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?

[An update on total neoadjuvant treatment of adenocarcinoma of the rectum]

A major advance has been made in the management of rectal cancer, with the emergence in 2021 of total neoadjuvant treatment. The main publications from the RAPIDO and PRODIGE-23 trials reported a significant improvement in progression-free survival and the pathological complete response rate. The aim of this review is to synthesize recent data on neoadjuvant treatment of rectal cancer, to explain the long-term results of the RAPIDO and PRODIGE-23 trials, and to put them into perspective, considering current advances in de-escalation strategies. The update of the 5-year survival data from the RAPIDO trial highlights an increased risk of loco-regional relapse, with 11.7% of relapses in the experimental group and 8.1% in the control group, while the update of the PRODIGE-23 trial confirms the benefits of this treatment regimen, with a significant improvement in overall survival. In addition, the results of the OPRA and PROPSPECT trials confirm the benefit of total neoadjuvant treatment with induction chemotherapy, as well as the possibility of surgical de-escalation in the OPRA trial and radiotherapy in the PROSPECT trial. The challenge for the future is to identify patients who require total neoadjuvant treatment with the aim of curative surgery to obtain a cure without local or distant relapse, and those for whom therapeutic de-escalation can be envisaged.

Capecitabine-Induced Ileitis during Neoadjuvant Pelvic Radio-Chemotherapy for Locally Advanced Rectal Cancer: A Case Report with Literature Review

We report on a clinical case of capecitabine-induced acute ileitis in a patient treated with pre-operative concurrent chemoradiation with capecitabine for locally advanced rectal cancer and provide a comprehensive literature review. This a rare, but life-threatening, clinical situation, that clinicians should be aware of. Severe persistent diarrhea is the most frequent clinical feature and computed tomography is a valid tool for diagnosis. Conservative management includes capecitabine withdrawal, antidiarrheal therapy and endovenous hydration, together with dietary modifications and broad-spectrum antibiotics. Pelvic irradiation represents an adjunctive risk factor, which may increase the likelihood of occurrence of terminal ileitis. Early recognition and prompt intervention are crucial for successful clinical management.

Outcomes and Prognostic Factors for Locally Recurrent Rectal Cancer Treated With Proton Beam Therapy

Purpose

Our objective was to report the outcome and prognostic factors for patients with locally recurrent rectal cancer (LRRC) treated with proton beam therapy (PBT) at our institution.

Methods and Materials

The study included PBT-treated patients with LRRC between December 2008 and December 2019. Treatment response was stratified using an initial imaging test after PBT. Overall survival (OS), progression-free survival (PFS), and local control (LC) were estimated using the Kaplan-Meier method. Each outcome's prognostic factors were verified using the Cox proportional hazards model.

Results

Twenty-three patients were enrolled (median follow-up, 37.4 months). There were 11 patients with complete response (CR) or complete metabolic response (CMR), 8 with partial response or partial metabolic response, 2 with stable disease or stable metabolic response, and 2 with progressive disease or progressive metabolic disease. Three- and 5-year OS, PFS, and LC were 72.1% and 44.6%, 37.9% and 37.9%, and 55.0% and 47.2%, respectively, with 54.4 months' median survival time. The maximum standardized uptake value of fluorine-18-fluorodeoxyglucose-positron emission tomography-computed tomography (¹⁸F-FDG-PET/CT) before PBT (cutoff value, 10) showed significant differences in OS (P = .03), PFS (P = .027), and LC (P = .012). The patients who achieved CR or CMR after PBT had significantly better LC than those with non-CR or non-CMR (hazard ratio, 4.49; 95% confidence interval, 1.14-17.63; P = .021). Older patients (aged ≥65 years) had significantly higher LC and PFS rates. Patients with pain before PBT and larger tumors (≥30 mm) also had significantly lower PFS. Of 23 patients, 12 (52%) experienced further local recurrence after PBT. One patient developed grade 2 acute radiation dermatitis. Regarding late toxicity, grade 4 late gastrointestinal toxic effects were recorded in 3 patients, in 2 of whom reirradiation was associated with further local recurrence after PBT.

Conclusions

The results showed that PBT may have potential to be a good treatment option for LRRC. ¹⁸F-FDG-PET/CT before and after PBT may be useful for assessing tumor response and predicting outcomes.

Total neoadjuvant treatment and organ preservation strategies in the management of localized rectal cancer: a narrative review and evidence-based algorithm

The multimodal approach with total mesorectal excision preceded by neoadjuvant (chemo)radiotherapy represented the mainstay treatment for locally advanced rectal cancer (LARC) for a long time. However, the benefit of adjuvant chemotherapy in terms of distant relapse reduction is limited. Recently, chemotherapy regimens administered before surgery and incorporated with (chemo)radiotherapy in total neoadjuvant treatment protocols have been established as new options in the management of LARC. Meanwhile, patients with clinical complete response to neoadjuvant treatment can benefit from organ preservation strategies, aimed at sparing surgery and long-term post-operative morbidities, while preserving an adequate disease control. However, the introduction of a non-operative management in clinical practice is a matter of debate with some concerns regarding the risk of local recurrence and long-term outcomes. In this review, we discuss how these recent advances are reshaping the multimodal management of localized rectal cancer and propose an algorithm to place them in the clinical practice.

Essential updates 2020/2021: Advancing precision medicine for comprehensive rectal cancer treatment

In the paradigm shift related to rectal cancer treatment, we have to understand a variety of new emerging topics to provide appropriate treatment for individual patients as precision medicine. However, information on surgery, genomic medicine, and pharmacotherapy is highly specialized and subdivided, creating a barrier to achieving thorough knowledge. In this review, we summarize the perspective for rectal cancer treatment and management from the current standard-of-care to the latest findings to help optimize treatment strategy.

An endorectal ultrasound-based radiomics signature for preoperative prediction of lymphovascular invasion of rectal cancer

Objective

To investigate whether radiomics based on ultrasound images can predict lymphovascular invasion (LVI) of rectal cancer (RC) before surgery.

Methods

A total of 203 patients with RC were enrolled retrospectively, and they were divided into a training set (143 patients) and a validation set (60 patients). We extracted the radiomic features from the largest gray ultrasound image of the RC lesion. The intraclass correlation coefficient (ICC) was applied to test the repeatability of the radiomic features. The least absolute shrinkage and selection operator (LASSO) was used to reduce the data dimension and select significant features. Logistic regression (LR) analysis was applied to establish the radiomics model. The receiver operating characteristic (ROC) curve, calibration curve, and decision curve analysis (DCA) were used to evaluate the comprehensive performance of the model.

Results

Among the 203 patients, 33 (16.7%) were LVI positive and 170 (83.7%) were LVI negative. A total of 5350 (90.1%) radiomic features with ICC values of ≥ 0.75 were reported, which were subsequently subjected to hypothesis testing and LASSO regression dimension reduction analysis. Finally, 15 selected features were used to construct the radiomics model. The area under the curve (AUC) of the training set was 0.849, and the AUC of the validation set was 0.781. The calibration curve indicated that the radiomics model had good calibration, and DCA demonstrated that the model had clinical benefits.

Conclusion

The proposed endorectal ultrasound-based radiomics model has the potential to predict LVI preoperatively in RC.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12880-022-00813-6.

Biomarkers in Locally Advanced Rectal Cancer: A Review

Locally advanced rectal cancers (LARC) are the subject of a rapidly evolving treatment paradigm. The critical timepoints where management decisions are required during the care of the LARC patient are: prior to the institution of any treatment, post neoadjuvant therapy and post-surgery. This article reviews the clinical, imaging, blood-based, tissue-based, and molecular biomarkers that can assist clinicians at these timepoints in the patient's management, in prognosticating for their LARC patients or in predicting responses to therapy in the multi-modality neoadjuvant treatment era.

Tumor-Infiltrating Cytotoxic T Cells and Tumor-Associated Macrophages Correlate With the Outcomes of Neoadjuvant Chemoradiotherapy for Locally Advanced Rectal Cancer

BACKGROUND

Tumor-infiltrating immune cells (TIICs) play a key role in immunoregulatory networks and are related to tumor development. Emerging evidence shows that these cells are associated with sensitivity to chemotherapy and radiotherapy. However, the predictive role of TIICs in the outcomes of neoadjuvant chemoradiotherapy (nCRT) for locally advanced rectal cancer (LARC) is unclear.

METHODS

Imaging mass cytometry (IMC) was performed to comprehensively assess the immune status before nCRT in 6 patients with LARC (3 achieved pathological complete response (pCR), 3 did not) with matched clinicopathological parameters. Immunohistochemistry (IHC) for CD8, CD163 and Foxp3 on biopsy samples from 70 patients prior to nCRT and logistic regression analysis were combined to further evaluate its predictive value for treatment responses in an independent validation group.

RESULTS

A trend of increased CD8+ cytotoxic T lymphocytes (CTLs) and decreased CD163+ tumor-associated macrophages (TAMs) and Foxp3+ regulatory T cells (Tregs) in the pCR group was revealed by IMC. In the validation group, CTLs and TAMs were strong predictors of the clinical response to nCRT. High levels of CTLs were positively associated with the pCR ratio (OR=1.042; 95% CI: 1.015~1.070, p=0.002), whereas TAMs were correlated with a poor response (OR=0.969; 95% CI: 0.941~0.998, p=0.036). A high density of TAMs was also associated with an advanced cN stage.

CONCLUSION

CTLs in the tumor microenvironment (TME) may improve the response to nCRT, whereas TAMs have the opposite effect. These results suggest that these cells might be potential markers for the clinical outcomes of nCRT and aid in the clinical decision-making of LARC for improved clinical outcomes.

The Use of Single-Agent Versus Multiple-Agent Concurrent Chemoradiotherapy in the Treatment of Locally Advanced Rectal Cancer

PURPOSE

The use of concurrent chemoradiotherapy is frequently recommended in the treatment of locally advanced rectal cancer; however, the ideal chemotherapy regimen remains unknown, and there is variability in chemotherapy agents used among different institutions. We sought to examine differences in overall survival between patients receiving single versus multiple-agent concurrent chemoradiotherapy.

METHODS

The National Cancer Database was used to identify 31,025 patients with rectal cancer who received concurrent chemoradiotherapy between 01/2006 and 12/2016. We compared patients who received single-agent chemotherapy with those who received multiple-agent concurrent chemoradiotherapy. The primary outcome of interest was overall survival. The groups were compared using univariate analysis and Cox proportional hazard models to adjust for potential confounding factors.

RESULTS

18,544 patients received single-agent and 12,481 patients received multiple-agent chemotherapy. The former were older with more comorbidities as evidenced by their higher Charlson-Deyo Scores. Those receiving multiple-agent chemotherapy were more likely to have clinical stage III disease (52.9% vs 43.3%, p < 0.001) and less likely to have well-differentiated cancer (6.9% vs 7.7%, p < 0.001). The rates of negative resection margin were identical (p = 0.225) between the two groups. On multivariable analysis after adjusting for comorbidities, radiation dose, and resection margins, single-agent chemotherapy was associated with worse overall survival (HR 1.09, 95% CI 1.057-1.124, p < 0.001).

CONCLUSION

Multiple-agent chemoradiotherapy is associated with improved overall survival in locally advanced rectal cancer; however, chemotherapy regimen does not affect resection margins. The modest overall survival benefit with multiple-agent chemotherapy must be balanced with the potential associated toxicity.

[Neoadjuvant treatment for rectal cancer]

The management of patients with locally advanced rectal cancer has improved significantly in the past few years with preoperative radiotherapy (RT) and total mesorectal excision. The rate of local recurrence is now around 5 % while the risk of metastatic recurrence has not been reduced which is about 30 %. The benefit of adjuvant chemotherapy remains questionable apart from patients with ypN+tumor after preoperative chemoradiotherapy (CRT) for whom FOLFOX is an option. In recent years, several therapeutic trials have evaluated the benefit of extending the time between the end of RT and surgery and/or the benefit of neoadjuvant chemotherapy, administered as induction (before RT) or in consolidation (after RT and before surgery). The first results of two positive phase 3 trials, PRODIGE 23 and RAPIDO, have been reported in 2020. The two regimens evaluated in these trials are markedly different but have shown that neoadjuvant chemotherapy significantly reduces the risk of distant metastasis. Current developments largely related to a de-escalation of therapy: organ conservation according to a "Watch and Wait" strategy or local resection of the scar, administration of neoadjuvant chemotherapy without RT. These therapeutic strategies have not yet been validated but should be in the news tomorrow. The purpose of this review is to present recent data reported in patients with locally advanced rectal cancer.

Long-term Outcomes of Lower Rectal Cancer Patients Treated with Total Mesorectal Excision and Lateral Pelvic Lymph Node Dissection after Preoperative Radiotherapy or Chemoradiotherapy

Objectives:

The standard strategy for advanced rectal cancer (RC) is preoperative short-course radiotherapy (SCRT)/chemoradiotherapy (CRT) plus total mesorectal excision (TME) in Western countries; however, the survival benefit of adding chemotherapy to radiotherapy remains unclear. There is accumulating evidence that either SCRT/CRT or lateral pelvic lymph node dissection (LPND) alone may not be sufficient for local control of advanced RC. We herein retrospectively evaluated the clinical outcomes of patients who were treated by SCRT/CRT+TME+LPND, particularly focusing on the prognostic impact of lateral pelvic lymph node metastasis (LPNM).

Methods:

Patients diagnosed as having clinical Stage II and III lower RC who received SCRT/CRT+TME+LPND between 1999 and 2012 at our hospital were enrolled. Adverse events (AEs), surgery-related complications (SRC), and therapeutic effects were retrospectively analyzed.

Results:

Fifty cases (SCRT:25, CRT:25) were analyzed. No significant differences were observed in overall survival (OS), relapse-free survival (RFS), local recurrence (LR), AE, and SRC between the SCRT and CRT groups, although the pathological therapeutic effect was higher in the CRT group. The patients with LPNM showed significantly inferior 5-year OS and 5-year RFS than those without LPNM.

Conclusions:

There were no significant differences in OS, RFS, or LR between SCRT and CRT, although CRT had a significantly greater histological therapeutic effect. The prognosis of the pathological LPNM-positive cases was significantly poorer than that of pathological LPNM-negative cases.

The survival benefit of adjuvant radiotherapy for pathological T4N2M0 colon cancer in the Modern Chemotherapy Era: evidence from the SEER database 2004-2015

Neoadjuvant chemoradiotherapy has been established as the standard treatment for patients with locally advanced rectal cancer. However, the role of radiotherapy (RT) has not been fully confirmed in advanced colon cancer (LACC). We postulated that patients with pathological T4N2 locally advanced colon cancer would benefit more from RT. 6715 pT4N2M0 colon cancer patients were included in the Surveillance, Epidemiology, and End Results (SEER) database. The primary endpoints were 5-year overall survival (OS) and cancer-specific survival (CSS). Propensity score matching (PSM) with Kaplan-Meier and Cox proportional hazards' models was performed to estimate prognosis. Before PSM, patients underwent RT had better OS and CSS as compared to patients did not receive RT (OS: 40.1% vs 27.6%, p < .001; CSS: 49.6% vs 41.1%, p = .002). After PSM, 239 matched pairs were formed for further analysis. RT group also presented significantly improved prognosis (OS: 40.1% vs 25.7%, p = .008; CSS: 49.6% vs 38.2%, p = .042). Multivariable Cox regression analysis showed that RT was a protective factor [OS：Hazard ratio (HR) =0.677, 95% Confidence interval (CI): 0.532-0.862, p = .002; CSS: HR = 0.708, 95% CI: 0.533-0.941, p = .018]. For pT4N2M0 colon cancer patients, the addition of RT seems to confer survival benefit as compared to patients who did not receive RT.

Predictive factors associated with complete pathological response after neoadjuvant treatment for rectal cancer

PURPOSE

A proportion of 10 to 30% of patients treated by chemoradiotherapy followed by total mesorectal excision surgery for a locally advanced rectal cancer can achieve a complete pathological response. We aimed to identify predictive factors associated with complete pathological response or no response and to assess the impact of each response on survival rates.

PATIENTS AND METHODS

Patients treated with long course chemoradiotherapy for locally advanced and/or node positive rectal cancer from 2010 to 2016 were retrospectively reviewed. Statistical analysis was carried out to determine predictors of tumor regression and treatment outcomes.

RESULTS

Records were available on 70 patients. In the univariate analysis, clinical factors associated with complete tumor response were tumor mobility in digital rectal examination (P=0.047), a limited parietal invasion (P=0.001), clinically negative lymph node (P<0.001) and a circumferential extent greater than 50% (P=0.001). On the other hand, a T4 classification and an endoscopic tumor size greater than 6cm were associated with no response to treatment (P=0.049 and P=0.017 respectively). On multivariate analysis, T2 clinical classification and N0 statement before treatment were independent predictive factors of pathologic complete response (P<0.001 and P=0.001) and a delayed surgery after 12 weeks was associated with no response to treatment (P=0.001).

CONCLUSION

The identification of predictive factors of histological response may help clinicians to predict the prognosis and to propose organ preservation for good responders.

Neoadjuvant chemotherapy with or without oxaliplatin after short-course radiotherapy in high-risk rectal cancer: A subgroup analysis from a prospective study

Aim

To evaluate the role of oxaliplatin in neoadjuvant chemotherapy delivered after short-course irradiation.

Background

Using oxaliplatin in the above setting is uncertain.

Patients and methods

A subgroup of 136 patients managed by short-course radiotherapy and 3 cycles of consolidation chemotherapy within the framework of a randomised study was included in this post-hoc analysis. Sixty-seven patients received FOLFOX4 (oxaliplatin group) while oxaliplatin was omitted in the second period of accrual in 69 patients because of protocol amendment (fluorouracil-only group).

Results

Grade 3+ acute toxicity from neoadjuvant treatment was observed in 30% of patients in the oxaliplatin group vs. 16% in the fluorouracil-only group (p = 0.053). The corresponding proportions of patients having radical surgery or achieving complete pathological response were 72% vs. 77% (odds ratio [OR] = 0.88; 95% confidence interval [CI]: 0.39-1.98; p = 0.75) and 15% vs. 7% (OR = 2.25; 95% CI: 0.83-6.94; p = 0.16), respectively. The long-term outcomes were similar in the two groups. Overall and disease-free survival rates at 5 years were 63% vs. 56% (p = 0.78) and 49% vs. 44% (p = 0.59), respectively. The corresponding numbers for cumulative incidence of local failure or distant metastases were 33% vs. 38% (hazard ratio [HR] = 0.89; 95% CI: 0.52-1.52; p = 0.68) and 33% vs. 33% (HR = 0.78; 95% CI: 0.43-1.40; p = 0.41), respectively.

Conclusion

Our findings do not support adding oxaliplatin to three cycles of chemotherapy delivered after short-course irradiation.

Outcome measures in multimodal rectal cancer trials

There is a large variability regarding the definition and choice of primary endpoints in phase 2 and phase 3 multimodal rectal cancer trials, resulting in inconsistency and difficulty of data interpretation. Also, surrogate properties of early and intermediate endpoints have not been systematically assessed. We provide a comprehensive review of clinical and surrogate endpoints used in trials for non-metastatic rectal cancer. The applicability, advantages, and disadvantages of these endpoints are summarised, with recommendations on clinical endpoints for the different phase trials, including limited surgery or non-operative management for organ preservation. We discuss how early and intermediate endpoints, including patient-reported outcomes and involvement of patients in decision making, can be used to guide trial design and facilitate consistency in reporting trial results in rectal cancer.

Prognostic Significance of Neoadjuvant Rectal Score and Indication for Postoperative Adjuvant Therapy in Rectal Cancer Patients After Neoadjuvant Chemoradiotherapy

BACKGROUND/AIM

Neoadjuvant chemoradiotherapy (CRT) is a standard treatment for patients with clinical Stage II/III rectal cancer. However, the benefit of postoperative adjuvant chemotherapy for patients after neoadjuvant CRT is uncertain. Recently, neoadjuvant rectal (NAR) score was suggested as an independent prognostic factor for patients with rectal cancer after neoadjuvant CRT. The aim of this study was to examine the prognostic significance of NAR score in rectal cancer patients who underwent neoadjuvant CRT followed by surgery, and to investigate which patients may benefit from postoperative adjuvant therapy.

PATIENTS AND METHODS

A total of 72 patients who underwent neoadjuvant CRT followed by R0 resection for clinical stage II /III rectal cancer were evaluated. The correlation between NAR score, various clinicopathological factors and disease recurrence were evaluated.

RESULTS

Disease recurrence was significantly more often observed in patients with incomplete neoadjuvant CRT, tumor regression grade (TRG) 3-4, and high NAR score. Multivariate analysis revealed that NAR score was an independent predictor of disease recurrence.

CONCLUSION

NAR score may be one of the predictive markers for disease recurrence in patients who underwent neoadjuvant CRT followed by surgery for rectal cancer. Patients with a low NAR score may benefit form postoperative adjuvant chemotherapy.

Locally advanced rectal cancer: The past, present, and future

From a series of clinical trials in the last several decades, current treatment paradigms for locally advanced rectal cancer include: (1) preoperative long-course radiotherapy (RT) combined with radiosensitizing chemotherapy; (2) preoperative short-course RT alone followed by adjuvant postoperative chemotherapy; and (3) total neoadjuvant therapy with induction chemotherapy followed by chemoradiotherapy. Other strategies under active investigation in both institutional and cooperative trials include neoadjuvant chemotherapy alone without RT in select patients, total neoadjuvant therapy, watchful waiting after a clinical complete response as an alternative to surgical resection, and the use of different chemotherapeutic and targeted agents. The focus of this review is on established and novel therapeutic strategies for locally advanced rectal cancer.

Neoadjuvant chemoradiotherapy might provide survival benefit in patients with stage IIIb/IIIc locally advanced rectal cancer: A retrospective single-institution study with propensity score-matched comparative analysis

BACKGROUND

Neoadjuvant chemoradiotherapy (NACRT) and total mesorectal excision (TME) are standard treatments of stage II/III locally advanced rectal cancer (LARC), currently. Here, we evaluated the oncological outcomes in LARC patients treated with NACRT compared to TME alone, and determined whether tumor regression grade (TRG) and pathologic response after NACRT was related to prognosis.

METHODS

This is a retrospective comparison of 358 LARC patients treated with either TME alone (non-NACRT group, n = 173) or NACRT plus TME (NACRT group, n = 185) during 2003-2013. Perioperative and oncologic outcomes, like overall survival (OS), disease-free survival (DFS) and recurrence were compared using 1:1 propensity score matching analysis.

RESULTS

A total of 133 patients were matched for the analysis. After a median follow-up of 45 months (8-97 months), the 5-year OS (NACRT vs non-NACRT: 75.42% vs 72.76%; P = 0.594) and 5-year DFS (NACRT vs non-NACRT: 74.25% vs 70.13%; P = 0.224) were comparable between NACRT and non-NACRT, whereas the 5-year DFS rate was higher in the NACRT group when only stage IIIb/IIIc patients were considered (NACRT vs. non-NACRT: 74.79% vs. 62.29%; P = 0.056). In the NACRT group of 185 patients, those with pCR/stage I (vs stage II/stage III disease) or TRG3/TRG4 disease (vs TRG0/TRG1/TRG2) had significantly better prognosis.

CONCLUSION

NACRT might provide survival benefit in patients with stage IIIb/IIIc locally advanced rectal cancer.

Neoadjuvant rectal score as individual-level surrogate for disease-free survival in rectal cancer in the CAO/ARO/AIO-04 randomized phase III trial

Background

Surrogate end points in rectal cancer after preoperative chemoradiation are lacking as their statistical validation poses major challenges, including confirmation based on large phase III trials. We examined the prognostic role and individual-level surrogacy of neoadjuvant rectal (NAR) score that incorporates weighted cT, ypT and ypN categories for disease-free survival (DFS) in 1191 patients with rectal carcinoma treated within the CAO/ARO/AIO-04 phase III trial.

Patients and methods

Cox regression models adjusted for treatment arm, resection status, and NAR score were used in multivariable analysis. The four Prentice criteria (PC1-4) were used to assess individual-level surrogacy of NAR for DFS.

Results

After a median follow-up of 50 months, the addition of oxaliplatin to fluorouracil-based chemoradiotherapy (CRT) significantly improved 3-year DFS [75.9% (95% confidence interval [CI] 72.30% to 79.50%) versus 71.3% (95% CI 67.60% to 74.90%); P = 0.034; PC 1) and resulted in a shift toward lower NAR groups (P = 0.034, PC 2) compared with fluorouracil-only CRT. The 3-year DFS was 91.7% (95% CI 88.2% to 95.2%), 81.8% (95% CI 78.4% to 85.1%), and 58.1% (95% CI 52.4% to 63.9%) for low, intermediate, and high NAR score, respectively (P < 0.001; PC 3). NAR score remained an independent prognostic factor for DFS [low versus high NAR: hazard ratio (HR) 4.670; 95% CI 3.106-7.020; P < 0.001; low versus intermediate NAR: HR 1.971; 95% CI 1.303-2.98; P = 0.001] in multivariable analysis. Notwithstanding the inherent methodological difficulty in interpretation of PC 4 to establish surrogacy, the treatment effect on DFS was captured by NAR, supporting satisfaction of individual-level PC 4.

Conclusion

Our study validates the prognostic role and individual-level surrogacy of NAR score for DFS within a large randomized phase III trial. NAR score could help oncologists to speed up response-adapted therapeutic decision, and further large phase III trial data sets should aim to confirm trial-level surrogacy.

The Role of Adjuvant Chemotherapy in ypT0N0 Rectal Adenocarcinoma

BACKGROUND

In patients who develop a complete pathologic response (ypT0N0) following neoadjuvant chemoradiation, the benefits of postoperative chemotherapy remain uncertain. This study aims to determine whether treatment with adjuvant chemotherapy in ypT0N0 patients affects short- and long-term outcomes.

METHODS

From January 2000 to December 2015, 992 patients at our institution underwent surgery for rectal adenocarcinoma following treatment with neoadjuvant chemoradiation. A complete pathologic response was noted in 96 (9.7%) patients. Adjuvant chemotherapy was administered to 60 (62.5%) patients. We reviewed clinical and pathological records and compared outcomes in ypT0N0 patients who received adjuvant chemotherapy to those who did not.

RESULTS

The mean age of patients who received adjuvant chemotherapy was 55.6 ± 11.5 years, compared to 62.1 ± 11.7 years for those who did not (p = 0.008). Among the two groups, mean follow-up time after surgery was 5.3 ± 4.1 years for the adjuvant group and 8.3 ± 5.5 years for the non-adjuvant cohort (p = 0.003). The 1, 3, and 5-year survival rates were 100.0%, 97.7%, and 92.1% for patients who received adjuvant chemotherapy and 97.2%, 94.1%, and 90.7% for those who did not (p = 0.382). In a subanalysis of patients with available follow-up information, we observed 3/53 (5.7%) disease recurrences in patients who received adjuvant chemotherapy, compared to 2/18 (11.1%) in those who were not treated postoperatively (p = 0.456).

CONCLUSION

In patients with ypT0N0 rectal adenocarcinoma, we found equivalent survival and recurrence outcomes. Further study will be necessary to determine the importance of adjuvant chemotherapy following ypT0N0 resection.

The 2017 Assisi Think Tank Meeting on rectal cancer: A positioning paper

BACKGROUND AND PURPOSES

To describe current practice in the management of rectal cancer, to identify uncertainties that usually arise in the multidisciplinary team (MDT)'s discussions ('grey zones') and propose next generation studies which may provide answers to them.

MATERIALS AND METHODS

A questionnaire on the areas of controversy in managing T2, T3 and T4 rectal cancer was drawn up and distributed to the Rectal-Assisi Think Tank Meeting (ATTM) Expert European Board. Less than 70% agreement on a treatment option was indicated as uncertainty and selected as a 'grey zone'. Topics with large disagreement were selected by the task force group for discussion at the Rectal-ATTM.

RESULTS

The controversial clinical issues that had been identified within cT2-cT3-cT4 needed further investigation. The discussions focused on the role of (1) neoadjuvant therapy and organ preservation on cT2-3a low-middle rectal cancer; (2) neoadjuvant therapy in cT3 low rectal cancer without high risk features; (3) total neoadjuvant therapy, radiotherapy boost and the best chemo-radiotherapy schedule in T4 tumors. A description of each area of investigation and trial proposals are reported.

CONCLUSION

The meeting successfully identified 'grey zones' and, in the light of new evidence, proposed clinical trials for treatment of early, intermediate and advanced stage rectal cancer.

mARC preoperative rectal cancer treatments vs. 3D conformal radiotherapy. A dose distribution comparative study

Purpose

mARC (modulated arc) is the arc therapy technique provided by Siemens. The present study analyses the dose distributions and treatment times corresponding to preoperative rectal cancer mARC treatments. The results are compared to those corresponding to 3D-CRT plans.

Methods

The plans of 30 patients, each having one mARC and one 3D-CRT plan, were evaluated. Every plan was calculated on a sequential two-phase treatment scheme with prescription doses of 45 Gy in the initial phase and 5.4 Gy in the boost phase. Dosimetric parameters and mean DVHs corresponding to the PTVs and OARs were assessed for both techniques.

Results

All mARC plans were considered valid for treatment and yielded a highly significant improvement in the CI over 3D-CRT plans (p <0.001). They also showed statistically significant advantage on the parameters D98%, D95% and D2% of the high dose PTV. Regarding the OARs, mARC plans showed reductions in the mean dose of 3.5 Gy in the bladder and greater than 4 Gy in the femoral heads. Considering the small bowel, the mARC plans resulted in a 2.7 Gy mean reduction in the mean dose and lower irradiated volumes over the entire dose range.

Conclusions

Arc therapy plans with the mARC technique for preoperative rectal cancer treatment in a sequential two-phase treatment scheme provide important advantages in the PTVs and OARs. mARC plans show superior protection of the femoral heads, bladder and small bowel, similar to the results found with other more widespread arc therapy techniques.

Evaluating the incidence of pathological complete response in current international rectal cancer practice: the barriers to widespread safe deferral of surgery

INTRODUCTION

The mainstay of management for locally advanced rectal cancer is chemoradiotherapy followed by surgical resection. Following chemoradiotherapy, a complete response may be detected clinically and radiologically (cCR) prior to surgery or pathologically after surgery (pCR). We aim to report the overall complete pathological response (pCR) rate and the reliability of detecting a cCR by conventional pre-operative imaging.

METHODS

A pre-planned analysis of the European Society of Coloproctology (ESCP) 2017 audit was performed. Patients treated by elective rectal resection were included. A pCR was defined as a ypT0 N0 EMVI negative primary tumour; a partial response represented any regression from baseline staging following chemoradiotherapy. The primary endpoint was the pCR rate. The secondary endpoint was agreement between post-treatment MRI restaging (yMRI) and final pathological staging.

RESULTS

Of 2572 patients undergoing rectal cancer surgery in 277 participating centres across 44 countries, 673 (26.2%) underwent chemoradiotherapy and surgery. The pCR rate was 10.3% (67/649), with a partial response in 35.9% (233/649) patients. Comparison of AJCC stage determined by post-treatment yMRI with final pathology showed understaging in 13% (55/429) and overstaging in 34% (148/429). Agreement between yMRI and final pathology for T-stage, N-stage, or AJCC status were each graded as 'fair' only (n = 429, Kappa 0.25, 0.26 and 0.35 respectively).

CONCLUSION

The reported pCR rate of 10% highlights the potential for non-operative management in selected cases. The limited strength of agreement between basic conventional post-chemoradiotherapy imaging assessment techniques and pathology suggest alternative markers of response should be considered, in the context of controlled clinical trials.

Preoperative radiotherapy or chemoradiotherapy in rectal cancer - Is survival improved? An update of the "Nordic" LARC study in non-resectable cancers

The randomized "Nordic" LARC study compared preoperative long-course radiotherapy alone (RT) or with chemotherapy (CRT) in the most locally advanced/ugly rectal cancers. Despite significantly better local control in the CRT group, no overall survival benefit was seen after 10 years follow-up. The relations between local control and survival are discussed.

Preoperative radiotherapy and local excision of rectal cancer: Long-term results of a randomised study

BACKGROUND AND PURPOSE

It is uncertain whether local control is acceptable after preoperative radiotherapy and local excision (LE). An optimal preoperative dose/fractionation schedule has not yet been established.

MATERIAL AND METHODS

In a phase III study, patients with cT1-2N0M0 or borderline cT2/T3N0M0 < 4 cm rectal adenocarcinomas were randomised to receive either 5 × 5 Gy plus 1 × 4 Gy boost or chemoradiation: 50.4 Gy in 28 fractions plus 3 × 1.8 Gy boost and 5-fluorouracil with leucovorin bolus. LE was performed 6-8 weeks later. Patients with ypT0-1R0 disease were observed. Completion total mesorectal excision (CTME) was recommended for poor responders, i.e. ypT1R1/ypT2-3.

RESULTS

Of 61 randomised patients, 10 were excluded leaving 51 for analysis; 29 in the short-course group and 22 in the chemoradiation group. YpT0-1R0 was observed in 66% of patients in the short-course group and in 86% in the chemoradiation group, p = 0.11. CTME was performed only in 46% of patients with ypT1R1/ypT2-3. The median follow-up was 8.7 years. Local recurrence incidences and overall survival at 10 years were respectively for the short-course group vs. the chemoradiation group 35% vs. 5%, p = 0.036 and 47% vs. 86%, p = 0.009. In total, local recurrence at 10 years was 79% for ypT1R1/T2-3 without CTME.

CONCLUSIONS

This trial suggests that in the LE setting, both local recurrence and survival are worse after short-course radiotherapy than after chemoradiation. Because of the risk of bias, a confirmatory study is desirable. Lack of CTME is associated with an unacceptably high local recurrence rate.

A Randomized Phase 2 Trial of Consolidation Chemotherapy After Preoperative Chemoradiation Therapy Versus Chemoradiation Therapy Alone for Locally Advanced Rectal Cancer: KCSG CO 14-03

PURPOSE

Preoperative chemoradiation therapy (CRT) followed by total mesorectal excision (TME) in locally advanced rectal cancer is the standard of care. To date, the role of consolidation chemotherapy after CRT has rarely been addressed through randomized trials. This study aimed to evaluate the efficacy of CRT followed by consolidation chemotherapy compared with CRT alone.

METHODS AND MATERIALS

This study enrolled patients with adenocarcinoma of the rectum and cT3 or cT4 disease with any N category and no metastasis. In arm A (control arm), we planned CRT (50.4 Gy in 28 fractions) with capecitabine followed by TME. In arm B, 2 cycles of capecitabine and oxaliplatin were administered 1 week after the completion of CRT before TME (capecitabine, 1700 mg/m² per day from day 1 to 14, and oxaliplatin, 100 mg/m² on day 1, every 3 weeks). The downstaging rate (the proportion of ypT0 to ypT2 and ypN0M0) was the primary endpoint, which was to be tested with a 1-sided type I error of 15% and with 85% power.

RESULTS

From September 2014 to February 2016, 110 patients (56 in arm A and 54 in arm B) were randomized and 108 (55 in arm A and 53 in arm B) started CRT. TME was conducted per protocol in 96 patients (52 in arm A and 44 in arm B). In arms A and B, downstaging was achieved in 21.2% and 36.4% (P = .077), respectively, and the pathologic complete response rate was 5.8% and 13.6% (P = .167), respectively. Grade ≥3 adverse events occurred in 3.6% of patients in arm A and 9.4% of patients in arm B during the preoperative treatment phase and in 1.9% and 9.0%, respectively, during the postoperative recovery phase.

CONCLUSIONS

Consolidation chemotherapy with 2 cycles of capecitabine and oxaliplatin demonstrated a marginal improvement in the downstaging rate. However, a phase 3 trial of this strategy is discouraged because of the high dropout rate and safety issues.

Current issues of preoperative radio(chemo)therapy and its future evolution in locally advanced rectal cancer

Neoadjuvant therapies are effective for local control and tumor downstaging. Up to date, preoperative long-course chemoradiotherapy and short-course radiotherapy are the two primary guideline-recommended neoadjuvant therapies for locally advanced rectal cancer patients. However, clinicians throughout the world are trying their best to further optimize the regimens and concepts of neoadjuvants. Hence, there is an urgent need to summarize evidence regarding indications of neaoadjuvant therapies and relative merits of current standard regimens. In addition, we also reviewed the optimized regimens mainly based on short-course radiotherapy with delayed surgery, consolidation chemotherapy, induction chemotherapy, chemotherapy alone without radiation and concepts in terms of organ preservation and personalized treatments to further explore the future evolution of neoadjuvant therapies in rectal cancer.

Addition of oxaliplatin to capecitabine-based preoperative chemoradiotherapy for locally advanced rectal cancer: Long-term outcome of a phase II study

Our previous study reported the favorable short-term outcome and good tolerance of integrating oxaliplatin into capecitabine-based (XELOX regimen) preoperative chemoradiotherapy (CRT) for locally advanced rectal cancer (LARC). The present study reported the long-term oncological outcome of this phase II study. A total of 47 patients with rectal adenocarcinoma (stage II or III) were enrolled and received radiotherapy (46 Gy in 23 fractions) in combination with capecitabine (1,000 mg/m², twice daily, on days 1–14 and 22–35) and oxaliplatin (130 mg/m² on days 1 and 22). Overall survival (OS) rate, disease-free survival (DFS) rate and cumulative incidence of recurrences and long-term complications were calculated or observed. As a result, 41 patients underwent surgery after preoperative CRT, and the cumulative OS rates at 1, 3 and 5 years for these patients were 100.0, 84.5 and 81.8%, respectively. For the 38 patients who received R0 resection, the cumulative OS rates at 1, 3 and 5 years were 100.0, 89.0 and 86.2%, respectively, while the cumulative DFS rates at 1, 3 and 5 years were 94.6, 75.3 and 69.7%, respectively. After follow-up at 84 months, the cumulative incidence rates of local and distant recurrences at 5 years were 6.6 and 28.2%, respectively. Oxaliplatin-associated long-term complications were seldom observed. Overall, the addition of oxaliplatin to capecitabine-based preoperative radiotherapy achieved favorable OS and DFS without increased long-term complications in patients with LARC. Therefore, this preoperative CRT strategy is a feasible option for such patients.

Pre-treatment carcinoembryonic antigen and outcome of patients with rectal cancer receiving neo-adjuvant chemo-radiation and surgical resection: a systematic review and meta-analysis

Neo-adjuvant chemo-radiation is the standard of care for patients with locally advanced rectal carcinoma. The aim of the present paper is to evaluate the relationship of the baseline serologic concentration of the carcinoembryonic antigen with the outcome. Data sources included MEDLINE and Web of Science databases. A systematic search of the databases by a predefined criterion has been conducted. Chemo-radiation followed by surgical resection of rectal tumors was the intervention of interest. From selected studies, the relationships between carcinoembryonic antigen and pathologic complete response, disease-free survival and overall survival were assessed. Carcinoembryonic antigen correlated significantly and inversely with the rate of pathologic complete responses (OR 2.00). Similar to this relationship, a low baseline carcinoembryonic antigen concentration was associated with a better disease-free survival (OR 1.88) and a better overall survival (OR 1.85). Heterogeneity of studies and publication bias were considerable in evaluating the relationship of baseline carcinoembryonic antigen and pathologic complete response. Baseline carcinoembryonic antigen should be regarded as a predictor of outcome of patients undergoing neo-adjuvant chemo-radiation. A calibration of the cutoff value from 5 to 3 ng/ml appears more appropriate to this patient population and should be evaluated in prospective trials.

Panitumumab in Combination With Preoperative Radiation Therapy in Patients With Locally Advanced RAS Wild-type Rectal Cancer: Results of the Multicenter Explorative Single-Arm Phase 2 Study NEORIT

PURPOSE

Studies investigating combinations of anti-epidermal growth factor receptor monoclonal antibodies such as panitumumab or cetuximab with standard chemoradiation therapy protocols in rectal cancer have yielded disappointing results. Because of the supposed negative interaction of epidermal growth factor receptor inhibition and chemoradiation therapy, we conducted a phase 2 study using single-agent panitumumab in combination with radiation therapy in patients with RAS wild-type locally advanced rectal cancer.

METHODS AND MATERIALS

Patients with RAS wild-type locally advanced (clinical stage II or III) rectal cancer localized 0 to 12 cm from the anus were eligible for study participation. The primary objective of the study was to determine pathologic complete response (pCR). Secondary objectives comprised assessing the safety, surgical morbidity, clinical response, tumor downstaging, and tumor regression grading according to Dworak.

RESULTS

A total of 54 patients with a median age of 58 years were treated. In 3.7% of patients, pCR was achieved. Downstaging of the primary tumor or lymph nodes was seen in 65% of patients. No grade ≥2 hematologic toxicity was seen. The most common grade ≥3 nonhematologic toxicities were skin toxicity (24%) and diarrhea (10%).

CONCLUSIONS

Panitumumab in combination with radiation therapy as neoadjuvant treatment for locally advanced rectal cancer showed a favorable toxicity profile but failed to meet the predefined pCR rate to justify further clinical trials.

Evolving Role of Radiotherapy in the Management of Rectal Carcinoma

Management of locally advanced rectal cancer has evolved over time from surgical resection alone to multimodality therapy with preoperative radiation, chemotherapy, and total mesorectal excision resulting in excellent local control rates. Refinements in neoadjuvant therapies and their sequencing have improved pathologic complete response rates such that consideration of selective radiation and nonoperative management are now active clinical trial questions. Advances in radiation treatment planning and delivery techniques may allow for further reduction in acute treatment-related toxicity in select patient populations. Collectively, therapeutic strategies remain focused on improving outcomes for patients with higher-risk disease and reducing the morbidity of treatment.

Pathologic complete response and disease-free survival are not surrogate endpoints for 5-year survival in rectal cancer: an analysis of 22 randomized trials

BACKGROUND

We performed a literature-based analysis of randomized clinical trials to assess the pathologic complete response (pCR) (ypT0N0 after neoadjuvant therapy) and 3-year disease-free survival (DFS) as potential surrogate endpoints for 5-year overall survival (OS) in rectal cancer treated with neoadjuvant (chemo)radiotherapy (CT)RT.

METHODS

A systematic literature search of PubMed, EMBASE, the Web of Science, SCOPUS, CINAHL, and the Cochrane Library was performed. Treatment effects on 3-year DFS and 5-year OS were expressed as rates of patients alive (%), and those on pCR as differences in pCR rates (∆^pCR%). A weighted regression analysis was performed at individual- and trial-level to test the association between treatment effects on surrogate (∆^pCR% and ∆^3yDFS) and the main clinical outcome (∆^5yOS).

RESULTS

Twenty-two trials involving 10,050 patients, were included in the analysis. The individual level surrogacy showed that the pCR% and 3-year DFS were poorly correlated with 5-year OS (R=0.52; 95% CI, 0.31-0.91; P=0.002; and R=0.60; 95% CI, 0.36-1; P=0.002). The trial-level surrogacy analysis confirmed that the two treatment effects on surrogates (∆^pCR% and ∆^3yDFS) are not strong surrogates for treatment effects on 5-year OS % (R=0.2; 95% CI, -0.29-0.78; P=0.5 and R=0.64; 95% CI, 0.29-1; P=0.06). These findings were confirmed in neoadjuvant CTRT studies but not in phase III trials were 3-year DFS could still represent a valid surrogate.

CONCLUSIONS

This analysis does not support the use of pCR and 3-year DFS% as appropriate surrogate endpoints for 5-year OS% in patients with rectal cancer treated with neoadjuvant therapy.

A Retrospective Analysis on Two-week Short-course Pre-operative Radiotherapy in Elderly Patients with Resectable Locally Advanced Rectal Cancer

To validate that a two-week short-course pre-operative radiotherapy regimen is feasible, safe, and effective for the management of elderly patients with locally advanced rectal cancer (LARC), we retrospectively analyzed 99 radiotherapy-naive patients ≥70 years of age with LARC. Patients received pelvic radiation therapy (3D-CRT 30Gy/10f/2w) followed by TME surgery; some patients received adjuvant chemotherapy. The primary endpoint was OS, while the secondary endpoints were DFS, safety and response rate. The median follow-up time was 5.1 years. The 5-year OS and DFS rates were 58.3% and 51.2%, respectively. The completion rate of radiotherapy (RT) was 99.0% (98 of 99). Grade 3 acute adverse events, which resulted from RT, occurred in only 1 patient (1.0%). In addition, no grade 4 acute adverse events induced by RT were observed. All 99 patients (100%) were able to undergo R0 surgical resection, and 68.6% of the patients received sphincter-sparing surgery. The rate of occurrence of clinically relevant post-operative complications was 12.1%. Three patients (3.0%) achieved pathologic complete responses, and forty-three patients (43.4%) achieved pathologic partial responses. The rates of T-downsizing and N-downstaging were 30.3% and 55.7%, respectively. Therefore, we believe that a two-week short-course pre-operative radiotherapy is feasible in elderly patients with resectable LARC.

Drug Combinations in Preoperative Chemoradiation for Rectal Cancer

Preoperative radiotherapy has an accepted role in reducing the risk of local recurrence in locally advanced resectable rectal cancer, particularly when the circumferential resection margin is breached or threatened, according to magnetic resonance imaging. Fluoropyrimidine-based chemoradiation can obtain a significant down-sizing response and a curative resection can then be achieved. Approximately, 20% of the patients can also obtain a pathological complete response, which is associated with less local recurrences and increased survival. Patients who achieve a sustained complete clinical response may also avoid radical surgery. In unresectable or borderline resectable tumors, around 20% of the patients still fail to achieve a sufficient down-staging response with the current chemoradiation schedules. Hence, investigators have aspired to increase pathological complete response rates, aiming to improve curative resection rates, enhance survival, and potentially avoid mutilating surgery. However, adding additional cytotoxic or biological agents have not produced dramatic improvements in outcome and often led to excess surgical morbidity and higher levels of acute toxicity, which effects on compliance and in the global efficacy of chemoradiation.

Preoperative Chemoradiation in Locally Advanced Rectal Cancer: Efficacy and Safety

Background

Preoperative chemoradiation (CRT) is considered the standard of care in the management of stage II/III rectal cancer. The aim of this retrospective study was to assess the efficacy and safety of preoperative CRT in our patient cohort with locally advanced rectal adenocarcinoma.

Methods

Forty patients with cT3-4N0-2M0 adenocarcinoma of the lower (n = 26) and mid/upper (n = 14) rectum were enrolled in this study between 2001 and 2012. Radiotherapy (RT) was given to the pelvis. The median prescribed dose was 45 Gy (daily dose, 1.8 - 2.0 Gy). All patients received chemotherapy concurrently with RT and underwent surgery 6 - 8 weeks after CRT. Low anterior resection (LAR) was achieved in 21 patients. Total mesorectal excision (TME) was performed in 24 patients.

Results

Tumor downstaging (expressed as TN downstaging) was observed in 15 patients (38%); a pathological complete response (pCR) was pathologically confirmed in six of them. In nine out of the 26 (23%) patients with low lying tumors, sphincter preservation (SP) was possible. SP was also possible in all but one patient (13%) who achieved a pCR. In three out of 15 patients (8%) with preoperative sphincter infiltration, SP was achieved. With a median follow-up of 58 months, the 4-year local control (LC), distant metastases-free survival (DMFS), disease-free survival (DFS) and overall survival (OS) rates were 89.7%, 86.9%, 79.5% and 81.2%, respectively. The pretreatment tumor size was predictive of response to preoperative CRT. The response to preoperative CRT did show a significant impact on DFS and on OS. TME resulted in a statistically significant increased DFS rate. No grade 3/4 acute toxicity was reported. Three patients developed grade 3 late side effects.

Conclusion

Preoperative CRT demonstrates encouraging rates of disease control and facilitates complete resection and SP in advanced rectal cancer with acceptable late toxicity.

Rectal Radiotherapy--Intensity-modulated Radiotherapy Delivery, Delineation and Doses

The use of intensity-modulated radiotherapy in rectal cancer is attractive in that it may reduce acute and late toxicities and potentially facilitate dose escalation. Intensity-modulated radiotherapy probably has a role in selected patients, but further investigation is required to identify the parameters for selection. Delineation of specific nodal groups allows maximal sparing of bladder and small bowel. In locally advanced tumours a simultaneous integrated boost allows dose escalation incorporating hypofractionation and a shorter overall treatment time. However, due to a sparsity of data on late toxicity in doses ≥ 60 Gy, doses at this level should be used with caution, ideally within prospective trials. Future studies investigating dose escalation must ascertain late toxicity as well as local control, as both can significantly affect quality of life and without both, the risk-benefit ratio cannot be calculated.

[Oncological principles for local control of primary tumor]

OBJECTIVE

Review of the databases of carcinogenesis and the principles of local control of the primary tumor in order to decrease the risk of tumor progression and predict metastatic behavior.

MATERIALS AND METHODS

Review of the literature using Medline databases based on scientific relevance. Research was centered on the characteristics of solid tumor development, the basics of local control of the primary tumor, latest advance in genomics and the oncological principles applied on prostate cancer surgery.

RESULTS

The cornerstone in order to cure a local or locally advanced cancer is to eradicate the primary tumor. This should be done using effective methods that can assure local control, decrease the risk of progression and metastasis. The oncological surgery is the most important step in order to have this tumor control, beside radiotherapy and systemic therapy associated. In localized prostate cancer, surgery remains the gold standard between the multiple therapeutic modalities proposed.

CONCLUSION

The local control of solid malignant tumor is primordial in order to change the natural history of the disease and decrease its risk of progression. This is the goal of oncological surgery, and starting from these principles radical prostatectomy was favored.

A Randomized Phase 2 Study of Neoadjuvant Chemoradiaton Therapy With 5-Fluorouracil/Leucovorin or Irinotecan/S-1 in Patients With Locally Advanced Rectal Cancer

PURPOSE

The purpose of this study was to evaluate the rate of pathologic complete response (pCR) in patients with locally advanced rectal cancer (LARC) treated with neoadjuvant chemoradiation therapy (CRT) with leucovorin (FL) versus irinotecan/S-1 (IS).

METHODS AND MATERIALS

Patients with resectable LARC (clinical stage T3/4, lymph node positive, or both) were randomly assigned to receive preoperative radiation (45-50.4 Gy in 25 to 28 daily fractions) and concomitant chemotherapy either with a bolus injection of FL (400 mg/m(2)/day 5-fluorouracil and 20 mg/m(2)/day leucovorin) for 3 consecutive days every 4 weeks for 2 cycles (FL group) or with 40 mg/m(2) irinotecan on days 1, 8, 15, 22, and 29, and 35 mg/m(2) S-1 twice on the day of irradiation (IS group). Curative surgery was performed approximately 4 to 8 weeks after the completion of CRT. The postoperative chemotherapy regimen was FL with a primary endpoint of a pCR rate evaluation.

RESULTS

One hundred forty-two eligible patients were randomly assigned, and the median follow-up duration was 43.8 months (95% confidence interval, 40.8-46.8 months). One hundred thirty-three patients (93.7%) of 142 underwent total mesorectal excision; pCR was achieved in 11 (16.7%) of 66 patients in the FL group and 17 (25.8%) of 67 patients in the IS group (P=.246). When good responders were defined as patients with Mandard grades 1 and 2, the rate of good responders was significantly higher in the IS group than in the FL group (54.6% vs 36.4%, respectively, P=.036). The preoperative rates of grade 3 and 4 toxicities were higher in the IS group (7.0%) than in the FL group (1.4%, P=.095). The 3-year disease-free survival was not significantly different between the 2 groups (79.7% vs 76.6%, respectively, P=.896).

CONCLUSIONS

IS-based preoperative CRT did not increase pCR rate, but it did increase acute toxicities compared with standard 5-FU treatment. Therefore, further investigation is needed.

Phase 1 dose de-escalation trial of the endogenous folate [6R]-5,10-methylene tetrahydrofolate in combination with fixed-dose pemetrexed as neoadjuvant therapy in patients with resectable rectal cancer

Background Modufolin® ([6R]-5,10-methylene tetrahydrofolate; [6R]-MTHF) is an endogenous biomodulator that is being developed as an alternative to leucovorin, a folate prodrug used in the treatment of colorectal cancer. The objective of this phase 1 dose de-escalation trial was to estimate the minimum tolerated dose of [6R]-MTHF to be used in combination with pemetrexed 500 mg/m² in the neoadjuvant treatment of patients with rectal cancer. Methods Adult patients (≥18 years) with resectable rectal adenocarcinoma were allocated to [6R]-MTHF doses of 500, 100, 50, and 10 mg/m² in combination with pemetrexed 500 mg/m². [6R]-MTHF was administered as an intravenous (i.v.) bolus injection 1 week prior to the first dose of pemetrexed and then once weekly for 9 weeks; pemetrexed was administered by i.v. infusion once every 21 days for three cycles. Results Twenty-four patients (mean [SD] age, 63.1 [12.9] years) were enrolled in the study. A total of 72 treatment-related adverse events (AEs) were reported, of which the most common were fatigue (n = 17; 23.6 %), nausea (n = 10; 13.9 %), and diarrhea (n = 5; 6.9 %). The incidence of treatment-related AEs by [6R]-MTHF dose level (500, 100, 50, 10 mg/m²) was 11.1 % (n = 8), 13.9 % (n = 10), 45.8 % (n = 33), and 29.2 % (n = 21), respectively. There were no dose-limiting toxicities, and only two (2.8 %) treatment-related AEs were grade 3 in severity. Of the 11 serious AEs reported, none were considered to be related to [6R]-MTHF treatment. Conclusions The results of this phase 1 study indicate that the estimated minimum tolerated dose of [6R]-MTHF was 100 mg/m² once weekly in combination with pemetrexed 500 mg/m². The low toxicity profile of [6R]-MTHF supports its further evaluation as a component of systemic chemotherapy in the management of colon and rectal cancer.