all irradiated groups and in animals that received high-dose 5-FU alone. 5-FU administration in high or low dose, with or without RT, induced more inflammation in the submucosa compared to controls (P < 0.05). Conclusively, RCT has no detrimental effect on the mechanical strength of colonic anastomosis in this rat model. However, RCT with high-dose 5-FU induces more histological alterations at the anastomotic site.

Local excision of T2 and T3 rectal cancers after downstaging chemoradiation

OBJECTIVE

To evaluate the safety and efficacy of local excision in patients with T2 and T3 distal rectal cancers that have been downstaged by preoperative chemoradiation.

SUMMARY BACKGROUND DATA

T2 and T3 cancers treated by local excision alone are associated with unacceptably high recurrence rates. The authors hypothesized that preoperative chemoradiation might downstage both T2 and T3 lesions and significantly expand the indications for local excision.

METHODS

Local excision was performed after preoperative chemoradiation on patients with a complete clinical response or on patients who were either ineligible for or refused to undergo abdominoperineal resection. Local excision was approached transanally by removing full-thickness rectal wall and the underlying mesorectum.

RESULTS

From 1994 to 2000, 95 patients with rectal cancers underwent preoperative chemoradiation and surgical resection for curative intent. Of these, 26 patients (28%), 19 men and 7 women, with a mean age of 63 years (range 44-90), underwent local excision. Pretreatment endoscopic ultrasound classifications included 5 T2N0, 13 T3N0, 7 T3N1, and 1 not done. Pathologic partial and complete responses were achieved in 9 of 26 (35%) and 17 of 26 (65%) patients, respectively. Two of nine partial responders underwent immediate abdominoperineal resection. The mean follow-up was 24 months (median 19, range 6-77). The only recurrence was in a patient who refused to undergo abdominoperineal resection after a partial response. There was one postoperative death from a stroke. This treatment was associated with a low rate of complications.

CONCLUSION

Local excision appears to be an effective alternative treatment to radical surgical resection for a highly select subset of patients with T2 and T3 adenocarcinomas of the distal rectum who show a complete pathologic response to preoperative chemoradiation.

Influence of preoperative combined radiochemotherapy on surgical outcome and colonic anastomotic healing: experimental study in the rat

PURPOSE

To study the influence of combined preoperative hyperfractionated irradiation with intraperitoneal 5-fluorouracil (5-FU) on surgical outcome and colonic anastomotic healing in a rat model.

METHODS

Male Wistar rats were given 41.6 Gy of preoperative radiotherapy (RT) or sham irradiation, with intraperitoneal 5-FU at low dose (10 mg/kg) or high dose (20 mg/kg). Animals were arranged in 6 groups: RT + low-dose 5-FU (RCT-L), RT + high-dose 5-FU (RCT-H), sham RT + low-dose 5-FU (CT-L), sham RT + high-dose 5-FU (CT-H), RT alone (R), and a control group (sham RT + intraperitoneal saline). Side-to-side colonic anastomoses were constructed from one irradiated and one nonirradiated limb 4 days after radiochemotherapy. Animals were sacrificed 10 days after surgery.

RESULTS

Compared to controls, more complications occurred in group RCT-H (50% versus 0%, p = 0.01). Adhesion formation was more intense in groups RCT-H and CT-H (p < 0.001 and p = 0.001, respectively). After therapy, white blood cell counts dropped significantly in all irradiated animals (p < 0.01), and platelet counts decreased significantly in group RCT-H (p = 0.01). No significant differences were noticed in anastomotic bursting pressure when the treated groups were compared to each other or to the control group.

CONCLUSIONS

Neoadjuvant radiochemotherapy has no adverse effect on the strength of colonic anastomosis in this rat model. However, the combined RT with high-dose 5-FU does increase operative morbidity and adhesion formation.

Colorectal carcinoma associated with serrated adenoma--prevalence, histological features, and prognosis

Serrated adenoma has been proposed to be a distinct entity among colorectal neoplasms. Progression to frank carcinoma has been suggested in individual cases, but the prevalence of carcinomas originating from serrated adenomas and their clinico-pathological characteristics are not known. In the present study, a large series of colorectal cancers was analysed for the occurrence of serrated adenoma in association with carcinoma and clinico-pathological features were compared in cases with and without serrated adenoma. Specimens from 466 colorectal carcinoma patients undergoing operations between 1986 and 1996 were re-evaluated for the presence of juxtaposed serrated adenoma and carcinoma. Clinico-pathological features such as location, Dukes' stage, histological grade, mucinous differentiation, and prognosis were evaluated. Twenty-seven carcinomas (5.8%) were found in association with an adjacent serrated adenoma. Eight of the patients were male and 19 were female. All of these adenocarcinomas showed a serrated appearance resembling that of serrated adenomas. Nine (33%) cases were mucinous and a mucinous component was present in 11 (41%) additional cases. The majority of the tumours were located either in the caecum (14 cases; 51%) or in the rectum (9 cases; 33%). DNA microsatellite instability was more common in carcinomas associated with serrated adenoma (37.5%) than in other carcinomas (11.0%). It is concluded that carcinoma associated with serrated adenoma is a distinct type of colorectal neoplasm, accounting for 5.8% of all colorectal carcinoma cases in this study. Predilection for the caecum and the rectum may reflect their aetiological factors. Female preponderance is contrary to that reported for hyperplastic polyps and serrated adenomas.

Preoperative combined modality therapy for clinically resectable uT3 rectal adenocarcinoma

PURPOSE

To determine the acute toxicity, outcome, and sphincter preservation rates in patients with clinically resectable uT3 adenocarcinoma of the rectum treated with preoperative combined modality therapy.

METHODS AND MATERIALS

A total of 72 patients were treated from 12/90-7/98 with preoperative 50.4 Gy plus 2 cycles of concurrent 5-fluorouracil (5-FU) and leucovorin (LV) bolus daily x 5 followed by sharp or total mesorectal excision and 4 cycles of postoperative 5-FU and LV.

RESULTS

Individual Grade 3+ toxicities during preoperative therapy included diarrhea, 11%; bowel movements, 9%; leukopenia, 18%; tenesmus, 1%; and thrombocytopenia, 1%. Total Grade 3+ toxicity was 28%. The pathologic complete response (CR) rate was 13%, and an additional 9% had a clinical CR for a total CR rate of 22%. Of the 35 patients who were judged clinically by their operating surgeon to require an abdominoperineal resection (APR) and were therefore treated with the goal of sphincter preservation, 89% were able to undergo sphincter-preserving surgery. Of the 21 patients eligible for analysis, 81% had good to excellent sphincter function. The 3-year actuarial patterns of failure were 2% local, 8% abdominal, and 13% distant. The 3-year actuarial survival was 95%.

CONCLUSIONS

Our data confirm our preliminary reports of encouraging rates of acute toxicity, local control, survival, sphincter preservation and function with preoperative combined modality therapy. It is an alternative approach for the treatment of uT3 clinically resectable rectal cancer.

Prospective trial of preoperative concomitant boost radiotherapy with continuous infusion 5-fluorouracil for locally advanced rectal cancer

RATIONALE

To evaluate the response to a concomitant boost given during standard chemoradiation for locally advanced rectal cancer.

METHODS AND MATERIALS

Concomitant boost radiotherapy was administered preoperatively to 45 patients with locally advanced rectal cancer in a prospective trial. Treatment consisted of 45 Gy to the pelvis with 18 mV photons at 1.8 Gy/fraction using a 3-field belly board technique with continuous infusion 5FU chemotherapy (300mg/m(2)) 5 days per week. The boost was given during the last week of therapy with a 6-hour inter-fraction interval to the tumor plus a 2-3 cm margin. The boost dose equaled 7.5 Gy/5 fractions (1.5 Gy/fraction); a total dose of 52.5 Gy/5 weeks was given to the primary tumor. Pretreatment tumor stage, determined by endorectal ultrasound and CT scan, included 29 with T3N0 [64%], 11 T3N1, 1 T3Nx, 2 T4N0, 1 T4N3, and 1 with TxN1 disease. Mean distance from the anal verge was 5 cm (range 0-13 cm). Median age was 55 years (range 33-77 years). The population consisted of 34 males and 11 females. Median time of follow-up is 8 months (range 1-24 months).

RESULTS

Sphincter preservation (SP) has been accomplished in 33 of 42 (79%) patients resected to date. Three patients did not undergo resection because of the development of metastatic disease in the interim between the completion of chemoradiation (CTX/XRT) and preoperative evaluation. The surgical procedures included proctectomy and coloanal anastomosis (n = 16), low anterior resection (n = 13), transanal resection (n = 4). Tumor down-staging was pathologically confirmed in 36 of the 42 (86%) resected patients, and 13 (31%) achieved a pathologic CR. Among the 28 tumors (67%) located <6 cm from the anal verge, SP was accomplished in 21 cases (75%). Although perioperative morbidity was higher, toxicity rates during CTX/XRT were comparable to that seen with conventional fractionation. Compared to our contemporary experience with conventional CTX/XRT (45Gy; 1.8 Gy per fraction), improvements were seen in SP (79% vs. 59%; p = 0.02), SP for tumors <6 cm from the anal verge (75% vs. 42%; p = 0.003), and down-staging (86% vs. 62%; p = 0.003).

CONCLUSION

The SP rate with concomitant boost radiation has been highly favorable with rates of response which are higher than those previously reported for chemoradiation without administration of a boost. Further evaluation of this radiotherapeutic strategy appears warranted.

Beta irradiation of recurrent ptergia: results and complications

Although postoperative beta irradiation for prevention of pterygium recurrence is widely used, its complication rate has not been widely appreciated. Thirty-six patients underwent pterygium excision followed by irradiation with 90Sr to between 1600 and 5300 cGy (median 2400) in two to four fractions over 7 to 27 days. A median of three fields were used in each treatment course (range two to 10). Most patients had undergone previous treatment for their pterygia, including surgery alone (25 patients), or both surgery and irradiation (5 patients). Overall, recurrences developed in 10 eyes (28%). Recurrence occurred in one eye after re-irradiation (20%), compared to 9 of 31 (29%) previously non-irradiated eyes (p greater than 0.1). There was no association with number of excisions and recurrences, although all but 6 patients had undergone more than one excision. Thirteen patients (36%) developed complications including: epithelial defect or corneal thinning (3), symblepharon (5), cataract (4) and corneal ulceration (1). Complications developed in 4 of the 5 (80%) re-irradiated eyes compared to 9 of 31 (29%) previously non-irradiated eyes (p less than 0.05). The power of the statistical analysis was limited by sample size, but no significant association was observed between the development of complications or recurrences and total dose, number of abutting fields, number of previous surgical excisions or patient age, even when re-irradiated patients were excluded. Recently described calibration uncertainties with the 90Sr applicator may explain in part these complications. Alternatively, technical factors such as the number of fields or volume treated may play a role. Excessive complications and recurrences with the use of postoperative beta irradiation in this series emphasize the danger of re-treatment and the need for alternative safe and effective therapies.