Preoperative concurrent chemoradiotherapy in locally advanced rectal cancer with high-dose radiation and oxaliplatin-containing regimen: the Lyon R0-04 phase II trial

The use of PET in assessing tumor response after neoadjuvant chemoradiation for rectal cancer

PURPOSE

To assess the correlation of 18F-FDG-PET (PET) response to pathological response after neoadjuvant chemoradiation (CRT) for locally advanced rectal cancer.

METHODS AND MATERIALS

Twenty patients with locally advanced rectal cancer were identified between 2001 and 2005. The median age was 57 years (range 37-72) with 14 males and 6 females. All patients were staged with endorectal ultrasound and/or MRI, CT, and PET. The clinical staging was T3N0M0 (16), T3N1M0 (2), and T3N0M1 (2). Restaging PET was performed after CRT, and prior to definitive surgery. The response on PET and pathology was assessed and correlated. Patient outcome according to PET response was also assessed.

RESULTS

Following CRT, a complete PET response occurred in 7 patients, incomplete response in 10, and no response in 3 patients. At surgery, complete pathological response was recorded in 7 patients, incomplete response in 10 and no response in 3. There was a good correlation of PET and pathological responses in complete responders (5/7 cases) and non-responders (3/3 cases). After a median follow-up of 62 months (range 7-73), twelve patients were alive with no evidence of disease. All patients achieving complete metabolic response were alive with no evidence of disease, while as those who had no metabolic response, all died as a result of metastatic disease.

CONCLUSIONS

PET is a promising complementary assessment tool for assessing tumor response after CRT if there is a complete or no response. PET response may also predict for outcome.

Phase I study of preoperative chemoradiation with s-1 and oxaliplatin in patients with locally advanced resectable rectal cancer

PURPOSE

To perform a Phase I study of preoperative chemoradiation (CRT) with S-1, a novel oral fluoropyrimidine, plus oxaliplatin in patients with locally advanced rectal cancer, to determine the maximum tolerated dose and the recommended dose.

METHODS AND MATERIALS

Radiotherapy was delivered to a total of 45 Gy in 25 fractions and followed by a coned-down boost of 5.4 Gy in 3 fractions. Concurrent chemotherapy consisted of a fixed dose of oxaliplatin (50 mg/m2/week) on Days 1, 8, 22, and 29 and escalated doses of S-1 on Days 1-14 and 22-35. The initial dose of S-1 was 50 mg/m2/day, gradually increasing to 60, 70, and 80 mg/m2/day. Surgery was performed within 6±2 weeks.

RESULTS

Twelve patients were enrolled and tolerated up to Dose Level 4 (3 patients at each dose level) without dose-limiting toxicity. An additional 3 patients were enrolled at Dose Level 4, with 1 experiencing a dose-limiting toxicity of Grade 3 diarrhea. Although maximum tolerated dose was not attained, Dose Level 4 (S-1 80 mg/m2/day) was chosen as the recommended dose for further Phase II studies. No Grade 4 toxicity was observed, and Grade 3 toxicities of leukopenia and diarrhea occurred in the same patient (1 of 15, 6.7%). Pathologic complete responses were observed in 2 of 15 patients (13.3%).

CONCLUSIONS

The recommended dose of S-1 was determined to be 80 mg/m2/day when combined with oxaliplatin in preoperative CRT, and a Phase II trial is now ongoing.

Comparison of two neoadjuvant chemoradiotherapy regimens for locally advanced rectal cancer: results of the phase III trial ACCORD 12/0405-Prodige 2

PURPOSE

Neoadjuvant chemoradiotherapy is considered a standard approach for T3-4 M0 rectal cancer. In this situation, we compared neoadjuvant radiotherapy plus capecitabine with dose-intensified radiotherapy plus capecitabine and oxaliplatin.

PATIENTS AND METHODS

We randomly assigned patients to receive 5 weeks of treatment with radiotherapy 45 Gy/25 fractions with concurrent capecitabine 800 mg/m(2) twice daily 5 days per week (Cap 45) or radiotherapy 50 Gy/25 fractions with capecitabine 800 mg/m(2) twice daily 5 days per week and oxaliplatin 50 mg/m(2) once weekly (Capox 50). The primary end point was complete sterilization of the operative specimen (ypCR).

RESULTS

Five hundred ninety-eight patients were randomly assigned to receive Cap 45 (n = 299) or Capox 50 (n = 299). More preoperative grade 3 to 4 toxicity occurred in the Capox 50 group (25 v 1%; P < .001). Surgery was performed in 98% of patients in both groups. There were no differences between groups in the rate of conservative surgery (75%) or postoperative deaths at 60 days (0.3%). The ypCR rate was 13.9% with Cap 45 and 19.2% with Capox 50 (P = .09). When ypCR was combined with yp few residual cells, the rate was respectively 28.9% with Cap 45 and 39.4% with Capox 50 (P = .008). The rate of positive circumferential rectal margins (between 0 and 2 mm) was 19.3% with Cap 45 and 9.9% with Capox 50 (P = .02).

CONCLUSION

The benefit of oxaliplatin was not demonstrated and this drug should not be used with concurrent irradiation. Cap 50 merits investigation for T3-4 rectal cancers.

Revised tumor and node categorization for rectal cancer based on surveillance, epidemiology, and end results and rectal pooled analysis outcomes

PURPOSE

The sixth edition of the American Joint Committee on Cancer (AJCC) rectal cancer staging subdivided stage II into IIA (T3N0) and IIB (T4N0) and stage III into IIIA (T1-2N1M0), IIIB (T3-4N1M0), and IIIC (anyTN2M0). Subsequent analyses supported revised substaging of stage III as a result of improved survival with T1-2N2 versus T3-4N2 and survival of T4N1 more similar to T3-4N2 than T3N1. The AJCC Hindgut Taskforce sought population-based validation that depth of invasion interacts with nodal status to affect survival.

METHODS

Surveillance, Epidemiology, and End Results (SEER) population-based data from January 1992 to December 2004 for 35,829 patients with rectal cancer were compared with rectal pooled analysis data (3,791 patients). T4N0 cancers were stratified by tumors that perforate visceral peritoneum (T4a) versus tumors that invade or are adherent to adjacent organs or structures (T4b). N1 and N2 were stratified by number of positive nodes as follows: N1a/N1b (one v two to three nodes) and N2a/N2b (four to six v > or = seven nodes). Five-year observed and relative survival rates were obtained for each TN category.

RESULTS

SEER rectal cancer analyses confirm that T1-2N2 cancers have better prognosis than T3-4N2, T4bN1 have similar prognosis to T4N2, T1-2N1 have similar prognosis to T2N0/T3N0, and T1-2N2a have similar prognosis to T2N0/T3N0 (T1N2a) or T4aN0 (T2N2a). Prognosis for T4a lesions is better than T4b by N category. The number of positive nodes affects prognosis.

CONCLUSION

This SEER population-based rectal cancer analysis validates the rectal pooled analyses and supports the shift of T1-2N2 lesions from IIIC to IIIA or IIIB and T4bN1 from IIIB to IIIC. SEER outcomes support subdividing T4, N1, and N2 and revised substaging of stages II and III. Survival by TN category suggests a complex biologic interaction between depth of invasion and nodal status.

[Individualizing treatment for locally advanced rectal cancer]

Based on results of the German Rectal Cancer Study Group CAO/ARO/AIO-94 trial, long-term chemoradiotherapy (RT/CTx) is recommended as standard treatment for locally advanced rectal cancer (UICC stages II/III) in the lower two thirds of the rectum (0-12 cm from the anocutaneous verge). Tumor response to neoadjuvant therapy is very heterogeneous, ranging from complete remission to total resistance to RT/CTx. To fulfill the clinical requirement of individual and risk-adapted multimodal treatment, distinct progress in translational research has been achieved (e.g. gene profiling). However, in clinical reality "individualization" of the therapy of rectal cancer patients has not actually been realized. This can be achieved only on the basis of successful randomized clinical trials (e.g. the CAO/ARO/AIO-04 and GAST-05 trials) translationally combined with basic scientific approaches. One simple first step toward individualizing rectal cancer therapy is being made with the ongoing GAST-05 trial. This investigator initiated phase II trial funded by the German Research Foundation (Deutsche Forschungsgemeinschaft) excludes preoperative RT/CTx for patients with rectal cancer localized in the upper third of the rectum, using only quality controlled principles of radical surgery (partial vs total mesorectal excision) followed by adjuvant chemotherapy.

Multidisciplinary treatment of locally advanced rectal cancer: a literature review. Part 1

In Western countries, colorectal cancer is the third most common cancer in terms of incidence and mortality. The management of rectal cancer has undergone and continues to undergo significant evolutions. In the last two decades, new multimodality strategies have been developed. Multimodality treatments have improved the prognosis of locally advanced rectal cancer with local recurrences decreasing from 40% to < 10% and overall survival increasing from 50% to 75% in the last 40 years. This review discusses the role of neoadjuvant chemoradiotherapy regimens used in the standard combined modality treatment programs for rectal cancer and focuses on the ongoing research to improve these regimens.

Rectal cancer

Surgery is the cornerstone of rectal cancer treatment. Oncological cure and overall survival continue to be the main goals, but sparing of the anal sphincter mechanism and functional results are also important. The modern management of rectal cancer is a multidisciplinary approach, and pre-operative staging is of crucial importance when planning treatment in these patients. Pre-operative staging is used to determine the indication for neoadjuvant therapy prior to surgical resection or to determine whether local excision is an option in carefully selected patients with early rectal cancer. Surgery in the form of total mesorectal excision (TME) has become the standard of care for mid and distal rectal cancers. Early rectal cancers do not require neoadjuvant therapy. For locally advanced cancers of the lower two-thirds of the rectum, the combination of surgical resection with chemoradiotherapy decreases local recurrence rates and probably improves overall survival. Whereas in the past local excision was only contemplated in patients who were unfit for radical surgery or for local palliation in cases of metastatic disease, over the last number of years there has been increasing interest in local treatment with curative intent in early rectal cancer.

Chromosomal copy number changes of locally advanced rectal cancers treated with preoperative chemoradiotherapy

Standard treatment of rectal cancer patients comprises preoperative chemoradiotherapy followed by radical surgery. However, clinicians are faced with the problem that response rates vary from one individual to another. Predictive biomarkers would therefore be helpful. To identify genomic imbalances that might assist in stratifying tumors into responsive or nonresponsive categories, we used metaphase comparative genomic hybridization to prospectively analyze pretherapeutic biopsies from 42 patients with locally advanced rectal cancers. These patients were subsequently treated with 5-fluorouracil-based preoperative chemoradiotherapy. Based on downsizing of the T-category, 21 rectal cancers were later classified as responsive, while the other 21 were nonresponsive. Comparing these two groups, we could show that gains of chromosomal regions 7q32 approximately q36 and 7q11 approximately q31, as well as amplifications of 20q11 approximately q13, were significantly associated with responsiveness to preoperative chemoradiotherapy (P<0.05). However, the probability of detecting these copy number changes by chance is high (P=0.21). Our primary results suggest that pretherapeutic evaluation of chromosomal copy number changes may be of value for response prediction of rectal cancers to preoperative chemoradiotherapy. This will require validation in a larger cohort of patients.

Early clinical results from chemoradiation with 5-fluorouracil and oxaliplatin for locally advanced rectal cancer

PURPOSE

Preoperative chemoradiation with 5-fluorouracil (5-FU) has improved local control and resectability in patients with locally advanced rectal adenocarcinoma. The possible benefit of adding oxaliplatin is being investigated. We present background on the use of oxaliplatin as well as institutional experience assessing treatment tolerability and early outcome data.

PATIENTS AND METHODS

From August 2001 to August 2006, 15 patients were treated with concurrent 5-FU, oxaliplatin, and radiation. Each had locally advanced rectal carcinoma with staging as follows: T3 (10 patients), T4 (5 patients), N1 (3 patients), and M1 (1 patient). Three patients were treated for local recurrence; 2 had received previous radiation therapy. All patients received continuous-infusion 5-FU at 225 mg/m2 per day. The oxaliplatin dose was 70 mg/m2 in 1 patient and 85 mg/m2 in the others, administered every other week x 3 weeks starting on day 1 of radiation. Resection followed completion of radiation by 6 weeks.

RESULTS

The treatment was tolerable, with the most frequent hematologic toxicity being grade 1/2 anemia. Twelve patients were evaluable, with 11 treated preoperatively. All were able to undergo resection with negative margins, with T stage at resection as follows: T4 (2 patients, 1 with 5% viable tumor), T3 (4 patients), T2 (1 patient), T1 (2 patients); there were pathologic complete responses in 4 patients. At resection, 2 patients had N2 disease; 1 of these was also found to have a peritoneal metastasis. Two patients with clinical N1 disease initially were N0 at resection. With median follow-up of 13 months (range, 4-36 months), 9 patients have clinically no evidence of disease. There have been no local recurrences and 1 death from disease.

CONCLUSION

We present tolerability and early clinical efficacy data for patients treated with concurrent 5-FU and oxaliplatin chemoradiation. The oxaliplatin-based regimen was tolerable. All patients were able to undergo resection with negative margins, with encouraging downstaging, local control, and survival.

Oxaliplatin-based chemotherapy in the management of colorectal cancer

Oxaliplatin is the only third-generation platinum derivative compound that has found a place in the routine treatment of colorectal cancer (CRC). The appearance of oxaliplatin, as well as irinotecan, in the CRC treatment armamentarium has offered new standards for adjuvant treatment and greater hopes in metastatic disease. Moreover, the combination of oxaliplatin-based chemotherapy with new targeted drugs has improved response rates and survival of these patients. Despite these new approaches, the prognosis of CRC remains poor and a better understanding of the molecular pathways is needed to optimize the use of these new approaches. In this review, the authors examine the development of oxaliplatin as well as the main trials that have positioned oxaliplatin as a key drug in the treatment of CRC.

Radiation changes do not interfere with postchemoradiation restaging of patients with rectal cancer by FDG PET/CT before curative surgical therapy

PURPOSE

Changes in F-18 fluorodeoxyglucose (FDG) uptake in normal tissues after chemoradiation therapy (CRT) potentially limit the ability of positron emission tomography (PET) to provide early assessment of therapeutic response. This study evaluated whether such changes negatively impact interpretation of posttherapy PET performed within 6 weeks of CRT completion and before definitive surgery in patients with locally advanced rectal cancer. The positive predictive value (PPV) and specificity of post-CRT PET, read clinically, was determined in 63 consecutive rectal cancer patients who had undergone preoperative CRT.

METHODS AND MATERIALS

A schema for identifying and scoring postradiation effects on PET was prospectively defined and applied in a blinded manner. This was compared with initial clinical reporting of response. Histologic assessment of the operative specimens was used as the reference standard. Correlation between clinical proctitis during CRT and radiation changes on subsequent PET was also assessed.

RESULTS

Clinical reporting of post-CRT PET yielded a high PPV (94%; 95% confidence interval, 89--100%) but may have been exaggerated by the low prevalence of complete tumor clearance (16%). The specificity was 80% with only two false-positive results. On blinded reading, significant post-CRT effects on PET were recorded in 4 of 63 patients (6% 95% confidence interval, 0-13%), but pattern recognition converted both false-positive PET results to a complete metabolic response. Clinical CRT proctitis was not correlated with PET findings.

CONCLUSION

Postradiation effects do not appear to significantly compromise the interpretation of PET for therapeutic response assessment. The proposed PET pattern of response may further improve the specificity of PET.

Phase I study of preoperative radiation therapy with concurrent infusional 5-fluorouracil and oxaliplatin followed by surgery and postoperative 5-fluorouracil plus leucovorin for T3/T4 rectal adenocarcinoma: ECOG E1297

PURPOSE

Oxaliplatin is a platinum analog and radiosensitizer active in colorectal cancer. We performed a Phase I trial to test the safety and preliminary efficacy of adding oxaliplatin to standard preoperative chemoradiation therapy for rectal cancer.

METHODS AND MATERIALS

Eligible patients had T3 to T4 rectal adenocarcinoma. Patients received standard-dose radiation (50.4 Gy for 5.5 weeks) with concurrent infused 5-fluorouracil (5-FU) at 200 mg/m2 per day, 7 days per week. Oxaliplatin was given three times at 14-day intervals at 55, 70, or 85 mg/m2 during the 5.5-week radiation period, before resection. Adjuvant therapy consisted of four cycles of 5-FU (500 mg/m2 per week) with leucovorin (500 mg/m2 per week) given every 6 weeks. The main goals were to identify the maximum tolerated dose of oxaliplatin and the dose-limiting toxicities when given with 5-FU and RT. Secondary goals were to determine resectability, pathologic response, sphincter preservation, and overall survival rates.

RESULTS

Twenty-one patients were enrolled, 5 at the 55 mg/m2 oxaliplatin dose level, 5 at 70 mg/m2, and 11 at 85 mg/m2. All patients were able to complete the preoperative chemoradiation regimen with no dose adjustments. No dose-limiting toxicities or differences in the type or extent of toxicity were noted among the groups. Nineteen patients underwent surgery (three abdominopelvic resections and 16 low anterior resections), for an 84% sphincter preservation rate. The pathologic complete response rate was 26% (5 patients), and minimal microscopic residual tumor was found in 21% (4 additional patients).

CONCLUSIONS

Oxaliplatin was well tolerated at 85 mg/m2 given every 2 weeks in combination with standard preoperative chemoradiation for rectal cancer. The rates of major pathologic response and sphincter preservation are promising.

Performing nondiagnostic research biopsies in irradiated tissue: a review of scientific, clinical, and ethical considerations

PURPOSE

Recent development of drugs that target specific pathways in tumors has increased scientific interest in studying drug effects on tumor tissue. As a result, biopsies have become an important part of many early-phase clinical trials. Performing nondiagnostic tumor biopsies raises technical and ethical concerns mostly related to the use of a potentially harmful procedure with no potential benefit to the patient. This issue is complicated by uncertainty about whether performing biopsies in irradiated fields adds significant risk. This article reviews the clinical, scientific, and ethical considerations involved in performing nondiagnostic tumor biopsies in competent adults for research purposes, with a focus on biopsies performed in the setting of therapeutic irradiation.

METHODS

Clinical trials that performed biopsies during or within 4 months of the completion of radiotherapy were identified with a literature review.

RESULTS

Twenty-nine studies with 2,160 patients were identified. Sixteen of 29 studies reported adverse events (AEs) but did not report active evaluation for biopsy complications. Ten studies did not mention AEs within the study report. At least three studies actively evaluated patients for biopsy complications. Taking this into consideration, 17 (>1%) of 2,160 patients were reported to have biopsy complications, although reporting of AEs was suboptimal in most studies.

CONCLUSION

Limited data suggest that biopsies can be performed in irradiated tissues without clinically significant excess risk. Ongoing and future trials including nondiagnostic research biopsies should record and report AEs related to this procedure to provide additional data on safety and toxicity.

Phase I study of oxaliplatin in combination with capecitabine and radiotherapy as postoperative treatment for stage II and III rectal cancer

PURPOSE

A Phase I study was conducted to determine the maximal tolerated dose and the dose-limiting toxicity (DLT) of oxaliplatin (OXA) combined with capecitabine and radiotherapy as adjuvant treatment in patients with operable rectal cancer.

PATIENTS AND METHODS

A total of 21 patients with Stage II or III rectal adenocarcinoma after curative surgery were treated with radiotherapy to a total dose of 50 Gy in 5 weeks. OXA was administered at a dosage of 40 (n = 6), 50 (n = 3),60 (n = 3), 70 (n = 3), or 80 mg/m(2) (n = 6) once a week for 2 weeks (first cycle) followed by a second cycle after a 7-day break. Capecitabine at a fixed dose of 1,300 mg/m(2)/d was administered orally at the same schedule as for OXA. DLT was defined as Grade 3 or 4 hematologic and nonhematologic toxicity.

RESULTS

Grade 1-3 leukopenia, diarrhea, and nausea/vomiting were the most common toxic side effects, and most were Grade 1-2. A DLT was first observed in 1 of 3 patients at 40 mg/m(2) (Grade 3 diarrhea) but was not observed in the next 3 patients at the same level or in patients who received a dose level of 50-70 mg/m(2). At 80 mg/m(2), DLT occurred in 3 of 6 patients (1 Grade 4 leukopenia and 2 Grade 3 diarrhea).

CONCLUSIONS

OXA combined with a fixed dose of capecitabine at 625 mg/m(2) twice daily by mouth plus radiotherapy in the adjuvant setting was tolerable and clinically feasible. The maximal tolerated dose of OXA in this setting was 80 mg/m(2), comparable to the maximal tolerated dose of OXA in the neoadjuvant setting.

Infusional 5-fluorouracil and ZD1839 (Gefitinib-Iressa) in combination with preoperative radiotherapy in patients with locally advanced rectal cancer: a phase I and II Trial (1839IL/0092)

PURPOSE

To report the final data of a Phase I and II study (1839IL/0092) on the combination of an anti-epidermal growth factor receptor drug (gefitinib), infusional 5-fluorouracil, and preoperative radiotherapy in locally advanced, resectable rectal cancer.

METHODS AND MATERIALS

Patients received 45 Gy in the posterior pelvis plus a boost of 5.4 Gy on the tumor and corresponding mesorectum. Infusional 5-fluorouracil (5-FU) and gefitinib (250 and 500 mg/day) were delivered during all radiotherapy course. An IORT boost of 10 Gy was allowed. The main endpoints of the study were to establish dose-limiting toxicity (DLT) and to evaluate the rate of pathologic response according to the tumor regression grade (TRG) Mandard score.

RESULTS

A total of 41 patients were enrolled. The DLT was not reached in the 6 patients enrolled in the dose-escalation part of the study. Of the 33 patients in the Phase II, TRG 1 was recorded in 10 patients (30.3%) and TRG 2 in 7 patients (21.2 %); overall 17 of 33 patients (51.5%) had a favorable endpoint. Overall, Grade 3+ toxicity was recorded in 16 patients (41%); these included Grade 3+ gastrointestinal toxicity in 8 patients (20.5%), Grade 3+ skin toxicity in 6 (15.3%), and Grade 3+ genitourinary toxicity in 4 (10.2%). A dose reduction of gefitinib was necessary in 24 patients (61.5%).

CONCLUSIONS

Gefitinib can be associated with 5-FU-based preoperative chemoradiation at the dose of 500 mg without any life-threatening toxicity and with a high pCR (30.3%). The relevant rate of Grade 3 gastrointestinal toxicity suggests that 250 mg would be more tolerable dose in a neaoadjuvant approach with radiotherapy and infusional 5-FU.

Irinotecan+5-fluorouracil with concomitant pre-operative radiotherapy in locally advanced non-resectable rectal cancer: a phase I/II study

In the UK, 10% of patients diagnosed with rectal cancer have inoperable disease at presentation. This study ascertained whether the resectability rate of inoperable locally advanced rectal cancer was improved by administration of intravenous irinotecan, 5-fluorouracil (5-FU) and pelvic radiotherapy. During phase I of the trial (n=12), the dose of irinotecan was escalated in three-patient cohorts from 50 mg m⁻² to 60 mg m⁻² to 70 mg m⁻² to identify the maximum tolerated dose (60 mg m⁻²). In phase II, 31 patients with non-resectable disease received 45 Gy radiotherapy and 5-FU infusions (200 mg m⁻² per day) for 5 weeks. Irinotecan (60 mg m⁻²) was given on days 1, 8, 15 and 22. After treatment, patients were operated on if possible. Thirty patients completed the protocol, 28 underwent surgery. Before surgery, MRI restaging of 24 patients showed that 19 (79%) had a reduction in tumour stage after treatment (seven complete clinical response and 12 partial). Of 27 patients followed up after surgery, 22 (81%) had clear circumferential resection margins. Disease-free and overall survival estimates at 3 years were 65 and 90%, respectively. The regimen was well tolerated. Irinotecan, 5-FU and radiotherapy results in tumour downgrading, allowing resection of previously inoperable tumour with acceptable toxicity.

Histopathological response after preoperative radiochemotherapy in rectal carcinoma is associated with improved overall survival

BACKGROUND

Recent studies showed improved local control after preoperative radiochemotherapy (RCTX) in patients with locally advanced rectal carcinoma, but failed to demonstrate a survival benefit. Our aims were to determine outcome and impact of histopathological response after preoperative RCTX.

METHODS

One hundred four patients with uT3 rectal carcinoma were treated with preoperative RCTX of 45 Gy and continuous 5-FU infusion between 1997 and 2001 (group I). Histopathological response was evaluated in all specimens after tumor resection. Group II consisted of 114 patients with uT3 rectal carcinoma treated with postoperative RCTX between 1988 and 1997.

RESULTS

Group I showed a 6.1% 5-year local recurrence rate compared to 15.3% in group II (P = 0.023). Overall survival rates did not differ significantly between both groups (P = 0.225). Histopathological responders had a significantly improved 5-year overall survival with 89.1 (7.8)% compared to 68.7 (6.7)% of the non-responders (P = 0.008) and were identified as an independent prognostic factor.

CONCLUSIONS

Significant improvement of overall survival was observed for histopathological tumor responders after neoadjuvant radiochemotherapy. Our protocol of preoperative radiochemotherapy confirms the results of the multi-center studies in regard to local control and overall survival.

Tumor response to neoadjuvant chemoradiation in rectal cancer: predictor for surgical morbidity?

BACKGROUND

Increasing the rate of pathological complete remissions after neoadjuvant chemoradiation of rectal cancer has become a strategy to further improve the long-term oncological outcome of patients. This report evaluates the influence of preoperative intensified radiochemotherapy on the rate and outcome of surgical complications.

MATERIALS AND METHODS

Patients with primary rectal cancer at stages cT3/4cNx or N+ without metastasis were preoperatively treated either with capecitabine and irinotecan or with capecitabine, irinotecan and ceutximab with a concurrent radiation (50.4 Gy). Surgery was scheduled 4-7 weeks after completion of the chemoradiation. Perioperative complications were prospectively documented during the patient's hospital stay.

RESULTS

Fifty-nine patients (median age 60; male/female: 46/13) undergoing surgery at a single center were analysed. The median distance of the tumour from the dentate line was 5 cm. The operations performed were low anterior resection (n=45), Hartmann's procedure (n=4) and abdominoperineal resection (n=10). Total mesorectal excision with R0-resection was accomplished in all but one patients. Histopathological regression was described in four grades (0-3) as defined by the Japanese Society for Cancer of the Colon and Rectum. Tumors were called major responsive when assigned to the regression grades 3 or 2, and minor or nonresponsive at regression grades 1 or 0. In total, 33 patients (55.9%) had a regression grade 2 or 3. Among them, 12 patients showed a pathological complete response without any residual cancer cell (20.3%). Seven out of 45 patients (15.5%) with sphincter-preserving surgery suffered from suture breakdown; they all had previously shown a major response of the resected tumor. Two of them died during the hospital stay.

CONCLUSIONS

While in general, patients undergoing neoadjuvant intensified treatment suffer from a slight increase in surgical complications, this is markedly enhanced in patients with good treatment responses. Our results underline the oncological benefit of intensified neoadjuvant chemoradiation, but the severity of complications in low rectal anastomosis of patients with good response after neoadjuvant therapy should alert surgeons and oncologists.

Adjuvant and neoadjuvant chemoradiation or radiotherapy in rectal cancer--a review focusing on open questions

BACKGROUND

The therapy of rectal cancer has been a matter of debate since decades, especially with regard to the benefits of neoadjuvant or adjuvant therapies. Principles of additional therapies have been established nearly two decades ago and are questioned nowadays on the basis of more recently modified operative techniques. Benefits and sequelae of therapies have to be balanced against each other, and it seems somewhat likely that a more differentiated strategy than simply stating that every patient with stage II and III rectal cancer needs chemoradiation or radiotherapy will, in long term, be recommended.

CONCLUSION

It should be kept in mind that results of centers of excellence and of phase-III studies with their positively selected patient populations are not representative for all the patients with rectal cancer and physicians treating them.

Chemoradiotherapy for rectal cancer: an updated analysis of factors affecting pathological response

AIMS

With the aim of improving locoregional control, the use of preoperative chemoradiotherapy (CRT) for rectal cancer has increased. A pathological complete response (pCR) is often used as a surrogate marker for the efficacy of different CRT schedules. By analysing factors affecting pCR, this analysis aims to guide the development of future trials.

MATERIALS AND METHODS

Searches of Medline, EMBASE and the electronic American Society of Clinical Oncology abstract databases were carried out to identify prospective phase II and phase III trials using preoperative CRT to treat rectal cancer. Trials were eligible for inclusion if they defined: the CRT drugs, the radiation dose and the pCR rate. Phase I patients were excluded from the analysis. A multivariate analysis examined the effect of the above variables on the pCR rate and in addition the use of neoadjuvant chemotherapy, the type of publication (peer reviewed vs abstract), the year of publication and whether the cancers were stated to be inoperable, fixed or threatening the circumferential resection margin were included. The method of analysis used was weighted linear modelling of the pCR rate.

RESULTS

Sixty-four phase II and seven phase III trials were identified including a total of 4732 patients. Statistically significant factors associated with pCR were the use of two drugs, the method of fluoropyrimidine administration (with continuous intravenous 5-fluorouracil being the most effective) and a higher radiotherapy dose. Although the use of two drugs was associated with a higher rate of pCR, no single schedule seemed to be more effective. None of the other factors analysed significantly influenced pCR.

CONCLUSIONS

A higher rate of pCR is seen in studies using two drugs, infusional 5-fluorouracil and a radiotherapy dose of 45 Gy and above.

Preoperative Chemoradiotherapy for Rectal Cancer: Randomized Trial Comparing Oral Uracil and Tegafur and Oral Leucovorin Vs. Intravenous 5-Fluorouracil and Leucovorin

PURPOSE

To compare, in a randomized trial, 5-fluorouracil (FU) plus leucovorin (LV) (FU+LV) vs. oral uracil and tegafur (UFT) plus LV (UFT+LV) given concomitantly with preoperative irradiation in patients with cT3-4 or N+ rectal cancer.

METHODS AND MATERIALS

A total of 155 patients were entered onto the trial. Patients received pelvic radiotherapy (4500-5,040 cGy in 5 to 6 weeks) and chemotherapy consisting of two 5-day courses of 20 mg/m(2)/d LV and 350 mg/m(2)/d FU in the first and fifth weeks of radiotherapy (77 patients) or one course of 25 mg/d oral LV and 300 mg/m(2)/d UFT for 4 weeks beginning in the second week of radiotherapy (78 patients). The primary endpoints were pathologic complete response (pCR) and resectability rate. Secondary endpoints included downstaging rate, toxicity, and survival.

RESULTS

Grade 3-5 acute hematologic toxicity occurred only with FU+LV (leukopenia 9%; p = 0.02). There were no differences in resectability rates (92.1% vs. 93.4%; p = 0.82). The pCR rate was 13.2% in both arms. Tumor downstaging was more frequent with UFT+LV (59.2% vs. 43.3%; p = 0.04). Three-year overall survival was 87% with FU+LV and 74% with UFT+LV (p = 0.37). The 3-year cumulative incidences of local recurrence were 7.5% and 8.9%, respectively (p = 0.619; relative risk, 1.46; 95% confidence interval 0.32-6.55).

CONCLUSION

Although this study lacked statistical power to exclude clinically significant differences between both groups, the outcome of patients treated with UFT+LV did not differ significantly from that of patients treated with FU+LV, and hematologic toxicity was significantly lower in the experimental arm.

Effect of time interval between surgery and preoperative chemoradiotherapy with 5-fluorouracil or 5-fluorouracil and oxaliplatin on outcomes in rectal cancer

BACKGROUND AND OBJECTIVES

Preoperative chemoradiotherapy for locally advanced rectal cancer is now considered "standard of care." However, the optimal time interval for resection after neoadjuvant therapy is unknown.

METHODS

Between 11/90 and 11/04, 107 patients with rectal adenocarcinoma underwent preoperative chemo/RT at the University of Pennsylvania. Fifty-six percent had LAR and 40% had APR. Chemotherapy consisted of 5-FU/oxaliplatin in 28% and 5-FU in 72% of patients. All patients received preoperative RT.

RESULTS

A longer time interval between chemo/RT and surgery was associated with tumor downstaging (OR 1.24, P = 0.02). A longer time interval was not associated with: nodal downstaging (OR 1.00, P = 0.98); pathologic complete response (PCR) (OR 0.97, P = 0.80); likelihood of performing an LAR (OR 0.90, P = 0.47); improved disease free survival (DFS), local control, or distant control (HR 1.05, P = 0.49; HR 1.14, P = 0.22; HR 1.06, P = 0.52, respectively). The PCR rate was 34.5% in the 5-FU/oxaliplatin/radiation group, and 13.7% in the 5-FU/radiation group. If patients with microscopic CR were excluded, then the PCR rate for 5FU/OX was 21.4% and for 5-FU was 12.2%.

CONCLUSIONS

Time interval between surgery and chemo/RT appeared to have little effect on PCR or LAR rates. Patients receiving 5 FU/oxaliplatin/RT had a high PCR rate. A prospective randomized trial to test superiority of 5 FU/oxaliplatin is warranted.

Phase I Study of Oxaliplatin, Full-Dose Gemcitabine, and Concurrent Radiation Therapy in Pancreatic Cancer

Purpose

To determine a biweekly dose of oxaliplatin for combination with full-dose gemcitabine and concurrent radiation therapy (RT) in pancreatic cancer.

Patients and Methods

Patients with previously untreated pancreatic cancer received gemcitabine days 1, 8, and 15, and oxaliplatin days 1 and 15, repeated at 28-day intervals. RT (27 Gy in 1.8-Gy fractions) was administered during cycle 1. Dose escalation was guided using the time-to-event continuous reassessment method. Dose levels 1 to 4 included gemcitabine 1 g/m2intravenously (IV) during 30 minutes and oxaliplatin 40, 55, 70, or 85 mg/m2IV during 90 minutes, respectively; for dose levels 5 and 6, oxaliplatin dose remained 85 mg/m2but infusion time for gemcitabine 1 g/m2was increased to 65 or 100 minutes, respectively. The trial objective was to determine the dose level associated with dose-limiting toxicity (DLT) through cycle 2 in ≤ 20% of patients.

Results

Forty-four patients were enrolled (median age, 64 years; 27 men, 17 women) with resectable (n = 12), unresectable (n = 29), and metastatic (n = 3) pancreatic cancer. Ten DLTs occurred in nine patients, including grade 4 platelets (n = 4), decline in performance status (n = 2), GI bleeding (n = 2), and GI toxicity (n = 2). The estimated probability of DLT for dose level 3 was .21 (90% posterior probability interval [PI], .12 to .33); for dose level 4, the estimated probability was .24 (90% PI, .14 to .36).

Conclusion

The addition of oxaliplatin 85 mg/m2days 1 and 15 to full-dose gemcitabine and radiation therapy was well tolerated. On the basis of these results, a multi-institutional neoadjuvant phase II study in resectable pancreatic cancer is planned.

[Experience with only preoperative radiotherapy of non-metastatic rectal tumours]

INTRODUCTION

It is an accepted fact that the local recurrence rate can be decreased up to 50% for the metastatic rectum tumours irradiated only preoperatively.

MATERIALS AND METHODS

181 patients having rectum tumour were irradiated preoperatively with 36 or 40 Gy between 1990 and 2001. The classification was made according to the modified Astler-Coller pathological staging system. The radiation treatment was carried out with telecobalt unit or high energy photon of linear accelerator after computerized radiation treatment planning.

RESULTS

The most important characterizing factor for the efficiency of the preoperative irradiation is the local recurrence rate that was found to be 21.56% in our investigation. The survival rate was significantly influenced by the age of the patient and the applied dose.

CONCLUSION

Our statistical analysis was applied to investigate the efficiency of the only preoperatively irradiated patients. The results are in agreement with the reported contributions.

High dose rate endorectal brachytherapy as a neoadjuvant treatment for patients with resectable rectal cancer

In the era of total mesorectal surgery, the issue of radiation toxicity is raised. A novel endocavitary brachytherapy technique was tested as a neoadjuvant treatment for patients with resectable rectal cancer. The objectives of the study were to evaluate the treatment-related toxicity and effects on local recurrence. A dose of 26 Gy was prescribed to the gross tumour volume and intramesorectal deposits seen on magnetic resonance imaging and given over four daily treatments, using the high dose rate delivery system followed by surgery 6-8 weeks later. The study included 93 T3, four T4 and three T2 tumours. Acute proctitis of grade 2 was observed in all patients, but one required transfusion. At a median follow-up time of 60 months, the 5-year actual local recurrence rate was 5%, disease-free survival was 65%, and overall survival was 70%. High dose rate endorectal brachytherapy seems to prevent local recurrence and has a favourable toxicity pattern compared with external beam radiotherapy.

Efficacy of preoperative combined 18-fluorodeoxyglucose positron emission tomography and computed tomography for assessing primary rectal cancer response to neoadjuvant therapy

PURPOSE

Efficacy of F-18 fluorodeoxyglucose positron emission tomography combined with computed tomography (FDG-PET/CT) for determining neoadjuvant therapy response in rectal cancer is not well established. We sought to evaluate serial FDG-PET/CT for assessing tumor down-staging, percentage residual tumor, and complete response or microscopic disease with rectal cancer neoadjuvant therapy.

METHODS

Patients with rectal cancer undergoing neoadjuvant therapy, definitive surgical resection, and FDG-PET/CT before and 4-6 weeks after neoadjuvant treatment were included. Tumors were evaluated pretreatment and on final pathology for size and stage. FDG-PET/CT parameters assessed were visual response score (VRS), standardized uptake value (SUV), PET-derived tumor volume (PETvol), CT-derived tumor volume (CTvol), and total lesion glycolysis (delta TLG).

RESULTS

Twenty-one rectal cancer patients over 3 years underwent neoadjuvant treatment, serial FDG-PET/CT, and resection. Complete response or microscopic disease (n = 7, 33%) was associated with higher Delta CTvol (AUC = 0.82, p = 0.004) and Delta SUV (AUC = 0.79, p = 0.01). Tumor down-staging (n = 14, 67%) was associated with greater Delta PETvol (AUC = 0.82, p < 0.001) and Delta SUV (AUC = 0.82, p < 0.001). Pathologic lymph node disease (n = 7, 33%) correlated with Delta CTvol (AUC = 0.75, p = 0.03) and Delta PETvol (AUC = 0.70, p = 0.08).

CONCLUSION

FDG-PET/CT parameters were best for assessing tumor down-staging and percentage of residual tumor after neoadjuvant treatment of rectal cancer and can potentially assist in treatment planning.

Adjuvant therapy for rectal cancer

Patients with stage II and III rectal cancer benefit from a multidisciplinary approach to treatment. Studies of postoperative adjuvant therapy consistently demonstrate decreases in locoregional recurrence with the use of radiation therapy. The use of postoperative chemotherapy results in improved disease-free survival and overall survival in certain studies. Preoperative radiation therapy decreases locoregional recurrence and in one study demonstrated an improvement in survival. The addition of chemotherapy to preoperative radiation results in improved locoregional control, but not survival. Preoperative chemoradiation is the standard of care for patients with clinical stage II and III rectal cancer in the United States due to improved local recurrence, acute and late toxicity, and sphincter preservation compared with postoperative chemoradiation. Promising approaches include the incorporation of new chemotherapeutic and biologic agents into chemoradiation and adjuvant chemotherapy regimens; new radiation techniques, such as the use of intraoperative radiation therapy and an accelerated concomitant radiation boost; and gene and protein expression profiling, to better predict response to treatment and prognosis.

Preoperative chemoradiotherapy with capecitabine and oxaliplatin in locally advanced rectal cancer. A phase I-II multicenter study of the Dutch Colorectal Cancer Group

Background

We studied the maximum tolerated dose (MTD) and efficacy of oxaliplatin added to capecitabine and radiotherapy (Capox-RT) as neoadjuvant therapy for rectal cancer.

Methods

T3-4 rectal cancer patients received escalating doses of oxaliplatin (day 1 and 29) with a fixed dose of capecitabine of 1000 mg/m² twice daily (days 1–14, 25–38) added to RT with 50.4 Gy and surgery after 6–8 weeks. The MTD, determined during phase I, was used in the subsequent phase II, in which R0 resection rate (a negative circumferential resection margin) was the primary end point.

Results

Twenty-one patients were evaluable. In the phase I part, oxaliplatin at 85 mg/m² was established as MTD. In phase II, the main toxicity was grade III diarrhea (18%). All patients underwent surgery, and 20 patients had a resectable tumor. An R0 was achieved in 17/21 patients, downstaging to T0-2 in 7/21 and a pCR in 2/21.

Conclusion

Combination of Capox-RT has an acceptable acute toxicity profile and a high R0 resection rate of 81% in locally advanced rectal cancer. However the pCR rate was low.

Mitomycin-C/5-fluorouracil/leucovorin and hyperfractionated radiation therapy for rectal carcinoma: a phase II study with long-term follow-up

PURPOSE

Preoperative chemotherapy followed by surgery and adjuvant chemotherapy is a standard treatment for most patients with rectal cancer. We aimed to determine efficacy and tolerability of preoperative mitomycin, fluorouracil (5-FU), and leucovorin (LV) concurrent with hyperfractionated radiation therapy (RT) followed by surgery and adjuvant chemotherapy.

PATIENTS AND METHODS

Patients with clinical stage II/III disease were treated with mitomycin 10 mg/m(2) on day 1, continuous venous infusion 5-FU 600 mg/m(2) per day for 96 hours, and oral LV 25 mg every 6 hours on days 1-5. All patients received concurrent RT in fractions of 150 cGy twice daily beginning on day 1. Unfixed tumors received 3000 cGy, whereas fixed tumors received a dose of 4500 cGy. Patients then underwent resection and postoperative adjuvant chemotherapy with oral LV and continuous venous infusion 5-FU 600 mg/m(2) per day on days 1-5 on a 28-day cycle for 6 cycles. Primary endpoints were to determine the rate of pathologic response and downstaging, long-term locoregional control, progression-free survival, and overall survival.

RESULTS

Between the years 1993 and 2000, 83 patients were enrolled. Eighteen patients (31%) were downstaged. Six patients (7%) had pathologic complete response. Median follow-up was 62 months with a 5-year overall survival of 71%. Local control rate was 96%. Treatment was well tolerated with stomatitis, diarrhea, and radiation proctitis being the most common toxicities.

CONCLUSION

This regimen is effective in the treatment of rectal carcinoma. The favorable toxicity profile of mitomycin and hyperfractionated RT allows these strategies to be utilized with the newer chemotherapies for this disease.

Early changes in apparent diffusion coefficient predict the quantitative antitumoral activity of capecitabine, oxaliplatin, and irradiation in HT29 xenografts in athymic nude mice

PURPOSE

The purpose of this study was to evaluate the possible use of changes in apparent diffusion coefficient (ADC) measured by magnetic resonance imaging for pretreatment prediction and early detection of tumor response in a mouse model during fractionated chemoradiotherapy.

MATERIALS AND METHODS

Athymic mice with bilateral HT29 xenografts on rear flanks were allocated into three groups: control, capecitabine, and capecitabine and oxaliplatin. The left flanks of the mice received daily irradiation. T2 and diffusion images were acquired before therapy and weekly for the following 9 weeks. Pretreatment and changes in ADC were calculated and compared with tumor doubling growth delay.

RESULTS

No correlations between pretreatment ADC and changes in tumor volumes after therapy were seen. All treated tumors, except those receiving capecitabine (P = .06), showed increased mean tumor ADC values 11 days after initialization of therapy (P < .05) before returning to pretreatment values within 5 days posttherapy (day 18 after onset of therapy). This increase in mean tumor ADC showed a strong positive correlation (r = 0.92, P < .01) with mean tumor doubling growth delay.

CONCLUSIONS

Pretreatment ADC values did not predict the effectiveness of therapy, whereas early changes in mean ADC quantitatively correlated with treatment outcome.

Bevacizumab, Oxaliplatin, and Capecitabine With Radiation Therapy in Rectal Cancer: Phase I Trial Results

PURPOSE

The overexpression of vascular endothelial growth factor (VEGF) is associated with poor outcomes in colorectal cancer patients. Bevacizumab, a VEGF inhibitor, enhances the effects of chemotherapy and radiation therapy on tumor cytotoxicity in preclinical models, including colorectal cancer. A Phase I trial was undertaken to evaluate the combination of bevacizumab, capecitabine, oxaliplatin, and radiation therapy in patients with rectal cancer.

METHODS AND MATERIALS

Patients with pathologically confirmed adenocarcinoma of the rectum were eligible. Pretreatment staging included computerized tomography, endoscopic ultrasound, and surgical evaluation. Patients received 50.4 Gy of external beam radiation therapy (EBRT) to the tumor in 28 fractions. Capecitabine, oxaliplatin, and bevacizumab were administered concurrently with radiation therapy. After EBRT completion, patients were restaged and evaluated for surgery. Primary endpoints included the determination of dose-limiting toxicity and a recommended Phase II dose, non dose-limiting toxicity, and preliminary radiographic and pathologic response rates.

RESULTS

Eleven patients were enrolled. All were evaluable for toxicity and efficacy. Dose level 2 was associated with unacceptable toxicity (primarily diarrhea). Dose level 1 had an acceptable toxicity profile. The recommended Phase II dose in our study was bevacizumab 15 mg/kg Day 1 + 10 mg/kg Days 8 and 22, oxaliplatin 50 mg/m2 weekly, and capecitabine 625 mg/m2 bid during radiation days. Six patients had clinical responses. Two patients had a pathologic complete response, and 3 had microscopic disease only. One patient experienced a postoperative abscess, one a syncopal episode during adjuvant chemotherapy, and one a subclinical myocardial infarction during adjuvant chemotherapy.

CONCLUSIONS

The combination of bevacizumab, capecitabine, oxaliplatin, and radiation therapy in rectal cancer was tolerable, with encouraging response rates. Further investigation with this regimen is being pursued in a Phase II setting.

Sequential FDG-PET/CT reliably predicts response of locally advanced rectal cancer to neo-adjuvant chemo-radiation therapy

PURPOSE

Prediction of rectal cancer response to preoperative, neo-adjuvant chemo-radiation therapy (CRT) provides the opportunity to identify patients in whom a major response is expected and who may therefore benefit from alternative surgical approaches. Traditional morphological imaging techniques are effective in defining tumour extension in the initial diagnostic and staging work-up, but perform poorly in distinguishing residual neoplastic tissue from scarring post CRT, when restaging the patient before surgery. Fluorine-18 fluorodeoxyglucose positron emission tomography (FDG-PET) is a promising tool for monitoring the effect of anti-tumour therapy. The aim of this study was to prospectively assess the value of sequential FDG-PET scans in predicting the response of locally advanced rectal cancer to neo-adjuvant CRT.

METHODS

Forty-four consecutive patients with locally advanced (cT3-4) primary rectal cancer and four patients with pelvic recurrence of rectal cancer were enrolled in this prospective study. Treatment consisted of external beam intensified radiotherapy (50 Gy to the posterior pelvis, 56 Gy to the tumour), chemotherapy (in most cases PVI 5-FU at 300 mg/m(2) per day) and, 8-10 weeks later, surgery with curative intent. All patients underwent FDG-PET/CT both before CRT and 5-6 weeks after completing CRT. One patient died before surgery because of acute myocardial infarction, and was therefore excluded from further analysis. Semi-quantitative measurements of FDG uptake (SUV(max)), absolute difference (DeltaSUV(max)) and percent SUV(max) difference (Response Index, RI) between pre- and post-CRT PET scans were considered. Results were correlated with pathological response, assessed both by histopathological staging of the surgical specimens (pTNM) and by the tumour regression grade (TRG) according to Mandard's criteria (patients with TRG1-2 being defined as responders and patients with TRG3-5 as non-responders).

RESULTS

Following neo-adjuvant CRT, of the 45 patients submitted to surgery, 23 (51.1%) were classified as responders according to Mandard's criteria (8 TRG1 and 15 TRG2), while the remaining 22 (48.9%) were non-responders (9 TRG3 and 13 TRG4-5). Considering all patients, the mean pre-CRT SUV(max) was 15.6, significantly higher than the mean value of 5.4 post CRT (p < 0.001). Nevertheless, when stratifying patients according to response to CRT (using Mandard's criteria), the mean RI was significantly higher in responders than in non-responders (75.9% versus 46.9%,p = 0.0015). Using a 66.2% SUV(max) decrease as the cut-off value (identified by ROC analysis) for defining response to therapy, the following parameters were obtained: 79.2% specificity, 81.2% sensitivity, 77% positive predictive value, 89% negative predictive value and 80% overall accuracy.

CONCLUSION

The results suggest the potential utility of FDG-PET as a complementary diagnostic and prognostic procedure in the assessment of neo-adjuvant CRT response of locally advanced rectal cancer. DeltaSUV(max) and RI seem the best predictors of CRT response.

Intensified neoadjuvant radiochemotherapy for locally advanced rectal cancer: a review

BACKGROUND

The rate of local recurrence of locally advanced rectal cancer (stage III and IV according to the criteria of Union Internationale Contre Le Cancer) is still high, and also the rate of distant metastases. There are a lot of phase I/II trails of intensified neoadjuvant radiochemotherapy with different chemotherapeutic agents and current protocols to radiotherapy.

AIM

The objective of this review of literature was to evaluate the necessity, the results, and comparability of the different regimes and to evaluate a potential impact on later adjuvant chemotherapy.

Neoadjuvant radiochemotherapy for rectal cancer

During the past few decades, significant progress has been achieved in the management of rectal cancer with the introduction of total mesorectal excision. The role of radiotherapy in improving local control and survival has been investigated extensively. Randomized trials of preoperative radiotherapy reported statistically significant lower local recurrence rates with either short regimens (25 Gy in 5 fractions) or conventionally fractionated regimens (45-50 Gy in 25 fractions) and some also showed a survival improvement. Preoperative radiotherapy appears more effective in terms of local control and toxicity compared to postoperative therapy. Several recent studies show that 5-FU-based chemotherapy enhances tumor response to radiotherapy and preoperative chemoradiotherapy is being increasingly used for stage II and III disease.

5-fluorouracil and weekly oxaliplatin combined with radiotherapy for locally advanced rectal cancer: surgical complications and long-term results

BACKGROUND

We undertook this study to evaluate early surgical complications and long-term results after preoperative radiotherapy and chemotherapy (RCT) using 5-fluorouracil (5-FU) and oxaliplatin (OXA) for rectal cancer.

METHODS

Forty six TNM stage II-III rectal cancer patients were studied, who were given preoperative RT (50.4 Gy/28 fractions) combined with 5-FU (200-225 mg/m(2)/day by continuous venous infusion) and weekly OXA (25-60 mg/m(2)). Major complications and reoperations were recorded overall, whereas outcome analyses were performed only for patients who received the recommended regimen dosage.

RESULTS

Forty three patients (M:F, 25:18; median age 59 years) were available for analysis. All patients received the planned RT dose. There were no postoperative deaths; seven patients had early major surgical complications, four requiring re-operation. One additional patient had a second surgical procedure due to a duodenal fistula complicating the resection of an aortic aneurysm performed concomitantly with rectal cancer surgery. At a median follow-up of 49 months, two of the 23 patients treated at the recommended doses developed recurrence (one local, and one local and distant), and two died of cancer progression. Following the Kaplan-Meier method, the estimated 5-year overall and disease-free survival rates were 92 and 89%, respectively.

CONCLUSIONS

The preoperative RCT regimen used in the present study incurs a low rate of recurrence with an acceptable surgical morbidity.

Phase II Trial of Preoperative Chemoradiation With a Hyperfractionated Radiation Boost in Locally Advanced Rectal Cancer

PURPOSE

The purpose of this phase II study was to prospectively determine the efficacy of preoperative chemoradiation with a hyperfractionated (Hfx) RT boost to 61.8 Gy in locally advanced rectal cancer.

METHODS

Eligibility stipulated that the primary lesion had to be either T4; or T3 and >4 cm or 40% of the bowel circumference. Radiation (RT) consisted of 45 Gy to the pelvis (1.8 Gy per fraction) followed by 1.2 Gy twice daily (to the gross tumor volume) to a total RT dose of 61.8 Gy. There was 5-FU infused at 1 g/m2/24 hours for 4 days during the 1st and 6th weeks of RT (concurrent with the Hfx boost). Surgical resection was planned 4 to 6 weeks later. Adjuvant chemotherapy (bolus 5-FU/leucovorin) was scheduled for 4 cycles at 28-day intervals.

RESULTS

There were 22 patients, ages 22 to 81 years (median, 64) enrolled in the study. Of the 20 patients evaluable for response, 10 (50%) had evidence of clinical downstaging and 5 patients (25%) had > or =90% fibrosis in the resected specimen. With a median f/u of 40 months (7-158), the 4 years actuarial rate for all patients (n = 22) of OS was 64%, of DFS 62%, and of LC 84%. 3/21 patients (14%) had positive margins, all of whom developed a local failure (P < 0.001).

CONCLUSION

This regimen of high dose preoperative chemoRT with a Hfx RT boost (to 61.8 Gy) in patients with bulky, locally advanced rectal cancer results in clinical downstaging in half of the patients with significant fibrosis in the operative specimen.

Preoperative Radiotherapy Alone or Combined With Chemotherapy Followed by Transanal Excision for Rectal Adenocarcinoma

OBJECTIVE

To evaluate the efficacy of preoperative radiotherapy (RT) and chemoradiation (CRT) followed by transanal excision (TAE) for rectal adenocarcinoma.

METHODS

Thirty-two patients were treated between July 1988 and April 2004 and followed from 2 to 123 months (median, 27 months).

RESULTS

The 3-year outcomes were: locoregional control, 79%; distant metastasis-free survival, 80%; cause-specific survival, 88%; and overall survival, 75%. Outcomes were better for patients with T1-T2 tumors and those who experienced a complete response to preoperative RT or CRT. Two patients (6%) had chronic RT proctitis after treatment.

CONCLUSION

A select subset of patients with T2/T3 tumors will experience similar outcomes after preoperative RT or CRT and TAE compared with radical proctectomy. Reliably predictive clinicopathologic features to define this subgroup would best be elicited in the context of large prospective randomized trials, as would the optimal combination and schedule of systemic agents delivered in conjunction with preoperative RT. Patients who experience a complete response (cCR) after preoperative CRT are excellent candidates for TAE; those with less than a cCR have a less-favorable prognosis and are probably better treated with a low anterior resection or abdominal-perineal resection.