A Predictive Model to Evaluate Pathologic Complete Response in Rectal Adenocarcinoma

Introduction: Neoadjuvant chemo-radiotherapy (nCRT) before surgery was a standard treatment strategy for locally advanced rectal cancer (LARC). The aim of this study was to assess the relationship between the predictive factors and pathological complete response (pCR) in rectal cancer patients, especially in ultra-low ones. Method: A total of 402 patients were involved in this retrospective study. The logistic regression analyses were used to compare the different subgroups in univariate analysis. Multivariate analysis was performed to determine the independent predictive factors of pCR by using a logistic regression model. Results: A total of 402 patients received preoperative CRT. In all patients, multivariate analysis revealed that circumferential tumor extent rate (CER) (≤ 2/3cycle vs >2/3 cycle, P < .001, OR = 4.834, 95% CI: 2.309-10.121), carcinoembryonic antigen (CEA) level (both ≤ 5 vs pre > 5 and post ≤ 5 vs both > 5, P = .033, OR = 1.537, 95% CI: 1.035-2.281), and interval time between the end of CRT and surgery (P = .031, OR = 2.412, 95% CI: 1.086-5.358) were predictive factors for pCR. The area under the curve (AUC) of the predictive model was 0.709 (95% CI: 0.649-0.769), which was significantly higher than the CER (0.646, 95% CI: 0.584-0.709), interval time (0.563, 95% CI: 0.495-0.631) and CEA level (0.586, 95% CI: 0.518-0.655). In ultra-low rectal patients, multivariate logistic regression analysis revealed that CER (≤ 2/3 cycle vs > 2/3 cycle, P = .003, OR = 7.203, 95% CI: 1.934-26.823) and mismatch repair (MMR) status (pMMR vs dMMR, P = .016, OR = 0.173, 95% CI: 0.041-0.720) were predictive factors for pCR. The AUC of the predictive model was 0.653 (95% CI: 0.474-0.832). Conclusion: New predictive models were varied by the histologic types and MMR statuses to evaluate the trend of tumor response to nCRT in all RC cases and ultra-low RC patients, which may be used to individualize stratify for selected LARC patients.

Neoadjuvant Chemo-Radiation Using IGRT in Patients with Locally Advanced Gastric Cancer

The goal of this study was to see how effective and safe neoadjuvant chemoradiation with image-guided IMRT was in patients with locally advanced resectable gastric cancer. Between January 2013 and June 2019, patients with locally advanced (cT3/cT4 or N+) gastric cancer treated with neoadjuvant chemoradiotherapy at PUMCH (Peking Union Medical College Hospital) were retrospectively studied. Using concurrent chemotherapy (Capecitabine alone or XELOX*2 cycles), radiotherapy (IMRT (intensity-modulated radiation therapy) 45 Gy, 25#, 5 weeks) was delivered with IGRT (image-guided radiotherapy) before the start of each weeks therapy to ensure accuracy and repeatability. A total of 95 patients were enrolled in the study, 93 (97.9%) stage cT3/T4 and 85 (89.5%) stage N+. Of these, 85 patients (89.5%) had a tumor located in the upper 1/3 of the stomach, and 93/95 patients (97.9%) completed neoadjuvant chemoradiation, with 80 patients (84.2%) undergoing stomach resection (58 D2 and 22 D1 gastrostomies). Pathology downstaging was found in 68 patients (85.0%), with 66 patients (82.5%) receiving T downstaging and 56 patients (70.0%) receiving N downstaging. There were 11 individuals (13.8%) who had a pathological complete response (PCR). The average period of follow-up was 44.7 months (19-96 months). The 5-year OS (overall survival), LRFS (local recurrence-free survival), and DMFS (distant metastasis free survival) rates of patients were 47.0% (95% CI: 38.6-55.4), 86.55% (95% CI: 79.1-93.99) and 60.71% (95% CI: 51.49-69.93%), respectively. Thirteen (13.7%) patients had grade 3-4 leukopenia, anemia, and thrombocytopenia, while 9 (9.5%) patients had grade 3-4 anemia, and 5 (5.3%) patients had grade 3-4 thrombocytopenia. PCR was found to be a significant predictive factor for OS in multivariate analysis (HR = 11.211, 95% CI: 1.500-83.813, p = 0.024). The method of using IGRT image-guided IMRT (45 Gy, 25 fractions, 5 weeks) combined with concurrent chemotherapy in patients with locally advanced resectable gastric cancer was equally effective when compared to the clinical efficacy of neoadjuvant chemoradiotherapy, with clinical outcomes achieving equal efficacy, with similar PCR rates and high rates of OS, LRFS, and DMFS, as well as good tolerances of concurrent chemoradiotherapy with acceptable side effects.

Critical role of bevacizumab scheduling in combination with pre-surgical chemo-radiotherapy in MRI-defined high-risk locally advanced rectal cancer: Results of the BRANCH trial

BACKGROUND

We have previously shown that an intensified preoperative regimen including oxaliplatin plus raltitrexed and 5-fluorouracil/folinic acid (OXATOM/FUFA) during preoperative pelvic radiotherapy produced promising results in locally advanced rectal cancer (LARC). Preclinical evidence suggests that the scheduling of bevacizumab may be crucial to optimize its combination with chemo-radiotherapy.

PATIENTS AND METHODS

This non-randomized, non-comparative, phase II study was conducted in MRI-defined high-risk LARC. Patients received three biweekly cycles of OXATOM/FUFA during RT. Bevacizumab was given 2 weeks before the start of chemo-radiotherapy, and on the same day of chemotherapy for 3 cycles (concomitant-schedule A) or 4 days prior to the first and second cycle of chemotherapy (sequential-schedule B). Primary end point was pathological complete tumor regression (TRG1) rate.

RESULTS

The accrual for the concomitant-schedule was early terminated because the number of TRG1 (2 out of 16 patients) was statistically inconsistent with the hypothesis of activity (30%) to be tested. Conversely, the endpoint was reached with the sequential-schedule and the final TRG1 rate among 46 enrolled patients was 50% (95% CI 35%-65%). Neutropenia was the most common grade ≥ 3 toxicity with both schedules, but it was less pronounced with the sequential than concomitant-schedule (30% vs. 44%). Postoperative complications occurred in 8/15 (53%) and 13/46 (28%) patients in schedule A and B, respectively. At 5 year follow-up the probability of PFS and OS was 80% (95%CI, 66%-89%) and 85% (95%CI, 69%-93%), respectively, for the sequential-schedule.

CONCLUSIONS

These results highlights the relevance of bevacizumab scheduling to optimize its combination with preoperative chemo-radiotherapy in the management of LARC.

Phase 1/2 study of valproic acid and short-course radiotherapy plus capecitabine as preoperative treatment in low-moderate risk rectal cancer-V-shoRT-R3 (Valproic acid--short Radiotherapy--rectum 3rd trial)

BACKGROUND

Locally advanced rectal cancer (LARC) is a heterogeneous group of tumors where a risk-adapted therapeutic strategy is needed. Short-course radiotherapy (SCRT) is a more convenient option for LARC patients than preoperative long-course RT plus capecitabine. Histone-deacetylase inhibitors (HDACi) have shown activity in combination with RT and chemotherapy in the treatment of solid tumors. Valproic acid (VPA) is an anti-epileptic drug with HDACi and anticancer activity. In preclinical studies, our group showed that the addition of HDACi, including VPA, to capecitabine produces synergistic antitumour effects by up-regulating thymidine phosphorylase (TP), the key enzyme converting capecitabine to 5-FU, and by downregulating thymidylate synthase (TS), the 5-FU target.

METHODS/DESIGN

Two parallel phase-1 studies will assess the safety of preoperative SCRT (5 fractions each of 5 Gy, on days 1 to 5) combined with (a) capecitabine alone (increasing dose levels: 500-825 mg/m2/bid), on days 1-21, or (b) capecitabine as above plus VPA (oral daily day -14 to 21, with an intra-patient titration for a target serum level of 50-100 microg/ml) followed by surgery 8 weeks after the end of SCRT, in low-moderate risk RC patients. Also, a randomized phase-2 study will be performed to explore whether the addition of VPA and/or capecitabine to preoperative SCRT might increase pathologic complete tumor regression (TRG1) rate. A sample size of 86 patients (21-22/arm) was calculated under the hypothesis that the addition of capecitabine or VPA to SCRT can improve the TRG1 rate from 5% to 20%, with one-sided alpha = 0.10 and 80% power.Several biomarkers will be evaluated comparing normal mucosa with tumor (TP, TS, VEGF, RAD51, XRCC1, Histones/proteins acetylation, HDAC isoforms) and on blood samples (polymorphisms of DPD, TS, XRCC1, GSTP1, RAD51 and XRCC3, circulating endothelial and progenitors cells; PBMCs-Histones/proteins acetylation). Tumor metabolism will be measured by 18FDG-PET at baseline and 15 days after the beginning of SCRT.

DISCUSSION

This project aims to improve the efficacy of preoperative treatment of LARC and to decrease the inconvenience and the cost of standard long-course RT. Correlative studies could identify both prognostic and predictive biomarkers and could add new insight in the mechanism of interaction between VPA, capecitabine and RT.EudraCT Number: 2012-002831-28.

TRIAL REGISTRATION

ClinicalTrials.gov number, NCT01898104.