Primary tumor response to preoperative chemoradiation with or without oxaliplatin in locally advanced rectal cancer: pathologic results of the STAR-01 randomized phase III trial

What is the clinical benefit of preoperative chemoradiotherapy with 5FU/leucovorin for T3-4 rectal cancer in a pooled analysis of EORTC 22921 and FFCD 9203 trials: surrogacy in question?

BACKGROUND

Two phase III trials of neoadjuvant treatment in T3-4 rectal cancer established that adding chemotherapy (CRT) to radiotherapy (RT) improves pathological complete response (pCR) and local control (LC). We combined trials to assess the clinical benefit of CRT on overall (OS) and progression free survival (PFS) and to explore the surrogacy of pCR and LC.

PATIENTS AND METHODS

Individual patient data from European Organisation for Research and Treatment of Cancer (EORTC) 22921 (1011 patients) and FFCD 9203 (756 patients) were pooled. Meta-analysis methodology was used to compare neoadjuvant CRT to RT for OS, PFS LC and distant progression (DP). Weighted linear regression was used to estimate trial-level association (surrogacy R(2)) between treatment effects on candidate surrogate (pCR, LC, DP) and OS.

RESULTS

The median follow-up was 5.6 years. Compared to RT (881 pts), CRT (886 pts) did not prolong OS, DP or PFS. The 5-y OS-rate was 66.3% with CRT versus 65.9% in RT (hazard ratios (HR) = 1.04 {0.88-1.21}). CRT significantly improved LC (HR = 0.54, 95%confidence interval (CI): 0.41-0.72). PFS was validated as surrogate for OS with R(2) = 0.88. Neoadjuvant treatment effects on LC (R(2) = 0.17) or DP (R(2) = 0.31) did not predict effects on OS.

CONCLUSION

Preoperative CRT does not prolong OS or PFS. pCR or LC do not qualify as surrogate for PFS or OS while PFS is surrogate. Phase III trials should use OS or PFS as primary endpoint.

Chemoradiotherapy with capecitabine versus fluorouracil for locally advanced rectal cancer: a randomised, multicentre, non-inferiority, phase 3 trial

BACKGROUND

Fluorouracil-based chemoradiotherapy is regarded as a standard perioperative treatment in locally advanced rectal cancer. We investigated the efficacy and safety of substituting fluorouracil with the oral prodrug capecitabine.

METHODS

This randomised, open-label, multicentre, non-inferiority, phase 3 trial began in March, 2002, as an adjuvant trial comparing capecitabine-based chemoradiotherapy with fluorouracil-based chemoradiotherapy, in patients aged 18 years or older with pathological stage II-III locally advanced rectal cancer from 35 German institutions. Patients in the capecitabine group were scheduled to receive two cycles of capecitabine (2500 mg/m(2) days 1-14, repeated day 22), followed by chemoradiotherapy (50·4 Gy plus capecitabine 1650 mg/m(2) days 1-38), then three cycles of capecitabine. Patients in the fluorouracil group received two cycles of bolus fluorouracil (500 mg/m(2) days 1-5, repeated day 29), followed by chemoradiotherapy (50·4 Gy plus infusional fluorouracil 225 mg/m(2) daily), then two cycles of bolus fluorouracil. The protocol was amended in March, 2005, to allow a neoadjuvant cohort in which patients in the capecitabine group received chemoradiotherapy (50·4 Gy plus capecitabine 1650 mg/m(2) daily) followed by radical surgery and five cycles of capecitabine (2500 mg/m(2) per day for 14 days) and patients in the fluorouracil group received chemoradiotherapy (50·4 Gy plus infusional fluorouracil 1000 mg/m(2) days 1-5 and 29-33) followed by radical surgery and four cycles of bolus fluorouracil (500 mg/m(2) for 5 days). Patients were randomly assigned to treatment group in a 1:1 ratio using permuted blocks, with stratification by centre and tumour stage. The primary endpoint was overall survival; analyses were done based on all patients with post-randomisation data. Non-inferiority of capecitabine in terms of 5-year overall survival was tested with a 12·5% margin. This trial is registered with ClinicalTrials.gov, number NCT01500993.

FINDINGS

Between March, 2002, and December, 2007, 401 patients were randomly allocated; 392 patients were evaluable (197 in the capecitabine group, 195 in the fluorouracil group), with a median follow-up of 52 months (IQR 41-72). 5-year overall survival in the capecitabine group was non-inferior to that in the fluorouracil group (76% [95% CI 67-82] vs 67% [58-74]; p=0·0004; post-hoc test for superiority p=0·05). 3-year disease-free survival was 75% (95% CI 68-81) in the capecitabine group and 67% (59-73) in the fluorouracil group (p=0·07). Similar numbers of patients had local recurrences in each group (12 [6%] in the capecitabine group vs 14 [7%] in the fluorouracil group, p=0·67), but fewer patients developed distant metastases in the capecitabine group (37 [19%] vs 54 [28%]; p=0·04). Diarrhoea was the most common adverse event in both groups (any grade: 104 [53%] patients in the capecitabine group vs 85 [44%] in the fluorouracil group; grade 3-4: 17 [9%] vs four [2%]). Patients in the capecitabine group had more hand-foot skin reactions (62 [31%] any grade, four [2%] grade 3-4 vs three [2%] any grade, no grade 3-4), fatigue (55 [28%] any grade, no grade 3-4 vs 29 [15%], two [1%] grade 3-4), and proctitis (31 [16%] any grade, one [<1%] grade 3-4 vs ten [5%], one [<1%] grade 3-4) than did those in the fluorouracil group, whereas leucopenia was more frequent with fluorouracil than with capecitabine (68 [35%] any grade, 16 [8%] grade 3-4 vs 50 [25%] any grade, three [2%] grade 3-4).

INTERPRETATION

Capecitabine could replace fluorouracil in adjuvant or neoadjuvant chemoradiotherapy regimens for patients with locally advanced rectal cancer.

FUNDING

Roche Pharma AG (Grenzach-Wyhlen, Germany).

Multicenter randomized phase II clinical trial comparing neoadjuvant oxaliplatin, capecitabine, and preoperative radiotherapy with or without cetuximab followed by total mesorectal excision in patients with high-risk rectal cancer (EXPERT-C)

PURPOSE

To evaluate the addition of cetuximab to neoadjuvant chemotherapy before chemoradiotherapy in high-risk rectal cancer.

PATIENTS AND METHODS

Patients with operable magnetic resonance imaging-defined high-risk rectal cancer received four cycles of capecitabine/oxaliplatin (CAPOX) followed by capecitabine chemoradiotherapy, surgery, and adjuvant CAPOX (four cycles) or the same regimen plus weekly cetuximab (CAPOX+C). The primary end point was complete response (CR; pathologic CR or, in patients not undergoing surgery, radiologic CR) in patients with KRAS/BRAF wild-type tumors. Secondary end points were radiologic response (RR), progression-free survival (PFS), overall survival (OS), and safety in the wild-type and overall populations and a molecular biomarker analysis.

RESULTS

One hundred sixty-five eligible patients were randomly assigned. Ninety (60%) of 149 assessable tumors were KRAS or BRAF wild type (CAPOX, n = 44; CAPOX+C, n = 46), and in these patients, the addition of cetuximab did not improve the primary end point of CR (9% v 11%, respectively; P = 1.0; odds ratio, 1.22) or PFS (hazard ratio [HR], 0.65; P = .363). Cetuximab significantly improved RR (CAPOX v CAPOX+C: after chemotherapy, 51% v 71%, respectively; P = .038; after chemoradiation, 75% v 93%, respectively; P = .028) and OS (HR, 0.27; P = .034). Skin toxicity and diarrhea were more frequent in the CAPOX+C arm.

CONCLUSION

Cetuximab led to a significant increase in RR and OS in patients with KRAS/BRAF wild-type rectal cancer, but the primary end point of improved CR was not met.

Management of local rectal cancer: evidence, controversies and future perspectives in radiotherapy

SUMMARY Rectal cancer comprises approximately 25% of all primary colorectal cancers. The optimal diagnostic and treatment approach for this heterogeneous malignancy is still contentious, and improvements in general multidisciplinary management are required. During recent years a number of randomized studies led by European investigators have shown optimization in preoperative staging, improvements in surgical technique and the histopathological assessment of the resected specimen, and the benefit of combined modality treatment. The main recommendations and the trends in research on radiotherapy and integrated treatments will be summarized with an overview on some relevant points about imaging and pathological staging.

Simultaneous neoadjuvant radiochemotherapy with capecitabine and oxaliplatin for locally advanced rectal cancer. Treatment outcome outside clinical trials

BACKGROUND

Phase II trials of neoadjuvant treatment in UICC-TNM stage II and III rectal cancer with capecitabine and oxaliplatin demonstrated favourable rates on tumour regression with acceptable toxicity.

PATIENTS AND METHODS

Retrospective evaluation of 34 patients treated from 2005-2008 outside clinical trials (CTR) with neoadjuvant irradiation (45-50.4 Gy) and simultaneous capecitabine 825 mg/m(2) b.i.d. on days 1-14 and 22-35 and oxaliplatin 50 mg/m(2) on days 1, 8, 22 and 29 (CAPOX). Twenty-six (77%) patients received one or two courses of capecitabine 1,000 mg/m(2) b.i.d. on days 1-14 and oxaliplatin 130 mg/m(2) on day 1 (XELOX) prior to simultaneous chemoradiotherapy.

RESULTS

UICC-TNM stage regression was observed in 60% (n = 20). Dworak's regression grades 3 and 4 were achieved in 18.2% (n = 6) and 15.1% (n = 5) of the patients. Sphincter-preserving surgery was performed in 53% (n = 8) of patients with a tumour of the lower rectum. Within the mean observation of 24 months, none of the patients relapsed locally, 1 patient had progressive disease and 5 patients (15%) relapsed distantly. Toxicity of grade 3 and 4 was mainly diarrhoea 18% (n = 6) and perianal pain 9% (n = 3). Nevertheless, severe cardiac events (n = 2), severe electrolyte disturbances (n = 2), and syncopes (n = 2) were observed as well.

CONCLUSION

Treatment efficacy and common toxicity are similar to the reports of phase I/II trials. However, several severe adverse events were observed in our cohort study. The predisposing factors for these events have yet to be studied and may have implications for the selection of patients outside CTR.

A phase II study of neoadjuvant bevacizumab plus capecitabine and concomitant radiotherapy in patients with locally advanced rectal cancer

PURPOSE

To assess safety and activity of neoadjuvant bevacizumab, capecitabine and standard radiotherapy in locally advanced rectal cancer as well as potential predictive biomarkers.

PATIENTS AND METHODS

The multicentric phase II study enrolled 43 patients who received bevacizumab infusion (5 mg/kg) every 2 weeks for 4 cycles; oral capecitabine at 825 mg/m(2) twice a day for 5.5 weeks with external-beam irradiation (50.4 Gy in 28 fractions over 5.5 weeks). We determined certain biomarkers before and after therapy for correlation with response.

RESULTS

Post-operative histologic examination revealed no residual cancer cells in 6 of the 43 patients (14%; 95% confidence limits 3.60-24.31%). In another 22 patients (51.2%) a varying percentage of cancer cells in residual areas of fibrosis/ necrosis was found, corresponding to Mandard TRG 2 or 3 classification. Tumor resection with negative circumferential margin was achieved in 38/40 (95%) operated patients. Sphincter-sparing surgery was obtained in 31 (72.1%) patients. Primary tumor and lymph nodes downstaging was observed in 15 (34.9%) and 16 (37.2%) cases, respectively. Neoadjuvant therapy was safe and well tolerated. The most frequent side effects were G1-2 diarrhea, proctitis, rectal bleeding and hypertension. No biomarker tested was significantly predictive of both pathological complete response and disease-free survival. Pre-treatment CD-34 vessel density, post-treatment Ki-67 labeling index and VEGFR-2 cancer cells expression significantly correlated with residual tumor area.

CONCLUSIONS

The schedule of neoadjuvant therapy tested was safe and active. Pre-treatment vessel density by the panendothelial marker anti CD-34 antibody, post-treatment Ki-67 labeling index and VEGFR-2 expression were significantly associated to residual tumor area. The biomarkers correlations warrant further evaluation in prospective clinical trials.

High-dose radiotherapy (60 Gy) with oral UFT/folinic acid and escalating doses of oxaliplatin in patients with non-resectable locally advanced rectal cancer (LARC): a phase I trial

BACKGROUND

Consensus is that patients with locally advanced rectal cancer (LARC) should receive long-term chemoradiotherapy (CRT) before surgery. With the intent to offer the patients intensified concomitant chemotherapy (CT) to improve outcome and to assess tolerability and toxicity of oxaliplatin (Ox) a phase I trial of high dose pelvic radiotherapy (RT), fixed dose of oral UFT/l-leucovorin and increasing doses of weekly Ox were performed.

METHODS

Pelvic RT with 48.6 Gy/27 fractions was given to the primary tumour and the regional lymph nodes and a concurrent boost of 5.4 Gy/27 fractions with a final boost of 6 Gy/3 fractions was given to the gross tumour volume (GTV) (60 Gy/30 fractions). Concurrent with RT patients received a daily dose of UFT 300 mg/m(2) plus fixed dose l-leucovorin 22.5 mg 5/7 days and increasing weekly doses of Ox with 10 mg/m(2)/week from a start dose of 30 mg/m(2)/week to a maximum of 60 mg/m(2)/week. In addition, before and after CRT the patients received one course of TEGAFOX (UFT 300 mg/m(2) with l/leucovorin 22.5 mg Days 1-14 and Ox 130 mg/m(2) given on Day 1). Surgery was planned at least six weeks after the completion of the CRT.

RESULTS

From May 2005 to March 2009, 18 patients with LARC (16 primary, two recurrent) were included in this phase I trial. Toxicity was low with only 5-17% grade 3-4 toxicity. Fifteen patients (83%) were operated (14 R0 resection and 1 R1 resection) after completion of CRT. Five (33%) patients had a pathological complete response (ypCR). When ypCR was combined with yp few residual cells, the rate was 60%. Thirteen patients are still alive December 2011.

CONCLUSION

Preoperative high-dose RT and concomitant UFT with increasing doses of Ox up to 60 mg/m(2)/week was feasible with low toxicity, high ypCR rates and promising OS in patients with non-resectable LARC.

Oxaliplatin as a radiosensitiser for upper and lower gastrointestinal tract malignancies: what have we learned from a decade of translational research?

Some of the greatest advances in the treatment of solid malignancies have resulted from the combination of chemotherapy and radiotherapy treatments. This article comprehensively reviews the current clinical evidence for oxaliplatin-based chemo-radiotherapy that may improve local control and survival. In order to understand how clinical studies should be designed, the pre-clinical evidence for the use of oxaliplatin chemotherapy as a radiosensitising agent is appraised. Particular focus is placed on oxaliplatin's biological mechanisms of action, including cell cycle effects, the formation of DNA adducts and interstrand cross-links and the role of DNA repair proteins. At a clinical level, there is currently no evidence to suggest that oxaliplatin provides an additional benefit to concurrent chemo-radiation regimes that utilise fluoropyrimidines; we evaluate the reasons for this observation, the limitations of clinical trial design and the opportunities that currently exist to design clinical trials which are underpinned by an understanding of the basic biology.

Neoadjuvant treatment in rectal cancer: do we always need radiotherapy-or can we risk assess locally advanced rectal cancer better?

There is good quality evidence that preoperative radiotherapy reduces local recurrence but there is little impact on overall survival. This is not completely unexpected as radiotherapy is a localised treatment and local control may not prevent systemic failure. Optimal quality-controlled surgery for patients with operable rectal cancer in the trial setting can be associated with local recurrence rates of less than 10 % whether patients receive radiotherapy or not (Quirke et al. 2009). However, despite the reassuring results of randomised trials, concerns remain that radiotherapy increases surgical morbidity (Horisberger et al. 2008; Stelzmueller et al. 2009; Swellengrebel et al. 2011), which can compromise the delivery of postoperative adjuvant chemotherapy. There are also significant late effects from pelvic radiotherapy (Peeters et al. 2005; Lange et al. 2007) and a risk of second malignancies (Birgisson et al. 2005; van Gijn et al. 2011). If preoperative radiotherapy does not impact on survival, can it be omitted in selected cases? The answer is yes-with the proviso that we are using good quality magnetic resonance imaging and good quality TME surgery within the mesorectal plane and the predicted risk of subsequent metastatic disease justifies its use. In this case, the concept of neoadjuvant chemotherapy (NACT) is a potentially attractive alternative strategy which might have less early and long-term side effects compared to preoperative radiotherapy-particularly where the MRI predicts a high risk of metastatic disease in the context of a modest risk of local recurrence. This chapter discusses a more precise method of risk categorisation for locally advanced rectal cancer, and discusses possible options for neoadjuvant chemotherapy (NACT).

Radiation in rectal cancer: what are the options and if/when can it be avoided?

Treatment of rectal cancer has improved greatly over recent decades. This review looks at the pivotal trials in the development of the current standard of therapy as well as new directions for more individualized therapy for rectal cancer. Rates of local recurrence and overall survival (OS) for surgery alone have improved with the use of (neo)adjuvant 5-fluorouracil (5-FU)-based chemoradiation. New surgical techniques have improved outcomes, but preoperative radiotherapy still confers an additional benefit. Despite benefits in the metastatic setting, the addition of oxaliplatin to 5-FU and radiotherapy has not shown improved outcomes, although it increased toxicity. Preoperative therapy also allows for the identification of predictive and prognostic markers for response to treatment, which has great potential to individualize treatment. Currently, the search for validated biomarkers and the refinement of risk stratification are the focus of ongoing study. Tailored therapy may include modification of the pelvic radiotherapy field, nonoperative therapy, or avoidance of radiotherapy.

Clinically relevant study end points in rectal cancer

In rectal cancer currently there are no clearly validated early end points which can serve as surrogates for long-term clinical outcome such as local control and survival. However, the use of a variety of response rates (i.e. pathological complete response, downsizing the primary tumor, tumor regression grade (TRG), radiological response) as endpoints in early (phase II) clinical trials is common since objective response to therapy is an early indication of activity. Disease-free survival (DFS) has been proposed as the most appropriate end point in adjuvant trials and is one of the most frequently used in newer rectal cancer trials. Due to the devastating nature of local recurrence in locally advanced rectal cancer, local control (which is itself a subset of the overall DFS endpoint) is still considered an important endpoint. Recently, circumferential resection margin (CRM) has been proposed as novel early end point because the CRM status can account for effects on DFS and overall survival after chemoradiation, radiation (RT), or surgery alone. Consensus is needed to define the most appropriate end points in both early and phase III trials in locally advanced cancer.

[Locally advanced rectal cancer management: which role for the pathologist in 2011?]

Locally advanced rectal cancers mainly correspond to lieberkünhien adenocarcinomas and are defined by T3-T4 lesions with or without regional metastatic lymph nodes. Such tumors benefit from neoadjuvant treatment combining chemotherapy and radiotherapy, followed by surgery with total mesorectum excision. Such a strategy can decrease the rate of local relapse and lead to an easier complementary surgery. The pathologist plays an important role in the management of locally advanced rectal cancer. Indeed, he is involved in the gross examination of the mesorectum excision quality and in the exhaustive sampling of the most informative areas. He also has to perform a precise histopathological analysis, including the determination of the circumferential margin or clearance and the evaluation of tumor regression. All these parameters are major prognostic factors which have to be clearly included in the pathology report. Moreover, the next challenge for the pathologist will be to determine and validate new prognostic and predictive markers, notably by using pre-therapeutic biopsies. The goal of this mini-review is to emphasize the pathologist's role in the different steps of the management of locally advanced rectal cancers and to underline its implication in the determination of potential biomarkers of aggressiveness and response.

Methylenetetrahydrofolate reductase genetic polymorphisms and toxicity to 5-FU-based chemoradiation in rectal cancer

BACKGROUND

There is a large degree of variation in tumour response and host toxicities associated with neoadjuvant chemoradiation for rectal cancer patients. We performed a complimentary pharmacogenetic study to investigate germline polymorphisms of genes involved in 5-fluorouracil (5-FU) and irinotecan pathways and their potential association with clinical outcomes and toxicities from neoadjuvant chemoradiation in patients with rectal cancer treated in a prospective genotype-directed study.

METHODS

The germline DNA of 131 patients was genotyped for 10 variants in TYMS, MTHFR, DPYD, UGT1A1, ABCC1 and SLCO1B1 genes. Ninety-six patients were treated with 5-FU/radiotherapy (RT) and 35 received 5-FU/RT/irinotecan. Relationships between genetic variants and adverse events, tumour response, overall and disease-free survivals were assessed.

RESULTS

MTHFR 1298A>C and MTHFR diplotypes (for 677C>T and 1298A>C) were associated with chemoradiation-related toxicity when 5-FU was used alone. MTHFR haplotypes (677C-1298C) and diplotypes (CA-TA and TA-TA) showed, respectively, a protective and a negative effect on the incidence of severe diarrhoea or mucositis. No association was observed between genetic markers and drug response.

CONCLUSION

MTHFR polymorphisms can potentially predict toxicity in patients treated with 5-FU as a single chemotherapeutic drug.

Pathologic complete response to neoadjuvant therapy in patients with pancreatic ductal adenocarcinoma is associated with a better prognosis

In patients with pancreatic ductal adenocarcinoma (PDA) who received neoadjuvant therapy and pancreatectomy, pathologic complete response (pCR) is rarely observed and the prognostic significance of pCR is not clear. In this study, we identified 11 patients with pCR (2.5%) from 442 patients with PDA who received neoadjuvant treatment and pancreatectomy from 1995 to 2010. There were 6 men and 5 women, with a median age of 61 years. Four patients had either synchronous or history of extrapancreatic cancer. Five patients received neoadjuvant chemotherapy followed by chemoradiation, and 6 received chemoradiation alone. Ten patients had pancreaticoduodenectomy, and 1 had distal pancreatectomy. Scar and chronic pancreatitis consistent with therapy effect were present in all cases (100%). Pancreatic intraepithelial neoplasia (PanIN) 3/carcinoma in situ was present in 5 cases, and PanIN1 and PanIN2 in 5 cases. However, no residual invasive carcinoma or lymph node metastasis was identified in all cases. Follow-up information was available in 10 patients. Follow-up time ranges from 6 to 194 months (median, 63 months). During the follow-up, 3 patients died of other causes, and 1 developed a second primary PDA in the tail of the pancreas at 84 months after the initial pancreaticoduodenectomy and died at 105 months after the initial diagnosis of PDA. The other 6 patients were alive with no evidence of disease. Patients with pCR had a better survival than did those who had posttherapy stage I or IIA disease (P < .001). Patients with PDA who received neoadjuvant therapy and had pCR in pancreatectomy are rare but have a better prognosis.

[Chemotherapy and rectal cancer]

Chemotherapy does not increase the survival time of patients treated for rectal cancer. Chemotherapy given concomitantly to radiotherapy and combined before or after radiation significantly reduces the risk of local recurrence. The sterilization of the tumour (complete pathological response) by chemotherapy is a favourable prognostic factor. New trials on optimisation of pathological complete response rates are based on using drugs effective on metastatic colorectal cancer, given prior to chemoradiotherapy and followed by a resection at least 8 weeks after the end of the radiotherapy. The level of evidence for postoperative chemotherapy is low due to lack of specific study. The indication of postoperative chemotherapy depends on the disease extent after preoperative treatment.

Neoadjuvant capecitabine, radiotherapy, and bevacizumab (CRAB) in locally advanced rectal cancer: results of an open-label phase II study

Background

Preoperative capecitabine-based chemoradiation is a standard treatment for locally advanced rectal cancer (LARC). Here, we explored the safety and efficacy of the addition of bevacizumab to capecitabine and concurrent radiotherapy for LARC.

Methods

Patients with MRI-confirmed stage II/III rectal cancer received bevacizumab 5 mg/kg i.v. 2 weeks prior to neoadjuvant chemoradiotherapy followed by bevacizumab 5 mg/kg on Days 1, 15 and 29, capecitabine 825 mg/m² twice daily on Days 1-38, and concurrent radiotherapy 50.4 Gy (1.8 Gy/day, 5 days/week for 5 weeks + three 1.8 Gy/day), starting on Day 1. Total mesorectal excision was scheduled 6-8 weeks after completion of chemoradiotherapy. Tumour regression grades (TRG) were evaluated on surgical specimens according to Dworak. The primary endpoint was pathological complete response (pCR).

Results

61 patients were enrolled (median age 60 years [range 31-80], 64% male). Twelve patients (19.7%) had T3N0 tumours, 1 patient T2N1, 19 patients (31.1%) T3N1, 2 patients (3.3%) T2N2, 22 patients (36.1%) T3N2 and 5 patients (8.2%) T4N2. Median tumour distance from the anal verge was 6 cm (range 0-11). Grade 3 adverse events included dermatitis (n = 6, 9.8%), proteinuria (n = 4, 6.5%) and leucocytopenia (n = 3, 4.9%). Radical resection was achieved in 57 patients (95%), and 42 patients (70%) underwent sphincter-preserving surgery. TRG 4 (pCR) was recorded in 8 patients (13.3%) and TRG 3 in 9 patients (15.0%). T-, N- and overall downstaging rates were 45.2%, 73.8%, and 73.8%, respectively.

Conclusions

This study demonstrates the feasibility of preoperative chemoradiotherapy with bevacizumab and capecitabine. The observed adverse events of neoadjuvant treatment are comparable with those previously reported, but the pCR rate was lower.

The current landscape of locally advanced rectal cancer

Postoperative adjuvant chemoradiotherapy was recommended as the standard treatment for patients with rectal cancer because it reduces local recurrence. This paradigm shifted with the use of neoadjuvant chemoradiotherapy, which not only reduces local recurrence but also improves sphincter preservation and surgical outcomes. However, the treatment of rectal carcinoma remains complicated. The accuracy of tumor staging can be compromised depending on the imaging modality used. The addition of modern chemotherapeutics and biologics to 5-fluorouracil as radiation sensitizers is questionable. Oxaliplatin as a radiation sensitizer has minimal effects on the pathologic complete response, but improves the radiographical response at the expense of an increased risk of toxicities. The role of biologics in addition to radiation therapy continues to be explored. Attention has focused on improving diagnostic imaging, radiation oncology, and surgical techniques, treatment regimens, and on exploring a role of molecular markers for patients with rectal cancers. We review the pivotal trials that have led to the current treatment paradigm for locally advanced rectal cancer and discuss novel methodologies that are being developed for the treatment of this prevalent malignancy.

Thymidylate synthase genotype-directed neoadjuvant chemoradiation for patients with rectal adenocarcinoma

PURPOSE

Downstaging (DS) of rectal cancers is achieved in approximately 45% of patients with neoadjuvant fluorouracil (FU) -based chemoradiotherapy (CRT). Polymorphisms in the thymidylate synthase gene (TYMS) had previously defined two risk groups associated with disparate tumor DS rates (60% v 22%). We conducted a prospective single-institution phase II study using TYMS genotyping to direct neoadjuvant CRT for patients with rectal cancer.

PATIENTS AND METHODS

Patients with T3/T4, N0-2, M0-1 rectal adenocarcinoma were evaluated for germline TYMS genotyping. Patients with TYMS *2/*2, *2/*3, or *2/*4 (good risk) were treated with standard chemoradiotherapy using infusional FU at 225 mg/m²/d. Patients with TYMS *3/*3 or *3/*4 (poor risk) were treated with FU/RT plus weekly intravenous irinotecan at 50 mg/m². The primary end point was pathologic DS. Secondary end points included complete tumor response (ypT0), toxicity, recurrence rates, and overall survival.

RESULTS

Overall, 135 patients were enrolled, of whom 27.4% (37 of 135) were considered poor risk. The prespecified statistical goals were achieved, with DS and ypT0 rates reaching 64.4% and 20% for good-risk and 64.5% and 42% for poor-risk patients, respectively.

CONCLUSION

To our knowledge, this is the first study to prospectively use TYMS genotyping to direct neoadjuvant CRT in patients with rectal cancer. High rates of DS and ypT0 were achieved among both risk groups when personalized treatment was based on TYMS genotype. These results are encouraging, and further evaluation of this genotype-based strategy using a randomized study design for locally advanced rectal cancer is warranted.

Recent advances in gastrointestinal oncology--updates and insights from the 2009 annual meeting of the American society of clinical oncology

We have reviewed the pivotal presentations related to gastrointestinal malignancies from 2009 annual meeting of the American Society of Clinical Oncology with the theme of "personalizing cancer care". We have discussed the scientific findings and the impact on practice guidelines and ongoing clinical trials. Adding trastuzumab to chemotherapy improved the survival of patients with advanced gastric cancer overexpressing human epidermal growth factor receptor 2. Gemcitabine plus cisplatin has become a new standard for first-line treatment of advanced biliary cancer. Octreotide LAR significantly lengthened median time to tumor progression compared with placebo in patients with metastatic neuroendocrine tumors of the midgut. Addition of oxaliplatin to fluoropyrimidines for preoperative chemoradiotherapy in patients with stage II or III rectal cancer did not improve local tumor response but increased toxicities. Bevacizumab did not provide additional benefit to chemotherapy in adjuvant chemotherapy for stage II or III colon cancer. In patients with resected stage II colon cancer, recurrence score estimated by multigene RT-PCR assay has been shown to provide additional risk stratification. In stage IV colorectal cancer, data have supported the routine use of prophylactic skin treatment in patients receiving antibody against epidermal growth factor receptor, and the use of upfront chemotherapy as initial management in patients with synchronous metastasis without obstruction or bleeding from the primary site.

Chemoradiotherapy with 5-fluorouracil/leucovorin, surgery and adjuvant chemotherapy for locally advanced rectal cancer

The aim of this study was to demonstrate a pathologic complete response (pCR) rate of at least 10% with an acceptable toxicity achieved by preoperative chemoradiotherapy with 5-fluorouracil (5-FU)/leucovorin in patients with locally advanced rectal cancer. Patients were treated by radiotherapy targeting 50 Gy and 5-FU/leucovorin intravenously during the 1st, 4th and 7th week after start of radiotherapy followed by surgery and adjuvant chemotherapy. In 71 evaluable patients, the pCR rate was 14.1% (95% CI, 6.0-22.2); the local relapse rate, 6.1%; the 5-year disease-free survival, 54% and the overall 5-year survival, 68%. The most severe adverse events were neutropenia (17%), diarrhoea (17%), infection (8%) and fatal cardiovascular function (1%). This therapy yielded a high rate of pCR, a low rate of local relapse and a long disease-free and overall survival. To increase its feasibility, radiation dose reduction to 45 Gy and administration of only two preoperative cycles of chemotherapy is recommended.