Determining the optimal interval between neoadjuvant radiochemotherapy and surgery in rectal cancer: a retrospective cohort study.

INTRODUCTION: In locally advanced rectal cancer, the optimal interval between completion of neoadjuvant radiochemotherapy (RT-ChT) and surgical resection remains unclear due to contradictory data on the benefits of extending this interval. Therefore, the aim of this retrospective study was to determine the impact of this interval on outcomes in patients treated for rectal cancer at our center. METHODS: We retrospectively reviewed 382 consecutive patients treated for stage II/III rectal cancer between October 1, 2012, and December 31, 2017. We evaluated four different cut-off points (56, 63, 70, and 77 days) to determine which had the greatest impact on treatment outcomes. RESULTS: The median time between completion of RT-ChT and surgery was 67.2 days (range, 28-294). Intervals > 8 weeks (56 days) were associated with worse therapeutic outcomes. Specifically, an interval ≥ 77 days was associated with a significant decrease in overall survival (OS; 84% vs. 70%; p = 0.004), which is why we selected this interval for the comparative analysis. Several outcome variables were significantly better in the short interval (< 77 days) group, including margin involvement (5.2% vs. 13.9%; p = 0.01), sphincter preservation (78% vs. 59.3%; p = 0.003), and distant dissemination (22.6% vs. 32.5%; p = 0.04). No significant between-group differences were found in complete/nearly complete response rates (19.2% vs. 24.4%; p = 0.3). Time to surgery was statistically significant on both the univariate and multivariate analyses. CONCLUSIONS: Our findings suggest that surgery should not be delayed more than 8 weeks (56 days) after neoadjuvant treatment. An interval > 8 weeks should only be considered in patients who demonstrate a good response to neoadjuvant RT-ChT.

Phase II randomized trial of capecitabine with bevacizumab and external beam radiation therapy as preoperative treatment for patients with resectable locally advanced rectal adenocarcinoma: long term results.

BACKGROUND: Preoperative chemoradiotherapy with capecitabine is considered as a standard of care for locally advanced rectal cancer. The "Tratamiento de Tumores Digestivos" group (TTD) previously reported in a randomized Ph II study that the addition of Bevacizumab to capecitabine-RT conferred no differences in the pre-defined efficacy endpoint (pathological complete response). We present the follow-up results of progression-free survival, distant relapse-free survival, and overall survival data at 3 and 5 years. METHODS: Patients (pts) were randomized to receive 5 weeks of radiotherapy (45 Gy/25 fractions) with concurrent Capecitabine 825 mg/m2 twice daily, 5 days per week with (arm A) or without (arm b) bevacizumab (5 mg/kg once every 2 weeks). RESULTS: In our study, the addition of bevacizumab to capecitabine and radiotherapy in the neoadjuvant setting shows no differences in pathological complete response (15.9% vs 10.9%), distant relapse-free survival (81.0 vs 80.4 and 76.2% vs 78.2% at 3 and 5 years respectively), disease-free survival (75% vs 71.7 and 68.1% vs 69.57% at 3 and 5 years respectively) nor overall survival at 5-years of follow-up (81.8% vs 86.9%). CONCLUSIONS: the addition of bevacizumab to capecitabine plus radiotherapy does not confer statistically significant advantages neither in distant relapse-free survival nor in disease-free survival nor in Overall Survival in the short or long term. TRIAL REGISTRATION: EudraCT number: 2009-010192-24 . Clinicaltrials.gov number: NCT01043484 .

Results of surgery for pelvic recurrence of rectal cancer. Experience in a referral center. / Resultados de la cirugía de la recidiva pélvica de cáncer de recto. Experiencia en un centro de referencia.

INTRODUCTION: The only curative treatment of pelvic recurrence of rectal cancer is radical resection. The aim of this paper is to analyze our experience in surgery for local recurrence of rectal cancer. METHODS: We performed a descriptive retrospective analysis of patients treated with curative intent for local recurrence of rectal cancer from May 2000 to January 2014. The presence of resectable liver or lung metastases was not an exclusion criterion. The descriptive results, overall survival and disease free survival are presented. RESULTS: A total of 35 patients were included. In 18 patients an abdomino-perineal resection of the remaining rectum was performed. Two of them included excision of lower sacral vertebrae, while in 17 patients, sphincter sparing surgery was performed. The most frequent postoperative complications were pelvic collection and postoperative ileus. Seven patients required reoperation and one patient died. Overall survival at one year was 91.2%, at 2 years 75.6% and at 5 years 37%. CONCLUSIONS: Local recurrence of rectal cancer is a disease with high curability rate. The only curative option is radical surgery, with acceptable mortality.

Phase II study of preoperative bevacizumab, capecitabine and radiotherapy for resectable locally-advanced rectal cancer.

BACKGROUND: To evaluate whether the addition of bevacizumab (BVZ) to capecitabine-based chemoradiotherapy in the preoperative treatment of locally advanced rectal cancer (LARC) improves efficacy measured by the pathological complete response (pCR) rate. METHODS: A phase II two-step design was performed. Patients received four cycles of therapy consisting of: BVZ 10 mg/kg in first infusion on day 1 and 5 mg/kg on days 15, 29, 43, capecitabine 1800 mg/m(2)/day 5 days per week during radiotherapy, which consisted of external-beam irradiation (45 Gy in 1.8 Gy dose per session over 5 sessions/week for 5 weeks). Six to eight weeks after completion of all therapies surgery was undergone. To profile the biological behaviour during BVZ treatment we measured molecular biomarkers before treatment, during BVZ monotherapy, and during and after combination therapy. Microvessel density (MVD) was measured after surgery. RESULTS: Forty-three patients were assessed and 41 were included in the study. Three patients achieved a pathological complete response (3/40: 7.5%) and 27 (67.5%) had a pathological partial response, (overall pathological response rate of 75%). A further 8 patients (20%) had stable disease, giving a disease control rate of 95%. Downstaging occurred in 31 (31/40: 77.5%) of the patients evaluated. This treatment resulted in an actuarial 4-year disease-free and overall survival of 85.4 and 92.7% respectively. BVZ with chemoradiotherapy showed acceptable toxicity. No correlations were observed between biomarker results and efficacy variables. CONCLUSION: BVZ with capecitabine and radiotherapy seem safe and active and produce promising survival results in LARC. TRIAL REGISTRATION: ClinicalTrials.gov Identifier NCT00847119 . Trial registration date: February 18, 2009.

Association of Bevacizumab Plus Oxaliplatin-Based Chemotherapy With Disease-Free Survival and Overall Survival in Patients With Stage II Colon Cancer: A Secondary Analysis of the AVANT Trial.

Importance: In the pivotal Bevacizumab-Avastin Adjuvant (AVANT) trial, patients with high-risk stage II colon cancer (CC) had 5-year and 10-year overall survival (OS) rates of 88% and 75%, respectively, with adjuvant fluorouracil and oxaliplatin-based chemotherapy; however, the trial did not demonstrate a disease-free survival (DFS) benefit of adding bevacizumab to oxaliplatin-based chemotherapy in stage III CC and suggested a detrimental effect on OS. The Long-term Survival AVANT (S-AVANT) study was designed to collect extended follow-up for patients in the AVANT trial. Objective: To explore the efficacy of adjuvant bevacizumab combined with oxaliplatin-based chemotherapy in patients with high-risk, stage II CC. Design, Setting, and Participants: This prespecified secondary end point analysis of the AVANT and S-AVANT studies included 573 patients with curatively resected high-risk stage II CC and at least 1 of the following criteria: stage T4, bowel obstruction or perforation, blood and/or lymphatic vascular invasion and/or perineural invasion, age younger than 50 years, or fewer than 12 nodes analyzed. The AVANT study was a multicenter randomized stage 3 clinical trial. Data were collected from December 2004 to February 2019, and data for this study were analyzed from March to September 2019. Intervention: Patients were randomly assigned to receive 5-fluorouracil, leucovorin, and oxaliplatin (FOLFOX4), FOLFOX4 with bevacizumab, or capecitabine and oxaliplatin (XELOX) with bevacizumab. Main Outcomes and Measures: The primary end points of this secondary analysis were DFS and OS in patients with high-risk stage II CC. Results: The AVANT study included 3451 patients, of whom 573 (16.6%) had high-risk stage II CC (192 [33.5%] randomized to FOLFOX4 group; 194 [33.9%] randomized to FOLFOX4 with bevacizumab group; 187 [32.6%] randomized to XELOX with bevacizumab group). With a median (interquartile range) age of 57.0 (47.2-65.7) years, the study population comprised 325 men (56.7%) and 248 women (43.3%). After a median (interquartile range) follow-up of 6.9 (6.1-11.3) years, the 3-year DFS and 5-year OS rates were 88.2% (95% CI, 83.7%-93.0%) and 89.7% (95% CI, 85.4%-94.2%) in the FOLFOX4 group, 86.6% (95% CI, 81.8%-91.6%) and 89.7% (95% CI, 85.4%-94.2%) in the FOLFOX4 with bevacizumab group, and 86.7% (95% CI, 81.8%-91.8%) and 93.2% (95% CI, 89.6%-97.0%) in the XELOX with bevacizumab group, respectively. The DFS hazard ratio was 0.94 (95% CI, 0.59-1.48; P = .78) for FOLFOX4 with bevacizumab vs FOLFOX4 and 1.07 (95% CI, 0.69-1.67; P = .76) for XELOX with bevacizumab vs FOLFOX4. The OS hazard ratio was 0.92 (95% CI, 0.55-1.55; P = .76) for FOLFOX4 with bevacizumab vs FOLFOX4 and 0.85 (95% CI, 0.50-1.44; P = .55) for XELOX with bevacizumab vs FOLFOX4. Conclusions and Relevance: In this secondary analysis of data from the AVANT trial, adding bevacizumab to oxaliplatin-based chemotherapy was not associated with longer DFS or OS in patients with high-risk stage II CC. The findings suggest that the definition of high-risk stage II CC needs to be revisited. Trial Registration: ClinicalTrial.gov Identifiers: AVANT (NCT00112918); S-AVANT (NCT02228668).

A prospective, multicenter, population-based study of BRAF mutational analysis for Lynch syndrome screening.

BACKGROUND & AIMS: Mismatch repair (MMR) deficiencies are the hallmark of tumors arising in Lynch syndrome, however, in approximately 15% of sporadic colorectal cancers (CRC) these deficiencies most often are associated with somatic methylation of the MMR gene MLH1. Recently, an oncogenic mutation in the BRAF gene has been involved in sporadic CRC showing MMR deficiencies as a result of MLH1 promoter methylation. The aim of this study was to evaluate the contribution of BRAF V600E mutation analysis in the identification of MSH2/MLH1 gene mutation carriers in newly diagnosed CRC patients. METHODS: BRAF V600E mutation was analyzed in CRC patients with MMR deficiencies (microsatellite instability and/or lack of MLH1/MSH2 protein expression) in the EPICOLON population-based study. The effectiveness and efficiency of different strategies were evaluated with respect to the presence of MSH2/MLH1 germline mutations. RESULTS: MMR deficiencies were detected in 119 of the 1222 CRC patients with tumors showing either microsatellite instability (n = 111) or loss of protein expression (n = 81). BRAF mutation was detected in 22 (18.5%) of the patients. None of the patients with unambiguous germline mutation had BRAF mutation. Regardless of the strategy used to identify MSH2/MLH1 gene carriers, the introduction of BRAF analysis in these patients slightly improves their effectiveness. The introduction of BRAF mutation analysis as a step before germline genetic testing in patients with MMR deficiencies achieved a significant reduction in costs per mutation detected. CONCLUSIONS: Detection of BRAF V600E mutation could simplify and improve the cost effectiveness of genetic testing for hereditary nonpolyposis colorectal cancer, especially in patients whose family history is incomplete or unknown.

Carcinoma-associated fibroblasts affect sensitivity to oxaliplatin and 5FU in colorectal cancer cells.

The importance of tumor microenvironment (TME) as a relevant contributor to cancer progression and its role in the development of de novo resistance to targeted therapies has become increasingly apparent. However, the mechanisms of microenvironment-mediated drug resistance for nonspecific conventional chemotherapeutic agents, such as platinum compounds or antimetabolites, are still unclear.Here we describe a mechanism induced by soluble factors released by carcinoma-associated fibroblasts (CAFs) that induce the translocation of AKT, Survivin and P38 to the nucleus of tumor cells. These changes are guided to ensure DNA repair and the correct entrance and exit from mitosis in the presence of chemotherapy. We used conditioned media (CM) from normal-colonic fibroblasts and paired CAFs to assess dose response curves of oxaliplatin and 5-fluorouracil, separately or combined, compared with standard culture medium. We also evaluated a colony-forming assay and cell death to demonstrate the protective role of CAF-CM. Immunofluorescence confirmed the translocation of AKT, P38 and Survivin to the nucleus induced by CAF-soluble factors. We also have shown that STAT3 or P38 inhibition provides a promising strategy for overcoming microenvironment-mediated resistance. Conversely, pharmacologic AKT inhibition induces an antagonistic effect that relieves a cMET and STAT3-mediated compensatory feedback that might explain the failure of AKT inhibitors in the clinic so far.

Two consecutive phase II trials of biweekly oxaliplatin plus weekly 48-hour continuous infusion of nonmodulated high-dose 5-fluorouracil as first-line treatment for advanced colorectal cancer.

The combination of 5-fluorouracil (5-FU) plus leucovorin (LV) with oxaliplatin has become one of the standard treatments for advanced colorectal cancer (CRC). Two consecutive phase II trials assessed the efficacy and safety of combined therapy with oxaliplatin and high-dose 5-FU without LV for patients with advanced CRC. A total of 89 patients were enrolled in both trials. Fifty-nine patients in trial A underwent a scheduled regimen of biweekly oxaliplatin 85 mg/m(2) and weekly nonmodulated 5-FU 3.0 g/m(2). Increased incidence of toxicity led to a 25% reduction in the starting dose of 5-FU (2.25 g/m(2)) for trial B. Patients treated in trial B showed a higher cumulative dose and relative dose intensity for oxaliplatin and 5-FU than those treated in trial A. Response to treatment, time to progression (TTP), overall survival (OS), and duration of response were evaluated as efficacy variables. Overall response rate was preserved despite the reduction in 5-FU dose (55.9% and 63.0%, respectively). Median durations of responses were 10.6 and 10.4 months, median TTPs were 7.7 and 7.3 months, and OS times were 21.7 and 13.1 months, respectively. Reduction in the starting 5-FU dose from 3.0 to 2.25 g/m(2) resulted in a decrease in the main grade 3/4 hematologic toxicities (neutropenia, 22.0% to 10.0%) and nonhematologic toxicities (diarrhea, 52.5% to 23.3%; nausea/vomiting, 18.6% to 3.3%). Neurosensory toxicity was similar in both trials (16.9% and 16.7%). Biweekly oxaliplatin in combination with nonmodulated high-dose 5-FU is an active, well-tolerated treatment that offers a lower cost than a modulated schedule for patients with advanced, metastatic CRC.

Colorectal cancer metastasis resectability after treatment with the combination of oxaliplatin, irinotecan and 5-fluorouracil. Final results of a phase II study.

PURPOSE: To investigate the response rate of the triple combination of oxaliplatin (L-OHP) in combination with irinotecan (CPT-11) and 5-fluorouracil (5-FU) and to assess its impact on secondary resectability of previously non-resectable liver metastasis (LM). PATIENTS AND METHODS: Patients > or = 18 with MCRC, ECOG grade 0-2, and no prior treatment received L-OHP (85 mg/m(2)), CPT-11 (150 mg/m(2)) and 5-FU (2 250 mg/m(2) in 48 h CI) on D1 every 15 days. RESULTS: Forty-seven patients with initially non-resectable metastatic disease were included. Median age 62 years (38-76); 28 males; 26 patients with 0 performance status (ECOG) 40 patients had prior surgery and four adjuvant chemotherapy. All patients were evaluable for toxicity and 42 for response. Main grade 3-4 toxicities were neutropenia (40%), febrile neutropenia (4%), diarrhea (21%), nausea/vomiting (11%/15%), fatigue (11%), anemia and alopecia (9% each); grade 3-4 neurotoxicity was observed in 28% patients. Secondary surgery was possible in 15 of 47 (31.9%) patients and 12/30 (40%) patients with only LM: in this cohort, median OS has not been reached at 22 months median follow-up, with 2/12 patients having died. Overall response rate was 69% (95% CI, 53-82%); 13 (31%) had stable disease. Median time to progression and overall survival (OS) were 10.9 (95% CI, 9.9-13.2) and 19.9 (95% CI, 11.7-TBD) months, respectively. CONCLUSION: This combination has shown promising activity with manageable toxicity as front-line treatment in MCRC, and has allowed the resectability of LM in a considerable number of patients, offering them the possibility of long-term survival.

Combined noninvasive imaging and luminometric quantification of luciferase-labeled human prostate tumors and metastases.

Noninvasive imaging should facilitate the analysis of changes in experimental tumors and metastases-expressing photoproteins and result in improved data consistency and experimental animal welfare. We analyzed quantitative aspects of noninvasive imaging of luciferase-labeled tumors by comparing the efficiency of noninvasive light detection with in vitro quantification of luciferase activity. An intensified charge coupled device video camera was used to noninvasively image luciferase-expressing human prostate tumors and metastases in nude mice, after ip inoculation of luciferin. Repeated imaging of anesthetized animals after intervening growth periods allowed monitoring of tumor and metastases development. Comparison of photon events recorded in tumor images with the number of relative light units from luminometric quantification of homogenates from the same tumors, revealed that the efficiency with which light escapes tumors is inversely related to tumor size and that intensified charge coupled device images alone are not sufficient for quantitative evaluation of tumor growth. However, a combined videometric and luminometric approach did allow quantification and was used to show the cytostatic effects of paclitaxel in three different human prostate tumors growing in nude mice.