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

Lymph node status and TS gene expression are prognostic markers in stage II/III rectal cancer after neoadjuvant fluorouracil-based chemoradiotherapy

PURPOSE

According to the CAO/ARO/AIO-94 trial of the German Rectal Cancer Study Group, preoperative combined fluorouracil (FU) -based long-term chemoradiotherapy (CT/RT) is recommended for patients with International Union Against Cancer (UICC) stage II/III rectal cancer. However, despite the local benefit of neoadjuvant treatment, the overall prognostic value remains uncertain in comparison with adjuvant CT/RT. Furthermore, the prognostic value of molecular biomarkers, such as thymidylate synthase (TS), thymidine phosphorylase (TP), and dihydropyrimidine dehydrogenase (DPD), all of which are involved in the FU metabolism, is unknown in neoadjuvant settings. We assessed the impact of standardized preoperative CT/RT and intratumoral TS, TP, and DPD levels on patient outcome.

PATIENTS AND METHODS

Forty patients with rectal cancer pretherapeutic UICC stage II/III, receiving preoperative FU-based CT/RT (CAO/ARO/AIO-94 trial) followed by standardized surgery, including total mesorectal excision, were investigated. Downsizing, downstaging, tumor regression, as well as TS, TP, and DPD gene expression of post-treatment surgical specimens were correlated with disease-free survival (DFS) and overall survival (OS).

RESULTS

Significant downsizing (P < .001) and downstaging (P = .001) were achieved with preoperative CT/RT. During a median follow-up of 49 months (95% CI, 43 to 58 months), the cancer recurrence rate was 28.2%. DFS and OS were significantly increased in patients with downstaging (P < .001 and P = .003, respectively), compared with patients without downstaging. All patients who developed cancer recurrence had a persistent positive lymph node status after preoperative CT/RT (P < .001) and a significantly higher TS gene expression (P = .035) compared with those patients without recurrence.

CONCLUSION

Persistent positive lymph node status and high intratumoral TS expression after preoperative CT/RT are predictive of an unfavorable prognosis in rectal cancer UICC stage II/III.

Complications, functional outcome and quality of life after intensive preoperative chemoradiotherapy for rectal cancer

AIMS

To investigate early and late complications in 44 patients with locally advanced mid-low rectal cancer enrolled in a phase I-II study, who had received an aggressive chemoradiation treatment (50.4Gy/28F; 5-FU continuous infusion and weekly Oxaliplatin) followed by total mesorectal excision and 5-FU based postoperative chemotherapy. The aim of the present study is also to evaluate functional outcome and quality of life (QoL) in a sub-group of 22 patients.

METHODS

Standardized forms for early and late surgical complications were completed for all patients. Anorectal function and QoL were also investigated in 22 patients who underwent surgery in the same surgical unit, using the fecal incontinence scoring system (FIS) and EORTC-QLQ-CR38 questionnaires, compiled before and after radiotherapy and at least 8 months after surgery. The differences over time in scores were analyzed using repeated measure ANOVA.

RESULTS

The median age of patients (25 males and 19 females) was 58 (range: 34-73) years. A low anterior resection was performed in 39 cases, radical resection in 41, and 12 patients had a pathological complete response. There were no operative deaths; 4 and 9 patients required re-operation for early and late complications, respectively. FIS score did not present a significant worsening over time. According to data in the EORTC-QLQ-CR38 questionnaire, a significant improvement over time was found only for "future perspective".

CONCLUSION

Our findings seem to indicate that this aggressive 5-FU-Oxalipaltin-based treatment implies no impairment of QoL and anorectal function, even if a high rate of late major complications was observed. Studies on larger series are required to confirm these results.

Biweekly oxaliplatin, raltitrexed, 5-fluorouracil and folinic acid combination chemotherapy during preoperative radiation therapy for locally advanced rectal cancer: a phase I-II study

Oxaliplatin (OXA), raltitrexed (RTX), 5-fluorouracil (FU) and folinic acid (FA) have shown activity in metastatic colorectal cancer, radioenhancing effect and synergism when combined. We evaluated a chemotherapy (CT) combination of OXA, RTX and FU/FA during preoperative radiotherapy (RT) in locally advanced rectal cancer (LARC) patients. Fifty-one patients with LARC at high risk of recurrence (T4, N+ or T3N0 ⩽5 cm from anal verge and/or circumferential resection margin ⩽5 mm) received three biweekly courses of CT during pelvic RT (45 Gy). Surgery was planned 8 weeks after CT-RT. Recommended doses (RDs) determined during phase I were utilised in the subsequent phase II trial, where the rate of tumour regression grade (TRG) 1 or 2 was the main end point. No toxic deaths occurred, and severe toxicity was easily managed. In phase II, RDs delivered in 31 patients were OXA 100 mg m⁻² and RTX 2.5 mg m⁻² on day 1, and FU 900 mg m⁻² and LFA 250 mg m⁻² on day 2. Main severe toxicities by patients were grade 4 neutropenia (23%) and grade 3 diarrhoea (19%). In 71% (95% confidence limits, 52–86%) of patients, TRG1 (13) or TRG2 (9) was obtained. All patients are alive and recurrence-free after a median follow-up of 29 months. Combination of OXA, RTX and FU/FA with pelvic RT has an acceptable toxicity and a high clinical activity in LARC and should be studied further in patients at high risk of recurrence.

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.

Improved incidence of pT0 downstaged surgical specimens in locally advanced rectal cancer (LARC) treated with induction oxaliplatin plus 5-fluorouracil and preoperative chemoradiation

PURPOSE

To compare efficacy in terms of pathologic response in LARC patients treated with preoperative chemoradiation, with or without a short-intense course of induction oxaliplatin.

PATIENTS AND METHODS

From 05/98 to 10/02, 114 patients were treated with preoperative chemoradiation (4500-5040 cGy + oral Tegafur 1200 mg/day) for cT(3)-(4)N(+/x)M(0) rectal cancer. Starting 05/01, 52 consecutive patients additionally received induction FOLFOX-4, oxaliplatin (85 mg/m(2) iv d1), 5-FU (400 mg/m(2) iv bolus d1) and 600 mg/m(2) iv continuous infusion in 22 h with leucovorin (200 mg iv) d1 and d2, every 15 days (2 cycles), followed by the previously described Tegafur chemoradiation regime. Surgery was performed in 5-6 weeks. Pathological assessment investigated post-treatment T and N status in the rectal wall and peri-rectal tissues.

RESULTS

Patients, tumor and treatment characteristics were comparable between groups. Incidence of pT(0) specimens was significantly increased by induction FOLFOX-4 (P = 0.006). Total T and N downstaging were 58% versus 75% and 42% versus 40%, respectively (P = ns). T downstaging of > or =2 categories was significantly superior in FOLFOX-4 group (P = 0.029).

CONCLUSIONS

Short-intense induction FOLFOX-4 significantly improves pathologic complete response in LARC patients treated with tegafur-sensitized preoperative chemoradiation. The 44% rate of pT(0)-(1) specimens observed in the oxaliplatin group should impulse innovative surgical approaches to promote ano-rectal sphincter conserving protocols.

Phase I/II study of preoperative oxaliplatin, fluorouracil, and external-beam radiation therapy in patients with locally advanced rectal cancer: Cancer and Leukemia Group B 89901

PURPOSE

The addition of oxaliplatin to fluorouracil in patients with advanced colorectal cancer improves survival. This phase I/II study evaluated the addition of weekly oxaliplatin to preoperative continuous infusion fluorouracil (FU) and external-beam radiation therapy (RT) in patients with locally advanced rectal adenocarcinoma.

PATIENTS AND METHODS

Patients with clinical T3/T4 rectal adenocarcinoma and no evidence of metastases were treated with weekly oxaliplatin, continuous infusion FU 200 mg/m2 intravenously, and RT. A total of 6 weekly doses of oxaliplatin were planned. RT dose was 1.8 Gy/fraction to a total dose of 50.4 Gy. In the phase I portion, oxaliplatin was escalated from 30 to 60 mg/m2.

RESULTS

Forty-four patients were entered onto the study, 18 on the phase I portion and 26 on the phase II portion. The maximum-tolerated dose (MTD) for oxaliplatin was determined to be 60 mg/m2. At the MTD, 12 patients experienced grade 3 or 4 diarrhea, two patients experienced grade 3 neutropenia, and one patient experienced grade 3 thrombocytopenia. Fifty-six percent of patients entered at the MTD completed all 6 weeks of oxaliplatin. Eight (25%) of 32 patients enrolled at the phase II dose experienced a pathologic complete response.

CONCLUSION

In this multicenter study, the addition of oxaliplatin to intravenous continuous infusion FU and RT for patients with locally advanced rectal cancer was associated with a high pathologic complete response rate but more toxicity than when FU is used alone. A regimen of weekly oxaliplatin, continuous infusion FU, and radiation therapy is now being evaluated by the National Surgical Adjuvant Breast and Bowel Project.

Neoadjuvant and adjuvant therapy for rectal cancer

The currently available evidence from randomized clinical trials clearly supports the use of adjuvant therapy in general and preoperative combined modality therapy in particular as effective means of decreasing the rates of local recurrence, improving sphincter preservation rates, and probably im-proving overall survival when managing patients with locally advanced adenocarcinomas of the lower two thirds of the rectum. A radical surgical approach with adequately performed, sharp TME remains the standard of care for those patients. There is clearly a need to develop and validate surrogate biomarkers for the identification of patients who respond favorably to preoperative treatment. There is still a significant fraction of rectal cancer patients who ultimately die from their disease. The armamentarium of avail-able therapies is evolving rapidly, and hopefully local control rates and overall survival of rectal cancer patients will continue to improve in the near future.

Pre-operative combined modality therapy in the management of locally advanced rectal cancer

AIMS

To review the use of pre-operative combined modality therapy (CMT, chemotherapy with radiotherapy) in the management of resectable rectal cancer.

METHODS

A systematic search was performed on pre-operative CMT and rectal cancer. Additional information was retrieved from hand searching the literature and from relevant congress proceedings. We addressed the following issues: Phase II studies of pre-operative CMT, pre-operative radiotherapy (RT) alone vs pre-operative CMT, pre-operative vs post-operative CMT, functional outcome and pathologic downstaging after CMT, prediction and importance of complete response to CMT.

RESULTS

Pre-operative CMT results in an average pathological complete response (pCR) rate of 18.5% in Phase II studies. Compared with pre-operative RT alone, the addition of CT significantly improves tumour response but not overall survival while acute toxicity increases and the effect on sphincter preservation is at present unclear. Pre-operative CMT has been proven to be superior to post-operative CMT in a German multicenter randomized trial. The scarce available data suggest that the addition of CT might worsen anorectal function compared to pre-operative RT alone. Although a significant pathological response is prognostically favourable, the clinical and imaging tools available at present do not allow to accurately predict pCR in clinical complete responders confirming the indication for surgery in this subgroup.

CONCLUSIONS

Pre-operative CMT enhances tumour response and could therefore, have a role in patients with possibly invaded resection margins or low lying cancers, although both acute toxicity and anorectal function are worse compared to RT alone. The final results of ongoing randomized trials will more accurately establish the role of pre-operative CMT in resectable rectal cancer patients.

Role of radiotherapy with surgery for T3 and resectable T4 rectal cancer: evidence from randomized trials

PURPOSE

The main treatment for resectable rectal cancer T2-T4 N0-N2 M0 is surgery. The benefit of preoperative or postoperative radiation therapy can be analyzed in terms of improvement of local control, sphincter preservation, and survival weighted against increased toxicity.

METHODS

Only randomized trials can provide strong evidence of a positive cost-benefit ratio of such combined approach. The most recent trials were reviewed.

RESULTS

Three randomized trials, including the latest German CAO-ARO trial, have demonstrated the superiority of preoperative radiotherapy with or without chemotherapy (vs. postoperative) in terms of local control and toxicity. The Ducth TME trial showed that even with modern standard surgery, preoperative radiotherapy improved local control. Preoperative irradiation using a high dose in a small volume and a long interval before surgery may improve sphincter preservation (Lyon trials). Concurrent chemoradiation (FFCD 9203, EORTC 22921, did not significantly improve sphincter preservation or survival but significantly reduced the local recurrence rate.

CONCLUSIONS

In 2005 examination of randomized trials provides evidence for the benefit of preoperative chemoradiation in improving local control and probably sphincter preservation in rectal cancer. Randomized trials should be designed to further demonstrate improved sphincter preservation and to increase survival using adjuvant medical treatments.

Neoadjuvant capecitabine and oxaliplatin followed by synchronous chemoradiation and total mesorectal excision in magnetic resonance imaging-defined poor-risk rectal cancer

PURPOSE

To evaluate neoadjuvant capecitabine/oxaliplatin before chemoradiotherapy (CRT) and total mesorectal excision (TME) in newly diagnosed patients with magnetic resonance imaging (MRI) -defined poor-risk rectal cancer.

PATIENTS AND METHODS

MRI criteria for poor-risk rectal cancer were tumors within 1 mm of mesorectal fascia (ie, circumferential resection margin threatened), T3 tumors at or below levators, tumors extending > or = 5 mm into perirectal fat, T4 tumors, and T1-4N2 tumors. Patients received 12 weeks of neoadjuvant capecitabine/oxaliplatin followed by concomitant capecitabine and radiotherapy. TME was planned 6 weeks after CRT. Postoperatively, patients received another 12 weeks of capecitabine.

RESULTS

Between November 2001 and August 2004, 77 eligible patients were recruited. After neoadjuvant capecitabine/oxaliplatin, the radiologic response rate was 88%. In addition, 86% of patients had symptomatic responses in a median of 32 days (ie, just over one cycle of capecitabine/oxaliplatin). After CRT, the tumor response rate was increased to 97%. Three patients remained inoperable. Sixty-seven patients proceeded to TME, and all but one patient had R0 resection. Pathologic complete response was observed in 16 patients (24%; 95% CI, 14% to 36%), and in an additional 32 patients (48%), only microscopic tumor foci were found on surgical specimens. Four deaths occurred during neoadjuvant capecitabine/oxaliplatin therapy as a result of pulmonary embolism, ischemic heart disease, sudden death with history of chest pain, and neutropenic colitis.

CONCLUSION

Capecitabine/oxaliplatin before synchronous CRT and TME results in substantial tumor regression, rapid symptomatic response, and achievement of R0 resection.

Randomized phase II study of neoadjuvant combined-modality chemoradiation for distal rectal cancer: Radiation Therapy Oncology Group Trial 0012

PURPOSE

To evaluate the rate of pathologic complete response and toxicity of neoadjuvant chemoradiation for advanced T3/T4 distal rectal cancers in a randomized phase II study

PATIENTS AND METHODS

Patients with clinical T3/T4 distal rectal cancers were randomly assigned in a phase II study to receive combined neoadjuvant chemoradiotherapy followed by surgical resection. Patients were randomly assigned to receive continuous venous infusion (CVI) fluorouracil (FU) 225 mg/m2 per day, 7 days per week, plus pelvic hyperfractionated radiation 55.2 to 60 Gy at 1.2 Gy bid (arm 1) or CVI FU 225 mg/m2 per day Monday to Friday, 120 hours per week plus irinotecan 50 mg/m2 once weekly for 4 weeks plus pelvic radiation therapy 50.4 to 54 Gy at 1.8 Gy per day (arm 2). Surgery was performed 4 to 10 weeks after completion of neoadjuvant therapy. The primary end point of this study was pathologic complete response (pCR). Secondary end points included acute and late normal tissue morbidity.

RESULTS

A total of 106 patients were entered onto the study, with 103 assessable for response. The overall resectability rate was 93%. The median time to surgery was 7 weeks. Tumor downstaging was observed in 78% of patients in both arms. The pCR rate for all assessable patients was 26% in each arm. For patients who had surgery, the pCR rate was also the same (28%) in both arms. Acute and late toxicity was also similar. Grade 3 and 4 acute hematologic and nonhematologic toxicity occurred in 13% and 38% in arm 1 and 12% and 45% in arm 2, respectively.

CONCLUSION

Although the overall complete response rate and toxicity seems similar in both arms, this is the first multi-institutional study to establish a relatively high (28%) pCR rate after neoadjuvant therapy.

Radiation Modifiers: Treatment Overview and Future Investigations

Many radiosensitizers are in current clinical use. In addition, a myriad of potential new targeted therapies, which may also interact with radiation, are in clinical development. The clinical utility of new targeted therapies, in combination with existing radiation sensitizers (chemotherapies) requires further evaluation, as does the understanding of their acute and late radiation effects. Free radical scavengers appear to show promise as radioprotectors, but data for mucoprotection are less convincing.

Pathological complete response following pre-operative chemoradiotherapy in rectal cancer: analysis of phase II/III trials

Pathological complete response (pCR) has been used as a marker for the efficacy of pre-operative chemoradiotherapy (CRT) schedules in rectal cancer. To date there have been no randomized trials comparing CRT regimens in rectal cancer. Prospective phase II and CRT arms of randomized trials reported up to January 2004 were included, providing they defined the following minimum variables: drugs employed during CRT, radiotherapy dose and pCR rate. Multivariate analysis was used to examine the relationship of these variables on the pCR rate. In addition, the use of neoadjuvant chemotherapy, the type of publication (peer reviewed vs meeting abstract) and whether the tumours were stated to be unresectable/clinically fixed or to have threatened circumferential margins were investigated. The method of analysis was weighted linear modelling of the pCR rate which was normalized by the arcsine transformation. Phase II and phase III trials were identified including a total of 3157 patients. On multivariate analysis only the use of continuous infusion 5FU (p = 0.01), the use of a second drug (p = 0.001) and radiation dose (p = 0.02) were associated with higher rates of pCR. The use of a two drug regimen, the mode of delivery of 5FU and the radiation dose appear to be related to the incidence of pCR following CRT for rectal cancer. These results may generate hypotheses for future randomized trials. Important factors not considered in this analysis include the variability in pathological examination and in the time interval between CRT and surgery. In addition, the toxicity of the CRT regimens requires further investigation.

Combined radiotherapy, 5-fluorouracil continuous infusion and weekly oxaliplatin in advanced rectal cancer: A phase I study

The aim of this study was to determine the maximum-tolerated dose (MTD) of weekly oxaliplatin combined with 5-fluorouracil (5FU) continuous infusion administered concomitantly with fractionated radiotherapy in patients presenting advanced rectal cancer. Forty-three patients with rectal cancer (stage T3/T4 (n = 24), metastatic (n = 17) and 2 with local recurrence), were included. The radiotherapy dose delivered was 45 Gy over 5 weeks (1.8 Gy/fraction/day, 5 days per week). The initial weekly oxaliplatin dosage was 30 mg/m2 and the 5FU dosage 150 mg/m2/d. The oxaliplatin and 5FU doses were escalated. Eight dose levels were tested. At dose level 8 (oxaliplatin 80 mg/m2, 5FU 225 mg/m2/d), 2 patients out of 4 presented dose-limiting toxicity (severe diarrhoea with dehydration and fatal shock, rectovesical fistula). At dose level 7, 2 further patients presented with grade 3 diarrhoea. The main toxicity of the combination was diarrhoea. The hematological and neurological toxicities were not severe and were not dose-limiting. Out of the 30 patients undergoing surgery, 4 (13.3%) presented with pathological complete response and 4 (13.3%) only presented with microscopic residual disease. The results from this study enabled determination of the recommended weekly oxaliplatin dose (60 mg/m2) combined with 5FU continuous infusion (225 mg/m2) and fractionated radiotherapy (45 Gy) in the pre-operative treatment of advanced rectal cancer. The good safety profile of the regimen, associated with promising results in terms of histological response, suggest that the regimen could be developed in future phase II/III studies.

A phase I dose escalation study of continuous oral capecitabine in combination with oxaliplatin and pelvic radiation (XELOX-RT) in patients with locally advanced rectal cancer

PURPOSE

To determine the maximum tolerated dose (MTD) of continuous oral capecitabine plus oxaliplatin and pre-operative pelvic radiotherapy (XELOX-RT).

PATIENTS AND METHODS

Patients with clinically unresectable rectal cancer or for whom resection with histologically clear (R0) surgical margins was unlikely received continuous capecitabine (500-825 mg/m2 twice daily, 7 days/week), oxaliplatin 2-h intravenous infusion (130 mg/m2 days 1 and 29) and pelvic radiotherapy (Monday-Friday for 5 weeks, total dose 45 Gy in 25 daily 1.8 Gy fractions). The MTD was the capecitabine dose causing dose-limiting toxicities (DLTs; treatment-related grade 3/4 toxicities) in one-third or more of patients treated per dose level.

RESULTS

Eighteen patients received three dose levels. The MTD was capecitabine 825 mg/m2 twice daily: DLTs occurred in two of six patients (grade 3 diarrhoea, rectal pain with local skin reaction). No DLTs occurred in six patients receiving capecitabine 650 mg/m2 twice daily. Grade 3/4 toxicity was rare, with minimal myelosuppression. Although predominantly a dose-finding study, XELOX-RT showed promising activity. Fourteen patients had histologically confirmed R0 resections and five had a pathological complete response.

CONCLUSIONS

The recommended dose for further study is capecitabine 650 mg/m2 twice daily with oxaliplatin and radiotherapy. XELOX-RT showed promising antitumour activity. Further evaluation is underway.

Capecitabine in combination with preoperative radiation therapy in locally advanced, resectable, rectal cancer: a multicentric phase II study

BACKGROUND

The aim of the study was to evaluate tolerance and efficacy of preoperative treatment with capecitabine in combination with radiation therapy (RT) in patients with locally advanced, resectable, rectal cancer.

PATIENTS AND METHODS

Fifty-three patients with potentially resectable T3, N0-2 (87%) and T4, N0-2 (13%) rectal cancer were treated with capecitabine (825 mg/m2, twice daily for 7 days/week) and concomitant RT (50.4 Gy/28 fractions). Patients underwent surgery after 6-8 weeks followed, upon physician's indications, by 4-months adjuvant capecitabine. The primary end point was to determine the rate of pathologic complete response. Secondary end points were to assess the rate of clinical response and the safety profile.

RESULTS

All patients but two completed the RT programme and 47 (89%) received 81%-100% of the capecitabine dose (100% of dose in 72% patients, 81%-95% in 17% patients and 48%-74% in 11% of patients). No patient had grade 4 toxicity. Grade 3 toxicity occurred in six patients (11%) and consisted mainly of leucopenia (4%) and hand-foot syndrome (4%). Mild or moderate toxicity was common and included leucopenia (72%), diarrhea (40%), proctitis (34%) and skin toxicity (20%). The overall clinical response rate was 58% and the downstaging rate was 57%, with a pathologic complete response rate of 24%. Among 34 patients with low-lying tumors (<or=5 cm from anal verge), 20 (59%) had a sphincter-saving operation.

CONCLUSIONS

Preoperative chemoradiation with capecitabine and RT appeared to be effective in locally advanced resectable, rectal cancer. The favorable safety profile of the combination might warrant the use of capecitabine and RT with other effective new drugs.

A phase I/II study of oxaliplatin when added to 5-fluorouracil and leucovorin and pelvic radiation in locally advanced rectal cancer: a Colorectal Clinical Oncology Group (CCOG) study

The purpose of this study was to evaluate the maximum tolerated dose (MTD) and recommended dose of oxaliplatin given synchronously with 5-fluorouracil (5FU), leucovorin (LV) and preoperative pelvic radiation for primary unresectable, locally advanced, rectal cancer. Preoperative pelvic radiotherapy using a three- or four-field technique and megavoltage photons comprised 45 Gy given in 25 fractions, 1.8 Gy per fraction, and delivered with escalating doses of oxaliplatin in combination with low-dose LV and 5FU. Chemotherapy was given synchronously with radiotherapy in weeks 1 and 5. Escalating doses of oxaliplatin (85, 130 and 150 mg m(-2)) were given on days 2 and 30, followed by low-dose LV (20 mg m(-2)) and 5FU (350 mg m(-2)), both given on days 1-5 and 29-33. Surgery was performed 6-10 weeks later. The MTD was determined as the dose causing more than a third of patients to have a dose-limiting toxicity (DLT). Once the MTD was reached, a further 14 patients were treated at the dose level below the MTD. In all, 32 patients received oxaliplatin at the three dose levels, median age 60 years (range 31-79), 24 males and eight females. The MTD was reached at 150 mg m(-2) when four out of six patients experienced DLT. Dose-limiting grade 3 or 4 diarrhoea was reported in two out of six patients at 85 mg m(-2), 5 out of 20 at 130 mg m(-2) and four out of 6 at 150 mg m(-2). Grade 3 neuropathy was reported at 130 mg m(-2) (1 out of 20) and at 150 mg m(-2) (two out of six), and serious haematological toxicity was minimal; one grade 3 anaemia at 150 mg m(-2). In all, 28 out of 32 patients completed all treatments as planned; three had radiotherapy interrupted and three a chemotherapy dose reduction. Four patients did not proceed to surgery due to the presence of metastatic disease (two), unfitness (one) or patient refusal (one). Also, 28 patients underwent surgical resection. Histopathology demonstrated histopathological complete response (pCR) 2 out of 27 (7%), Tmic 3 out of 27 (11%), pCR+Tmic 5 out of 27 (19%), pT0-2 6 out of 27 (22%) and histologically confirmed clear circumferential resection margins in 22 out of 27 (81%). Dose-limiting toxicity with oxaliplatin is 150 mg m(-2) given days 2 and 30 when added to the described 5FU LV and 45 Gy radiation preoperatively. The acceptable toxicity and compliance at 130 mg m(-2) recommend testing this dose in future phase II studies. The tumour downstaging and complete resection rates are encouragingly high for this very locally advanced group.

Phase II study of preoperative oxaliplatin, capecitabine and external beam radiotherapy in patients with rectal cancer: the RadiOxCape study

BACKGROUND

Preoperative radiotherapy has been shown to decrease the local recurrence rate of patients with locally advanced rectal cancer. Capecitabine and oxaliplatin are both active anticancer agents in the treatment of patients with advanced colorectal cancer and have radiosensitizing properties. Therefore, these drugs would be expected to improve effectiveness of preoperative radiotherapy in terms of local control and prevention of distant metastases.

PATIENTS AND METHODS

Forty patients with rectal cancer (T3-T4 and/or N+) received radiotherapy (1.8 Gy, 5 days a week over 5 weeks, total dose 45 Gy, 3D conformational technique) in combination with intravenous oxaliplatin 50 mg/m2 once weekly for 5 weeks and oral capecitabine 825 mg/m2 twice daily on each day of radiation. Surgery was performed 6-8 weeks after completion of radiotherapy. The main end points were safety and efficacy as assessed by the pathological complete response (pCR).

RESULTS

The most frequent grade 3/4 adverse event was diarrhea, occurring in 30% of patients. pCR was found in five (14%) patients. According to Dworak's classification, good regression was found in six (18%) additional patients.

CONCLUSIONS

Combination of preoperative radiotherapy with capecitabine and oxaliplatin is feasible for downstaging rectal cancer.

The multidisciplinary rectal cancer treatment: Main convergences, controversial aspects and investigational areas which support the need for an European Consensus

BACKGROUND AND PURPOSE

During the past decades staging and treatment of rectal cancer are used different in Europe and in North America. To promote a process to integrate the daily practice with the best evidence of the literature an International Conference was organized in Italy. Agreement between Experts, Centres, and specialists who participated in the Conference are reported.

METHODS

Five aspects were analyzed and a questionnaire was tailored for this purpose. The questionnaire had 159 questions. During the Conference, at the beginning of each Session, the moderators showed the answers from the Experts and the Centres, and, at the end of the session, the audience voted in all controversial issues. Agreements were scored at three levels: minimum, if it was between 51 and 74% of votes for each group; moderate, between 75 and 94%; large, more than 94%.

RESULTS

The main results are: staging: endoanal ultrasound was considered as mandatory in T staging, in the evaluation of sphincter infiltration, and in the restaging of T after chemoradiotherapy (chRT). Magnetic Resonance Imaging is mandatory in the evaluation of mesorectal fascia infiltration. Endoscopy had a moderate agreement for the definition of tumour location, and the barium enema as optional. Digital rectal examination is complementary for staging and PET-CT investigational for T, N and yT staging. Preoperative radiotherapy: for T4 stage chRT was always the preferred treatment, often with moderate agreement, for any tumour location and N status. For T3, chRT received the same agreement except for high location and N0-N1. For T2 stage, N2 and positive nodes outside the mesorectum, chRT received minimum agreement for low and middle tumours; for high tumours only positive nodes outside the mesorectum was agreed upon. Preoperative radiotherapy, negative specimen and sphincter preservation: chRT was agreed by many for all T stages and N presentations of lower third tumours, except for T1-2 N0-N1. Postoperative treatments: the selection for these treatments often received moderate agreement according to the infiltration of surrounding organs, positive nodal status and circumferential radial margins. Therapy of metastatic disease: an agreement was found for FOLFOX as first-line therapy and for FOLFIRI as second-line, although comparative studies show similar activity of FOLFOX and FOLFIRI regimens.

CONCLUSIONS

This process represents an expertise opinion process that may contribute to increased scientific debate and to promote the development of 'guidelines', 'clinical recommendations' and ultimately a Consensus on the evolving approach to rectal cancer treatment.

Etoposide sensitizes CT26 colorectal adenocarcinoma to radiation therapy in BALB/c mice

AIM: To investigate the combined effect of etoposide and radiation on CT26 colorectal adenocarcinoma implanted into BALB/c mice.

METHODS: We evaluated the radiosensitizing effect of etoposide on CT26 colorectal adenocarcinoma in a syngeneic animal model. BALB/c mice were subcutaneously implanted with CT26 cells and divided into four groups: control (intra-peritoneal saline2) group, etoposide (5 mg/kg intra-peritoneally2) group, radiation therapy (RT 5 Gy2 fractions) group, and combination therapy with etoposide (5 mg/kg intra-peritoneally 1 h before radiation) group.

RESULTS: Tumor growth was significantly inhibited by RT and combination therapy. The effect of combination therapy was better than that of RT. No significant changes were noted in body weight, plasma alanine aminotransferase, or creatinine in any group. The leukocyte count significantly but transiently decreased in the RT and combination therapy groups, but not in the etoposide and control groups. There was no skin change or hair loss in the RT and combination therapy groups.

CONCLUSION: Etoposide can sensitize CT26 colorectal adenocarcinoma in BALB/c mice to RT without significant toxicity.

Long-term anorectal dysfunction after postoperative radiotherapy for rectal cancer

PURPOSE

Adjuvant radiotherapy in the treatment of rectal cancer has been shown to increase long-term morbidity causing severe anorectal dysfunction with physiologic changes whose interaction remains poorly understood. This study examines long-term anorectal morbidity from adjuvant postoperative radiotherapy.

METHODS

In a prospective study, patients with Dukes B or C rectal carcinoma were randomized to postoperative radiotherapy or no adjuvant treatment after anterior resection. The long-term effect of radiotherapy on anorectal function in a subset of surviving patients was assessed from a questionnaire on subjective symptoms and from physiology laboratory evaluation and flexible sigmoidoscopy.

RESULTS

Twelve of 15 patients (80 percent) treated with radiotherapy had increased bowel frequency compared with 3 of the 13 patients (23 percent) who did not have radiation therapy (P = 0.003). The former group had loose or liquid stool more often (60 vs. 23 percent, P = 0.05), had fecal incontinence more often (60 vs. 8 percent, P = 0.004), and wore pad more often (47 vs. 0 percent, P = 0.004). They also experienced fecal urgency and were unable to differentiate stool from gas more often. Endoscopy revealed a pale and atrophied mucosa and telangiectasias in the irradiated patients. Anorectal physiology showed a reduced rectal capacity (146 vs. 215 ml, P = 0.03) and maximum squeeze pressure (59 vs. 93 cm H2O, P = 0.003) in the radiotherapy group. Impedance planimetry demonstrated a reduced rectal distensibility in these patients (P < 0.0001).

CONCLUSIONS

Adjuvant postoperative radiotherapy after anterior resection causes severe long-term anorectal dysfunction, which is mainly the result of a weakened, less sensitive anal sphincter and an undistensible rectum with reduced capacity.

Capecitabine Versus Continuous-Infusion 5-Fluorouracil for Colorectal Cancer: A Retrospective Efficacy and Safety Comparison

For more than 40 years, 5-fluorouracil (5-FU) has been considered the most effective systemic agent for managing advanced colorectal cancer. However, continuous-infusion (CI) schedules of 5-FU require central venous access devices, which are associated with catheter complications and are an inconvenience to patients. The novel oral fluoropyrimidine capecitabine appears to offer comparable efficacy while providing a more convenient schedule that is often preferred by patients. Published phase II/III clinical studies of capecitabine-based regimens for colorectal cancer were compared with key studies of CI 5-FU-based regimens to assess safety, efficacy, quality of life, and pharmacoeconomics. Studies were identified via Medline searches and conference abstracts dating back to 1997. Qualitative analyses show that capecitabine as a single agent as well as in combination regimens is an effective first-line treatment for metastatic colorectal cancer, providing a higher response rate compared with standard 5-FU/leucovorin. Costs associated with capecitabine also appear to be lower than those associated with catheter-based therapies. Capecitabine offers physicians a more convenient treatment for advanced colorectal cancer, with manageable toxicity and antitumor activity comparable to that of CI therapies.

Promising results of a cooperative group phase II trial of preoperative chemoradiation for locally advanced rectal cancer (TROG 9801)

PURPOSE

This article reports the overall survival, failure-free survival, local failure, and late radiation toxicity of a phase II trial of preoperative radiotherapy with continuous infusion 5-fluorouracil for rectal cancer after a minimum 3.5 years of follow-up.

METHODS

Eligible patients were those with newly diagnosed localized adenocarcinoma of the rectum, within 12 cm of the anal verge, staged T3-T4 and deemed suitable for curative resection. Radiotherapy (50.4 Gy in 28 fractions in five weeks and three days) was given with continuous infusion 5-fluorouracil throughout the course of radiotherapy.

RESULTS

A total of 82 patients were accrued in 13 months. The median follow-up time was 4.1 (range, 2.3-4.5) years. There were 55 males (67 percent) and the median age was 59 (range, 27-87) years. Patients were staged pretreatment as T3 (89 percent) and resectable T4 (11 percent). Endorectal ultrasound was performed in 70 percent and magnetic resonance imaging in another 5 percent. The four-year overall and failure-free survival rates were 82 percent (95 percent CI: 72-89) and 69 percent (95 percent CI: 58-78), respectively. The cumulative incidence of local failure at four years was 3.9 percent (95 percent CI: 1.3-11). Risk of failures, local and distant, has not reached a plateau phase.

CONCLUSION

This regimen can be delivered safely and without leading to a significant increase in late toxicity. It provides excellent local control and favorable overall survival. There is a need for longer follow-up than has commonly been used for the proper evaluation of failures after an effective regimen of preoperative chemoradiation.

Intensified concurrent chemoradiotherapy with 5-fluorouracil and irinotecan as neoadjuvant treatment in patients with locally advanced rectal cancer

This study aimed to evaluate the feasibility and efficacy of neoadjuvant chemoradiotherapy intensified with irinotecan in patients with locally advanced rectal cancer. Eligible patients had nonmetastatic disease at a locally advanced stage that made R0 resection and sphincter preservation uncertain. They received preoperative radiation over 6 weeks to 45 Gy and boost of 5.4 Gy and concurrent continuous infusion 5-fluorouracil 250 mg m⁻² day⁻¹ and weekly irinotecan 40 mg m⁻². In all, 37 patients entered the study. T stage at baseline as determined by ultrasound was T2/T3/T4 in 2/19/16 patients; 31 patients had lymph node involvement. The predominant toxicity was diarrhoea (grade 3/4 in 10/2 patients). Haematologic toxicity and surgical complications were moderate. Among 36 patients undergoing surgery, 32 (89%) had R0 resection and 23 (64%) sphincter preservation. Pathologic complete response (pCR) was achieved in eight (22%) of 36 patients, and 10 patients (28%) had only microscopic residual disease. At 4 years, overall survival was 66%, disease-free survival 73%, local relapse rate 7%, and distant failure rate 24%. Extent of resection and postoperative nodal status were significant predictors of overall and disease-free survival. Intensified neoadjuvant chemoradiotherapy with irinotecan can be safely administered and results in a high pCR rate.

Radiotherapy and concurrent radiochemotherapy for rectal cancer

Adjuvant radiotherapy with or without chemotherapy has been used widely in an attempt to improve outcome in rectal cancer. For locally advanced disease, postoperative radiochemotherapy significantly improved both local control and overall survival when compared with surgery alone or surgery plus irradiation. This prompted a National Cancer Institute Consensus Conference in the United States in 1990 to recommend postoperative radiochemotherapy for patients with TNM stage II and III rectal cancer as standard treatment. In Europe, several randomized studies tested preoperative radiotherapy in comparison to surgery alone and showed lower local failure rates. A recent meta-analysis concluded that the combination of preoperative radiotherapy and surgery, as compared with surgery alone, significantly improves local control and overall survival. These results are, however, challenged by more recent reports of extraordinarily low local failure rates following improved surgical techniques, including total mesorectal excision. Evidently, the current monolithic approaches to either apply the same schedule of postoperative radiochemotherapy to all patients with stage II/III rectal cancer or to give preoperative intensive short-course radiation according to the Swedish concept for all patients with resectable rectal cancer irrespective of tumor stage and treatment goal (e.g. sphincter preservation), need to be questioned.

A phase I-II study of weekly oxaliplatin, 5-fluorouracil continuous infusion and preoperative radiotherapy in locally advanced rectal cancer

BACKGROUND

Oxaliplatin (OXA) significantly enhanced the antitumour activity of 5-fluorouracil (FUra) in patients with advanced colorectal cancer and displayed radiosensitising properties in preclinical studies. This study was thus performed to test the feasibility, identify the recommended doses (RDs) and explore preliminarily the clinical activity of weekly OXA and infused FUra combined with preoperative pelvic radiotherapy.

PATIENTS AND METHODS

Forty-six patients with recurrent or locally advanced (cT3-4 and/or N+) adenocarcinomas of the mid-low rectum were treated with escalating doses of OXA (25, 35, 45, 60 mg/m2, weekly for 6 weeks) and FUra (200-225 mg/m2/day, 6-week infusion) concurrent to preoperative pelvic radiotherapy (50.4 Gy/28 fractions). The RDs for the phase II part of the study were immediately below the level resulting in dose-limiting toxicities in more than one third of the patients, or corresponded to the last planned dose level.

RESULTS

In the escalation phase, dose-limiting toxicities only occurred in one patient at the fourth level and one of six patients treated at the last planned dose level (grade III diarrhoea). OXA 60 mg/m2 and FUra 225 mg/m2/day are therefore the RDs for the regimen. Among 25 patients globally treated at these doses (phase II part), the incidence of grade III diarrhoea was 16% with no grade IV toxicity. Neurotoxicity did not exceed grade II (12%). All patients completed radiotherapy and were operated on as scheduled. Twenty-one of 25 patients had the tumour down-staged after chemoradiation with seven (28%) pathological complete responses and 12 (48%) residual tumours limited to ypT1-2N0.

CONCLUSIONS

Weekly OXA, at doses potentially active systemically, can be combined with full-dose, infused FUra and radiotherapy. Given the low toxicity and promising activity, this regimen is being compared to standard FUra-based pelvic chemoradiation in a randomised study.

Chemoradiotherapy for gastrointestinal cancers

New combinations of chemotherapy with radiotherapy for gastrointestinal cancers are showing evidence that improved outcomes may result from toxicity profiles associated with "targeted" systemic radiosensitizing agents. These new agents are also clinically attractive owing to such factors as oral bioavailability and patient dosing schedules, making them practical and convenient compared with older intravenous administration requirements. Several new classes of radiosensitizing agents are discussed here and underscore aspects of molecular activation in tumors rather than normal tissues because of differences in pathways of metabolism or based on the process of tumor-associated angiogenesis.

Gastrointestinal cancer: recent developments in medical oncology

BACKGROUND

Progress in the medical oncological treatment of gastrointestinal cancer has resulted from advances in tumour biology as well as randomised clinical trials. This review updates oncologists on developments in perioperative therapy for gastrointestinal tumours, optimal use of chemotherapy for colorectal cancer, and novel targeted monoclonal antibodies (mAbs).

METHODS

The recent literature, including published abstracts, was reviewed with respect to current and developing treatments for gastrointestinal cancers. Emphasis was given to randomised clinical trials published within the last 5 years.

RESULTS

Randomised evidence exists to support the use of pre-operative chemotherapy in patients with resectable oesophageal cancer and pre-operative chemo-radiotherapy for rectal cancer. There is preliminary randomised evidence to support the use of perioperative chemotherapy for gastric cancer. Adjuvant therapy for pancreatic cancer has been shown to improve survival. Improved disease-free survival for colorectal cancer patients treated with either adjuvant capecitabine or oxaliplatin has been demonstrated. MAbs targeting epidermal growth factor receptor and vascular endothelial growth factor have been shown to improve outcomes in patients with advanced colorectal cancer.

CONCLUSIONS

Multidisciplinary strategies for patients with localised gastrointestinal cancers; and improved systemic therapies for patients with advanced disease are leading to superior patient outcomes. Further improvements are required, and targeted agents may contribute to future progress.

Effectiveness of gene expression profiling for response prediction of rectal adenocarcinomas to preoperative chemoradiotherapy

PURPOSE

There is a wide spectrum of tumor responsiveness of rectal adenocarcinomas to preoperative chemoradiotherapy ranging from complete response to complete resistance. This study aimed to investigate whether parallel gene expression profiling of the primary tumor can contribute to stratification of patients into groups of responders or nonresponders.

PATIENTS AND METHODS

Pretherapeutic biopsies from 30 locally advanced rectal carcinomas were analyzed for gene expression signatures using microarrays. All patients were participants of a phase III clinical trial (CAO/ARO/AIO-94, German Rectal Cancer Trial) and were randomized to receive a preoperative combined-modality therapy including fluorouracil and radiation. Class comparison was used to identify a set of genes that were differentially expressed between responders and nonresponders as measured by T level downsizing and histopathologic tumor regression grading.

RESULTS

In an initial set of 23 patients, responders and nonresponders showed significantly different expression levels for 54 genes (P < .001). The ability to predict response to therapy using gene expression profiles was rigorously evaluated using leave-one-out cross-validation. Tumor behavior was correctly predicted in 83% of patients (P = .02). Sensitivity (correct prediction of response) was 78%, and specificity (correct prediction of nonresponse) was 86%, with a positive and negative predictive value of 78% and 86%, respectively.

CONCLUSION

Our results suggest that pretherapeutic gene expression profiling may assist in response prediction of rectal adenocarcinomas to preoperative chemoradiotherapy. The implementation of gene expression profiles for treatment stratification and clinical management of cancer patients requires validation in large, independent studies, which are now warranted.

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.

Preoperative Concomitant Hyperfractionated Radiotherapy and Gemcitabine for Locally Advanced Rectal Cancers

PURPOSE

The purpose of this study was to determine the maximum tolerated dose of gemcitabine when it was administered concomitantly with hyperfractionated radiotherapy before surgery in patients with locally advanced rectal cancers and to investigate the midterm efficacy of such a regimen.

PATIENTS AND METHODS

Thirty-seven patients with stage II-III tumors as assessed by computed tomography/echoendoscopy were enrolled. Radiotherapy consisted of 50 Gy given in two daily fractions of 1.25 Gy over 4 weeks. The starting dose of gemcitabine was 10 mg/m(2)/day (in a 30-minute i.v. perfusion) twice weekly with planned escalation steps of 5 mg/m(2)/day. Surgery was planned at 6 weeks after the end of radiotherapy. Main end-points of the study were complete pathological tumor response, the rate of clear margin resection, and actuarial locoregional control and disease-free survival. The median follow-up for all patients was 32 months (range: 10-51 months).

RESULTS

At the level of 45 mg/m(2), two of four patients presented with dose-limiting rectal toxicities (severe acute proctitis requiring hospitalization in the immediate postradiotherapy period). Thus, the gemcitabine biweekly dose of 40 mg/m(2) was considered to be the maximum tolerated dose. Among the 36 patients who underwent surgery, 17 (47%) had a marked pathological response, including six patients (17%) with a microscopically complete response and 11 (30%) with only microscopically residual carcinoma of less than 1 cm. All of them had clear surgical margins. At 3 years, actuarial overall survival rate was 85%, locoregional control was 94.5%, and disease-free survival was 67%.

DISCUSSION

The present study determined the recommended dose of gemcitabine to be 40 mg/m(2) when administered concurrently twice a week with 50 Gy hyperfractionated radiotherapy for the preoperative treatment of locally advanced rectal cancers. The encouraging pathological response rate and the very low locoregional recurrence rate suggest that this innovative approach merits further investigation.

Effects of Irradiation Combined with Cis-diamminedichloroplatinum (CDDP) Suppository in Rabbit VX2 Rectal Tumors

To decrease local recurrence and increase disease free survival, various preoperative therapies for patients with advanced rectal cancer have been studied. Cis-diamminedichloroplatinum (II) (CDDP) has become one of the most widely used cancer chemotherapeutic drugs. It has also been found to have radiosensitizing properties. In this experimental study, the efficacy of chemoradiotherapy using a novel CDDP suppository, and one with mixed micelles, was examined in a rabbit VX2 rectal tumor model. Rabbits were divided into four groups: control group, irradiation (R) group, CDDP suppository plus irradiation (CR) group, and mixed micelles plus CDDP suppository plus irradiation (CMR) group. Tumor growth ratios were reduced significantly in the CR and CMR groups as compared with the ratio in the control group. Microscopically, response rates of main tumors were 0%, 33.3%, 70.0%, and 91. 7%, respectively. The number of metastatic lymph nodes in the CR and CMR groups decreased significantly compared to the control group and the R group. The microscopic response rates of metastatic lymph nodes were 0%, 11.1%, 40.0%, and 41.7%, respectively. Lung metastases were observed in three rabbits in the R group, and in one rabbit in the CMR group. Tissue platinum concentrations both in tumors and in regional lymph nodes increased significantly when mixed micelles were used. Chemoradiotherapy using the CDDP suppository and mixed micelles was effective for local control in the rabbit VX2 rectal tumor model.

Combined modality treatment for rectal cancer

Significant gains have been achieved in the integration of radiation therapy (RT) and chemotherapy with surgery in the management of patients with localized rectal cancer. Treatment combinations of RT and chemotherapy with surgery have evolved to neoadjuvant approaches of these modalities to enhance sphincter preservation, tumor control, and reduction of acute and late treatment-related morbidity. Although 5-fluorouracil (5-FU)-based chemotherapy in combination with RT remains the standard adjuvant therapy for rectal cancer, the integration of novel chemotherapeutic agents and biologic modulators is being actively investigated.

Developments in treatment of primary irresectable rectal cancer

Abstract The treatment options for primary irresectable rectal cancers are discussed. Assessment of tumour stage is the first step for an appropriate choice of treatment. Following a diagnosis of rectal cancer, a vast array of diagnostic procedures is available to determine its stage, and thereby its best treatment options. From the many (new) diagnostic options the merits and drawbacks are discussed. If a diagnosis of irresectability is made, further treatment options should include radiotherapy in most cases, some aspects of timing and application, i.e. intra-operative treatment are discussed. Chemotherapy options are manifold, the results are discussed and some new options are explored.

Oxaliplatin activity in head and neck cancer cell lines

Oxaliplatin (cis-[(1R,2R)-1,2-cyclohexanediamine-N,N'] [oxalato(2-)-O,O'] platinum; Eloxatin) is a third-generation platinum compound with a 1,2-diaminocyclohexane (DACH) carrier ligand, which has a wide spectrum of anticancer activity in vitro systems and has displayed preclinical and clinical activity in a wide variety of tumors. To investigate its in vitro activity against head and neck cancer, we exposed two head and neck cancer cell lines to the compound, created a variant resistant to cisplatin to study cross-resistance to the compound and analyzed the potential radiosensitizing effect of the drug. We report here that oxaliplatin was cytotoxic at similar doses to cisplatin in these cells. There was no cross-resistance to cisplatin, as demonstrated by different IC50 values in these cell lines and the sensitivity to oxaliplatin of the cisplatin-resistant cell line. There was an effective radiosensitizer effect of the compound in either cell line. Additional in vitro and in vivo experimentation is warranted in order to support the use of oxaliplatin as a radiosensitizer in head and neck cancer patients.

Chemoradiation with raltitrexed and oxaliplatin in preoperative treatment of stage II-III resectable rectal cancer: Phase I and II studies

PURPOSE

Two separate studies were conducted, the first to evaluate the maximal tolerated dose and the second the efficacy of raltitrexed plus oxaliplatin in conjunction with preoperative chemoradiation in patients with resectable T3 rectal carcinoma.

METHODS AND MATERIALS

A total of 48 patients received radiotherapy (50 Gy) administered to the posterior pelvis 5 d/wk for 5 weeks. Combination raltitrexed (3 mg/m(2)) and oxaliplatin (60 to 130 mg/m(2)) was administered on Days 1, 19, and 38.

RESULTS

The recommended dose of oxaliplatin is 130 mg/m(2) (maximal tolerated dose not reached). No patients developed Grade 4 acute toxicity. Grade 3 acute toxicity occurred in 9 patients (18.7%). It was hematologic in 1 patient and GI in 1 patient; 7 patients had an asymptomatic increase of transaminase. Surgery was performed in 47 (98%) of 48 patients. Of the 47 patients, 42 underwent sphincter-saving surgery; in 19, the tumor at diagnosis was located <30 mm from the anorectal ring. Chemoradiation in combination with raltitrexed and oxaliplatin produced high rates of tumor response. The overall tumor downstaging rate was 73% for T and N stages. A complete pathologic tumor response (pT0) or microscopic tumor foci (pTmic) was observed in 28 patients. The tumor regression grade (TRG), using the Mandard scoring system, was TRG1 in 16 patients (43.2%), TRG2 in 12 (32.4%), TRG3 in 12 (32.4%), TRG4 in 6 (16.2%), and TRG5 in 1 patient (2.7%).

CONCLUSION

Raltitrexed plus oxaliplatin combined with pelvic radiotherapy was effective and well tolerated in patients with resectable T3 rectal carcinoma.

Treatment of locally advanced rectal cancer

Historically, locally advanced rectal cancer is known for its dismal prognosis. The treatment of locally advanced rectal cancer is subject to continuous change due to development of new and better diagnostic tools, radiotherapeutic techniques, chemotherapeutic agents and understanding of the subject. It is clear, that a multimodality approach is the only way to achieve satisfactory local recurrence and survival rates in this type of cancer. However, which multimodality strategy is to be used still remains a point of controversy. This review summarises recent developments in imaging, (neo-) adjuvant therapy and surgical techniques in the treatment of primary locally advanced rectal cancer.

Combined-Modality Therapy of Rectal Cancer with Oxaliplatin-Based Regimens

There are 2 conventional treatments for clinically resectable rectal cancer. First is surgery and, if the tumor is stage T3 and/or N1/2, this is followed by postoperative combined modality therapy. The second is preoperative combined modality therapy followed by surgery and postoperative combined modality therapy if the tumor is stage uT3/4 and/or node-positive. There are a number of new chemotherapeutic agents that have been developed for the treatment of patients with colorectal cancer. Phase I/II trials examining the use of these new chemotherapeutic agents in combination with pelvic radiation therapy, most commonly in the preoperative setting are in progress and suggest higher complete response rates. There is considerable interest in integrating oxaliplatin into preoperative combined modality therapy regimens for rectal cancer. Based on results from phase I/II trials, the recommended regimen for patients who receive oxaliplatin-based combined modality therapy is continuous infusion 5-fluorouracil or capecitabine with pelvic radiation.

Phase I study of 5-fluorouracil and leucovorin by continuous infusion chronotherapy and pelvic radiotherapy in patients with locally advanced or recurrent rectal cancer

PURPOSE

To determine the maximal tolerated dose of chronomodulated 5-fluorouracil (5-FU) and leucovorin (LV) given concurrently with radiotherapy in patients with rectal cancer.

METHODS AND MATERIALS

Forty-five patients with T3, T4 or recurrent rectal cancer received concurrent radiotherapy to a minimal dose of 4500 cGy. Chemotherapy was administered by a programmable pump in chronomodulated fashion, with 62.5% of the total dose given within 7 hours around 9:30 pm. The starting doses were LV at 5 mg/m2/d and 5-FU at 150 mg/m2/d. LV was escalated in 5-mg/m2 increments to 20 mg/m2/d; 5-FU was then escalated in 25 mg/m2 increments to the maximal tolerated dose.

RESULTS

Diarrhea and stomatitis were dose limiting, with Grade 3 or worse toxicity occurring in 16% and 5% of patients, respectively. Thirty-seven patients (84%) received their scheduled dose of radiotherapy (range, 4500-6000 cGy). Thirty-two patients had clinical T3 disease; all were treated with definitive surgery; 23 (71%) underwent sphincter-sparing surgery with complete resection in 28 (87%). Ten patients (31%) had no evidence of tumor in the pathologic specimen.

CONCLUSION

Preoperative chemoradiotherapy in rectal cancer using chronomodulated 5-FU and LV is feasible. The recommended Phase II dose is 5-FU 200 mg/m2 and LV 20 mg/m2 daily for 5 weeks.

Chemotherapeutic and biologic agents as radiosensitizers in rectal cancer

Over the past 25 years, important advances have been made in the management of patients with resectable rectal cancer. Clinical studies have shown the efficacy of combined chemoradiation therapy in enhancing resectability and sphincter preservation rates, decreasing local recurrence, and improving survival of patients with rectal cancer. Although 5-fluorouracil (5-FU) remains the standard chemotherapeutic agent used concurrently with radiation therapy, newer chemotherapeutic agents including capecitabine, irinotecan, and oxaliplatin have also been studied as radiosensitizers in this setting. Novel targeted biologic agents including celecoxib and bevacizumab are being explored in combination with standard chemotherapy and radiation therapy. In this review, we will discuss the mechanism of action and the key clinical studies of each agent as a radiosensitizer.

Where next with preoperative radiation therapy for rectal cancer?

PURPOSE

The basic question for radiation oncologists is what we hope to achieve from treatments that are adjuvant to surgery: better local (pelvic) control and, hopefully, because of that, fewer metastases. Chemotherapy could add to the local effect of irradiation and may also decrease distant metastases directly. Selection criteria for individual treatment could enhance the therapeutic index.

LOCAL CONTROL

Total mesorectal excision reduces the incidence of local recurrence, but preoperative (chemo) radiation is still indicated for more advanced tumors (T3-T4) and for lymph node involvement. Pelvic recurrences arise from tumor clonogens residual beyond the surgical margins. Thus, the practice of shrinking fields to boost the dose to the primary tumor makes no sense, except for tumors that invade residual structures, such as the sacrum. Subclinical disease beyond the future surgical margins grows more quickly than the primary tumor, and hence treatment should be as intense as tolerable. A short treatment course (e.g. 5 x 5 Gy) is desirable, but this regimen, which is currently the gold standard, should be compared (as in the recently closed randomized Polish trial) with higher-dose, longer-duration chemoradiotherapy regimens. The recently closed EORTC trial 22921 examines the benefit of pre- and postoperative chemotherapy combined with a long schedule of radiation. Likewise, continuous infusion of a cycle-active agent rather than bolus administration is a logical addition to radiation therapy in the treatment of fast-growing subclinical tumor extensions.

SYSTEMIC DISEASE

The reduction in distant metastasis rates attributable to adjuvant chemotherapy varies greatly among reports. If the reduction is of the order of 10-25%, the efficacy of chemotherapy equates to as little as about 5 to 12.5 Gy and not more than 20 Gy of total body irradiation.

INTERVAL BETWEEN RADIATION THERAPY AND POSTRADIATION SURGERY

Early excision after preoperative irradiation would be desirable if the primary tumor were still disseminating viable metastatic clonogens. Most tumors do not metastasize until they contain enough viable clonogens to render them clinically detectable. A dose of 10 Gy in 2 Gy fractions reduces at least 30-fold the absolute number of viable clonogens in the primary tumor, to levels that do not yield metastases from the untreated tumor. After a dose of 44-50 Gy in 2 Gy fractions, there is little chance that the surviving tumor clonogens could regrow to a metastasis-yielding volume in any reasonable radiation-surgery interval. Thus there is no tumor-related necessity for early postradiation surgery. The importance of the interval between radiation and surgery is currently being addressed in a Swedish randomized trial.

PROGNOSTIC AND PREDICTIVE CHARACTERIZATION

Tumor volume should be included in the staging system. There are many tumor- and host-related characteristics that can be used to fingerprint the tumor to help select appropriate individual treatment.

[Indications for neoadjuvant therapy in rectal carcinoma]

Pre- and postoperative adjuvant treatments for locally advanced, operable (R0 resection) rectum carcinoma have led to improved results. In principle, according to the interdisciplinary consensus of the German Cancer Society, the recommended treatment for rectum carcinoma (T3/4; N0; M0; any T stage; N+; M0) is still postoperative adjuvant radiochemotherapy. In the meantime, however, based on the good results obtained from various clinical trials preoperative adjuvant treatment is favored internationally. Not only does this treatment scheme show a comparably better compliance of the patients but it also seems to be better tolerated. One treatment option for resectable T3 tumors immediately followed by surgery is the sole hypofractionated preoperative 3-4 field external beam radiotherapy. An additional benefit can be expected from protracted preoperative radiochemotherapy (single dose 2 Gy, total dose >40 Gy, chemotherapy based on 5-FU) followed by operation several weeks later. For T4 tumors with expected R1 or R2 resection, preoperative treatment is urgently recommended. A further aim in compliance with the surgical approach (R0 resection!) and multimodal treatment may be for individual cases the preservation of continence.