Time to surgery and pathologic complete response after neoadjuvant chemoradiation in rectal cancer: A population study on 2094 patients.

BACKGROUND: To retrospectively evaluate the difference in terms of pathologic complete response (pCR) according to time elapsed between chemoradiation (CRT) and total mesorectal excision (TME) on a large unselected real-life dataset of locally advanced rectal cancer (LARC) patients. METHODS: A multicentre retrospective cohort study of LARC patients from 21 Italian Radiotherapy Institutions was performed. Patients were stratified into 3 different time intervals from CRT. The 1st group included 300 patients who underwent TME within 6 weeks, the 2nd 1598 patients (TME within 7-12 weeks) and the 3rd 196 patients (TME within 13 or more weeks after CRT), respectively. RESULTS: Data on 2094 LARC patients treated between 1997 and 2016 were considered suitable for analysis. Overall, 578 patients had stage II while 1516 had stage III histological proven invasive rectal adenocarcinoma. A CRT schedule of one agent (N = 1585) or 2-drugs (N = 509) was administered. Overall, pCR was 22.3% (N = 468 patients). The proportion of patients achieving pCR with respect to time interval was, as follows: 12.6% (1st group), 23% (2nd group) and 31.1% (3rd group) (p < 0.001), respectively. The pCR relative risk comparison of 2nd to 1st group was 1.8, while 3rd to 2nd group was 1.3. Moreover, between the 3rd and 1st group, a pCR relative risk of 2.4 (p < 0.01) was noted. At univariate analysis, clinical stage III (p < 0.001), radiotherapy dose >5040 cGy (p = 0.002) and longer interval (p < 0.001) were significantly correlated to pCR. The positive impact of interval (p < 0.001) was confirmed at multivariate analysis as the only correlated factor. CONCLUSION: We confirmed on a population-level that lengthening the interval (>13 weeks) from CRT to surgery improves the pathological response (pCR and pathologic partial response; pPR) in comparison to historic data. Furthermore, radiotherapy dose >5040 cGy and two drugs chemotherapy correlated with pPR rate.

Value of (18)F-FDG PET for Predicting Response to Neoadjuvant Therapy in Rectal Cancer: Systematic Review and Meta-Analysis.

OBJECTIVE: The purpose of this study was to assess the predictive value of (18)F-FDG PET/ CT for pathologic response to neoadjuvant chemoradiotherapy in locally advanced rectal cancer. MATERIALS AND METHODS: A systematic search was performed (PubMed and Cochrane databases) for potentially relevant studies up to January 2014. Pooled sensitivity and specificity were calculated. The AUCs of the global cohort and for "major response," "complete response," "only PET after chemoradiotherapy," "ad interim PET," "major response excluding ad interim studies," "complete response excluding ad interim studies," "response index (RI)," "posttreatment maximum standardized uptake value (SUV(max) post)," "visual response analysis (VRA)," "percentage reduction of the total lesion glycolysis (ΔTLG)," and "percentage reduction of the metabolic tumor volume (ΔMTV)" were analyzed. Heterogeneity was explored for multiple variables. Pooled prevalence and 95% CI were calculated. RESULTS: Thirty-four of 131 (26%) initial articles met the inclusion criteria. Those articles included 1526 patients. PET/CT showed good pooled accuracy both in the global cohort (pooled sensitivity, 73%; pooled specificity, 77%; pooled AUC, 0.83) and for subgroups. Pooled accuracy was similar for early PET restaging and at 1 and 2 weeks after beginning chemoradiotherapy (pooled sensitivity, 84%; pooled specificity, 81%; pooled AUC, 0.89). The major response group showed similar sensitivity to the complete response group (74% and 71%, respectively). RI, SUV(max), and VRA were the most frequent parameters used. Pooled RI and SUV(max) postcutoff values were 63% and 4.4. Pooled time to PET during and after chemoradiotherapy was 1.5 and 6.5 weeks, respectively. CONCLUSION: This meta-analysis supports the use of FDG PET for restaging locally advanced rectal cancer.

Adjuvant chemoradiotherapy in gastric cancer: a pooled analysis of the AIRO gastrointestinal group experience.

BACKGROUND: Given the poor compliance with adjuvant chemoradiotherapy (CRT) in gastric cancer reported in previous studies, a survey was conducted among 18 Italian institutions within the AIRO Gastrointestinal Group to investigate current treatment modalities, toxicities, and compliance with adjuvant CRT. PATIENTS AND METHODS: Data from 348 patients operated on for gastric cancer were collected retrospectively from September 2000 to June 2008 and analyzed. The adjuvant treatments included CRT according to center guidelines. In multivariate analysis, acute hematological, gastrointestinal, and renal toxicity (according to the RTOG Acute Radiation Morbidity Scoring Criteria) and compliance with treatment were studied, as well as risk factors for local control, metastasis-free survival, disease-free survival, and overall survival. RESULTS: Compliance with treatment was excellent: 95.7% of patients completed CRT. During CRT, acute G3-G4 ­hematological toxicity was 3.7% and acute G3-G4 gastrointestinal toxicity 4%. 78.4% of patients completed chemotherapy (CT), either before or after CRT. During CT acute G3-G4 hematological toxicity was 5.4% and acute G3-G4 gastrointestinal toxicity 6%. Overall, 74.1% of patients completed the prescribed treatment (CRT and CT). Doses greater than 4500 cGy did not compensate for more aggressive disease. The 5-year overall survival was 51%. CONCLUSIONS: The adjuvant treatment of gastric cancer within the AIRO group was diverse, but radiotherapy treatment was homogeneous (in terms of technique) and well tolerated. Toxicity was low and compliance with treatment was good during CRT; these results may be due to the radiotherapy technique applied. This survey could be used as a benchmark for further studies.

Adjuvant chemotherapy in rectal cancer: defining subgroups who may benefit after neoadjuvant chemoradiation and resection: a pooled analysis of 3,313 patients.

Recent literature suggests that the benefit of adjuvant chemotherapy (aCT) for rectal cancer patients might depend on the response to neoadjuvant chemoradiation (CRT). Aim was to evaluate whether the effect of aCT in rectal cancer is modified by response to CRT and to identify which patients benefit from aCT after CRT, by means of a pooled analysis of individual patient data from 13 datasets. Patients were categorized into three groups: pCR (ypT0N0), ypT1-2 tumour and ypT3-4 tumour. Hazard ratios (HR) for the effect of aCT were derived from multivariable Cox regression analyses. Primary outcome measure was recurrence-free survival (RFS). One thousand seven hundred and twenty three (1723) (52%) of 3,313 included patients received aCT. Eight hundred and ninety eight (898) patients had a pCR, 966 had a ypT1-2 tumour and 1,302 had a ypT3-4 tumour. For 122 patients response, category was missing and 25 patients had ypT0N+. Median follow-up for all patients was 51 (0-219) months. HR for RFS with 95% CI for patients treated with aCT were 1.25(0.68-2.29), 0.58(0.37-0.89) and 0.83(0.66-1.10) for patients with pCR, ypT1-2 and ypT3-4 tumours, respectively. The effect of aCT in rectal cancer patients treated with CRT differs between subgroups. Patients with a pCR after CRT may not benefit from aCT, whereas patients with residual tumour had superior outcomes when aCT was administered. The test for interaction did not reach statistical significance, but the results support further investigation of a more individualized approach to administer aCT after CRT and surgery based on pathologic staging.

Biological target volume overlapping segmentation system method for avoiding false-positive PET findings in assessing response to neoadjuvant chemoradiation therapy in rectal cancer.

PURPOSE: FDG PET/CT has a recognized high predictive power to assess the response to neoadjuvant chemoradiation therapy (CRT) in patients affected by locally advanced rectal cancer (LARC), but a relatively high number of false-positive findings decrease its specificity: with the aim to solve this problem, a new method of imaging analysis is here proposed. METHODS: The new method here described, named Biological target volume (BTV) Overlapping Segmentation System (BOSS), has been applied on 24 consecutive patients with LARC that were all previously classified as nonresponders to CRT by means of the response index criterion that is adopted in our center. The BOSS method is based on the quantification of the amount of superimposition between pretreatment and posttreatment BTV. All BTVpre was down using a threshold of 60% of SUVmax in the tumor (BTV60). The results (overlap volumes and percentage of overlap volumes) were then matched up with postoperative pathology classified by the Mandard's tumor regression grade (TRG) system. RESULTS: Eleven patients were classified as responders (TRG1-2) and 13 as nonresponders (TRG 3-5). Among all the results obtained by BOSS method, only the percentage of overlap volume data between BTV60 and BTVpost (%Over_60) was able to correctly distinguish between responders and nonresponders. In our experience, a cutoff of 56% on the %Over_60 provided the best results in terms of true negative (11 cases), true positive (12 cases), false negative (1 case), and false positive (none). CONCLUSIONS: This new method, we developed, appears able to unmask the false-positive cases, improving the specificity of FDG PET/CT to predict the response to CRT patients with LARC.

Postoperative 5-FU based radiochemotherapy in rectal cancer: retrospective long term results and prognostic factors of a pooled analysis on 1,338 patients.

AIM: To evaluate survival outcomes of patients in pStage II-III rectal cancer treated with adjuvant 5-fluorouracil-based radiochemotherapy and to retrospectively analyze the impact of prognostic variables on local control, metastasis-free survival and cause-specific survival. PATIENTS AND METHODS: A total of 1,338 patients, treated between 1985-2005 for locally advanced rectal cancer, who underwent surgery and postoperative 5-fluorouracil-based chemoradiation, were selected. RESULTS: The actuarial 5- and 10-year outcomes were: local control 87.0%-84.1%, disease-free survival 61.6%-52.1%, metastasis-free survival 72.0%-67.2%, cause-specific survival 70.4%-57.5%, and overall survival 63.8%-53.4%. Better outcomes were observed in patients with IIA, IIIA stage. Multivariate analyses showed that variables significantly affecting metastasis-free survival were pT4 and pN2, while for cancer-specific survival those variables were age >65 years, pT4, pN1, pN2, distal tumors and number of lymph nodes removed ≤ 12. CONCLUSION: This study confirmed that among stage II-III rectal cancer patients there are subgroups of patients with different clinical outcomes.

Proposal of a new 18F-FDG PET/CT predictor of response in rectal cancer treated by neoadjuvant chemoradiation therapy and comparison with PERCIST criteria.

PURPOSE: The aim of this study was to correlate PERCIST criteria and a new criterion developed in our center that we named PREDIST (PET Residual Disease in Solid Tumor) with tumor regression grade (TRG) classification of pathologic response to neoadjuvant chemoradiotherapy (CRT) in patients affected by rectal cancer. METHODS: Seventy-three consecutive patients affected by locally advanced rectal cancer (LARC) were retrospectively included. FDG-PET/CT scans were performed at staging time and after the end of CRT (mean time 6.5 weeks). The analysis was performed by PERCIST criteria 1.0 and PREDIST criteria based on a new definition of residual disease. We split the TRG system into responders (TRG1-2) and nonresponders (TRG3-5). Pearson chi-square analysis by cross-tabulations was performed. RESULTS: PREDIST classification was statistically predictive of TRG response (P = 0.004, sensitivity 81.8% and specificity 54.9%). On the contrary, PERCIST criteria was not statistically correlated to TRG (P = 0.128) caused by a very low specificity (9.8%). CONCLUSIONS: FDG-PET/CT scan is an accurate tool to predict preoperatively the response to CRT in LARC patients. The novel proposed criterion (PREDIST) seems to be helpful to discriminate responder by nonresponder patients.

Fifteen different 18F-FDG PET/CT qualitative and quantitative parameters investigated as pathological response predictors of locally advanced rectal cancer treated by neoadjuvant chemoradiation therapy.

PURPOSE: The aim of this study was to correlate qualitative visual response and various PET quantification factors with the tumour regression grade (TRG) classification of pathological response to neoadjuvant chemoradiotherapy (CRT) proposed by Mandard. METHODS: Included in this retrospective study were 69 consecutive patients with locally advanced rectal cancer (LARC). FDG PET/CT scans were performed at staging and after CRT (mean 6.7 weeks). Tumour SUVmax and its related arithmetic and percentage decrease (response index, RI) were calculated. Qualitative analysis was performed by visual response assessment (VRA), PERCIST 1.0 and response cut-off classification based on a new definition of residual disease. Metabolic tumour volume (MTV) was calculated using a 40 % SUVmax threshold, and the total lesion glycolysis (TLG) both before and after CRT and their arithmetic and percentage change were also calculated. We split the patients into responders (TRG 1 or 2) and nonresponders (TRG 3-5). RESULTS: SUVmax MTV and TLG after CRT, RI, ΔMTV% and ΔTLG% parameters were significantly correlated with pathological treatment response (p < 0.01) with a ROC curve cut-off values of 5.1, 2.1 cm(3), 23.4 cm(3), 61.8 %, 81.4 % and 94.2 %, respectively. SUVmax after CRT had the highest ROC AUC (0.846), with a sensitivity of 86 % and a specificity of 80 %. VRA and response cut-off classification were also significantly predictive of TRG response (VRA with the best accuracy: sensitivity 86 % and specificity 55 %). In contrast, assessment using PERCIST was not significantly correlated with TRG. CONCLUSION: FDG PET/CT can accurately stratify patients with LARC preoperatively, independently of the method chosen to interpret the images. Among many PET parameters, some of which are not immediately obtainable, the most commonly used in clinical practice (SUVmax after CRT and VRA) showed the best accuracy in predicting TRG.

Neoadjuvant therapy with weekly docetaxel and cisplatin, 5-fluorouracil continuous infusion, and concurrent radiotherapy in patients with locally advanced esophageal cancer produced a high percentage of long-lasting pathological complete response: a phase 2 study.

BACKGROUND: This phase 2 study was aimed at defining the pathological response rate of a neoadjuvant schedule including weekly docetaxel and cisplatin, continuous infusion (c.i.) of 5-fluorouracil (5-FU) and concomitant radiotherapy (RT) in untreated stage II-III adenocarcinoma and squamous cell carcinoma of mid-distal thoracic esophagus. METHODS: The schedule consisted of a first phase of chemotherapy alone and of a second phase of concurrent chemoradiation. Doses were as follows: docetaxel 35 mg/m(2) and cisplatin 25 mg/m(2) on days 1, 8, 15, 29, 36, 43, 50, and 57 plus 5-FU c.i. (180 mg/m(2) on days 1-21 and 150 mg/m(2) on days 29-63); RT (50 Gy) started at day 29. Surgery was planned 6 to 8 weeks after the completion of chemoradiation. RESULTS: A total of 74 patients were enrolled; pathological complete remission (pCR) was found in 47% (35 of 74) and near pCR (microfoci of tumor cells on the primary tumor without lymph nodal metastases) (pnCR) in 15% of the patients (11 of 74). Grade 3-4 neutropenia, nonhematological toxicity, and toxic deaths occurred in 13.5%, 32.4%, and 4% of the patients, respectively. Median follow-up was 55 months (range, 3-108 months). Median survival of all 74 patients was 55 months, whereas it was not reached in the pCR subset. The 3- and 5-year survival rates were, respectively, 83% and 77% for pCR, 73% and 44% for pnCR, and 21% and 14% for Residual Tumor subsets (P < .001). CONCLUSIONS: This study shows that 1) this intensive weekly schedule produced a high pathological response rate, 2) responders had high and long-term durable survival rates.

A new methodological approach for PET implementation in radiotherapy treatment planning.

In this paper, a new methodological approach to using PET information in radiotherapy treatment planning has been discussed. Computed tomography (CT) represents the primary modality to plan personalized radiation treatment, because it provides the basic electron density map for correct dose calculation. If PET scanning is also performed it is typically coregistered with the CT study. This operation can be executed automatically by a hybrid PET/CT scanner or, if the PET and CT imaging sets have been acquired through different equipment, by a dedicated module of the radiotherapy treatment planning system. Both approaches have some disadvantages: in the first case, the bore of a PET/CT system generally used in clinical practice often does not allow the use of certain bulky devices for patient immobilization in radiotherapy, whereas in the second case the result could be affected by limitations in window/level visualization of two different image modalities, and the displayed PET volumes can appear not to be related to the actual uptake into the patient. To overcome these problems, at our centre a specific procedure has been studied and tested in 30 patients, allowing good results of precision in the target contouring to be obtained. The process consists of segmentation of the biological target volume by a dedicated PET/CT console and its export to a dedicated radiotherapy system, where an image registration between the CT images acquired by the PET/CT scanner and a large-bore CT is performed. The planning target volume is contoured only on the large-bore CT and is used for virtual simulation, to individuate permanent skin markers on the patient.

Information for decision making by patients with early-stage prostate cancer: a comparison across 9 countries.

PURPOSE: To describe decisional roles of patients with early-stage prostate cancer in 9 countries and to compare the information they rated important for decision making (DM). METHOD: A survey of recently treated patients was conducted in Canada, Italy, England, Germany, Poland, Portugal, Netherlands, Spain, and Turkey. Participants indicated their decisional role in their actual decision and the role they would prefer now. Each participant also rated (essential/desired/no opinion/avoid) the importance of obtaining answers, between diagnosis and treatment decision, to each of 92 questions. For each essential/desired question, participants specified all purposes for that information (to help them: understand/decide/plan/not sure/other). RESULTS: A total of 659 patients participated with country-specific response rates between 58%-77%. Between 83%-96% of each country's participants recalled actually taking an active decisional role and, in most countries, that increased slightly if they were to make the decision today; there were no significant differences among countries. There was a small reliable difference in the mean number of questions rated essential for DM across countries. More striking, however, was the wide variability within each country: no question was rated essential for DM by even 50% of its participants but almost every question was rated essential by some. CONCLUSIONS: Almost all participants from each country want to participate in their treatment decisions. Although there are country-specific differences in the amount of information required, wide variation within each country suggests that information that patients feel is essential or desired for DM should be addressed on an individual basis in all countries.

Patient-reported outcomes after neoadjuvant chemoradiotherapy for rectal cancer: a multicenter prospective observational study.

OBJECTIVE: To prospectively describe patient-reported outcomes (PROs) after preoperative chemoradiotherapy (pCRT) for rectal cancer. BACKGROUND: Little evidence is available on PROs after pCRT for rectal cancer. PATIENTS AND METHODS: Patients with rectal cancer, candidates to receive pCRT, were enrolled in a multicenter prospective observational trial. Health-related quality of life was assessed using the European Organisation for Research and Treatment of Cancer (EORTC) QLQ-C30 and its colorectal cancer module (QLQ-CR38), and fecal incontinence and bowel function were evaluated using the fecal incontinence score questionnaire and a set of ad hoc questions. Questionnaires were filled out before CRT (t0), 2 to 3 weeks after completion of CRT (t1), and at 6 (t2) and 12 months (t3) after surgery. Primary analysis of selected scales included: global quality of life, physical functioning, social functioning, fatigue, body image, future prospective, and gender-related sexual problems. RESULTS: Of 149 eligible patients, questionnaires were completed in 100%, 95%, 88% and 77% of cases at t0, t1, t2, and t3, respectively. At t3, 78% of patients reported stool fractionation and 72% sensation of incomplete defecation. Only 14% of patients had optimal continence. Physical/social functioning, fatigue, and body image showed a decrease just after pCRT and returned to baseline levels at 1 year after treatment. Global quality of life was stable over time. Male sexual problems were greatly impaired throughout the study period (P < 0.001) with major clinically meaningful changes between baseline and 1 year after treatment. CONCLUSIONS: These findings add to the body of evidence available regarding pCRT and help clinicians to make more informed treatment decisions.

Development and external validation of a predictive model for pathological complete response of rectal cancer patients including sequential PET-CT imaging.

PURPOSE: To develop and validate an accurate predictive model and a nomogram for pathologic complete response (pCR) after chemoradiotherapy (CRT) for rectal cancer based on clinical and sequential PET-CT data. Accurate prediction could enable more individualised surgical approaches, including less extensive resection or even a wait-and-see policy. METHODS AND MATERIALS: Population based databases from 953 patients were collected from four different institutes and divided into three groups: clinical factors (training: 677 patients, validation: 85 patients), pre-CRT PET-CT (training: 114 patients, validation: 37 patients) and post-CRT PET-CT (training: 107 patients, validation: 55 patients). A pCR was defined as ypT0N0 reported by pathology after surgery. The data were analysed using a linear multivariate classification model (support vector machine), and the model's performance was evaluated using the area under the curve (AUC) of the receiver operating characteristic (ROC) curve. RESULTS: The occurrence rate of pCR in the datasets was between 15% and 31%. The model based on clinical variables (AUC(train)=0.61±0.03, AUC(validation)=0.69±0.08) resulted in the following predictors: cT- and cN-stage and tumour length. Addition of pre-CRT PET data did not result in a significantly higher performance (AUC(train)=0.68±0.08, AUC(validation)=0.68±0.10) and revealed maximal radioactive isotope uptake (SUV(max)) and tumour location as extra predictors. The best model achieved was based on the addition of post-CRT PET-data (AUC(train)=0.83±0.05, AUC(validation)=0.86±0.05) and included the following predictors: tumour length, post-CRT SUV(max) and relative change of SUV(max). This model performed significantly better than the clinical model (p(train)<0.001, p(validation)=0.056). CONCLUSIONS: The model and the nomogram developed based on clinical and sequential PET-CT data can accurately predict pCR, and can be used as a decision support tool for surgery after prospective validation.

Information needs of early-stage prostate cancer patients: a comparison of nine countries.

BACKGROUND AND PURPOSE: Providing information to patients can improve their medical and psychological outcomes. We sought to identify core information needs common to most early-stage prostate cancer patients in participating countries. MATERIAL AND METHODS: Convenience samples of patients treated 3-24 months earlier were surveyed in Canada, England, Italy, Germany, Poland, Portugal, Netherlands, Spain, and Turkey. Each participant rated the importance of addressing each of 92 questions in the diagnosis-to-treatment decision interval (essential/desired/no opinion/avoid). Multivariate modelling determined the extent of variance accounted by covariates, and produced an unbiased prediction of the proportion of essential responses for each question. RESULTS: Six hundred and fifty-nine patients responded (response rates 45-77%). On average, 35-53 questions were essential within each country; similar questions were essential to most patients in most countries. Beyond cross-country similarities, each country showed wide variability in the number and which questions were essential. Multivariate modelling showed an adjusted R-squared with predictors country, age, education, and treatment group of only 6% of the variance. A core of 20 questions were predicted to be essential to >2/3 of patients. CONCLUSIONS: Core information can be identified across countries. However, providing the core should only be a first step; each country should then provide information tailored to the needs of the individual patient.

The role of dual-time combined 18-fluorodeoxyglucose positron emission tomography and computed tomography in the staging and restaging workup of locally advanced rectal cancer, treated with preoperative chemoradiation therapy and radical surgery.

PURPOSE: In patients with locally advanced rectal cancer (LARC) staging and, after preoperative chemo-radiation therapy (CRT), restaging workup could be useful to tailor therapeutic approaches. Fluorine-18-fluorodeoxyglucose positron emission tomography ([(18)F]FDG-PET) is a promising tool for monitoring the effect of antitumor therapy. This study was aimed to evaluate the possible role of dual time sequential FDG-PET scans in the staging and restaging workup of LARC. METHODS AND MATERIALS: Eighty-seven consecutive patients with LARC were enrolled. CRT consisted of external-beam intensified radiotherapy (concurrent boost), with concomitant chemotherapy PVI 5-FU (300 mg/m(2)/day) followed 8-10 weeks later by surgery. All patients underwent [(18)F]FDG-PET/CT before and 5-6 weeks later after the completion of CRT. Measurements of FDG uptake (SUV(max)), and percentage of SUV(max) difference (Response Index = RI) between pre- and post-CRT [(18)F]FDG-PET scans were evaluated. RESULTS: Six of 87 patients were excluded due to protocol deviation. Following CRT, 40/81 patients (49%) were classified as responders according to Mandard's criteria (TRG1-2). The mean pre-CRT SUV(max) was significantly higher than post-CRT (15.8, vs 5.9; p < 0.001). The mean RI was significantly higher in responders than in nonresponder patients (71.3% vs 38%; p = 0.0038). Using a RI cut-off of 65% for defining response to therapy, the following parameters have been obtained: 84.5% sensitivity, 80% specificity, 81.4% positive predictive value, 84.2% negative predictive value, and 81% overall accuracy. CONCLUSION: These results suggest the potential role of [(18)F]FDG-PET in the restaging workup after preoperative CRT in LARC. RI seems the best predictor to identify CRT response.

Prognostic value of pathologic complete response after neoadjuvant therapy in locally advanced rectal cancer: long-term analysis of 566 ypCR patients.

PURPOSE: In the literature, a favorable prognosis was observed for complete pathologic response after preoperative therapy (ypCR) in patients with locally advanced rectal cancer. The aim of this study is to verify whether ypCR predicts a favorable outcome in a large series of patients. METHODS AND MATERIALS: The Gastro-Intestinal Working Group of the Italian Association of Radiation Oncology collected clinical data for 566 patients with ypCR (ypT0N0) after neoadjuvant therapy. Eligibility criteria included locally advanced rectal cancer with no evidence of metastases at the time of diagnosis, evidence of ypCR after preoperative radiotherapy +/- chemotherapy (CT). RESULTS: Median radiation dose was 50 Gy. A total of 527 patients (93%) received one of 12 different neoadjuvant CT schedules. Sphincter preservation, anteroposterior resection, and endoscopic surgery were performed in 73%, 22%, and 5% of patients, respectively. Adjuvant CT was administered to 22% of patients. Median follow-up was 46.4 months. Locoregional recurrence occurred in 7 patients (1.6%). Distant metastases occurred in 49 patients (8.9%). Overall, 5-year rates of disease-free survival, overall survival, and cancer-specific survival were 85%, 90%, and 94%, respectively. In multivariate analysis, only age and clinical stage statistically correlated with survival outcome. Adjuvant CT was still of borderline significance (worse for adjuvant CT). No relation was found between survival and neoadjuvant CT schedules. CONCLUSION: A ypCR after neoadjuvant therapy identified a favorable group of patients, even in this large series of 566 patients collected in 61 centers. Locoregional recurrence occurred only in 1.6% patients.

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

PURPOSE: Prediction of rectal cancer response to preoperative, neo-adjuvant chemo-radiation therapy (CRT) provides the opportunity to identify patients in whom a major response is expected and who may therefore benefit from alternative surgical approaches. Traditional morphological imaging techniques are effective in defining tumour extension in the initial diagnostic and staging work-up, but perform poorly in distinguishing residual neoplastic tissue from scarring post CRT, when restaging the patient before surgery. Fluorine-18 fluorodeoxyglucose positron emission tomography (FDG-PET) is a promising tool for monitoring the effect of anti-tumour therapy. The aim of this study was to prospectively assess the value of sequential FDG-PET scans in predicting the response of locally advanced rectal cancer to neo-adjuvant CRT. METHODS: Forty-four consecutive patients with locally advanced (cT3-4) primary rectal cancer and four patients with pelvic recurrence of rectal cancer were enrolled in this prospective study. Treatment consisted of external beam intensified radiotherapy (50 Gy to the posterior pelvis, 56 Gy to the tumour), chemotherapy (in most cases PVI 5-FU at 300 mg/m(2) per day) and, 8-10 weeks later, surgery with curative intent. All patients underwent FDG-PET/CT both before CRT and 5-6 weeks after completing CRT. One patient died before surgery because of acute myocardial infarction, and was therefore excluded from further analysis. Semi-quantitative measurements of FDG uptake (SUV(max)), absolute difference (DeltaSUV(max)) and percent SUV(max) difference (Response Index, RI) between pre- and post-CRT PET scans were considered. Results were correlated with pathological response, assessed both by histopathological staging of the surgical specimens (pTNM) and by the tumour regression grade (TRG) according to Mandard's criteria (patients with TRG1-2 being defined as responders and patients with TRG3-5 as non-responders). RESULTS: Following neo-adjuvant CRT, of the 45 patients submitted to surgery, 23 (51.1%) were classified as responders according to Mandard's criteria (8 TRG1 and 15 TRG2), while the remaining 22 (48.9%) were non-responders (9 TRG3 and 13 TRG4-5). Considering all patients, the mean pre-CRT SUV(max) was 15.6, significantly higher than the mean value of 5.4 post CRT (p < 0.001). Nevertheless, when stratifying patients according to response to CRT (using Mandard's criteria), the mean RI was significantly higher in responders than in non-responders (75.9% versus 46.9%,p = 0.0015). Using a 66.2% SUV(max) decrease as the cut-off value (identified by ROC analysis) for defining response to therapy, the following parameters were obtained: 79.2% specificity, 81.2% sensitivity, 77% positive predictive value, 89% negative predictive value and 80% overall accuracy. CONCLUSION: The results suggest the potential utility of FDG-PET as a complementary diagnostic and prognostic procedure in the assessment of neo-adjuvant CRT response of locally advanced rectal cancer. DeltaSUV(max) and RI seem the best predictors of CRT response.

Long-term prognostic value of 18F-FDG PET in patients with locally advanced rectal cancer previously treated with neoadjuvant radiochemotherapy.

OBJECTIVE: The purpose of this study was to assess the prognostic value of (18)F-FDG PET performed at restaging in patients with locally advanced rectal cancer who previously underwent neoadjuvant radiochemotherapy. SUBJECTS AND METHODS: Eighty-eight patients with histologically proven rectal cancer classified at clinical TNM stages II and III were enrolled. Six weeks after radiochemotherapy completion, all patients were restaged by sonography, CT, MRI, endoscopy, and (18)F-FDG PET. Surgery was performed in all patients within 8-9 weeks from completion of radiochemotherapy. Median follow-up after surgery was 38 months (range, 6-66 months). RESULTS: The 5-year overall survival and disease-free survival were 83% and 73%, respectively. Cox multivariate analysis showed that only two parameters at restaging were independent prognostic predictors of both overall survival and disease-free survival: pathologic stage and, especially, after radiochemotherapy (18)F-FDG PET findings. The 5-year overall survival was 91% in patients with a negative PET after radiochemotherapy versus 72% in those with a positive PET (p = 0.024) after radiochemotherapy, whereas disease-free survival was 81% and 62% (p = 0.003) for those with the negative and positive PET findings, respectively. Statistical data were further enhanced when combining the pathologic stage with the (18)F-FDG PET results: 95% 5-year overall survival in the PET-negative pathologic stages 0 and I patients versus 70% in PET-positive pathologic stages II-IV patients (p = 0.001), whereas disease-free survival was 93% and 65% (p = 0.0003) for the negative and positive PETs, respectively. CONCLUSION: In patients with locally advanced rectal cancer previously treated with neoadjuvant radiochemotherapy, the combined evaluation of pathologic stage and after-radiochemotherapy (18)F-FDG PET at restaging identified a subgroup of patients characterized by good response to radiochemotherapy and a more favorable prognosis. In these patients, a conservative surgical approach might be considered.