"Sandwich" preoperative and postoperative combined chemotherapy and radiation in tethered and fixed rectal cancer: impact of treatment intensity on local control and survival

Stereotactic MR-guided adaptive radiotherapy (SMART) for primary rectal cancer: evaluation of early toxicity and pathological response

Background

The purpose of this study is to measure the effects of stereotactic MR-guided adaptive radiotherapy (SMART) for rectal cancer patients in terms of early toxicity and pathological response.

Materials and methods

For this prospective pilot study, patients diagnosed with locally advanced rectal cancer (LARC) with positive lymph node clinical staging underwent SMART on rectal lesion and mesorectum using hybrid MR-Linac (MRIdian ViewRay). Dose prescription at 80% isodose for the rectal lesion and mesorectum was 40 Gy (8 Gy/fr) and 25 Gy (5 Gy/fr), respectively, delivered on 5 days (3 fr/week). Response assessment by MRI was performed 3 weeks after SMART, then patients fit for surgery underwent total mesorectal excision. Primary endpoint was evaluation of adverse effect of radiotherapy. Secondary endpoint was pathological complete response rate. Early toxicity was graded according to the Common Terminology Criteria for Adverse Events (CTCAE v5.0).

Results

From October 2020 to January 2022, twenty patients underwent rectal SMART. No grade 3-5 toxicity was recorded. Twelve patients were eligible for total mesorectal excision (TME). Mean interval between the completion of SMART and surgery was 4 weeks. Pathological downstaging occurred in all patients; rate of pathological complete response (pCR) was 17%. pCR occurred with a prolonged time to surgery (> 7 weeks).

Conclusion

To our knowledge, this is the first study to use stereotactic radiotherapy for primary rectal cancer. SMART for rectal cancer is well tolerated and effective in terms of tumor regression, especially if followed by delayed surgery.

Downstaging after chemoradiotherapy for locally advanced rectal cancer: is there more (tumor) than meets the eye?

PURPOSE

Preoperative chemoradiotherapy can lead to pathologic complete response of rectal cancer. This study was designed to determine the relationship between postchemoradiotherapy pathologic T stage (ypT stage) and nodal metastases and to evaluate whether pathologic complete response of the primary tumor results in sterilization of mesorectal lymph nodes.

METHODS

Clinicopathological data from 1997 to 2007 of a prospectively maintained colorectal cancer database were examined. Inclusion criteria were patients with extraperitoneal rectal cancer who underwent preoperative chemoradiotherapy and subsequent radical resection. Statistical analysis was performed by use of Kruskall-Wallis and Wilcoxon rank-sum tests.

RESULTS

Two hundred forty-two patients were identified (73.1% male, median age, 57 y (range, 36-85 y)). Data regarding preoperative chemoradiotherapy were available for 177 patients (73.1%). The median dose of radiotherapy was 5040 cGy (3060-6100 cGy). The mean preoperative radiotherapy dose and interval between chemoradiotherapy and surgery are similar when stratified by ypT stage (P = .55 and P = .72, respectively). Low anterior resection was performed in 174 patients (71.6%), and the remainder underwent abdominoperineal resection. A mural pathologic complete response was achieved in 62 patients (25.6%). In this pathologic complete-response group, positive lymph nodes were found in 2 patients (3.2%). The rate of metastatic lymph nodes increased as ypT stage increased (ypT1 = 11.1%, ypT2 = 29.2%, ypT3 = 37.3%).

CONCLUSION

Patients with a mural pathologic complete response have a low rate of positive lymph nodes. These findings may have implications for the management strategies of these patients, including the use of local resection or a watch-and-wait policy. When the response to chemoradiotherapy is not complete, radical surgery should remain the treatment based on high rates of lymph node involvement.

The prognostic value of lymph node metastases and tumour regression grade in rectal cancer patients treated with long-course preoperative chemoradiotherapy

OBJECTIVE

The purpose of the present study was to investigate the impact of tumour regression and the post-treatment lymph node status on the prognosis of rectal cancer treated by preoperative neoadjuvant chemoradiotherapy.

METHOD

One hundred and thirty-five patients with locally advanced T3 and T4 rectal tumours received preoperative long-course chemoradiation, to a dose of 60 Gy external radiation and oral 5-fluorouracil 300 mg/m(2) daily and Leukovorin 22.5 mg/day 5 days a week. Surgery was performed 8 weeks after the end of treatment. The tumour response was evaluated according to the tumour regression grade system and lymph node status in the surgical specimen was assessed. The prognostic value of clinico-pathological parameters was analysed using univariate analysis and Kaplan-Meier methods for comparison of groups.

RESULTS

All patients responded to treatment and 47% had a major response, including 25 (19%) complete responders. The median follow-up was 26 months (range 12-94 months). The cancer specific survival was 82% and there was a significant lower survival rate in the group of patients with post-treatment lymph node metastases compared to lymph-node negative patients [63% and 87% respectively (P = 0.007)]. Furthermore patients with a major tumour response and no lymph node metastases in the surgical specimen after treatment had a survival rate of 100% compared with 60% in the group of patients with major response but lymph node metastases after surgery (P < 0.01).

CONCLUSION

The combined assessment of lymph-node status and tumour response has strong prognostic value in locally advanced rectal cancer patient treated with preoperative long-course chemoradiation.

Prediction of rectal lymph node metastasis by pelvic computed tomography measurement

AIM

Rectal cancer staging represents a crucial step to select the best treatment for this tumour. Particularly after neo-adjuvant chemoradiotherapy (CRT), it may influence the surgical procedure (e.g. radical resection vs. local excision). The aim of this study was to determine the best lymph node size cut-off at computed tomography (CT) to predict nodal metastasis in rectal cancer patients with and without preoperative CRT.

METHODS

A consecutive series of patients operated on for primary mid-low rectal adenocarcinoma, all staged with pelvic CT scan, were subdivided as follows: those who underwent surgery alone treatment without CRT (Group A) and those who underwent preoperative CRT (Group B). All CT scans were re-viewed by a single radiologist and, based on the lymph node size, findings were compared with pathologic lymph node status (pN). At each lymph node size cut-off value, the following were calculated: accuracy, sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV). The best cut-off value was defined as having an accuracy >or=70% with the highest NPV.

RESULTS

The study population consisted of 162 patients: Group A (n=52) and Group B (n=110). Patients classified as pN-positive (n=45) had a higher number of and larger sized lymph nodes by CT scan than patients classified as pN-negative (n=117). The cut-off values with an accuracy >or=70% ranged between 7 and 11 mm in Group A and between 9 and 14 mm in Group B. The cut-off with the best NPV was 7 mm for Group A and 10mm for Group B.

CONCLUSIONS

Acknowledging the limitations of the dimensional criterion, lymph node size cut-off values found in our study may be useful for planning rectal cancer treatment using CT scan.

Oncologic outcomes after neoadjuvant chemoradiation followed by curative resection with tumor-specific mesorectal excision for fixed locally advanced rectal cancer: Impact of postirradiated pathologic downstaging on local recurrence and survival

OBJECTIVE

The purpose of this study was to determine the oncologic outcomes and clinical factors affecting survival in patients who underwent neoadjuvant chemoradiotherapy following tumor specific mesorectal excision for locally advanced, fixed rectal cancer.

SUMMARY BACKGROUND DATA

Neoadjuvant chemoradiation therapy has resulted in significant tumor downstaging, which enhances curative resection and subsequently improves local disease control for rectal cancer. However, oncologic outcomes, according to clinical factors, have not yet been fully understood in locally advanced and fixed rectal cancer.

METHODS

A total of 114 patients who had undergone neoadjuvant chemoradiation for advanced rectal cancer (T3 or T4 and node positive) were investigated retrospectively. Chemotherapy was administered intravenously with 5-FU and leucovorin during weeks 1 and 5 of radiotherapy. The total radiation dose was 5040 cGY in 25 fractions delivered over 5 weeks. Tumor-specific mesorectal excision was done 4 to 6 weeks after the completion of neoadjuvant chemoradiation. Survival and recurrence rates, according to the pathologic stage, were evaluated. Moreover, factors affecting survival were investigated.

RESULTS

The 5-year survival rates according to pathologic stage were: 100% in pathologic complete remission (n = 10), 80% in stage I (n = 23), 56.8% in stage II (n = 34), and 42.3% in stage III (n = 47) (P = 0.0000). Local, systemic, and combined recurrence rates were 11.4%, 22.8%, and 3.5%, respectively. Multivariate analysis showed that the pathologic N stage and operation method were the independent factors affecting survival rate.

CONCLUSION

Pathologic complete remission showed excellent oncologic outcomes, and the pathologic N stage was the most important factor for oncologic outcomes.

A haplotype of the methylenetetrahydrofolate reductase gene predicts poor tumor response in rectal cancer patients receiving preoperative chemoradiation

OBJECTIVE

The objective of the present study was to evaluate whether germline methylenetetrahydrofolate reductase (MTHFR) C677T and A1298C polymorphisms as well as polymorphisms in the thymidylate synthase gene promoter, namely the variable number tandem repeat polymorphism (TS VNTR) and the intrarepeat G to C single nucleotide polymorphism (TS SNP), are predictive markers of tumor regression in rectal cancer patients following preoperative chemoradiotherapy.

BASIC METHODS

Blood samples from 125 patients with primary adenocarcinoma of the mid-low rectum who received 5-fluorouracil-based chemotherapy and external beam radiotherapy (median dose 48.4 Gy), 125 patients (women n=45, men n=80; median age 60 years, range 31-79 years) were genotyped. Response to preoperative treatment was evaluated employing the Tumor Regression Grade criteria. On the basis of the pathologic response, patients were classified as responders (TRG 1-2, n=48) and non-responders (TRG 3-5, n=74). Three patients were excluded because of insufficient data.

MAIN RESULTS

Among the polymorphic variants examined, the MTHFR 677T-1298A haplotype was, upon univariate analysis, the only variable found associated with tumor regression (P=0.004). Moreover, at multivariate analysis, the MTHFR 677T-1298A haplotype was an independent predictor of tumor regression. Patients not carrying the MTHFR 677T-1298A haplotype (odds ratio 0.29, 95% confidence interval 0.13-0.64, P=0.002) displayed a higher response rate than patients with the MTHFR 677T-1298A haplotype.

CONCLUSIONS

Unlike TS VNTR and SNP polymorphisms, MTHFR 677T-1298A haplotype in genomic DNA has the potential to be a predictive marker of tumor response in rectal cancer patients submitted to preoperative chemoradiotherapy.

Preoperative versus postoperative treatment for locally advanced rectal carcinoma

EPIDEMIOLOGY

Overall mortality of rectal cancer at 5 years is approximately 40%. This cancer is commonly diagnosed at an early stage, but because of local relapse and/or metastatic disease, only half of radically resected patients can be considered disease free.

COMMON TREATMENT

The value of adding radiotherapy to surgery in the treatment of patients with resectable rectal cancer has been assessed in trials using either preoperative or postoperative irradiation.

IMPROVEMENTS IN TREATMENT

Preoperative radiotherapy and complete resection are established modalities for Stage II and III rectal cancer whilst data reporting improvement of survival by preoperative chemoradiotherapy are still not available. At present, the improved results reported by Phase II trials in terms of local control, sphincter saving and tumor regression grade make neoadjuvant treatment the 'standard' therapy only in North America and some other countries, but the concept of preoperative combined modality treatment is not supported globally.

Can Rectal Cancers With Pathologic T0 After Neoadjuvant Chemoradiation (ypT0) Be Treated by Transanal Excision Alone?

BACKGROUND

Patients with rectal cancer who have complete rectal wall tumor regression after neoadjuvant chemoradiation probably have eradication of tumor cells in the mesorectum as well, thus raising the possibility of transanal excision.

METHODS

All pathology reports of all patients with locally advanced low and mid rectal cancer who underwent preoperative chemoradiation followed by radical resection from May 2000 to June 2004 were reviewed to evaluate the correlation between complete tumor response (ypT0) and nodal response.

RESULTS

One hundred one consecutive patients had neoadjuvant chemoradiation followed by definitive operation. Four were excluded, leaving 64 men and 33 women (median age, 62 years). Fifty-three patients (55%) had mid rectal cancer, and 44 (45%) had low rectal cancer. Fifty-eight patients (60%) underwent low anterior resection, and 36 (37%) underwent abdominoperineal resection. In 17 patients (18%), no residual tumor cells were present within the rectal wall. One patient (6%) with ypT0 disease had positive lymph nodes.

CONCLUSIONS

No residual tumor in the rectal wall correlates with the absence of viable cancer cells in the mesorectal tissue (94%). Approximately 10% of T1 tumors have involved lymph nodes, and local excision is an accepted option. Transanal excision could probably be considered in a highly selected group of patients with a mural pathologic complete response to neoadjuvant therapy. This approach should be prospectively investigated, and strict selection guidelines should be used.

Neoadjuvant treatment for locally advanced rectal carcinoma

Rectal cancer is one of the most common neoplasms of Western Countries. Overall mortality at 5 years is about 40%. This cancer is commonly diagnosed at a precocious stage, but because of local relapse and/or metastatic disease, only half of radically resected patients can be considered disease free. The value of adding radiotherapy to surgery in the treatment of patients with resectable rectal cancer has been assessed in trials using either preoperative or postoperative irradiation. Preoperative irradiation is more "dose-effective" than postoperative radiotherapy; that is, a higher dose is needed postoperatively to reduce rates of local recurrence to the same extent as preoperative radiation. Nevertheless, preoperative treatment has not been routinely recommended, mainly because it has not been shown to improve overall survival and because in some trials it has been associated with increased postoperative mortality. This paper critically reviews clinical trials of chemoradiotherapy on whether an optimal combination exists for locally advanced rectal cancer. Even if in the latest years, recent advances in surgery have improved the local control of disease, the next steps in rectal cancer care should aim at the improvement of local cure rates and the enhancement of systemic control. New approaches to CT treatment are necessary. Patient enrollment into rigorous and well-conducted clinical trials will generate new information regarding investigational therapies and it will offer improved therapies for patients with this disease.

Posttreatment TNM staging is a prognostic indicator of survival and recurrence in tethered or fixed rectal carcinoma after preoperative chemotherapy and radiotherapy

PURPOSE

To evaluate the prognostic value of the posttreatment TNM stage as a predictor of outcome in locally advanced rectal cancers treated with preoperative chemotherapy and radiotherapy.

METHODS AND MATERIALS

Between 1993 and 2000, 128 patients with tethered (103) or fixed (25) rectal cancers were treated with 50 Gy preoperative pelvic radiotherapy and two cycles of concurrent 5-fluorouracil infusion (20 mg/kg/d) and leucovorin (200 mg/m(2)/d) chemotherapy on Days 1-4 and 22-25 and a single bolus mitomycin C injection (8 mg/m(2)) on Day 1. Of the 128 patients, 111 had Stage T3 and 17 Stage T4 according to the rectal ultrasound or CT findings and clinical evaluation. All 128 patients underwent surgery 8 weeks after chemoradiotherapy. Postoperatively, the disease stage was determined according to the surgical and pathologic findings using the American Joint Committee on Cancer TNM staging system.

RESULTS

Of the 128 patients, 32 had postchemoradiotherapy (pCR) Stage 0 (T0N0M0), 37 pCR Stage I, 26 pCR Stage II, 28 pCR Stage III, and 5 pCR Stage IV disease. Of the 128 patients, 79 had pCR Stage T0-T2, 35 pCR Stage T3, and 14 pCR Stage T4. The rate of T stage downstaging was 66% (84 of 128). Of the 128 patients, 25% achieved a pathologic complete response, and 31 (24%) had positive nodal disease. Lymphovascular or perineural invasion was found in 13 patients (10%). The 5-year disease-specific survival rate was 97% for pCR Stage 0, 88% for pCR Stage I, 74% for pCR Stage II, 44% for pCR Stage III, and 0% for pCR Stage IV (p = 0.0000059). The 5-year relapse-free survival rate was 97% for pCR Stage 0, 80% for pCR Stage I, 72% for pCR Stage II, 42% for pCR Stage III, and 0% for pCR Stage IV (p < 0.000001). In univariate analysis, the pretreatment tumor status (fixed vs. tethered tumors), the pCR TNM stage, T stage downstaging, pathologic T4 tumors, node-positive disease after chemoradiotherapy, and lymphovascular or perineural invasion were statistically significant prognosticators of disease-specific survival and relapse-free survival. pCR Stage T4 disease was a strong predictor of local recurrence. The 5-year local control rate was 98% for pCR T0-T2, 89% for pCR T3, and 65% for pCR T4 disease (p = 0.00044). In multivariate analysis, the pCR TNM stage was the most statistically significant independent predictor of survival (p = 0.003) and relapse-free survival (p < 0.001).

CONCLUSION

For patients who underwent preoperative chemoradiotherapy for locally advanced rectal cancer, the pCR TNM stage was a strong prognosticator of recurrence and survival. It can be used to identify high-risk patients for additional postoperative therapy.

Relationship between pathologic T-stage and nodal metastasis after preoperative chemoradiotherapy for locally advanced rectal cancer

BACKGROUND

We investigated the relationship between pathologic T-stage and mesorectal metastases after preoperative chemoradiotherapy (CRT) for clinical stage II to III rectal carcinoma.

METHODS

The records of consecutive patients with clinical stage II to III carcinoma of the mid or low rectum who underwent surgery after CRT were reviewed. Indications for preoperative CRT were cancer up to 11 cm from the anal verge, Eastern Cooperative Oncology Group performance status of 0 to 2, age 18 to 75 years, and clinical tumor-node-metastasis stage II or III.

RESULTS

The study group consisted of 235 patients (148 men and 87 women; median age, 61 years). The pretreatment tumor-node-metastasis stage was as follows: I, n = 1; II, n = 96; and III, n = 138. Radiotherapy was delivered at a median dose of 50.4 Gy. A pathologic complete response on the rectal wall was found in 24% of patients, and nodal metastases were found in 20% of patients. According to the pT stage, the rate of node positivity was 2% for pT0, 15% for pT1, 17% for pT2, 38% for pT3, and 33% for pT4 cases. At multivariate analysis, the best model for predicting pathologic node involvement included young age, positive pretreatment N status, and pT status. On considering pT stage alone, the odds ratio was in the region of 10 for pT1/2 and >20 for pT3/4 patients.

CONCLUSIONS

In patients with pT0 after preoperative CRT for clinical stage II to III mid or low rectal cancer, the risk of nodal metastases is very low. More conservative surgery (local excision) may be considered in these cases.

Complete pathologic response following preoperative chemoradiation therapy for middle to lower rectal cancer is not a prognostic factor for a better outcome

PURPOSE

The aim of this study was to evaluate factors associated with pathologic tumor response following pre-operative chemoradiation therapy, and the prognostic impact of pathologic response on overall and disease-free survival.

METHODS

Between 1994 and 2002, 132 patients underwent chemoradiation therapy followed by surgery for middle to lower rectal cancer. After excluding 26 cases (metastatic cancer, n = 13; nonradical surgery, n = 6; local excision procedure, n = 4; non-5-fluorouracil-based chemotherapy, n = 2; incomplete data on preoperative chemoradiation therapy regimen used, n = 1), the remaining 106 patients were included in the study. Variables considered were the following: age, gender, tumor location, pretreatment T and N stage, modality of 5-fluorouracil administration, total radiotherapy dose delivered, chemoradiation therapy regimen used (Regimen A: chemotherapy (bolus of 5-fluorouracil and leucovorin, days 1-5 and 29-33) + radiotherapy (45 Gy/25 F/1.8 Gy/F); Regimen B: chemotherapy (5-fluorouracil continuous venous infusion +/- weekly bolus of carboplatin or oxaliplatin) + radiotherapy (50.4 Gy/28 F/1.8 Gy/F)), time interval between completion of chemoradiation therapy and surgery, postoperative chemotherapy administration, surgical procedures, pT, pN, and pTNM stage, and response to chemoradiation therapy defined as tumor regression grade, scored from 1 (no tumor on surgical specimen) to 5 (absence of regressive changes). Statistical analysis was performed by means of logistic regression analysis (Cox's model for overall and disease-free survival).

RESULTS

Median age of the 106 patients was 60 (range, 31-79) years and the male:female ratio, 66:40. Median distance of tumor from the anal verge was 6 (range, 1-11) cm. Pretreatment TNM stage, available in 104 patients, was cT3T4N0, n = 41; cT2N1, n = 9; cT3N1, n = 39; and cT4N1, n = 17. The median radiotherapy dose delivered was 50.4 (range, 40-56) Gy; 58 patients received 5-fluorouracil by continuous venous infusion, and carboplatin with oxaliplatin was added to the chemotherapy schedule in 71 cases. Patients were given Regimen A in 47 cases and Regimen B in 59. The median interval between chemoradiation therapy and surgery was 42.5 (range, 19-136) days, and 94 patients underwent a sphincter-saving procedure. Tumor regression grade, available in 104 cases, was 1, n = 19; 2, n = 18; 3, n = 15; 4, n = 13; and 5, n = 39. At a median follow-up of 42 (range, 1-110) months, 11 patients had died, and 95 were alive. None of the patients had local recurrences, but 13 had distant recurrences. At logistic regression analysis, the chemoradiation therapy regimen used was the only independent predictor of tumor response following preoperative chemoradiation therapy (odds ratio = 0.29, 95% confidence interval = 0.13-0.67, P = 0.003). At Cox's regression analysis, pretreatment T stage was the only independent prognostic factor for both disease-free survival (relative risk = 7.13, 95% confidence interval = 2.3-21.8, P = 0.001) and overall survival (relative risk = 4.83, 95% confidence interval = 1.1-19.9, P = 0.029).

CONCLUSIONS

Tumor response following preoperative chemoradiation therapy is mainly related to the preoperative regimen used. For patients receiving preoperative chemoradiation therapy, pretreatment T stage, but not tumor response to preoperative chemoradiation therapy, is prognostic for outcome (both disease-free and overall survival).

Quality assurance of surgery in gastric and rectal cancer

Multimodality and quality controlled treatment result in improved treatment outcome in patients with solid tumours. Quality assurance focuses on identifying and reducing variations in treatment strategy. Treatment outcome is subsequently improved through the introduction of programs that reduce treatment variations to an acceptable level and implement standardised treatment. In chemotherapy and radiotherapy, such programmes have been introduced successfully. In surgery however, there has been little attention for quality assurance so far. Surgery is the mainstay in the treatment of patients with gastric and rectal cancer. In gastric cancer, the extent of surgery is continuously being debated. In Japan, extended lymph node dissection is favoured whereas in the West this type of surgery is not routinely performed with two large European trials concluding that there is no survival benefit from regional lymph node clearance. Post-operative chemoradiation is part of the standard treatment in the United States, although its role in combination with adequate surgery has not been established yet. These global differences in treatment policy clearly relate to the extent and quality of surgical treatment. As for gastric cancer, surgical treatment of rectal cancer patients determines patient's prognosis to a large extent. With the introduction of total mesorectal excision, local control and survival have improved substantially. Most rectal cancer patients receive adjuvant treatment, either pre- or post-operatively. The efficacy of many adjuvant treatment regimens has been investigated in combination with conventional suboptimal surgery. Traditional indications of adjuvant treatment might have to be re-examined, considering the substantial changes in surgical practise. Quality assurance programs enable the introduction of standardised and quality controlled surgery. Promising adjuvant regimens should be investigated in combination with optimal surgery.

Phase II trial of preoperative 3D conformal radiotherapy, protracted venous infusion 5-fluorouracil, and weekly CPT-11, followed by surgery for ultrasound-staged T3 rectal cancer

PURPOSE

CPT-11 sensitizes tumor cells to radiation and in combination therapy with 5-fluorouracil (5-FU) results in enhanced cytotoxicity to metastatic colorectal cancer. We report the results from a Phase II trial of preoperative radiotherapy (RT), CPT-11, and 5-FU for patients with ultrasound-staged T3 rectal cancer.

METHODS AND MATERIALS

Between April 1999 and August 2001, 32 patients (21 men, 11 women; median age 52 years, range 40-74) with biopsy-proven adenocarcinoma of the rectum were enrolled in the study. All patients underwent endorectal ultrasonography for staging (uT3N0 = 19; uT3N1 = 13; uT2N1 = 1). RT was prescribed to the draining lymph nodes (45 Gy in 1.8-Gy daily fractions) and tumor (50.4 Gy in 1.8-Gy daily fractions). Patients also received concurrent CPT-11 (50 mg/m(2), Days 1, 8, 15, and 22) and 5-FU (200 mg/m(2) daily, 7 d/wk, Days 1-33). Surgical resection was performed 6-10 weeks after completing chemoradiotherapy.

RESULTS

Acute toxicity was frequently observed, and 18 patients (56%) required either a chemotherapy dose reduction or RT interruption of >3 days. One patient withdrew because of diarrhea and abdominal cramping (Grade III) after 10 days of treatment. Although no Grade IV toxicity was observed, Grade III diarrhea (n = 9, 28%), mucositis (n = 7, 21%), rectal sores (n = 7, 21%), abdominal cramping (n = 3, 9%) were noted. Of the 32 patients who underwent surgery, 12 had a complete pathologic response. Of the 32 patients, the disease of 23 (71%) was downstaged. The average length of hospitalization was between 5 and 12 days, with 1 patient staying 33 days. All patients were followed for disease-free survival.

CONCLUSION

Although associated with frequent acute toxicity, the regimen is associated with significant tumor "downstaging." Additional patients and longer follow-up are necessary to define the role of this regimen fully.

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.

Chemoradiotherapy for rectal cancer--is there an optimal combination?

PURPOSE

Chemoradiotherapy is increasingly used in the primary management of rectal cancer. A critical review of present knowledge of whether an optimal combination exists was made for each of the major clinical situations.

RESULTS

As preoperative therapy to reduce local recurrence rates in primarily resectable rectal cancers, radiotherapy has almost exclusively been used as single modality, and combined chemoradiotherapy should remain experimental until further evidence is available. This can only be achieved in randomised trials. Postoperatively, a combination of chemotherapy and radiotherapy appears to be more efficient in reducing local failure rates and improving survival than either modality alone, but the literature-based evidence is partly conflicting. As a reference treatment, a combination of continuous infusion 5-fluorouracil (5-FU) and radiotherapy can be advocated based upon one trial. In primarily irresectable cancer, there is some support that chemoradiotherapy may be more efficient than radiotherapy alone in causing tumour regression allowing radical surgery, but the literature is again conflicting. A great number of phase II studies have been performed in these cancers and in those considered to be locally advanced, revealing promising activity and claims of superiority to radiotherapy alone or other schedules. The studies are, however, inconclusive with respect to antitumour activity, and patient selection may be of greater relevance for the results. Chemoradiation has also increasingly been used to facilitate a sphincter-preserving procedure in low-lying cancers. Again, literature is inconclusive as to whether an optimal combination exists, whether it is superior to radiotherapy alone, or if it actually facilitates sphincter preservation at all. Long-term functional outcome is poorly known. Again, 5-FU has been most extensively used, but many other drugs are presently being tested in various combinations.

CONCLUSIONS

An optimal combination of chemoradiotherapy for rectal cancer does not exist. Actually, a critical review of the literature shows that the support for superiority of chemoradiation over radiation alone is weak, or lacking. There is a great need of both more conclusive study designs and a more rational exploration of drug-radiation interactions prior to clinical testing.

Radiotherapy, concomitant protracted-venous-infusion 5-fluorouracil, and surgery for ultrasound-staged T3 or T4 rectal cancer

BACKGROUND

A prospective study was undertaken to evaluate the response and toxicity of neoadjuvant chemoradiotherapy for ultrasound-staged T3 or T4 rectal cancer.

PATIENTS AND METHODS

Since 1995, 30 patients (18 males; median age, 56 (range, 25-83) years) have received preoperative chemoradiotherapy for ultrasound-staged T3 or T4 rectal cancer. All patients underwent an endorectal ultrasound, CT scan, and review in our multidisciplinary Gastrointestinal Tumor Board before treatment. All patients had pathology-demonstrated invasive adenocarcinoma of the rectum. Eleven patients were Stage T3N0, 14 were T3N1, and five were T4N1. Patients received radiotherapy to the primary tumor and draining lymph nodes (45 Gy) followed by a tumor boost (50.4-54 Gy). Protracted-venous-infusion 5-fluorouracil (225 mg/m2 per day, seven days per week) was administered throughout treatment. Surgical resection was performed six to ten weeks after completing chemoradiotherapy. Using endorectal ultrasound measurements, the primary tumor was a median of 4 (range, 0-12) cm from the anal verge, encompassed 50 (range, 20-90) percent of the rectal circumference, and was 6 (range, 3-12) cm in diameter.

RESULTS

No Grade 4 toxicity was observed during chemoradiotherapy. Three patients experienced Grade 3 toxicity (diarrhea), and four patients required a treatment interruption of greater than three days. All patients completed at least 90 percent of the prescribed radiotherapy dose. All patients underwent surgical resection. Ninety-four percent had clear surgical margins. All pathologic specimens had significant evidence of necrosis, hyalinization, and fibrosis. Thirty-three percent of the specimens had a complete pathologic response (defined as no evidence of viable tumor cells). Of the 19 patients with ultrasound-staged N1 disease, only five had pathologic evidence of nodal involvement after chemoradiotherapy. Of the 25 patients with ultrasound-staged T3 disease, pathologic staging revealed eight with T0, two with T1, five with T2, and ten with T3 disease. Of the five patients with ultrasound-staged T4 disease, pathologic staging revealed two with T0, one with T2, and two with T3 disease. No patient developed progressive disease while on treatment. Two patients have experienced local failure at 6 and 20 months, and one patient failed in the liver at seven months. Twenty-seven patients remain free of disease with a median follow-up of 20 (range, 3-53) months.

CONCLUSION

Our experience suggests that preoperative chemoradiotherapy is well tolerated, down-stages tumors, and sterilizes regional lymph nodes.

Preoperative chemotherapy and pelvic radiation for tethered or fixed rectal cancer: a phase II dose escalation study

PURPOSE

To study the impact of preoperative radiation dose escalation and postoperative adjuvant chemotherapy on the outcome of tethered and fixed rectal carcinoma.

METHODS AND MATERIALS

We have treated 156 patients with 3 consecutive preoperative chemoradiation protocols with escalating treatment intensity. Schedule 1 consisted of 40 Gy radiation with concurrent 5-fluorouracil (5-FU) infusion and mitomycin C. Schedule 2 used a sandwich design with preoperative (40 Gy) and postoperative (18 Gy) radiation with concomitant 5-FU infusion, leucovorin, and mitomycin C. In schedule 3, the preoperative radiation dose was increased to 50 Gy and adjuvant 5-FU/leucovorin chemotherapy was added following surgery. There were 54, 27, and 75 patients treated in schedules 1, 2, and 3, respectively.

RESULTS

The resectability was 91% for schedule 1 and 100% for both schedules 2 and 3. A dose-response relationship was observed between the radiation dose and the tumor downstaging and local control. The pathological complete response (T0N0M0) rates for schedules 1, 2, and 3 were 4%, 15%, and 25%, respectively. The respective rates of tumor downstaging were 41%, 33%, and 68%, respectively. The 5-year local relapse-free rates were 67% for schedule 1 (40 Gy), 96% for schedule 2 (58 Gy), and 92% for schedule 3 (50 Gy) (p = 0.0011). The addition of postoperative chemotherapy appeared to improve both the survival and the relapse-free survival. The 5-year survival was increased from 52% to 84% (p = 0.0004) and the 5-year progression-free survival was improved from 48% to 74% (p = 0.0008).

CONCLUSION

Preoperative 5-FU infusion, leucovorin, mitomycin C, and 50-Gy pelvic radiation, followed by postoperative bolus 5-FU/leucovorin chemotherapy, appeared to be an effective treatment for tethered/fixed rectal cancers. However, its therapeutic efficacy could only be validated in randomized studies.

Combined modality therapy of rectal cancers

Rectal cancer accounts for about 10% of new cancer cases each year. It strikes men and women at nearly the same rate, generally in the range of 50-80 years of age, with rising incidence with age. Despite simple screening procedures rectal cancer is often advanced when discovered. Current trends in the management of cancer have focused on organ preservation and improved quality of life without compromising the overall survival. During the last decade substantial progress has been made in treatment modalities: new and improved radiation techniques (conformal radiotherapy, altered fractionation, brachytherapy), chemotherapy (protracted infusion, use of radiosensitizers) and development of surgical procedures-enabling safer postoperative irradiation. In patients with advanced/unresectable disease aggressive combined chemoradiation can be added prior to surgery to downstage the tumour and increase the proportion treated with anal-rectal-sparing procedures. Preoperative chemoradiation therapy regimens are as safe and tolerable as the standard postoperative treatment. In this presentation indications for preoperative radiochemotherapy will be discussed in detail, together with treatment-related side effects, prognostic parameters, tumour response and outcome. Different irradiation settings and chemotherapy schedules are described. In patients with primary resectable disease (mainly Dukes C) several prospective randomised trials have shown less local recurrence with postoperative combined modality therapy.