Preoperative short-course radiotherapy in rectal cancer patients: results and prognostic factors

Objective

The purpose of this study was to evaluate the clinical outcome of preoperative short-course radiotherapy for rectal cancer patients.

Methods

The study group comprised 210 patients with pathologically proven resectable rectal cancer. Between 2001 and 2013, they were treated preoperatively with short-course radiotherapy (25 Gy delivered in five fractions), followed by total mesorectal excision. Adjuvant 5-fluorouracil-based chemotherapy was administered at the discretion of the treating physician, depending on the pathological stage.

Results

After a median follow-up of 57 months, the following 5-year survival rates were observed: overall survival-66.4%, disease-free survival-67.2%, locoregional relapse-free survival-91.7%, and distant metastases-free survival-71.5%. The local failure was observed in 15 patients. Ten patients (4.8%) achieved pathologic complete response. The multivariate analysis demonstrated the regional lymph node involvement to be statistically significant for unfavorable outcomes in terms of all estimated survival rates. Lymphovascular invasion was found to be a strong predictor of survival (HR = 1.68; 95% CI 1.29-3.55) and treatment failure (HR = 1.54; 95% CI 1.08-3.34). The presence of positive surgical circumferential margin was related to six times higher risk of locoregional recurrence. Early and late severe treatment-induced toxicity was reported in 1 and 7.6% patients, respectively.

Conclusions

Preoperative short-course radiotherapy followed by total mesorectal excision and adjuvant chemotherapy allows to achieve excellent local control and favorable survival rates. The treatment-induced toxicity is acceptable.

Do t3 rectal cancers always need radiochemotherapy?

The limitation of the traditional method of stratifying patients with rectal cancer for prognosis using magnetic resonance imaging (MRI) and computerised tomography (CT)-TNM staging-is that cT3 tumors comprise the vast majority of rectal cancers. There is a wide variability in outcomes for cT3. Despite this observation, many still advocate routine short course preoperative radiotherapy (SCPRT) or chemoradiation (CRT) for all patients staged as cT3N0 regardless of tumour location, proximity to other structures or extent, despite the fact that advances in imaging with MRI now offer the ability to predict potential outcomes in terms of the risk of local and metastatic recurrence for the individual. Preoperative CRT is designed to reduce local recurrence. The majority of local recurrences historically reflected inadequate quality of the mesorectal resection. Currently, optimal quality-controlled surgery in terms of total mesorectal excision (TME) in the trial setting can be associated with much lower local recurrence rates of less than 10 % whether patients receive radiotherapy or not. Because of the high risk of metastatic disease in selected patients, integrating more active chemotherapy is now attractive. Chemoradiotherapy (CRT) achieves shrinkage and sometimes eradication of tumour-i.e. a pathological complete response (pCR), and reduces local recurrence, but has no impact on overall survival. CRT also increases surgical morbidity and impacts on anorectal, urinary and sexual function with an increased risk of second malignancies. Hence, the predominant aims of CRT have been to shrink/downstage a tumour to allow an R0 resection to be performed, or to increase the chances of performing sphincter-sparing surgery. However, it remains unclear why shrinkage/downstaging is meaningful to a patient unless the tumour is initially borderline resectable or unresectable (i.e. the CRM is threatened) or the aim is to perform a lesser operation (i.e. sphincter-sparing or local excision) or for organ-sparing, i.e. to avoid surgery altogether. If it is important to shrink the cancer-ie there is a predicted threat to the CRM, then CRT is currently the treatment of choice. If the cancer is resectable and the aim is simply to lower the risk of local recurrence and preoperative CRT does not impact on survival, can CRT be omitted in selected cases? The answer is yes-with the proviso that we are using good quality MRI and the surgeon is performing good quality TME surgery within the mesorectal plane.

Pre-operative chemoradiation for non-metastatic locally advanced rectal cancer

BACKGROUND

This review sets out to assess the efficacy of pre-operative chemoradiation when compared to radiotherapy alone before surgery in the treatment of advanced non metastatic rectal surgery.

OBJECTIVES

To determine the efficacy of pre-operative chemoradiation (CRT) compared with radiation (RT) alone, in locally advanced rectal cancer with respect to overall survival, local recurrence and 30 day mortality, sphincter preservation and toxicity of treatment (both acute and late).

SEARCH METHODS

In September 2011, we searched clinical trial registers, the Cochrane Central Register of Controlled Trials, Web of Science, EMBASE and MEDLINE and reviewed reference lists. Further hand searches were conducted of relevant journal proceedings. No language constraints were applied.The following search terms were used: colorectal, rectal, rectum, cancer, carcinoma, tumour, radiotherapy, chemotherapy, chemoradiotherapy, chemoradiation, 5-Fluorouracil, 5-FU, neo-adjuvant, preoperative, surgery, anterior resection, abdominoperineal resection, total mesorectal excision.

SELECTION CRITERIA

Male and female patients aged over 18 years undergoing preoperative chemoradiation or radiotherapy followed by surgery for locally advanced non-metastatic rectal cancer. There was no upper age limit for participants. Locally advanced non-metastatic cancer was defined as stage 3 rectal tumours. These are tumours of any T stage with nodal involvement, without evidence of distant metastases.

DATA COLLECTION AND ANALYSIS

Primary outcome parameters included overall survival and local recurrence rate. Secondary outcome parameters included 30 day mortality, sphincter preservation, pathological response of tumour, acute and late toxicity of treatment. The outcome parameters were summarized using the odds ratio and 95% confidence intervals (CI).

MAIN RESULTS

There were 6 randomised controlled trials eligible for inclusion. A reduction in local recurrence was seen in the CRT group in comparison to the RT group (OR 0.56, 95% CI 0.42-0.75, P<0.0001). The results for overall survival were (OR=1.01 95%CI 0.85-1.20, P=0.88).The 30 day mortality was the same for both groups, CRT vs RT (OR 1.73, 95% CI 0.88-3.38). Sphincter preservation (stoma rate) was also similar for the two interventions (OR 1.02, 95% CI 0.85-1.21, P=0.64). An increase in acute grade 3/4 treatment related toxicity was seen in the CRT group versus the RT group (OR 3.96, 95% CI 3.03, 5.17, P<0.00001), although this result did display heterogeneity P=0.0005. Late toxicity events were similar between the two groups (OR 0.88, 95% CI 0.50, 1.54, P=0.65).

AUTHORS' CONCLUSIONS

RT was compared to the more intensive CRT in the treatment of T3-4, node positive (locally advanced) rectal cancer. While there was no difference in overall survival between RT and CRT, CRT was associated with less local recurrence.

Role of radiotherapy for resectable rectal cancer

SUMMARY The role of radiation therapy in the treatment of resectable rectal cancer is better defined than at any point in history; however, as technology improves, increasing treatment options can lead to better patient care when used appropriately with adequate training. Understanding the risk factors for local recurrence can assist in delivering individualized treatment options. Technological improvements such as intensity-modulated radiation therapy have the potential to decrease toxicity, but without adequate training, highly conformal treatment can result in undertreating or missing critical areas. This review will provide an overview of treatment and standard treatment options for resectable rectal cancer, as well as an update on the state of radiation therapy as it relates to rectal cancer and the use of intensity-modulated radiation therapy.

Current practice in preoperative therapy and surgical management of locally advanced rectal cancer: a bi-national survey

AIM

The Australasian colorectal surgeon's current approach to preoperative rectal cancer management was compared with international guidelines.

METHOD

Members of the Colorectal Surgical Society of Australia and New Zealand were surveyed in 2010, on the use of MRI and the management of locally advanced rectal cancer. Surgeons had to decide the appropriate management in five scenarios that were developed from national guidelines.

RESULTS

Of 174 invitations sent, 108 (62.1%) replies were received. Most surgeons (98.1%) had access to MRI. Ninety-three (86.1%) would use MRI routinely for staging. The majority selected a tumour-specific mesorectal resection for upper rectal cancer (58.2%) and a total mesorectal excision for distal cancer (100%). Almost all restorative operations included a covering ileostomy. One third of surgeons recommended that patients with a favourable cT3 mid-rectal tumour (N0, clear circumferential resection margins) should not have preoperative therapy and should proceed directly to surgery. When high-risk features, such as threatened resection margins or cN1 stage, were present, 5% and 15% of surgeons, respectively, would continue to treat by standard resection without preoperative therapy.

CONCLUSION

Evidence-based international guidelines for the management of rectal cancer have changed little in the last 10 years. Despite this, there is a clear gap between these and clinical practice. The main variance relates to the role of radiotherapy in locally advanced rectal cancer. Despite considerable evidence that radiotherapy reduces local recurrence for all stages of rectal cancer, current practice in Australasia is for its selective use.

Prediction in rectal cancer

The treatment of rectal cancer largely depends on disease stage at diagnosis, based on which patients can be classified as low, intermediate, or high risk. Prognostic and predictive markers, specific to each risk category, can be applied for optimal risk classification and subsequent treatment allocation. These markers are either histopathological, determined with imaging, or have a biomolecular background. This review provides an overview of the current status of treatment options and the use of prognostic and predictive markers in each risk category. An effort was made to identify those markers that are currently lacking in, but have the potential to improve, the clinical decision process by discussing the data from recent studies aimed at the development of new prognostic and predictive markers. At this moment, none of the markers studied has been proven to be of significant, independent value, justifying implementation in daily clinical practice. However, recent developments in imaging techniques and biomolecular research do show great potential.

Comparison of preoperative short-course radiotherapy and long-course radiochemotherapy for locally advanced rectal cancer

BACKGROUND

The purpose of this work was to perform a single institution comparison between preoperative short-course radiotherapy (SC-RT) and long-course radiochemotherapy (LC-RCHT) for locally advanced rectal cancer.

METHODS

A total of 225 patients with clinical stage UICC II-III rectal cancer were treated with SC-RT (29 Gy in 10 twice daily fractions followed by immediate surgery; n = 108) or LC-RCHT (54 Gy in 28 fractions with simultaneous 5-fluorouracil (5-FU) ± oxaliplatin chemotherapy followed by delayed surgery; n = 117). All patients in the LC-RCHT cohort and patients in the SC-RT with pathological UICC stage ≥ II received adjuvant chemotherapy. Before 2004, the standard of care was SC-RT with LC-RCHT reserved for patients where downstaging was considered as required for sphincter preservation or curative resection. In the later period, SC-RT was practiced only for patients unfit for radiochemotherapy.

RESULTS

Patients in the LC-RCHT cohort had a significantly higher proportion of cT4 tumors, clinical node positivity, and lower tumor location. The 5-year local control (LC) and overall survival (OS) were 91% and 66% without differences between the SC-RT and LC-RCHT groups. Acute toxicity was increased during LC-RCHT (grade ≥ II 1% vs. 33%) and there were no differences in postoperative complications. Severe late toxicity grade ≥ III was increased after SC-RT (12% vs. 3%). Of patients aged >  80 years, 7 of 7 patients and 4 of 9 patients received curative surgery after SC-RT and LC-RCHT, respectively.

CONCLUSION

Despite the fact that patients with worse prognostic factors were treated with LC-RCHT, there were no significant differences in LC and OS between the SC-RT and LC-RCHT group. Age > 80 years was identified as a significant risk factor for LC-RCHT and these patients could be treated preferably with SC-RT.

Surgical oncology issues in locally advanced rectal cancer

The management of locally advanced (T3/4) rectal cancer is evolving. Randomized trials have shaped the current adjuvant treatment options, but yet there remain many unanswered questions. These include how best to define which patients to treat and choosing between short-course radiotherapy and long-course chemoradiotherapy. With respect to surgery, the optimal timing, the surgical approach in abdominoperineal resections and the role of laparoscopic surgery remain active areas of research. The possibility of avoiding surgery in selected patients is also a topic of great interest. A multidisciplinary team approach in managing rectal cancer patients is popular where possible and recommended in some guidelines.

Multidisciplinary treatment of patients with rectal cancer: Development during the past decades and plans for the future

In rectal cancer treatment, both the local primary and the regional and systemic tumour cell deposits must be taken care of in order to improve survival. The three main treatments, surgery, radiotherapy, and chemotherapy, each with their own advantages and limitations, must then be combined to improve results. Several large randomized trials have shown that combinations of the modalities have markedly reduced the loco-regional recurrences, but have not yet had any major influence on overall survival. The best integration of the weakest modality, to date the drugs (conventional cytotoxics and biologicals), is not known. A new generation of trials exploring the best sequence of treatments is required. Furthermore, treatment of rectal cancer is administered to populations of individuals, based upon clinical factors and imaging, and can presently not be further individualized. There is an urgent need to develop response predictors.

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.

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).

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: a comparison of management strategies

Traditionally, there has been a high local recurrence rate in rectal cancer and 10-40% of patients require a permanent stoma. Both short-course preoperative radiotherapy (SCPRT) and long-course preoperative chemoradiation (CRT) are used to reduce the risk of local recurrence and enable a curative resection. Total mesorectal excision has reduced the rate of local recurrence (even without radiotherapy) to below 10%, but has highlighted a high risk of metastatic disease in 30-40% of patients. Current trials suggest that in resectable cancers, where the preoperative magnetic resonance imaging (MRI) suggests the circumferential resection margin (CRM) is not potentially involved, then SCPRT and CRT are equivalent in terms of outcomes such as local recurrence, disease-free survival (DFS) and overall survival (OS). For patients with more advanced disease, where the CRM is breached or threatened according to the MRI, the integration of more active chemotherapy and biological agents into chemoradiation is an attractive strategy because of the high risk of metastases. However, in none of the trials published in the last decade has chemoradiation impacted on DFS or OS. We examine the strategies of neoadjuvant, concurrent, consolidation (after chemoradiation and before surgery) and postoperative adjuvant chemotherapy with cytotoxic agents, and the integration of biological agents for future potential strategies of treatment. We also compare the trials and compare the different strategies of long-course preoperative radiotherapy and SCPRT; the intensification of preoperative radiation and chemoradiation with dose escalation of external beam radiotherapy, using brachytherapy, intra-operative radiotherapy, hyperfractionation, and various available techniques such as intensity-modulated radiotherapy. We recommend examining dose escalation of radiotherapy to the primary tumour where MRI predicts a threatened CRM. Of the potential treatment strategies involving cytotoxic agents, such as neoadjuvant, concurrent, consolidation and postoperative adjuvant chemotherapy, the most promising would appear to be consolidation chemotherapy following chemoradiation in locally advanced disease, and neoadjuvant chemotherapy in MRI-selected patients who do not require radiation. Improvement in the quality of surgery is also an important future goal.

Neoadjuvant chemotherapy alone for early-stage rectal cancer: an evolving paradigm?

Current management of early-stage rectal cancer comprises combinations of surgery, radiotherapy, and chemotherapy, with the presence or absence of several validated high-risk features determining which treatment modalities will be used and the order of administration. In high-risk individuals, most centers have adopted neoadjuvant combined chemotherapy and radiotherapy followed by surgery as the initial approach. However, long-term toxicity, limited survival gains, and high rates of distant failure have called this approach into question, with early data suggesting that neoadjuvant chemotherapy alone may be feasible in selected patient groups. This review discusses the current data and feasibility of managing early stage rectal cancer with neoadjuvant chemotherapy before surgical resection.

Point: short-course radiation therapy is preferable in the neoadjuvant treatment of rectal cancer

There are 2 types of neoadjuvant radiation regimens accepted as standard for resectable rectal cancer: short-course (5 × 5 Gy) radiation therapy alone with immediate surgery and long-course combined chemoradiation therapy with delayed surgery. A Polish randomized study (n = 312) and an Australian randomized study (n = 326) compared these 2 schedules. Both trials showed a lower rate of early adverse effects using a short-course radiation regimen and no differences in long-term oncologic outcomes and late toxicity rates between groups. The small number of fractions makes short-course radiation less expensive and more convenient than chemoradiation therapy. These facts indicate that short-course radiation is preferable to chemoradiation for resectable cancers. Additionally, short-course preoperative radiation with a long interval to surgery is a valuable option for patients unfit for chemotherapy, with unresectable cancer or with a small tumor that is amenable to local excision. Moreover, short-course radiation enables the intensification of both radiotherapy and chemotherapy in patients with metastatic rectal cancer with potentially resectable synchronous metastatic disease.

T3N0 rectal cancer: radiation for all?

The optimal oncologic management for patients with T3N0 rectal cancer is currently controversial. Patients with pathologic T3N0 disease may have an "intermediate" risk of disease recurrence, suggesting that perhaps trimodality therapy may not be indicated for all patients. Adverse prognostic features, including a greater depth of perirectal fat invasion, poor tumor differentiation, the presence of lymphovascular invasion, abnormally elevated pretreatment carcinoembryonic antigen levels (>5 ng/mL), circumferential margin involvement, and a low-lying position may identify T3N0 patients at high risk for local recurrence who may benefit from the addition of radiation therapy. However, recent randomized data suggest an improvement in local control and disease-free survival with preoperative radiation therapy compared with selective postoperative radiation therapy in all patient subgroups, arguing in favor of routine preoperative therapy. Additionally, rates of clinical understaging may exceed 20%, representing the percentage of patients who would require the delivery of postoperative radiotherapy with its associated sequelae. Future prospective randomized studies of T3N0 patients with upfront stratification by known prognostic factors and studies evaluating the molecular profile of rectal cancers hold the promise of better classifying patients at high risk of local and systemic recurrence, and thus, in need of adjuvant radiation and chemotherapy.

Tolerability of combined modality therapy for rectal cancer in elderly patients aged 75 years and older

PURPOSE

To determine the rate of treatment deviations during combined modality therapy for rectal cancer in elderly patients aged 75 years and older.

METHODS AND MATERIALS

We reviewed the records of consecutively treated patients with rectal cancer aged 75 years and older treated with combined modality therapy at Massachusetts General Hospital and Brigham & Women's Hospital from 2002 to 2007. The primary endpoint was the rate of treatment deviation, defined as a treatment break, dose reduction, early discontinuation of therapy, or hospitalization during combined modality therapy. Patient comorbidity was rated using the validated Adult Comorbidity Evaluation 27 Test (ACE-27) comorbidity index. Fisher's exact test and the Mantel-Haenszel trend test were used to identify predictors of treatment tolerability.

RESULTS

Thirty-six eligible patients had a median age of 79.0 years (range, 75-87 years); 53% (19/36) had no or mild comorbidity and 47% (17/36) had moderate or severe comorbidity. In all, 58% of patients (21/36) were treated with preoperative chemoradiotherapy (CRT) and 33% (12/36) with postoperative CRT. Although 92% patients (33/36) completed the planned radiotherapy (RT) dose, 25% (9/36) required an RT-treatment break, 11% (4/36) were hospitalized, and 33% (12/36) had a dose reduction, break, or discontinuation of concurrent chemotherapy. In all, 39% of patients (14/36) completed≥4 months of adjuvant chemotherapy, and 17% (6/36) completed therapy without a treatment deviation. More patients with no to mild comorbidity completed treatment than did patients with moderate to severe comorbidity (21% vs. 12%, p=0.66). The rate of deviation did not differ between patients who had preoperative or postoperative CRT (19% vs. 17%, p=1.0).

CONCLUSIONS

The majority of elderly patients with rectal cancer in this series required early termination of treatment, treatment interruptions, or dose reductions. These data suggest that further intensification of combined modality therapy for rectal cancer should be performed with caution in elderly patients, who require aggressive supportive care to complete treatment.

American Society of Clinical Oncology 2010 colorectal update

The 2010 American Society of Clinical Oncology (ASCO) Gastrointestinal (Colorectal) Cancer Track included several notable presentations. The addition of cetuximab to FOLFOX in stage III colon cancer did not improve disease-free survival, but increased toxicity. In the metastatic setting, cetuximab demonstrated benefit only in a small subset of patients (KRAS wild-type and limited metastatic disease). Bevacizumab monotherapy may be equivalent to combination chemotherapy in the maintenance phase of treatment in advanced disease, and in another study bevacizumab did not appear to incur excess morbidity in patients with an intact primary tumor. Alternate strategies for the treatment of stage II/III rectal cancer included short-course radiotherapy with adjuvant chemotherapy and neoadjuvant FOLFOX-bevacizumab without radiation, both demonstrating promising results.