Metastasectomy in colorectal carcinoma (CRC) patients (pts) with mBRAF: Prospective database analysis

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Background: Role of metastasectomy in pts with mBRAF metastatic CRC is still controversial. We performed analysis of prospective multicentric database of pts with mBRAF mCRC to evaluate the efficacy of metastasectomy in such group of pts in the real clinical practice. Methods: We analyzed a database of pts with mCRC in 7 cancer clinics in Russia and chose pts with metastasectomy with different mutational status. The primary endpoints were disease free survival (DFS) and overall survival (OS), which were calculated from the time of metastasectomy. Analysis was performed with the SPSS v.20 software package. Results: The study included 126 pts: 26 pts with mBRAF, 57 pts with mRAS and 43 pts with wtRAS/BRAF. Pts with mBRAF more often had synchronous metastases (50%/19,3/11,6%, p<0,01), N2 status (38,5%/11%/19,6%, p=0,04). In mBRAF cohort all but 1 pt had V600 mutations; peritonectomy performed in 19,2%, liver resection – in 34,6%, lung resection, ovariectomy, metastasectomy in brain and retroperitoneal lymph nodes dissection with removal of the local relapse – over 11,5%; R0 resection was achieved in 88,5%. Median DFS was 7 months in mBRAF pts, 14 months in mRAS and not achieved in wtRAS/BRAF group treated (HR 2,1, 95%CI 1,5-3.1, p<0.01). Median OS was 26 months in mBRAF, 38 months in mRAS and not achieved in wtRAS/BRAF group (HR 1,5, 95%CI 1,0-2,4, p=0.06). Perioperative chemotherapy didn’t improve DFS in pts with mBRAF (HR 1,9, 95%CI 0,67-5,7, p=0,2). The best median DFS were in pts after ovariectomy – 10 months, the worst - after retroperitoneal lymph nodes dissection with removal of the local relapse – 2 months. Conclusions: Prognosis of pts with mBRAF after metastasectomy is worse than with other mutational phenotypes. However in selected cases metastasectomy might be considered in such aggressive mCRC.

Is antiangiogenic therapy necessary for patients with metastatic colorectal cancer (mCRC) and mutation in the BRAF gene? Results of the systematic review and meta-analysis

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Background: There are no direct prospective randomized studies supporting the need for antiangiogenic drugs in the treatment of patients with the m BRAF mCRC. However, subgroup analysis of different studies showed conflicting results. Therefore, we performed systemic review and meta-analysis to compare efficacy anti-angiogenic targeted therapy with chemotherapy and chemotherapy alone in patients with m BRAF mCRC in terms of progression free survival (PFS), and overall survival (OS). Methods: We performed a search of all prospective randomized phase III studies in PubMed, ASCO and ESMO congresses for all years before September, 2020, compared chemotherapy (CT) plus bevacizumab or aflibercept or ramucirumab and CT alone at the first-line or second-lines with information of the BRAF status. Primary outcome was hazard ratio (HR) for PFS and 95% confidence interval (CI); secondary–HR for OS and 95%CI. Fixed effects were used for analysis. Meta-analysis was conducted by "Review Manager" Ver. 5.3. Results: We identified 4 trials (AVF2107g, AGITG MAX, VELOUR and RAISE), which included 120 patients with mBRAF (anti-angiogenic plus CT–65 (54%) and CT alone–55 (46%). According to results of the meta-analysis there was a tendency for significant improvement in PFS (HR 0.64, 95% CI 0.4-1.02; p = 0.06; I2 = 0%, p for heterogeneity 0.7; 53trials) and significant improvement in OS (HR 0.51, 95% CI 0.32-0.82; p = 0.005; I2 = 0%, p for heterogeneity 0.52; 4 trials) in group of ani-angiogenic therapy. Conclusions: Addition of anti-angiogenic therapy to chemotherapy showed improvement in the PFS and OS in pts with m BRAF compared with chemotherapy alone. A prospective randomized trial is needed to determine the optimal regimen of systemic therapy for pts with m BRAF mCRC.

Olanzapine (OLN) versus aprepitant (APR) in patients receiving high-emetogenic chemotherapy: Final results of randomized phase II trial

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Background: Management of chemotherapy-induced nausea and vomiting (CINV) remains challenging. OLN might provide several benefits over APR which is current standard of care – particularly in terms of nausea control and cost effectiveness. However, sedation associated with recommended doses of olanzapine precludes its wide use in oncology practice. Methods: This was randomized phase II single center study aimed to compare OLN and APR in CINV prophylaxis. Key inclusion criteria were: chemo- and radio-therapy naïve patients, planned administration of high-emetogenic chemotherapy (cisplatin, carboplatin AUC≥4, doxorubicin etc). Patients were randomized 1:1 ratio in the following arms: olanzapine 5 QD day 0-4 or aprepitant 125 mg day 1, 80 mg day 2,3. All patients received ondansetron 16 mg day 1 and dexamethasone 8 mg day 1-3. Primary endpoint was complete nausea control (no nausea and no rescue medication) 0-120 hours after chemotherapy. Complete response (no emesis and no rescue medication) was a key secondary end point. Nausea was assessed using MASCC Antiemesis Tool. Sample size: 94 patients to increase nausea control rate from 40 to 70% (α = 0.05; β = 0.80; 10% of estimated data loss). Results: We included in the analysis 93 patients who could be evaluated. The groups were well balanced, median age was 49 years, vast majority of patients (95.6%) were females. The proportion of patients with complete nausea control in OLN and APR groups was 44.2% and 24.0% respectively (RR 2.5; 95% CI 1.04-6.08; p = 0.039). Complete response was achieved in 74.4% and 54.0% patients respectively (RR 2.48; 95% CI 1.026-5.99; p = 0.041). No differences in rates of undesired sedations were detected. Conclusions: Our data suggests superiority of OLN regimen in terms of nausea control. This regimen deserves further investigation. Clinical trial information: NCT03478605.

Incidence and prognostic factors in patents (pts) with mutant BRAF (mBRAF) metastatic colorectal cancer (mCRC) in Russia

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Background: m BRAF mCRC has the aggressive phenotype. The incidence of such mutation in Europe and the USA is around 8-14%, in Asian countries - 4-8%. The purpose of this population-based study was to determine the incidence and identifying prognostic factors in pts with mBRAF mCRC in Russia. Methods: A multicenter retrospective analysis of clinical data and treatment results of pts with mBRAF mCRC was performed. The main method for determining mutations was a PCR. The main efficacy endpoint was progression free survival (PFS) at the 1st line. Multivariate analysis was performed using Cox regression model. Results: 437 out of 8646 pts (5%) with a known mutational status had m BRAF (V600E). Clinical data were collected from 119/437 (27.2%): female - 65.5%, average age - 60 years (28-86), MSI-H -10%; the right-sided primary tumor – in 65%, left-sided – in 17%, rectum – in 18%; the primary tumor was removed in 76%; adjuvant chemotherapy was administered in 30%; lung metastases – in 15 %, liver - 45%, peritoneal metastases – in 38%; metastasectomy was performed in 13% pts. The first line was administered in 86 (72%) pts: FOLFIRI / XELIRI - 17 (20%), FOLFOX / XELOX - 50 (58%), FOLFOXIRI - 12 (14%), monotherapy of fluoropyrimidines – in 7 (8%). Bevacizumab was added to chemotherapy at 1st line in 25 (29%) patients, anti-EGFR – in 8 (9%) pts. PFS at the 1st line was 7 months: XELOX / FOLFOX - 7, FOLFOXIRI - 7, FOLFIRI / XELIRI - 6 and fluoropyrimidines - 2 months (HR 0.9, 95% CI 0.6-1.1, p = 0.3). None of the clinical or morphological factors except the presence of metastases in the retroperitoneal lymph nodes (HR 2.6, 95% CI 1.3-5.4, p = 0.006) did not have an independent negative prognostic value. Conclusions: In contrast to Western countries the incidence of mBRAF gene in the population of pts with mCRC in the Russia is low and we found a high incidence of localization of the primary tumor in the rectum. We didn’t reveal any prognostic factors except metastases in the retroperitoneal lymph nodes, and didn’t reveal any differences between the usual duplets and standard regimen for such mutation - FOLFOXIRI in term of 1st line PFS. This suggests we need a prospective randomized study to determine the optimal regimen of chemotherapy at 1st line for mBRAF mCRC pts.

Role of adjuvant chemotherapy in patients with locally advanced rectal carcinoma after preoperative chemoradiotherapy: Single center experience

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Background: Various national guidance provide different approaches in adjuvant chemotherapy for locally advanced rectal carcinoma initially treated with preoperative chemoradiotherapy. We evaluated the efficacy of adjuvant chemotherapy depending on the clinical stage of disease (prior to chemoradiotherapy) and yp stage (after surgery). Methods: Preoperative chemoradiotherapy was administered in 457 patients with locally advanced rectal carcinoma. Radiotherapy was performed in pts receiving capecitabine (64%), intravenous administration of 5-FU (16%) or combination fluoropyrimidines with oxaliplatin (20%). Adjuvant chemotherapy was administered in 98 patients (21%) (fluoropyrimidines alone (20%) or in combination with oxaliplatin (80% patients). Overall survival (OS) was the primary endpoint. Statistical analysis was performed in IBM SPSS statistics v.20 software package. Results: the mean age of patients was 56.6 years, male - 56%. Median of follow up was 42 months (2-141). Adjuvant chemotherapy did not result to better OS in any of clinical stage (p = 0.6 HR 1.1, 95% CI 0.6-2.1). However adjuvant chemotherapy tended to improve disease free survival (DFS) in stage ypT0-4N1-2M0 (р=0.1, HR=0.6, 95%CI 0.4-1.1). Subanalysis showed significant improvement of DFS in patients with ypT1-4N2M0: median of DFS in patients with adjuvant chemotherapy was 62 months, in patients from group of surveillance – 16 months (р<0.01, HR=0.3, 95%CI 0.14-0.7) and a tendency to improvement of OS (table). Conclusions: Our retrospective data confirmed the results of ADORE prospective trial, and showed that adjuvant chemotherapy for locally advanced rectal carcinoma after chemoradiotherapy should be administered only in patients with residual positive lymph nodes (yp stage III). [Table: see text]