The consensus Immunoscore adapted to biopsies in patients with locally advanced rectal cancer: Potential clinical significance for a “Watch and Wait” strategy

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Background: We investigated whether an adaptation to rectal biopsies of the recently validated consensus Immunoscore, could predict the response to neoadjuvant treatment and delineate clinical responders that could benefit from a “Watch and Wait” (W&W) strategy with acceptable outcomes. Methods: Initial biopsies from 273 patients with locally advanced rectal cancer (LARC) treated by neoadjuvant chemoradiotherapy (nCRT) followed by Total Mesorectal Excision (TME), were immunostained for CD3+ and cytotoxic CD8+ T cells and quantified by digital pathology to determine the Immunoscore within pre-treatment Biopsy (ISB). Expression level of 44 immune related genes post-neoadjuvant treatment was investigated by Nanostring technology (n = 64 patients). Results were correlated with response to neoadjuvant treatment, disease free survival (DFS) and time to recurrence (TTR). Prognostic performance of ISB was finally assessed in 73 LARC treated by W&W strategy. Results: ISB Low, Intermediate and High were respectively observed in 23.3, 50.4 and 26.3 % of the cohort. ISB was positively and significantly correlated with the response to nCRT, as evaluated by Dworak classification (P = .0034), ypTNM (P = .0003), down-staging (P = .0014), and neoadjuvant rectal (NAR) score, (P < .0001). ISB status was also positively associated with the degree of local immune activation post-neoadjuvant treatment. ISB High patients were at low risk of relapse, with 5-year DFS rates of 81.1 % (CI, 71.3-92.1 %) as compared to 57.8 % (CI, 45.9-72.9 %) in ISB low patients. In multivariate analysis, ISB was the only significant parameter at presentation associated with DFS (High vs Low: P = .001). Among W&W patients, significant difference was observed for TTR according to ISB status (High vs Low: P = .025). Conclusions: ISB could provide a reliable estimate of the response to nCRT and risk of recurrence in LARC patients' treated by TME or W&W strategy.

Results of bevacizumab biosimilar compared with RMP for the treatment of metastatic colorectal cancer

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Background: BEVZ92 has being developed as a proposed biosimilar approved reference medicine product (RMP). BEVZ92 has an identical amino acid sequence and highly similar physicochemical and in vitro functional properties to RMP. The aim of this study was to demonstrate pharmacokinetics (PK) similarity of BEVZ92 to RMP, in combination in combination with FOLFOX or FOLFIRI, as first-line treatment in patients with mCRC (NCT02069704). Methods: PK analysis for multiple dose studies was conducted, as per guidelines, measuring the total exposure area under the concentration-time profile (AUC0-336) at cycle 1, and to the end of the dosing interval at steady-state (AUCss) at cycle 7. PK similarity was achieved if 90% confidence interval (CI) for the test-to-reference ratios of AUC0-336h and AUCss were within 80.00–125.00% bioequivalence acceptance window. Secondary endpoints included other PK parameters, safety profile, immunogenicity and objective response rate (ORR). Results: A total of 142 patients were randomized and treated. Bevacizumab serum concentrations showed a ratio (90% CI) of geometric means for BEVZ92 and RMP were 99.4% (90.5%-109%) and 100% (90.2%–112%) for AUC0-336h and AUCss, respectively. All secondary PK endpoints which include Cmax, Ctrough, Tmax, t1/2, Kel, CL, Vd, and RA-AUC were also similar between the two arms. The ORR was 45% (95% CI, 33% to 57%) for BEVZ92, and 52% (95% CI, 40% to 64%) for RMP. Immunogenicity results showed a low incidence in the anti-drug antibodies de novo development and similar between both arms. Safety profile in terms of nature, frequency and severity was similar to the RMP and according to what is expected given the underlying disease and concurrent use of chemotherapy. Conclusions: These study results confirm the bioequivalence of BEVZ92 and the RMP in a real and common clinical setting, and translates the high similarity demonstrated in the in vitro and in vivo characterization into the clinical outcomes such as efficacy, immunogenicity and safety profile. Clinical trial information: NCT02069704.

Checkmate 649: A randomized, multicenter, open-label, phase 3 study of nivolumab (Nivo) plus ipilimumab (Ipi) versus oxaliplatin plus fluoropyrimidine in patients (Pts) with previously untreated advanced or metastatic gastric (G) or gastroesophageal junction (GEJ) cancer

TPS213

Background: The combination ofoxaliplatin and fluoropyrimidine is a standard-of-care (SOC) first-line treatment of pts with metastatic G/GEJ cancer, resulting in a median overall survival (OS) of 8–11 months and objective response rate (ORR) of 30%–50%. This is accompanied by up to 77% grade 3/4 toxicities. Therefore, new treatment options are needed to improve survival and decrease toxicity in G/GEJ cancer. Nivo, a fully human IgG4 monoclonal antibody (mAb) that targets programmed death 1 (PD-1) and ipi, a fully human IgG1 mAb that targets cytotoxic T-lymphocyte–associated protein 4, have demonstrated manageable safety profiles and efficacy in multiple tumor types and may have a synergistic effect. In a phase 1/2 study in chemotherapy-refractory pts with G/GEJ/esophageal cancer with or without PD-1 ligand 1 (PD-L1) expression, second-line nivo 1 mg/kg + ipi 3 mg/kg demonstrated a manageable safety profile and resulted in 26% ORR (44% ORR in pts with PD-L1+ tumors), median OS of 6.9 months, and a 34% OS rate at 12 months (Janjigian Y, et al. J Clin Oncol. 2016;34[suppl][abstract 4010]). This open-label, phase 3 trial will evaluate nivo + ipi as first-line therapy for pts with G/GEJ cancer (CheckMate 649; NCT02872116). Methods: In this study, 870 pts aged ≥ 18 years with untreated advanced or metastatic G/GEJ cancer with or without PD-L1 expression will be randomized to receive nivo + ipi (4 doses; followed by nivo monotherapy) or investigator’s choice of capecitabine/oxaliplatin (XELOX) or fluorouracil/leucovorin/oxaliplatin (FOLFOX). Tumor tissue for determination of PD-L1 status must be provided from ≤ 6 months before study treatment. Pts receiving chemotherapy or radiotherapy for G/GEJ cancer within the last 6 months or pts with suspected autoimmune disease, uncontrolled medical disorder, or active infection are excluded. Primary endpoint is OS in pts with PD-L1+ tumors. Secondary endpoints include OS in all pts and progression-free survival and time to symptom deterioration in all pts and pts with PD-L1+ tumors. Clinical trial information: NCT02872116.

CheckMate 577: A randomized, double-blind, phase 3 study of nivolumab (Nivo) or placebo in patients (Pts) with resected lower esophageal (E) or gastroesophageal junction (GEJ) cancer

TPS212

Background: Chemoradiotherapy (CRT) followed by surgical resection is a current standard of care (SOC) for pts with E/GEJ cancer, with 3- and 5-year survival rates ranging from 30% to 40%. Currently, no effective adjuvant SOC is available following resection. Expression of programmed death-1 (PD-1) ligands 1/2 (PD-L1/L2) has been associated with a poor prognosis in E/GEJ cancer, suggesting that PD-1 inhibition may improve outcomes. Nivo is a fully human IgG4 monoclonal antibody that targets PD-1, with demonstrated survival benefit in multiple tumor types and long-term responses in some patients. A phase 1/2 study of nivo monotherapy in chemotherapy-refractory pts with gastric/E/GEJ cancer demonstrated tumor regression, a median overall survival (OS) of 5 months, and a 12-month OS rate of 36% in pts with PD-L1+ and PD-L1- tumors (Janjigian Y, et al. J Clin Oncol. 2016;34:suppl; abstract 4010). This multinational, double-blind, phase 3 trial will evaluate nivo as an adjuvant therapy for pts with resected E/GEJ cancer (CheckMate 577; NCT02743494). Methods: In this study, an estimated 760 pts aged ≥ 18 years with stage II/III E/GEJ cancer are randomized to receive nivo or placebo. Prior to randomization, pts must have completed preoperative CRT followed by surgery and been diagnosed with residual pathological disease after being surgically rendered free of disease with negative margins following complete resection. Pts with stage 4 resectable disease, cervical esophageal cancer, or those who have not received concurrent CRT prior to surgery are not eligible for study enrollment. Primary endpoints are OS and disease-free survival. The secondary endpoint is OS rate at 1, 2, and 3 years. Clinical trial information: NCT02743494.

Is proliferative index (Ki-67) useful to stratify patients (pts) with G2 gastroenteropancreatic neuroendocrine tumors (GEP-NETs)? Clinicopathologic correlation

255

Background: Grade 2 (G2) Neuroendocrine tumors (NETs), of the digestive tract is a heterogeneous group of tumors. Several treatment options including chemotherapy and target therapy are available, but there is a lack of prospective trials assessing the role of pronostic factors in this population. Aim(s): to analyze prognostic factors and clinical characteristics in a population of patients with G2 GEP-NETs. To determine the role of ki 67 in the stratification of G2 population. Methods: Study population was obtained from our prospective database (Argentum Group). Survival was estimated using the Kaplan-Meier method and compared between Ki-67 quartiles using the log-rank test. Value of Ki-67 to discriminate mortality was assesed with a ROC curve analysis Results: 144 pts were evaluated. Mean age 54.9, 46.7% male. 102 (70.8%) with metastatic disease, mainly hepatic in 97 pts. (67.4%). 67.9 % underwent surgery. 34% received chemotherapy, and 10.9% target therapy. Median Ki-67 value was 6 (IQR 4-10), ROC curve=0.62 (95% CI 0.53 a 0.72 p=0.021. cut-off: 6.5 (sensitivity 62.2%, specificity 57.7%). Median survival was 97, 67, 51 and 27 months according stratification by quartile (p.001), 45 events (31.7%). Conclusions: Our results suggest that in the heterogenous G2 GEP-NETs there are significant differences in survival. This study was underpowered to detect differences between Ki-67 quartiles, we detected that chemotherapy was mostly used in the higher quartiles.

A high degree of LINE-1 hypomethylation is a unique feature of early-onset colorectal cancer

OBJECTIVE

Early-onset colorectal cancer (CRC) represents a clinically distinct form of CRC that is often associated with a poor prognosis. Methylation levels of genomic repeats such as LINE-1 elements have been recognized as independent factors for increased cancer-related mortality. The methylation status of LINE-1 elements in early-onset CRC has not been analyzed previously.

DESIGN

We analyzed 343 CRC tissues and 32 normal colonic mucosa samples, including 2 independent cohorts of CRC diagnosed ≤ 50 years old (n=188), a group of sporadic CRC >50 years (MSS n=89; MSI n=46), and a group of Lynch syndrome CRCs (n=20). Tumor mismatch repair protein expression, microsatellite instability status, LINE-1 and MLH1 methylation, somatic BRAF V600E mutation, and germline MUTYH mutations were evaluated.

RESULTS

Mean LINE-1 methylation levels (± SD) in the five study groups were early-onset CRC, 56.6% (8.6); sporadic MSI, 67.1% (5.5); sporadic MSS, 65.1% (6.3); Lynch syndrome, 66.3% (4.5) and normal mucosa, 76.5% (1.5). Early-onset CRC had significantly lower LINE-1 methylation than any other group (p<0.0001). Compared to patients with <65% LINE-1 methylation in tumors, those with ≥ 65% LINE-1 methylation had significantly better overall survival (p=0.026, log rank test).

CONCLUSIONS

LINE-1 hypomethylation constitutes a potentially important feature of early-onset CRC, and suggests a distinct molecular subtype. Further studies are needed to assess the potential of LINE-1 methylation status as a prognostic biomarker for young people with CRC.

F-box and WD repeat domain-containing 7 (FBXW7) mRNA and outcome in biliary tract cancer

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Background: Thestandard treatment for biliary tract cancer is gemcitabine plus platinum, but median progression-free survival (PFS) is only 5-8 months (m) (Valle et al, NEJM 2010). Gene expression or somatic mutations may influence the clinical phenotype, which will affect decisions on individualized treatment. Methods: We retrospectively analyzed tissue blocks from 54 advanced or metastatic cholangiocarcinoma, gallbladder or ampulllary cancer patients (p) treated with single-agent gemcitabine or gemcitabine plus carboplatin or cisplatin. Using RT-PCR, we analyzed the mRNA expression levels of oncogenes, tumor suppressors and DNA repair genes (BRCA1, RRM1, AEG-1, RAP80, SPINK1 and FBXW7) and correlated results with PFS, overall survival (OS) and response. In addition, FBXW7 hotspot mutations were assessed. Results: p characteristics: 72% females; median age, 60 (40-87). Only FBXW7 expression correlated with PFS and OS. When FBXW7 levels were dichotomized at the median value, PFS was 4.2 m for p with low levels vs 12.6 m for p with high levels (p=0.02). When FBXW7 expression was divided by terciles, PFS was 4.9 m for p in the lowest tercile, 7.6 for p in the intermediate tercile, and 26.9 m for p in the highest tercile (p=0.08). OS was 6.2 m for p in the lowest tercile, 8 m for p in the intermediate tercile, and not reached for p in the highest tercile. No other significant correlation was observed between expression levels of the other genes examined and PFS or OS. Only AEG-1 expression correlated with response (p=0.05). No FBXW7 hotspot mutations were detected. Conclusions: Although we did not find the FBXW7 hotspot mutations previously described in biliary tract cancer, FBXW7 mRNA expression significantly influenced PFS and OS. A separate cohort of p is being analyzed to validate the prognostic role of FBXW7.

Somatostatin receptor (SSTR) expression and proliferative index (Ki 67) in 100 patients (pts) with gastroenteropancreatic neuroendocrine tumors (GEP-NETs): Clinical-pathological correlation

e14598

Background: Somatostatin receptor expression (SSTR), mainly subtypes 2 and 5, is a feature of well differentiated GEP-NETs. Such expression has a prognostic and predictive value for the use of somatostatin analogs.Ki 67, present during the cycle phases (G1, S, G2 y M) is a nuclear antigen associated with cell proliferation. The correlation between both clinical and pathological factors is under active investigation in patients with GEP-NETs. Methods: An analysis including 100 patients in the database of the Argentum Group was performed. Consecutive patients were included during the 2006-2007 period. In all cases, a centralized revision of the sample was conducted for diagnosis confirmation.The study of SSTR receptors in tissue and Ki67 was conducted using IHQ.The Kaplan-Meier method was used to analyse survival. Log-rank test was used for the comparative analysis of the variables of interest. Results: The expression of at least one of the SSTRs 2 (a) or 5 was found in 86% and 62% of cases respectivevly in this population. The univariate analysis showed significant differences in the expression of SSTR2 (a) but not in the expression of SSTR 5.The expression of the proliferative index (Ki 67) was associated with significant differences in relation to OS at 5 years, 84% (Ki 67 under or equal to 2%), 66% (Ki 67 between 3 and 15%) and 13% (Ki 67 over 15%). The OS at 5 years in patients with SSTR 2/5 positive and Ki 67 under 2% was 86%, 64% in pts. with SSTR 2/5 positive and Ki 67 over 2% and 20 % in pts. with SSTR 2/5 negative, independent Ki 67 (p .0023). Conclusions: The expression of at least one of the SSTRs 2 (a) or 5 was found in 86% and 62% of cases respectivevly in this population. In the population with GEP-NETs under study, a subgroup of patients with a better prognosis was identified in association with the expression of SSTR 2/5 and Ki67 below 2%. The assessment of SSTR 2(a) and 5 in tissues, together with the study of the proliferative index are a useful tool for prognosis assessment in these patients.

[Treatment of patients with esophageal cancer in Argentina. Surgery or clinical research?]

In Accident the incidence of esophageal adenocarcinoma has increased at a rate exceeding that of all other tumors. In Argentina, the incidence of cancer of the oesophagus is unknown and patients are treated according to the classic medical or institutional experience and usually local and poorly effective treatment modalities are used. Currently, the prognosis of patients with this condition is very poor and there is a need to explore new therapeutics. We think that instead of treating patients with classic modalities with predictable results, the aim should be a search of alternatives based on clinical research.

[Resection of hepatic colorectal metastases]

Between October 1986 and March 1995, 35 patients had hepatic resections because of metastases of colorectal cancer: 24 (68.6%) metastasectomies were carried out and 11 formal resections. The surgical morbility was 34.3% (12/35 patients) and the mortality 5.7% (2/35 patients). The medium hospitalization was 13.1 days (range: 6-68). The medium follow up of our population was 30.3 months. From the 33 evaluable patients (2 out of the 35 patients were discarded from the analysis for intraoperatory death) 21 relapsed. The medium disease free survival was 18.9 months; 19/33 patients died (all from progressive disease). The medium survival for the 33 patients was 26.6 months. The 5 years survival was 42.4%, comparable with other international series. We consider that factors related with the strict selection of the patients contributed to achieve these encouraging results. The multidisciplinary work (that made easier the selection of the better candidates for surgery) involving surgeons, anesthesiologists, oncologists, radiologists and internists, were made possible in a public hospital.

Radiotherapy for bone metastases of hepatocellular carcinoma

Radiotherapeutic effects of 42 bone metastases in 26 hepatocellular carcinoma patients were retrospectively analyzed. Pain relief was observed in 79% of 37 bone metastases treated (29/37). Antitumor effects and improvement of paralysis were also observed in 88% (8/9) and 17% (1/6), respectively. The toxicities experienced were tolerable. Radiotherapy was an effective means of palliation in the treatment of hepatocellular carcinoma bone metastases.