Left-sided Tumors Research Articles

Efficacy of Reinforced Stapler Versus Hand-sewn Closure of the Pancreatic Stump During Pure Laparoscopic Distal Pancreatectomy to Reduce Pancreatic Fistula.

Laparoscopic distal pancreatectomy (L-DP) is the standard procedure for treating left-sided pancreatic tumors. Stapler closure of the pancreas is the preferred method for L-DP; however, postoperative pancreatic fistula (POPF) remains a challenging problem. The present study aimed to compare the surgical outcomes of staple closure using a reinforcing stapler (RS) and transection using an ultrasonic dissector followed by hand-sewn (HS) closure in a fish-mouth manner in pure L-DP and to determine independent perioperative risk factors for clinically relevant postoperative pancreatic fistula (CR-POPF). Among the 85 patients who underwent pure L-DP between February 2011 and August 2021, 80 of whom the pancreatic stump was closed with RS (n = 59) or HS (n = 21) were retrospectively investigated. Associations between potential risk factors and POPF were assessed using univariate analysis. The factors, of which the P value was determined to be <0.1 by univariate analysis, were entered into a multivariate regression analysis to ascertain independent predictive factors. The surgery time and estimated blood loss were not significantly different between the two groups. Overall, 13 patients (16.3%) developed CR-POPF (B = 12 and C = 1). The rate of CR-POPF was lower in RS than in HS; however, the difference was not statistically significant (RS vs HS: 11.9% vs 28.9%, P = 0.092). Consistent with the results for CR-POPF, the rate of Clavien-Dindo IIIa or more postoperative complications and the length of hospital stay were also not significantly different between the two groups (RS vs HS: 10.2, 12% vs 14.3%, 14d). In the univariate analysis of risk factors for CR-POPF, the pancreatic thickness at the transection site, procedure for stump closure, and estimated blood loss were associated with a significantly higher rate of CR-POPF. The multivariate analysis revealed that the pancreatic thickness at the transection site (cutoff: 12mm) was the only independent risk factor for CR-POPF (odds ratio: 6.5l, 95% CI: 1.4-30.4, P = 0.018). The rate of CR-POPF was much lower in RS than in HS for pancreatic thickness <12mm (RS vs HS: 4.1% vs 28.6%), whereas that was rather higher in RS than in HS for pancreatic thickness ≥12mm (RS vs HS: 50% vs 28.6%). RS closure was superior to HS closure for pancreatic thickness <12mm and for prevention of CR-POPF after pure L-DP. It is necessary to seek more reliable procedures for pancreatic stump closure in patients with a pancreatic thickness of ≥12mm.

Higher risk of intraoperative bleeding in right-sided renal tumors compared to left-sided tumors in robot-assisted partial nephrectomy.

To compare intraoperative blood loss in robot-assisted partial nephrectomy (RAPN) between the right and left sides. The data of patients who underwent RAPN at a single institution between 2013 and 2021 were retrospectively analyzed. Using propensity score matching, we compared estimated blood loss (EBL) between right- and left-sided tumors. This study included 1006 patients who underwent transperitoneal RAPN (N=726) and retroperitoneal RAPN (N=280). Through matching, 303 patients were selected for each group. The mean tumor size was 3.1 ± 1.4cm. The RENAL score was 4-6 in 270 (44.5%), 7-9 in 263 (43.3%), and 10-11 in 73 (12.0%) cases. The EBL on the right side was significantly higher than on the left side (102 vs 70 mL, P=.02). The most experienced surgeon showed significant differences in EBL (116 vs 73 mL, P=.024) and blood transfusion rate (2.5 vs 0%, P=0.025) between the right and left sides. In the retroperitoneal RAPN, 104 patients were selected in each group through matching. The EBL was significantly higher on the right side than on the left side (50 vs 24 mL, P=0.02). Operative time was longer on the right side than on the left side (120 vs 109 min, P=.05). Right-sided tumors had a significantly larger EBL than left-sided tumors in RAPN. The difference was evident in the most experienced surgeon who performed RAPN for larger and complicated cases. This information may help surgeons decide whether to clamp the renal artery and vein during tumor resection in large and complicated right-sided tumors.

Stroke and Noninfective Native Valvular Disease.

Embolic stroke of undetermined source is a challenging clinical entity. While less common than atrial fibrillation and endocarditis, many noninfective heart valve lesions have been associated with stroke and may be considered as culprits for cerebral infarcts when other more common causes are excluded. This review discusses the epidemiology, pathophysiology, and management of noninfective valvular diseases that are commonly associated with stroke. Calcific debris from degenerating aortic and mitral valves may embolize to the cerebral vasculature causing small- or large-vessel ischemia. Thrombus which may be adherent to calcified valvular structures or left-sided cardiac tumors may also embolize resulting in stroke. Tumors themselves, most commonly myxomas and papillary fibroelastomas, may fragment and travel to the cerebral vasculature. Despite this broad differential, many types of valve diseases are highly comorbid with atrial fibrillation and vascular atheromatous disease. Thus, a high index of suspicion for more common causes of stroke is needed, especially given that treatment for valvular lesions typically involves cardiac surgery whereas secondary prevention of stroke due to occult atrial fibrillation is readily accomplished with anticoagulation.

Tim3 and PD-1 as a therapeutic and prognostic targets in colorectal cancer: Relationship with sidedness, clinicopathological parameters, and survival.

Colorectal cancer (CRC) is a heterogeneous disease that complicates predicting patients' prognosis and their response to treatment. CRC prognosis is influenced by the tumor microenvironment (TME). The immune system is a critical component of the TME. Programmed cell death receptor 1 (PD-1) and T-cell immunoglobulin and mucin-domain containing-3 (Tim3) are inhibitory immune checkpoints that regulate immune response and may provide prognostic power. However, the effect of their expressions and co-expressions on the CRC prognosis remains unclear. Accordingly, this study aimed to investigate the prognostic value of the CD8, CD3, PD-1, Tim3 expression, and PD-1/Tim3 co-expression in patients with CRC. One hundred and thirty six patients with CRC who underwent curative surgery were enrolled in the study. Immunohistochemical staining was performed for PD-1, Tim3, CD8, and CD3, and the expression of each marker was evaluated in the center of the tumor (CT), invasive margin (IM), and adjacent normal-like tissue. Our results indicated that high expression of PD-1 in IM was significantly associated with lower TNM stage, T-stage, M-stage, lack of metastasis, the presence of tertiary lymphoid structure (TLS), lack of recurrence (in the left-sided tumors), and larger tumor size (in right-sided tumors) (P<0.05). High expression of PD-1 in IM was also associated with improved overall survival (OS) in a subgroup of patients with high CD8 expression. High Tim3 expression in CT was associated with higher M-stage (M1) (in left-sided CRCs) (P<0.05). It was also associated with decreased OS in total cohort and left-sided CRCs and represented an independent prognostic factor for CRC patients in multivariate analysis. PD-1 and Tim3 co-expression had no synergistic effects on predicting OS. Our findings suggest that the clinicopathological and prognostic significance of immune system-related markers such as CD8, PD-1, and Tim3 depends on the primary tumor sides. We also showed that Tim3 could act as a prognostic factor and therapeutic target in CRC. This marker is probably a more preferred target for immunotherapy than PD-1, especially in left-sided CRCs.

Oncomicrobial Community Profiling Identifies Clinicomolecular and Prognostic Subtypes of Colorectal Cancer

Dysbiosis of gut microbiota is linked to the development of colorectal cancer (CRC). However, microbiota-based stratification of CRC tissue and how this relates to clinicomolecular characteristics and prognosis remains to be clarified. Tumor and normal mucosa from 423 patients with stage I to IV CRC were profiled by bacterial 16S rRNA gene sequencing. Tumors were characterized for microsatellite instability (MSI), CpG island methylator phenotype (CIMP), APC, BRAF, KRAS, PIK3CA, FBXW7, SMAD4, and TP53 mutations, subsets for chromosome instability (CIN), mutation signatures, and consensus molecular subtypes (CMS). Microbial clusters were validated in an independent cohort of 293 stage II/III tumors. Tumors reproducibly stratified into 3 oncomicrobial community subtypes (OCSs) with distinguishing features: OCS1 (Fusobacterium/oral pathogens, proteolytic, 21%), right-sided, high-grade, MSI-high, CIMP-positive, CMS1, BRAF V600E, and FBXW7 mutated; OCS2 (Firmicutes/Bacteroidetes, saccharolytic, 44%), and OCS3 (Escherichia/Pseudescherichia/Shigella, fatty acid β-oxidation, 35%) both left-sided and exhibiting CIN. OCS1 was associated with MSI-related mutation signatures (SBS15, SBS20, ID2, and ID7) and OCS2 and OCS3 with SBS18 related to damage by reactive oxygen species. Among stage II/III patients, OCS1 and OCS3 both had poorer overall survival compared with OCS2 for microsatellite stable tumors (multivariate hazard ratio [HR], 1.85; 95% confidence interval [CI], 1.15-2.99; P= .012; and HR, 1.52; 95% CI 1.01-2.29; P= .044, respectively) and left-sided tumors (multivariate HR, 2.66; 95% CI, 1.45-4.86; P= .002; and HR, 1.76; 95% CI, 1.03-3.02; P= .039, respectively). OCS classification stratified CRCs into 3 distinct subgroups with different clinicomolecular features and outcomes. Our findings provide a framework for a microbiota-based stratification of CRC to refine prognostication and to inform the development of microbiota-targeted interventions.

Colorectal cancer statistics, 2023.

Colorectal cancer (CRC) is the second most common cause of cancer death in the United States. Every 3 years, the American Cancer Society provides an update of CRC statistics based on incidence from population-based cancer registries and mortality from the National Center for Health Statistics. In 2023, approximately 153,020 individuals will be diagnosed with CRC and 52,550 will die from the disease, including 19,550 cases and 3750 deaths in individuals younger than 50years. The decline in CRC incidence slowed from 3%-4% annually during the 2000s to 1% annually during 2011-2019, driven partly by an increase in individuals younger than 55years of 1%-2% annually since the mid-1990s. Consequently, the proportion of cases among those younger than 55years increased from 11% in 1995 to 20% in 2019. Incidence since circa 2010 increased in those younger than 65years for regional-stage disease by about 2%-3% annually and for distant-stage disease by 0.5%-3% annually, reversing the overall shift to earlier stage diagnosis that occurred during 1995 through 2005. For example, 60% of all new cases were advanced in 2019 versus 52% in the mid-2000s and 57% in 1995, before widespread screening. There is also a shift to left-sided tumors, with the proportion of rectal cancer increasing from 27% in 1995 to 31% in 2019. CRC mortality declinedby 2% annually from2011-2020overallbutincreased by0.5%-3%annuallyinindividuals younger than 50yearsandin Native Americansyoungerthan65years. In summary, despite continued overall declines, CRC is rapidly shifting to diagnosis at a younger age, at a more advanced stage, and in the left colon/rectum. Progress against CRC could be accelerated by uncovering the etiology of rising incidence in generations born since 1950 and increasing access to high-quality screening and treatment among all populations, especially Native Americans.

Middle East and North Africa Registry to Characterize Rate of RAS Testing Status in Newly Diagnosed Patients with Metastatic Colorectal Cancer.

Rat sarcoma virus mutational status guides first-line treatment in metastatic colorectal cancer. This study was a multi center, multi-country ambispective, observational study in the Middle East and North Africa assessing regional rat sarcoma virus testing practices in newly diagnosed patients. The retrospective arm (2011-2014) included adults with metastatic colorectal cancer who had initiated first-line therapy with ≥1 post-baseline visit and survival data. The prospective arm (2014-2019) enrolled newly diagnosed patients with histologically proven metastatic colorectal cancer with ≥1 measurable lesion per Response Evaluation Criteria in Solid Tumors, and tissue availability for biomarker analysis. Data look-back and follow-up were 2 years; the rate of RAS mutation was evaluated. RAS testing was ordered for patients in retrospective (326/417) and prospective (407/500) studies. In the former, testing was typically prescribed after first-line treatment initiation, significantly more in patients with stage IV disease (P < .005), resulting in the addition of targeted therapy (41.8% anti-epidermal growth factor receptor, 30.2% anti-vascular endothelial growth factor) in wild-type metastatic colorectal cancer, and significantly impacted the treatment of left-sided tumors (P = .037). In the latter, 58.4% were RAS wild-type; 41.6% were RAS mutant. Non-prescription of RAS testing was attributed to test unavailability, financial, or medical rea sons; predictors of testing prescription were older age, primary tumor in ascending colon, and high tumor grade. RAS status knowledge resulted in the addition of anti-vascular endothelial growth factor (20.4%) or anti-epidermal growth factor receptor therapy (21.2%). Before 2014, RAS testing in patients with colorectal cancer in the Middle East and North Africa was often performed after first-line treatment. Testing is more routine in newly diagnosed patients, potentially shifting early treatment patterns.

SCOT: Tumor Sidedness and the Influence of Adjuvant Chemotherapy Duration on Disease Free Survival (DFS)

AimPatients with loco-regional right-sided colorectal tumors have a worse overall survival (OS). Here we investigate the difference in disease free survival (DFS) between colorectal patients with right and left sided tumors in the SCOT study. MethodsThe SCOT study showed 3-months of oxaliplatin-containing adjuvant chemotherapy (OxFp) is non-inferior to 6-months for patients with stage III and high-risk stage II colorectal cancer. We divided the cohort into patients with left and right sided tumors, and evaluated the effect on DFS and the principle 3 versus 6-months analysis. Results6088 patients with Stage III/high risk Stage II colorectal cancers were randomized between 27th March 2008 and 29th November 2013 from 244 centers internationally. In February 2017 (3-years FU) information on sidedness was available for 3309 patients (1238 R-sided, 2071 L-sided). Patients with right-sided tumors had a significantly worse DFS (3-year DFS right: 73.3% (se = 1.3%), left: 80.2% (se = 0.9%) HR 1.423 (95% CI 1.237-1.637; P < .0001). Adjusting for T and N-stage reduced the HR to 1.230 (95% CI 1.066-1.420, P = .005). The data did not suggest that sidedness affected the impact of chemotherapy duration on 3-year DFS (R: HR 1.024 [0.831-1.261], L: HR 0.944 [0.783-1.139]). Test for heterogeneity, P = .571. Further sub-set analysis was limited due to cohort size. ConclusionsThis is the first study to show that unselected patients with right-sided tumors had a worse DFS compared to left-sided tumors. Tumor sidedness did not impact upon the 3-months versus 6-months comparison in SCOT.

Primary tumour side as a driver for treatment choice in RAS wild-type metastatic colorectal cancer patients: a systematic review and pooled analysis of randomised trials

BackgroundRetrospective subgroup analyses of previous trials in the first-line therapy of RAS wt metastatic colorectal cancer (mCRC) suggested a predictive impact of primary tumour side on the efficacy of anti-epidermal growth factor receptor (EGFR) agents. Recently, new head-to-head trials of doublets/bevacizumab versus doublets/anti-EGFR, PARADIGM and CAIRO5 were presented. Patients and methodsWe searched for phase II and III trials comparing doublet chemotherapy plus an anti-EGFR or bevacizumab as the first-line treatment for RAS wt mCRC patients. Overall survival (OS), progression-free survival (PFS), overall response rate (ORR) and radical resection rate result in the overall study populations and, according to the primary side, were pooled together in a two-stage analysis with random effects and fixed effect models. The interaction between sidedness and treatment effect was then analysed. ResultsWe identified five trials (PEAK, CALGB/SWOG 80405, FIRE-3, PARADIGM and CAIRO5), including 2739 patients, 77% left- and 23% right-sided. Among patients with left-sided mCRC, the use of anti-EGFRs was associated with higher ORR (74% versus 62%, OR = 1.77 [95% confidence interval {CI} 1.39–2.26–0.88], p < 0.0001), longer OS (hazard ratio [HR] = 0.77 [95% CI 0.68–0.88], p < 0.0001) and not significantly longer PFS (HR = 0.92, p = 0.19). Among patients with right-sided mCRC, the use of bevacizumab was associated with longer PFS (HR = 1.36 [95% CI 1.12–1.65], p = 0.002) and not significantly longer OS (HR = 1.17, p = 0.14). A subgroup analysis confirmed a significant interaction effect between the primary tumour side and treatment arm in terms of ORR (p = 0.02), PFS (p = 0.0004) and OS (p = 0.001). No differences in the radical resection rate were found according to treatment and sidedness. ConclusionsOur updated metanalysis corroborates the role of the primary tumour location in the choice of the upfront therapy for RAS wt mCRC patients, leading to strongly recommend anti-EGFRs in left-sided tumours and to prefer bevacizumab in the right-sided.

Regorafenib is suitable for advanced colorectal cancer patients who have previously received trifluridine/tipiracil plus bevacizumab

Regorafenib is a standard salvage line therapy used for advanced colorectal cancer (CRC). Recently, trifluridine/tipiracil (TFTD) plus bevacizumab also showed promising efficacy as a salvage line therapy for advanced CRC. However, the efficacy and safety of regorafenib for patients with advanced CRC who have previously received TFTD plus bevacizumab is unclear. We retrospectively collected clinicopathologic data from patients with advanced CRC who received regorafenib after TFTD plus bevacizumab in multiple institutions between April 2017 and June 2020.Thirty-four advanced CRC patients who received regorafenib were analyzed. The median age was 66.5 (range 43–81 years), 11 patients were male, and all had an ECOG performance status(PS) of 0 or 1. Twenty-two patients had left-sided tumors, 18 patients had RAS mutants, and 1 patient had a BRAF V600E mutation. The response rate was 0%, and the disease control rate was 31%. The median progression-free survival was 70 days (95% CI: 56–91), and the overall survival was 233 days (95% CI: 188–324). Treatment was discontinued in 32 patients, and 28 (82%) discontinued treatment due to progressive disease. The major grade 3 and4 toxicities were proteinurea (29%), hypertension (26%), hand-foot syndrome(15%), and platelet decrease (6%). Regorafenib after TFTD plus bevacizumab showed efficacy similar to that of the previous study, and no new adverse events were observed.

Association of primary tumor location with long-term oncological prognosis following hepatectomy for hepatocellular carcinoma:A multicenter propensity score matching analysis

PurposeThere is a striking laterality in the site of hepatocellular carcinoma (HCC), with a strong predominance for the right side; however, the impact of primary tumor location on long-term prognosis after hepatectomy of HCC remains unclear. This study aimed to investigate the effect of primary tumor location on long-term oncological prognosis after hepatectomy for HCC. Patients and methodsData of consecutive patients undergoing curative hepatectomy for HCC between 2008 and 2017 were analyzed. Overall survival (OS) and recurrence-free survival (RFS) of left-sided HCC (LS group) and right-sided HCC (RS group) were compared by using propensity score matching (PSM) analysis. COX regression analysis was performed to assess the adjusted effect of tumor location on long-term oncological prognosis. ResultsOf the 2799 included patients, 707 (25.3%) and 2092 (74.7%) were in the LS and RS groups, respectively. Using PSM analysis, 650 matched pairs of patients were created. In the PSM cohort, median OS (66.0 vs. 72.0 months, P = 0.001) and RFS (28.0 vs. 51.0 months, P < 0.001) were worse among patients in the LS group compared to individuals in the RS group. After further adjustment for other confounders using multivariable COX regression analyses, HCC located on the left side remained independently associated with worse OS and RFS. ConclusionTumors located on the left side are associated with poorer OS and RFS after hepatectomy for HCC. Careful surgical options selection and frequent follow-up to improve long-term survival may be justified for HCC patients with left-sided primary tumors.

Maintenance strategies after anti–EGFR-based induction in RAS wild-type (wt) metastatic colorectal cancer (mCRC): A systematic review and Bayesian network meta-analysis.

148 Background: In RAS wt mCRC the use of maintenance therapy after induction with fluoropyrimidine (FP)-based cytotoxic therapy (CT) plus anti-EGFR agents is controversial. Herein, we conducted a systematic review and network meta-analysis to compare different maintenance strategies. Methods: PubMed, CENTRAL, Embase and oncological meeting websites were screened to identify eligible studies. Phase II-III randomized trials which enrolled patients with previously untreated RAS wt mCRC, who switched to a maintenance strategy after an induction of CT combined with an anti-EGFR agent were included. Maintenance strategies considered were: observation, single agent anti-EGFR or FP, FP + anti-EGFR, doublet CT + anti-EGFR. Outcomes were progression-free survival (PFS), overall survival (OS) and safety (grade 3-4 adverse events). Subgroup analyses were performed in BRAF wt patients and left sided tumors. The meta-analysis was conducted using a random-effects model. A Markov Chain Monte Carlo simulation was used to estimate the posterior distributions. Strategies were ranked using the surface under the cumulative ranking (SUCRA) probabilities. Risk of bias was assessed with Cochrane Risk of Bias Tool. Results: Overall, 4207 records were screened and 10 trials were included in the analysis. Cumulative risk of bias was low-moderate. Maintenance therapy with FP + anti-EGFR (HR 0.56, 95% CrI 0.36-0.88) and doublet CT + anti-EGFR (HR 0.68, 95% CrI 0.46-1.01), showed the greatest PFS benefit compared to observation. On SUCRA analysis, FU + anti-EGFR had the highest likelihood of improving PFS (96.3%), compared to doublet CT + anti-EGFR (73.5%) or EGFR monotherapy (48.0%). In terms of OS, compared to observation, maintenance therapy with doublet CT + anti-EGFR (HR 0.51, 95% CrI 0.19-1.28), FU + anti-EGFR (HR 0.59, 95% CrI 0.19-1.68) or anti-EGFR monotherapy (HR 0.56, 95% CrI 0.24-1.34) yielded similar results. On SUCRA analysis probabilities were 78.3% with doublet CT + anti-EGFR, 64.5% with FP + anti-EGFR and 63.4% with anti-EGFR monotherapy. FP + anti-EGFR confirmed to be the best option in terms of PFS in BRAF wt patients (SUCRA: 96.3%) and left sided tumors (SUCRA: 89.6%). OS results in BRAF wt patients were consistent with the primary analysis. In left sided tumors, the OS benefit of adding CT seems limited compared to EGFR monotherapy. The addition of CT to anti-EGFR agents resulted in an increase of toxicity while FP monotherapy plus anti-EGFR showed a favourable safety profile compared to doublet CT + anti-EGFR. Conclusions: FP + anti-EGFR should be considered the best maintenance option in RAS wt mCRC in terms of PFS. Taking into account the similar OS performance of the different strategies, EGFR monotherapy could be considered, especially in left-sided tumors. Doublet CT + anti-EGFR, despite being effective, is limited by toxicities.

Sidedness and addition of chemotherapy associated with treatment outcomes of regorafenib for metastatic colorectal cancer (mCRC).

36 Background: Regorafenib is one of the options of salvage treatment for mCRC. We aimed to explore the prognostic factors of such regorafenib treatment. Methods: We searched the database of National Health Insurance, Taiwan for patients who initiated regorafenib treatment for mCRC from September 1, 2015, to December 31, 2018. Database interrogation of National Death Registry, Taiwan and Taiwan Cancer Registry was conducted for survival data and clinicopathological variables, respectively. Results: A total of 3,643 patients were included in the analysis. The median age was 61.2 years. The primary tumor was left-sided and KRAS mutant in 75.3% and 54.5% of patients, respectively; 28.9% of patients received chemotherapy simultaneously, with irinotecan as the most common companion. The median time to treatment discontinuation (TTD) was 2.3 months (95% confidence interval [CI]: 95% CI: 2.3-2.3), and the median overall survival (OS) was 7.2 months (95% CI: 6.9-7.4). Patients with left-sided primary tumors, compared with patients with right-sided tumors, exhibited significantly longer TTD (median, 2.4 vs. 2.1 months, p &lt; 0.001) and OS (median, 7.6 vs. 6.1 months, p &lt; 0.001). By contrast, TTD and OS of patients under regorafenib treatment were similar regardless the KRAS mutation status ( p = 0.415 and 0.643, respectively). Patients who received chemotherapy along with regorafenib, compared with patients who did not, also exhibited significantly longer TTD (median, 2.6 vs. 2.2 months, p &lt; 0.001) and OS (median, 8.3 vs. 6.7 months, p &lt; 0.001). In multivariate analysis adjusting age, sex, time from colorectal cancer diagnosis, hospital level, KRAS mutation, and initial regorafenib dose, left-sidedness of the primary tumor remained a predictor for better TTD (hazard ratio [HR]: 0.88, p = 0.002) and OS (HR: 0.92, p = 0.048), as well as addition of chemotherapy (for TTD, HR: 0.86, p &lt; 0.001; for OS, HR: 0.76, p &lt; 0.001). Due to the interaction between sidedness and KRAS mutation, we established separate Cox models and found that left-sided primary tumor was an independent predictor for better TTD and OS for KRAS wild-type tumors, but not for KRAS mutant tumors. Conclusions: In this population-wide cohort study, left-sided primary tumor and addition of chemotherapy were associated with better TTD and OS of regorafenib treatment for mCRC.

Plasma biomarkers to predict clinical outcomes of FOLFIRI plus ramucirumab (RAM) as second-line treatment for RAS wild-type metastatic colorectal cancer: JACCRO CC-16AR.

177 Background: Angiogenesis-factors (AFs) have been reported as prognostic biomarkers for metastatic colorectal cancer (mCRC). RAS status in circulating-tumor DNA (ctDNA) is considered to be associated with resistance and potential efficacy of re-challenge treatment of anti-EGFR antibody in mCRC with RAS wild-type tumors. However, there were few evidence to prospectively evaluate the dynamic change of AFs and association of RAS status in ctDNA with clinical outcomes in anti-angiogenic therapies after anti-EGFR therapy for mCRC. Methods: Plasma samples were collected at pre-, day 15 after, and post-treatments in the pre-planned biomarker study of the JACCRO CC-16 trial which evaluated 2nd-line FOLFIRI plus RAM after anti-EGFR therapy in mCRC patients with RAS wild-type tumors (UMIN000034885). In 42 enrolled patients (median age, 68-y; ECOG PS 0/1, 31/11; all pts with left-sided tumors; median PFS, 6.8 months; median OS, 21.4 months; ORR, 10.3 %), some AFs (VEGF-A, VEGF-D, PlGF, HGF, IL-8, and angiopoietin-2) and RAS status in plasma were measured using the multiplex assay with Luminex technology and OncoBEAM RAS CRC Kit, respectively. The associations between clinical outcomes and AFs/ RAS status were investigated at timepoint of pre-treatment, using t-test and log-rank test. The median value was used as the cut-off value of AFs for high or low. The associations between AFs and RAS status were investigated using Brunner-Munzel test. Results: AFs and RAS status were evaluable in 38 and 41 patients, respectively. The OS was significantly longer in patients with IL-8 low compared to patients with IL-8 high (32.2 vs. 14.5 months, HR 0.36, p= 0.024). However, there was no difference in PFS between patients with IL-8 high and low. On the contrary, RAS mutations were detected at pre-treatment in 18 (44%) patients: KRAS codon12 83%, codon13 17%, codon61 67%, codon117 6%, codon146 11%, NRAS codon12 39%, codon61 78% in RAS mutations. Median PFS was 6.4 months in patients with RAS mutations in ctDNA, while it was 7.4 months in patients without RAS mutations (p = 0.10). Median OS was significantly longer in patients without RAS mutations compared to patients with RAS mutations (25.4 vs. 14.5 months, HR 0.39, p = 0.024). The ORR was 14.3% and 5.6% in patients without RAS mutations and with RAS mutations, respectively. In an exploratory analysis regarding the relationship between AFs and RAS status, IL-8 level was significantly higher in patients with RAS mutations than those without in ctDNA. Conclusions: This biomarker study demonstrated the associations between clinical outcomes and IL-8/ RAS status in blood before treatment in RAS wild-type mCRC treated with 2nd-line FOLFIRI plus RAM after anti-EGFR antibody therapy. Clinical trial information: UMIN000034885 .

The impact of brain lesions on health-related quality of life in patients with WHO CNS grade 3 or 4 glioma: a lesion-function and resting-state fMRI analysis

PurposeIn glioma patients, tumor development and multimodality therapy are associated with changes in health-related quality of life (HRQoL). It is largely unknown how different types and locations of tumor- and treatment-related brain lesions, as well as their relationship to white matter tracts and functional brain networks, affect HRQoL.MethodsIn 121 patients with pretreated gliomas of WHO CNS grades 3 or 4, structural MRI, O-(2-[18F]fluoroethyl)-L-tyrosine (FET) PET, resting-state functional MRI (rs-fMRI) and self-reported HRQoL questionnaires (EORTC QLQ-C30/BN20) were obtained. Resection cavities, T1-enhancing lesions, T2/FLAIR hyperintensities, and lesions with pathologically increased FET uptake were delineated. Effects of tumor lateralization, involvement of white matter tracts or resting-state network nodes by different types of lesions and within-network rs-fMRI connectivity were analyzed in terms of their interaction with HRQoL scores.ResultsRight hemisphere gliomas were associated with significantly less favorable outcomes in physical, role, emotional and social functioning, compared with left-sided tumors. Most functional HRQoL scores correlated significantly with right-sided white-matter tracts involvement by T2/FLAIR hyperintensities and with loss of within-network functional connectivity of right-sided nodes. Tumors of the left hemisphere caused significantly more communication deficits.ConclusionIn pretreated high-grade gliomas, right hemisphere lesions are associated with reduced HRQoL scores in most functional domains except communication ability, compared to tumors of the left hemisphere. These relationships are mainly observed for T2/FLAIR lesions involving structural and functional networks in the right hemisphere. The data suggest that sparing the right hemisphere from treatment-related tissue damage may improve HRQoL in glioma patients.

Modified (m)-FOLFOXIRI plus cetuximab versus m-FOLFOXIRI plus bevacizumab as initial treatment of patients with unresectable RAS and BRAF wild-type metastatic colorectal cancer: Survival analysis of the phase II randomized DEEPER trial by JACCRO.

120 Background: Triplet regimen, FOLFOXIRI, plus bevacizumab is considered as one of standard first-line treatments in metastatic colorectal cancer (mCRC). On the contrary, FOLFOXIRI plus anti-EGFR antibody has been shown to be a promising regimen with greater depth of response (DpR) in patients with RAS wild-type mCRC from the VOLFI and MACBETH trials (J Clin Oncol 2019, JAMA Oncol 2018). We therefore performed a randomized phase II study, DEEPER trial (JACCRO CC-13) [NCT02515734], to investigate the efficacy and safety of cetuximab (cet) vs. bevacizumab (bev) in combination with modified (m)-FOLFOXIRI in previously untreated mCRC patients with RAS wild-type tumors. We have reported a significantly better DpR of m-FOLFOXIRI plus cet compared to bev as the primary endpoint (Tsuji A, et al. ASCO 2021). Methods: This trial was a randomized phase II trial to evaluate modified (m)-FOLFOXIRI (irinotecan 150 mg/m2, oxaliplatin 85 mg/m2, 5-FU 2400 mg/m2) plus cet vs. bev as initial treatment in terms of DpR during the entire course as the primary endpoint in 360 patients with RAS wild-type mCRC. The aim of the trial was to show that median DpR of cet arm was more than 12.5% higher than bev arm, with a power of 85% at a significance level of 0.05, in per protocol set (PPS) consisted of patients evaluable for the DpR. Secondary endpoints included progression-free survival, overall survival, overall response rate, early tumor shrinkage rate, secondary resection rate, and toxicity. A total of 359 patients were enrolled between July 2015 and June 2019. For the PPS (median age 65y, 64% male, PS0/1: 91%/9%, left/right primary: 84%/16%), 159 and 162 patients were randomly assigned to the cet and bev arms, respectively. Clinical outcomes will be analyzed according to primary tumor sidedness which is included in the stratification factor. Additionally, we will collect data of BRAF status, and analyze the clinical outcomes in mCRC patients with RAS/ BRAF wild-type tumors and/or left-sided tumors. Pre-planned survival analysis will be performed to compare the two treatment arms at the time of 3 years after last patients’ enrollment using a log-rank test. All statistical tests are two-sided, and P values ≤ 0.05 are deemed significant. Statistical analyses will be performed using SAS version 9.4. Clinical trial information: NCT02515734 .

Comprehensive characterization of mesothelin expression in colorectal cancer.

245 Background: Mesothelin (MSLN) is highly expressed in several malignancies including colorectal cancer (CRC) compared to normal tissue and is associated with tumor cell proliferation and worse patient survival. MSLN could be a potential target for antigen-specific therapy. Here, we characterized the MSLN expression in CRC and its association with molecular and immune-related markers. Methods: 15,673 CRC samples were tested by NGS (592, NextSeq; WES, NovaSeq), WTS (NovaSeq) (Caris Life Sciences, Phoenix, AZ). Microsatellite-instability (MSI) was tested by fragment analysis, IHC, and NGS. Tumor mutational burden (TMB) totaled somatic mutations per tumor (high&gt;10 mt/MB). Tumors with MSLN-high(H) and MSLN-low(L) expression were classified by top and bottom quartile, respectively. Real world overall survival (OS) was extracted from insurance claims and calculated using Kaplan-Meier estimates for molecularly defined cohorts from tissue collection to last contact. Statistical significance was determined using chi-square and Mann-Whitney U test with p-values adjusted for multiple comparisons (q&lt;0.05). Results: There was no difference in median age or gender distribution between MSLN-H and MSLN-L CRC tumors. Right-sided tumors had increased median MSLN expression compared to rectal, transverse, and left-sided tumors (6.12 vs 5.29 vs 5.35 vs 4.81 TPM, q&lt;0.05). Median MSLN expression was higher in metastatic compared to primary tumors (1.21-fold, q&lt;0.05). Median MSLN expression was highest in CMS4 (10.17 TPM), but, in MSS CRC, MSLN expression was highest in CMS1 (10.46 TPM, all q&lt;0.05). MSLN-H tumors had higher frequency of KRAS (59.8% vs 36.4% ) and BRAF (13.1% vs 9.2% ) mutations but lower frequency of APC mutations (67.5% vs 77.2%), TMB High (9.8% vs 12%) and dMMR/MSI-H (6.6% vs 8.9%) compared to MSLN-L tumors (q&lt;0.05). Further, MSLN-H tumors had higher MAPK activation score (MPAS) compared to MSLN-L tumors (1.72-fold, q&lt;0.05). Similarly, in the MSS only cohort, MSLN-H tumors had increased frequency of KRAS (62.2% vs 37.9%) BRAF (10.5% vs 5.0%) mutations but decreased APC mutations (70% vs 80.9%) (q&lt;0.05). MSLN-H tumors had higher expression of immune checkpoint genes ( CD274, PDCD1, PDCD1LG2, CTLA4, LAG3, HAVC2 and FOXP3, FC: 1.1-1.8) and T cell inflamed score (3.3-fold) (all q&lt;0.05). MSLN-H was associated with worse OS compared to MSLN-L in all CRC (934 vs 1253 days; HR: 1.21, 95% CI (1.10-1.32), p&lt;0.0001) and MSS CRC (972 vs 1168 days; HR: 1.15, 95% CI (1.06-1.23), p&lt;0.001) but not in MSI-H CRC (p=0.67). Conclusions: Our data suggest a strong association between MSLN expression and increased mutations in the RAS pathway and MAPK activation score, decreased mutations in WNT pathway genes, a differentially modulated immune tumor microenvironment, and poor overall survival. These findings support MSLN as a potential prognostic biomarker candidate in colorectal cancers pending further prospective validation.

Differences in tumor-associated T cell receptor repertoires between young-onset and average-onset colorectal cancer.

207 Background: The incidence of colorectal cancer (CRC) among individuals younger than age 50 (young-onset CRC; YOCRC) has increased, yet the etiology and molecular mechanisms underlying this alarming rise remain unclear. Some studies suggest that YOCRCs have more aggressive biology. Here, we compare tumor-associated T cell repertoires between patients with YOCRC and average-onset CRC (AOCRC). A robust, focused T cell response is a positive prognostic indicator; therefore, we hypothesized that YOCRCs demonstrate lower T cell abundance and greater T cell diversity than AOCRCs. Methods: The discovery cohort included 242 patients with histologically confirmed Stage I-IV CRC who underwent surgical resection at Cleveland Clinic from 2000 to 2020 and consented to a biorepository. YOCRC was defined as &lt; 50 years at diagnosis (N = 126), and AOCRC as &gt; 60 years (N = 116). DNA was extracted from frozen tumors, and T Cell Receptor (TCR) abundance and clonality were measured using immunoSEQ (Adaptive Biotechnologies). Following quality control, logistic regression models were used to evaluate the associations between TCR repertoire features and age of onset, adjusting for sex, race, tumor location, and stage. Findings were replicated in 152 YOCRC and 1,984 AOCRC cases from the Molecular Epidemiology of Colorectal Cancer Study with adjustment for sex, Jewish ethnicity, tumor location, and stage. Results: YOCRC patients were more likely to have left-sided tumors and be diagnosed at advanced stages in both cohorts. In the discovery cohort, YOCRC tumors had significantly lower TCR clonality (higher T cell diversity) compared to AOCRC tumors in a multivariable model adjusting for sex, race, tumor location and stage (OR: 0.38, 95% Confidence Interval (CI): 0.25-0.56, p &lt; 0.0001). This association was also observed in the replication cohort (OR: 0.74, 95% CI: 0.62-0.89, p = 0.0013). In the replication cohort, further adjustment for microsatellite instability status did not substantially change the association (OR: 0.73, 95% CI: 0.61-0.88 p = 0.0012). When restricting to microsatellite stable tumors, clonality remained statistically significant in both the discovery and replication cohorts. No significant difference in TCR abundance was observed between YOCRC and AOCRC in either cohort. Conclusions: Higher T cell repertoire diversity, indicating a less focused intratumoral T cell response, is more frequently observed in YOCRC. Further studies are warranted to investigate the role of T cell diversity in the etiology and outcomes of YOCRC.

Comprehensive characterization of KRAS mutations and inter-relation with primary tumor location in colorectal cancers.

231 Background: The recent development of KRAS G12C inhibitors underscores the potential to target KRAS mutations. Right-sided and left-sided colon tumors (RT and LT) exhibit different molecular features. We characterize the prevalence of KRAS-variants, interrelation with primary tumor location, and association with immune biomarkers in CRC. Methods: We retrospectively reviewed CRC tumors of all stages (with known sidedness) that underwent NGS with the Tempus xT assay (DNA-seq of 648 genes at 500x coverage, full transcriptome RNA-seq). Bivariate analyses were performed to compare KRAS alterations, immune biomarkers, and co-mutations by tumor location. P-values comparing individual co-mutations between groups were adjusted for false discovery (FDR). Results: A total of 3,391 CRC were analyzed (RT: n = 442 [13%], transverse: n = 116 [3%], LT; n = 2,833 [84%]) of which 1486 (44%) tumors harbored KRAS mutations. Overall, KRAS mutations were more frequent in RT compared to transverse tumors and LT (52% vs 41% vs 43%, p&lt;0.001, respectively). The most frequent KRAS mutation variants observed were G12D (29 %), G12V (22%), G13D (16%), and G12C (5.7%). There was no significant difference in the prevalence of KRAS variant types between LT and RT (p=0.5). Significant differences in genomic co-mutations with various KRAS variants were observed in the following genes: TP53, FBXW7, and NF1 (FDR- P&lt;0.05). RT and transverse tumors were more likely have MSI-H and TMB-H (&gt;10 mut/mb) status than LT (MSI-H: 18% vs 22% vs 2.2% and TMB-H (20% vs 22% vs 3%, P&lt;0.001), respectively. CRC tumors harboring G13D variants were more likely to be associated with and MSI-H and TMB-H status (and 7.7% and 8.5%) compared to G12D (2.8 % and 3.9 %), G12V (1.8 % and 2.1%), and G12C (0% and 2.4%); P = 0.003 and 0.001. Conclusions: The most frequent KRAS mutation variants observed in CRC tumors were G12D, G12V, G13D, and G12C. There was no significant difference in the prevalence of KRAS variant types between tumors of the left vs right colon. CRC tumors that harbored G13D variants were significantly more likely to be associated with MSI-H and TMB-H status. [Table: see text]

A phase II single-arm study of the FGFR inhibitor pemigatinib in patients with metastatic colorectal cancer (mCRC) harboring FGF/FGFR alterations.

139 Background: The fibroblast growth factor receptor (FGFR) pathway plays a key role in cellular proliferation, migration, survival and angiogenesis. Aberrant signaling through FGFR in colorectal cancer and other malignancies results from gene amplification or mutation, chromosomal translocation or ligand-dependent activation of the receptors. Pemigatinib is an oral inhibitor of FGFR1-3 with proven efficacy in FGFR-altered cholangiocarcinoma and myeloid/lymphoid neoplasms, among others. We hypothesized that pemigatinib would improve response rates compared to historical controls in patients with refractory FGF/FGFR-altered mCRC. Methods: ACCRU-GI-1701 was a multicenter, single-arm, Simon’s two-stage phase II clinical trial (NCT04096417) of the FGFR inhibitor pemigatinib in patients (pts) with FGF/FGFR-altered mCRC. Eligible pts had received prior fluoropyrimidine, oxaliplatin, irinotecan, and anti-VEGF/anti-EGFR/anti-PD-1 if eligible. Pts received pemigatinib 13.5 mg once daily on d1-21 of each cycle, with option to escalate to 18 mg in c2 if well tolerated. The primary endpoint was (unconfirmed) objective response (OR). A sample size of 21 evaluable pts would provide 82% power to detect a true OR rate of 20% or greater compared to a historical control of 5 % with a one-sided type I error rate of 0.1. A prespecified interim analysis for futility was planned after 12 evaluable patients. Results: A total of 14 patients were enrolled in the first stage of the study, and all were evaluable for the primary endpoint. No OR were observed (out of 12) crossing the futility boundary and resulting in permanent closure of the study. Among all enrolled patients, median age was 60.5 years, 71.4% were male, 92.9% Caucasian, 42.9% with no prior exposure to TAS-102 or regorafenib, and 64.3% with left-sided primary tumors. Treated patients all had tumors with FGFR1-4 mutations and/or FGF/FGFR amplifications by tissue- and/or blood-based molecular testing; no FGFR translocations were present. OR rate for this study was 0% (95% CI, 0-23.2%), with one patient achieving stable disease as best response. Median progression-free survival was 9.1 weeks (95% CI, 7.9-not evaluable [NE]), and median overall survival was 7.9 months (95% CI, 3.4-NE). Grade 3+ adverse events (AE) were seen in 42.9% of treated patients (including 1 grade 5 AE). Most commonly occurring AEs of any grade were anemia, hyperphosphatemia, alkaline phosphatase increased, aspartate aminotransferase increase, and fatigue. Conclusions: Pemigatinib demonstrated evidence of safety but not clinical activity in this population of patients with FGF/FGFR-altered mCRC. It is unknown whether pemigatinib would be active in mCRC patients with FGFR translocations/fusions as these were not represented in our trial. Translational studies are planned to investigate mechanisms of resistance to this therapy. Clinical trial information: NCT04096417 .