Right-sided Tumors Research Articles

Chemotherapy plus EGFR antibody as conversion treatment in RAS wild type, right-sided metastatic colon cancer: A systematic review and meta-analysis.

e15568 Background: The optimal conversion strategy for right-sided RAS wild type (WT) metastatic colorectal cancer (mCRC) remains a contentious issue, especially regarding the role of EGFR antibodies. EGFR antibody treatment might be an attractive option in patients with contraindications to bevacizumab or in hyperselected patients with microsatellite stable subtypes and without RAS/BRAF/HER2 alterations, potentially allowing a shorter time to conversion surgery. Methods: We performed a systematic search of PubMed/MEDLINE and EMBASE for randomized trials reporting the overall response rate (ORR) and resection rate following chemotherapy (CT) plus anti-EGFR agents (cetuximab or panitumumab) for right-sided mCRC. Studies were selected regardless of whether the resection rate was a study endpoint or not. We used a random-effects model with generic inverse variance to compute pooled ORR and resection rates and to compare CT regimens combined with anti-EGFR or anti-VEGF agents. Results: Ten randomized trials with a total of 4465 mCRC patients were included; seven trials reported the resection rate as a secondary endpoint. 828/4465 (18.5%) patients were right-sided, of whom 419/828 (50.6%) patients received CT doublet or triplet plus anti-EGFR, 263/828 (31.8%) treated with CT plus bevacizumab, and 146/828 (17.6%) patients with CT alone. The ORR was significantly higher in the anti-EGFR group compared to CT alone (50.89% vs 31.03%, OR: 2.23 [95% CI: 1.50-3.32], p < 0.01). No significant difference in ORR was observed between the CT plus anti-EGFR and CT plus bevacizumab groups (50.89% vs 53.32%, OR: 0.89 [95% CI: 0.65-1.21], p = 0.44). Resection rates were 8.08% for CT plus anti-EGFR, 4.79% for CT plus bevacizumab, and 12.24% for CT alone, with no significant differences among the three arms (χ2= 2.15, p = 0.34). Subgroup analysis of RAS/BRAF WT patients with right-sided tumors from the PARADIGM and PEAK trials showed no difference in progression-free survival (PFS) between the CT plus anti-EGFR or bevacizumab groups (11.01m vs 11.60m, HR = 1.04 [95% CI: 0.58-1.50]), but there was a trend toward improved overall survival (OS) with anti-EGFR treatment (30.66m vs 28.67m, HR = 0.81 [95% CI: 0.45-1.17]). Conclusions: The data indicate that augmenting chemotherapy with anti-EGFR could be a viable conversion therapy for patients with RAS/BRAF WT right-sided mCRC, underscoring its potential utility in this subset of patients.

The impact of metformin on clinical outcomes of metastatic colorectal cancer with known molecular profile treated with cytotoxic chemotherapy or immune checkpoint inhibitor.

e15580 Background: Colorectal cancer (CRC) is the third most common cancer in the US, with a dismal 5-year OS of 13% in mCRC. Concomitant metformin with chemotherapy or immune checkpoint inhibitors (ICIs) revealed improved outcomes in various cancers. Metformin's anti-cancer effects stem its effects on cancer metabolism, cell cycle modulation, cancer stem cells, gut microbiota, immunomodulatory properties. The aim of this retrospective study was to study the impact of concomitant metformin use with the type of systemic therapy (chemotherapy or ICIs) in CRC. Methods: CRC tumors were analyzed by NGS of DNA (592-gene) and RNA (whole transcriptome) at Caris Life Sciences. MSS was assessed by NGS, with MSI-H and MSS patients subcategorized by concomitant metformin use with ICI or with chemotherapy, respectively. Real-world OS, derived from insurance claims data, was calculated from the time of CRC sample collection to the last contact. Hazard ratio (HR) was calculated using the Cox proportional hazards model, with p values calculated using the log-rank test. Results: The study cohort included 31,083 CRC cases (male: female = 1.2, age: 80% > = 50 years). Common molecular alterations included TP53 (73.6%), APC (77.6%), KRAS (47.4%), CTNNB1 (2.0%), and HER2 amplification (1.7%). 1,503 patients were MSI-H (4.83%), 21,330 as MSS (68.6%), and 8,250 indeterminate. MSI-H patients receiving concurrent ICI/metformin had similar OS (52.7 vs. 55.4 months, HR = 0.78, 95% CI: 0.41 – 1.51, p = 0.462). Conversely, OS was increased in MSS patients on concomitant chemotherapy and metformin (38.1 vs 31.1 months, HR = 0.77, 95% CI: 0.69 – 0.86, p < 0.00001). In comparing real-world OS between left-sided and right-sided colorectal cancer (CRC), regardless of metformin use, multivariate analysis incorporating molecular alterations revealed longer OS for left-sided MSS CRC compared to right-sided (HR = 0.80, 95% CI: 0.76 – 0.84, p < 0.00001). However, further improvement in OS was associated with concurrent metformin use in both right-sided and left-sided tumors. Conclusions: In this retrospective analysis of real-world clinical outcomes, patients receiving concomitant metformin and cytotoxic chemotherapy had improved clinical outcomes in MSS CRC compared to those not on concurrent metformin. However, the concurrent use of metformin with ICIs in MSI-H CRC did not show an impact on clinical outcomes given low sample size. These results add to the existing body of literature on the potential benefits of metformin in the context of MSS CRC and underscore the importance of a prospective controlled study of concurrent metformin use with systemic chemotherapy in metastatic CRC. Limitations of this study involves the potential inclusion of cases with prior metformin use, small sample size, retrospective analyses, and the lack of control for the patients with type II DM.

The prevalence of sickle cell phenotype and its association with clinical outcomes in patients with solid malignancies.

10563 Background: Sickle cell disease (SCD) is the most common inherited blood disorder in the United States and is caused by a mutation of β-globin ( HBB-Mt). The risk of developing solid malignancies in this population remains controversial, with research showing increased rates of some solid tumors (colon, kidney, and thyroid) and decreased rates of others (breast and male genitourinary). We report the prevalence of HBB mutations across a cohort of solid tumors and clinical outcomes between HBB-Wild type (-Wt) v Mutant (-Mt) tumors. Methods: Non-small cell lung cancer (NSCLC, N = 3307), breast (BC, N = 1960), colorectal (CRC, N = 2161), prostate (N = 899), and gynecologic cancers (N = 2,805) in persons of African descentwere tested at Caris Life Sciences (Phoenix, AZ) with NextGen Sequencing of DNA (whole exome) and RNA (whole transcriptome). Her2/Neu (+: ≥3+ and >10%) and HR (ER or PR+: ≥1+ and ≥1%) expression was tested by immunohistochemistry. Tumors were assessed for single nucleotide variations (SNVs) and insertions/deletions (indels) in HBB associated with a sickle cell phenotype. Mutation prevalence for all other genes was calculated for pathogenic SNVs/indels. Differentially regulated pathways were assessed by gene set enrichment analysis (GSEA). Fisher’s Exact/χ2 tests were applied as appropriate with p-values adjusted for multiple comparisons ( p < .05). Real-world overall survival (OS) and ethnicity data was obtained from insurance claims and log-rank estimates were calculated for molecularly defined subpopulations. Results: Amongst persons of African descent, uterine sarcoma had the highest prevalence of HBB-Mt (17.1%, 43/251) followed by uterine serous carcinoma (9.1, 70/768) and endometrial carcinoma (7.8, 55/708). Tumors with the highest absolute number of HBB-Mt tumors were NSCLC (7.0, 230/3307), CRC (8.1, 176/2161) and BC (6.7, 131/1960). In CRC, there was no significant difference in the prevalence of right-sided tumors between HBB-Wt v Mt (42% v 51, p = .06), nor in the prevalence of HBB-Mt by consensus molecular subtype ( p = .34). No significant enrichment of HBB-Mt across BC subtypes was observed (HR- HER2-: 7.8%, HR-HER2+: 9.7, HR+/HER2-:5.8, HR+/HER2+: 8.1, p = .34). No difference in the prevalence of pathogenic alterations was observed between HBB-Mt vs -Wt across NSCLC, CRC, and BC ( p > .05). HBB-Mt NSCLC were significantly enriched (GSEA) for genes related interferon /, inflammatory response and IL6/JAK/STAT3. No significant difference in OS was observed in CRC (median survival HBB-Wt: 957 days v -Mt: 1034, p = .43), NSCLC (-Wt: 591 v -Mt: 648, p = .59) or BC (-Wt: 924 v -Mt: 922, p = .61). Conclusions: No significant differences in the genomic landscape nor in OS of HBB-Mt vs HBB-Wt NSCLC, CRC or BC were observed. NSCLC HBB-Mt was enriched with inflammatory response genes. Future work should focus on potential role HBB-Mt plays in NSCLC.

Real-world impact of KRAS mutations on clinical outcomes in metastatic colorectal cancer treated with trifluridine-tipiracil in the USA.

e15566 Background: Defining the impact of KRAS mutation status on outcomes to standard of care treatments in metastatic colorectal cancer (mCRC) is of increasing clinical relevance. We interrogated a large real-world genomic database to further explore the association between KRAS mutations and benefit to trifluridine-tipiracil (FTD-TPI) in patients with mCRC. Methods: 19,364 patients with mCRC and known KRAS mutation status were analyzed by next-generation sequencing (NextSeq, 592 Genes; NovaSeq, whole exome sequencing (WES)) at Caris Life Sciences. Real-world overall survival (rwOS) and time on treatment (ToT) was inferred from insurance claims data and calculated from time of start of treatment with FTD-TPI to last contact and time from first to last treatment with FTD-TPI with comparison done by the Kaplan-Meier test, respectively. Chi-square test was applied where appropriate, with p-value adjusted for multiple comparisons (p < 0.05). Results: 764 of 10,571 (7.2%) patients with wild-type (WT) KRAS, 768 of 6,984 (11%) with KRAS G12 mutation, and 170 of 1,809 (9.4%) with KRAS G13 mutation received FTD-TPI. Age distribution was similar among groups. Sidedness of primary site was reported in 692 (40.3%) patients; an increased proportion of right-sided tumors was observed in KRAS G12 (53.4% vs. 28.3%, p < 0.0001) and G13 (56% vs 28.3%, p < 0.0001) groups compared to KRAS WT. An increased proportion of TP53 mutations in KRAS WT was observed compared to KRAS G12 mutation (87% vs. 70%, p < 0.0001) and KRAS G13 mutation groups (87% vs. 75%, p < 0.0001). KRAS G12 mutation was associated with shorter median rwOS compared to KRAS WT (7.33 vs. 8.43 months (mo), HR 1.13 (95% CI 1.11-1.42), p = 0.041). KRAS G13 mutation was associated with similar rwOS to KRAS WT. Median ToT was shorter in patients with KRAS G12 mutations than KRAS WT (1.8 vs. 2 mo, HR of 1.22 (95% CI 1.11-1.42), p < 0.001). Median ToT was longer in patients with KRAS G13 versus KRAS G12 (2.3 vs. 1.8 mo, HR 0.82 (95% CI 0.68-0.98), p = 0.032). Conclusions: To our knowledge, this is the largest primarily US-based cohort of mCRC treated with FTD-TPI to be reported. KRAS G12 mutation, but not KRAS G13 mutation, was associated with shorter rwOS and ToT compared to KRAS WT, despite enrichment of TP53 and BRAF mutations in the KRAS WT group. This finding is consistent with previously published analyses of large randomized prospective trials of FTD-TPI in mCRC and further support KRAS mutation status as a predictive biomarker in this setting. [Table: see text]

Survival impact of KRAS mutation in metastatic colorectal cancer (mCCR) under first-line treatment.

3547 Background: Activating mutations in the MAPK pathway are predictive biomarkers in mCCR and 50% of patients (pts) present KRAS mutations. There is a large spectrum of molecular aberrations with a lack of data regarding tumor side correlations and their impact on treatment response and overall survival. Methods: Retrospective cohort of mCRC pts and KRAS activating mutations treated between 2019-2022 in a tertiary cancer center in Brazil. KRAS gene was analyzed by next-generation sequencing in tumor tissue samples. Electronic medical records were reviewed with case report forms registered in RedCap software. The primary endpoint was Overall survival (OS), estimated using Kaplan-Meir and compared with the log-rank test. Cox proportional models were applied to estimate hazard ratios (HR). Results: We included 490 patients with a mean age of 59 years (y), mostly male, 51.4%. Primary left-side location was present in 65.5% and liver metastasis in 66.7%. The spectrum of KRAS mutations found were G12D (31.2%), G12V (20.2%), G13D (15.1%), G12C (9.4%), G12A (4.9%), G12S (3.5%), and G12R (2%). First line regimen was 5-FU and Oxaliplatin (mFLOX) in 84.9% (n=388), with a median PFS of 9.2 months (95%CI 7.8 - 11.6) and OS of 21 months (95%CI;19-23) in this group. Treatment related outcomes in first-line therapy at first evaluation were 40% partial response, 20.4% stable disease, 30,9% disease progression and 1.3% complete response. G12S mutation was associated with better PFS 18.62 vs. 8.75m compared with other codon mutations (HR:0.52;95%CI 0.28-0.98) and OS NR vs. 21.58m HR (HR:0.48;95%CI;0.24-0.97). G12R was associated with worse PFS 5.31 vs. 9.90 m (HR:2.2;95%CI;1.09-4.47) and OS 17.89 vs. 21.88m (HR:1.61;0.79-3.24). Sideness was not associated with prolonged response or overall survival right-sided tumors 20.72 vs. vs. left-sided tumors 22.14m (HR:1.04;95%CI;0.82-1.31). Conclusions: Specific mutated codons in the KRAS gene impact PFS and OS independently of primary tumor sidedness. G12S mutation demonstrated an improved OS and PFS. [Table: see text]

Short- and long-term outcome differences between patients undergoing left and right colon cancer surgery: cohort study

PurposeSince the literature currently provides controversial data on the postoperative outcomes following right and left hemicolectomies, we carried out this study to examine the short- and long-term treatment outcomes.MethodsThis study included consecutive patients who underwent right or left-sided colonic resections from year 2014 to 2018 and then they were followed up. The short-term outcomes such as postoperative morbidity and mortality according to Clavien-Dindo score, duration of hospital stay, and 90-day readmission rate were evaluated as well as long-term outcomes of overall survival and disease-free survival. Multivariable Cox regression analysis was performed of overall and progression-free survival.ResultsIn total, 1107 patients with colon tumors were included in the study, 525 patients with right-sided tumors (RCC) and 582 cases with tumors in the left part of the colon (LCC). RCC group patients were older (P < 0.001), with a higher ASA score (P < 0.001), and with more cardiovascular comorbidities (P < 0.001). No differences were observed between groups in terms of postoperative outcomes such as morbidity and mortality, except 90-day readmission which was more frequent in the RCC group. Upon histopathological analysis, the RCC group’s patients had more removed lymph nodes (29 ± 14 vs 20 ± 11, P = 0.001) and more locally progressed (pT3-4) tumors (85.4% versus 73.4%, P = 0.001). Significantly greater 5-year overall survival and disease-free survival (P = 0.001) were observed for patients in the LCC group, according to univariate Kaplan-Meier analysis.ConclusionsPatients with right-sided colon cancer were older and had more advanced disease. Short-term surgical outcomes were similar, but patients in the LCC group resulted in better long-term outcomes.

Clinical and molecular heterogeneity associated with tumor sidedness in colorectal liver metastasis: a multicenter propensity cohort study.

Colorectal liver metastasis (CRLM) exhibits highly heterogeneity, with clinically and molecularly defined subgroups that differ in their prognosis. The aim of this study is to explore whether left-sided tumors is clinically and gnomically distinct from right-sided tumors in CRLM. This retrospective study included 1,307 patients who underwent primary tumor and metastases resection at three academic centers in China from January 1, 2012, to December 31, 2020. Propensity score matching with 1:1 ratio matching was performed. The prognostic impact of tumor sidedness was determined after stratifying by the KRAS mutational status. Moreover, whole-exome sequencing (WES) of 200 liver tumor tissues were performed to describe the heterogeneity across the analysis of somatic and germline profiles. The median follow-up was 68 months. Matching yielded 481 pairs of patients. Compared to right-sided CRLM, left-sided patients experienced with better 5-year overall survival (OS) in surgery responsiveness, with a 14.6 lower risk of death [hazard ratio (HR), 1.36, 95% confidence interval (CI), 1.10-1.69, P=0.004]. Interaction between tumor sidedness and KRAS status was statistically significant: left-sidedness was associated with better prognosis among KRAS wild-type patients (HR 1.71; 95% CI: 1.20-2.45; P=0.003), but not among KRAS mutated-type patients. Integrated molecular analyses showed that right-sided tumors more frequently harbored TP53, APC, KRAS, and BRAF alterations, and identified a critical role of KRAS mutation in correlation with their survival differences. Higher pathogenic germline variants were identified in the right-sided tumors compared with left-sided tumors (29.3% vs. 15.5%, P=0.03). We demonstrated that the prognostic impacts of tumor sidedness in CRLM is restricted patients with KRAS wild-type tumors. Tumor sidedness displays considerable clinical and molecular heterogeneity that may associate with their therapy benefits and prognosis.

National screening for colorectal cancer is associated with stage shift to earlier diagnosis.

Australia's National Bowel Cancer Screening Program consists of an immunohistochemical faecal occult blood test, targeting adults aged 50-74. Existing literature supports the principle of early detection of colorectal cancer (CRC) via national screening, but little is known about the association between colonoscopy or polypectomy rates and CRC stage over time. The aim of this study is to identify the longitudinal change to colonoscopy and polypectomy rates, and any stage shift associated with this screening program. A retrospective data-linkage study was performed using the Australian national health database (Medicare) to obtain colonoscopy and polypectomy rates between 1998 and 2017. A second prospective database of CRC resection specimens was analysed for this period. The cohort was divided based on time intervals related to the National Bowel Cancer Screening Program: pre-commencement 1998-2006 (Period A), immediately post-commencement 2007-2011 (Period B), and subsequent years 2012-2017 (Period C). Linear regression was used to test relation between annualized predictor and response variables. Annual colonoscopy rates doubled, and polypectomy rates tripled during the study (P < 0.001). Annual colonoscopy rate correlated to a lower T-stage (P = 0.038) and lower N-stage (P = 0.026), and there was a 7% increase in early CRC (stage I-II) in Period C (P < 0.001). Across the study period there was also a significant increase in right-sided tumours, and concurrent MMR deficiency and BRAF mutation. Polypectomy and colonoscopy rates increased after the introduction of the National Bowel Cancer screening program. There was a clinically significant shift to earlier CRC stage which manifested 5 years after its implementation.

Abstract 6696: Microbial signatures and serum markers in colon cancer of African American patients

Abstract Among all the racial/ethnic groups, African American (AA) patients have the highest incidence of CRC and mortality rate. There is growing evidence indicating that the oral bacteria might translocate to the intestine, potentially causing disruptions in the balance of gut microbes. Our study delves into the complex interplay between oral pathogens, gut microbiota, and colon carcinogenesis in AA patients. Methods: 16S rRNA sequencing of tumor and non-tumor tissues, utilized qPCR for detection of oral bacteria Fusobacterium nucleatum (Fn) and Porphyromonas gingivalis (Pg) relative abundance, performed cytokine profiling via multiplex ELISA, and employed NAPPA for antibody response assessment. Results: Colon tumor tissues had lower microbial diversity, notably in right-sided tumors, with distinct biofilm-associated bacteria. Novel discoveries emerged from differential abundance testing, revealing Prevotella intermedia and Treponema socranski to be associated with early cancer stage and left-sided location, and Fusobacterium necrophorum with advanced cancer stage and right-sided location. qPCR demonstrated Fn and Pg elevation in right-sided tumors and late cancer stages. Both were detected in 45% of tumors versus 37% in non-tumor tissues and 19.15% of tumors and 25.53% in non-tumor tissues, respectively. Fn-positive groups exhibited distinct microbial signatures, with altered bacterial abundances and dysbiosis, including increased CRC-associated bacteria Faecalibacterium and Helicobacter, increased oral pathogen abundance (Fusobacterium, Porphyromonas, Prevotella, Treponema), and reduced beneficial bacteria. Serological analysis highlighted elevated levels of IL-2, IL-10, IFN-γ, and RANK in advanced cancer stages and increased CRP levels in right-sided tumors. By NAPPA analysis, 30 bacterial proteins (anti-IgG) showed a seroprevalence of more than 15% in the samples, with those being the most seroprevalent anti-HP131 and anti-HP-1564 (68% and 61% of all samples) of Helicobacter pylori, and anti-msnK (64%) of Streptococcus gallolyticus. Conclusions: Our study emphasized the reduced diversity in tumor tissues, particularly in right-sided tumors in AA colon cancer. Fn presence in colonic tumors correlated with CRC-associated bacteria and oral pathogen aggregation, suggesting its potential role in cancer pathogenesis. Combining the analysis of cytokines and pathogenic bacteria antibodies may serve as broader serological biomarkers for disease severity and location. These findings advance our comprehension of microbiota-cancer interactions, directing personalized diagnostics and treatments in this population. Citation Format: Sofia Carolina Tortora, Emily Vogtmann, Laura Martello-Rooney. Microbial signatures and serum markers in colon cancer of African American patients [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 6696.

Abstract 925: Continuing anti-EGFR treatment prolonged survival in mCRC patients receiving conversion liver resection

Abstract Introduction: Anti-EGFR monoclonal antibody plus doublet chemotherapy is the mainstay of first-line treatment of RAS/BRAF wild-type metastatic colorectal cancer (mCRC) patients. Some of these patients might undergo secondary resection. However, there is no standardized suggestion on whether colorectal cancer liver metastasis patients should keep target therapy after secondary resection. NCCN guidelines suggest chemotherapy only in patients receiving primary liver resection. Whether we could spare the use of target therapy after secondary resection is the main aim of our study. Methods: Using Taiwan's National Health Insurance Research Database, we established a cohort of KRAS wild-type mCRC patients treated with first-line anti-EGFR therapy plus doublet chemotherapy between 2013 and 2018. Secondary surgery was defined as either resection of liver metastases or radiofrequency ablation. Results: 5694 stage IV mCRC patients received anti-EGFR MAb plus doublet chemotherapy as a first-line treatment between 2013 and 2018. 174 patients were enrolled in the final analysis, with 153 continuing anti-EGFR MAb after secondary resection and 21 patients without anti-EGFR MAb. Compared with those who without anti-EGFR therapy after secondary resection, patients who continued anti-EGFR MAb exhibited significantly longer overall survival (OS; median, 43.8 vs. 31.9 months, p = 0.031) but not in time to treatment failure (TTF; median, 22.2 vs. 26.6 months, p = 0.841). The OS benefits of continuing anti-EGFR MAb remained regardless of left-sided or right-sided primary tumors (40.9 vs. 43.0 months, p = 0.980). The patient cohort from 2016 to 2018 showed more prolonged survival than from 2012 to 2015 (not reached vs. 40.450, p = 0.0305). TTF has no statistical difference when considering patient cohort or primary tumor location. In multivariate analyses, continuing first-line anti-EGFR MAb therapy after secondary resection remained an independent predictor of longer OS. Conclusion: For mCRC patients who received secondary resection after first-line anti-EGFR and doublet chemotherapy, continuing anti-EGFR MAb after resection was associated with significantly longer OS regardless of primary tumor sidedness. Citation Format: Yao-Yu Hsieh, Chin-Wen Tsai, T-CARE Group, Yi-Hsieh Liang. Continuing anti-EGFR treatment prolonged survival in mCRC patients receiving conversion liver resection [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 925.

Proportions and characteristics of interval cancer in annual fecal immunochemical test screening and postcolonoscopy colorectal cancer: Results from a Japanese multicenter prospective study using questionnaires, the C-DETECT study.

There are several types of colorectal cancer (CRC) according to the detection methods and intervals, including interval CRC (iCRC) and postcolonoscopy CRC (PCCRC). We aimed to examine their proportions and characteristics. We conducted a multicenter prospective study using questionnaires in Japan ("C-DETECT study"), in which differences in CRC characteristics according to detection methods and intervals were examined from consecutive adult patients. Because the annual fecal immunochemical test (FIT) was used in population-based screening, the annual FIT-iCRC was assessed. In total, 1241 CRC patients (1064 with invasive CRC) were included. Annual FIT-iCRC (a), 3-year PCCRC (b), and CRC detected within 1 year after a positive FIT with noncompliance to colonoscopy (c) accounted for 4.5%, 7.0%, and 3.9% of all CRCs, respectively, and for 3.9%, 5.4%, and 4.3% of invasive CRCs, respectively. The comparison among these (a, b, c) and other CRCs (d) demonstrated differences in the proportions of ≥T2 invasion ([a] 58.9%, [b] 44.8%, [c] 87.5%, [d] 73.0%), metastasis ([a] 33.9%, [b] 21.8%, [c] 54.2%, [d] 43.9%), right-sided CRC ([a] 42.9%, [b] 40.2%, [c] 18.8%, [d] 28.6%), and female sex ([a] 53.6%, [b] 49.4%, [c] 27.1%, [d] 41.6%). In metastatic CRC, (a) and (b) showed a higher proportions of BRAF mutations ([a] [b] 12.0%, [c] [d] 3.1%). Annual FIT-iCRC and 3-year PCCRC existed in nonnegligible proportions. They were characterized by higher proportions of right-sided tumors, female sex, and BRAF mutations. These findings suggest that annual FIT-iCRC and 3-year PCCRC may have biological features different from those of other CRCs.

Modified Radiation Lobectomy Strategy of Radioembolization for Right-Sided Unresectable Primary Liver Tumors

PurposeTo assess the safety and effectiveness of using modified radiation lobectomy (mRL) to treat primary hepatic tumors located in the right hepatic lobe (Segments V–VIII) and to determine future liver remnant (FLR) hypertrophy. Materials and MethodsA retrospective review was performed at a single institution to include 19 consecutive patients (7 females, 12 males) who underwent single-session mRL for right-sided primary hepatic tumors: 15 received segmentectomy plus lobectomy (segmental dose of >190 Gy and lobar dose of >80 Gy); 4 were treated with the double-segmental approach (dominant segments of >190 Gy and nondominant segments of >80 Gy). Treated tumors included 13 hepatocellular carcinoma (HCC), 4 cholangiocarcinoma (CCA), and 2 mixed-type HCC-CCA with a median dominant tumor size of 5.3 cm (interquartile range [IQR], 3.7–7.3 cm). FLR of the left hepatic lobe was measured at baseline, T1 (4–8 weeks), T2 (2–4 months), T3 (4–6 months), and T4 (9–12 months). ResultsObjective tumor response and tumor control were achieved in 17 of the 19 (89.5%) and 18 of the 19 (94.7%) patients, respectively. FLR hypertrophy was observed at T1 (median, 47.8%; P = .025), T2 (median, 48.4%; P = .012), T3 (median, 50.4%; P = .015), and T4 (median, 59.1%; P < .001). Patients without cirrhosis demonstrated greater hypertrophy by 6 months (median, 55.8% vs 47.2%; P = .031). One patient developed a Grade 3 adverse event (ascites requiring paracentesis) at 1-month follow-up. Grade ≥2 serum toxicities were associated with worse baseline Child–Pugh Score, serum albumin, and total bilirubin (P < .05). Among 7 patients who underwent neoadjuvant mRL, 2 underwent resection and 1 received liver transplant. ConclusionsmRL appears safe and effective for treatment of right-sided primary hepatic tumors with the benefit of promoting FLR hypertrophy.

The colibactin-producing Escherichia coli alters the tumor microenvironment to immunosuppressive lipid overload facilitating colorectal cancer progression and chemoresistance

ABSTRACT Intratumoral bacteria flexibly contribute to cellular and molecular tumor heterogeneity for supporting cancer recurrence through poorly understood mechanisms. Using spatial metabolomic profiling technologies and 16SrRNA sequencing, we herein report that right-sided colorectal tumors are predominantly populated with Colibactin-producing Escherichia coli (CoPEC) that are locally establishing a high-glycerophospholipid microenvironment with lowered immunogenicity. It coincided with a reduced infiltration of CD8+ T lymphocytes that produce the cytotoxic cytokines IFN-γ where invading bacteria have been geolocated. Mechanistically, the accumulation of lipid droplets in infected cancer cells relied on the production of colibactin as a measure to limit genotoxic stress to some extent. Such heightened phosphatidylcholine remodeling by the enzyme of the Land’s cycle supplied CoPEC-infected cancer cells with sufficient energy for sustaining cell survival in response to chemotherapies. This accords with the lowered overall survival of colorectal patients at stage III-IV who were colonized by CoPEC when compared to patients at stage I-II. Accordingly, the sensitivity of CoPEC-infected cancer cells to chemotherapies was restored upon treatment with an acyl-CoA synthetase inhibitor. By contrast, such metabolic dysregulation leading to chemoresistance was not observed in human colon cancer cells that were infected with the mutant strain that did not produce colibactin (11G5∆ClbQ). This work revealed that CoPEC locally supports an energy trade-off lipid overload within tumors for lowering tumor immunogenicity. This may pave the way for improving chemoresistance and subsequently outcome of CRC patients who are colonized by CoPEC.

Tumor location matters, next generation sequencing mutation profiling of left-sided, rectal, and right-sided colorectal tumors in 552 patients

Despite the introduction of new molecular classifications, advanced colorectal cancer (CRC) is treated with chemotherapy supplemented with anti-EGFR and anti-VEGF targeted therapy. In this study, 552 CRC cases with different primary tumor locations (250 left side, 190 rectum, and 112 right side) were retrospectively analyzed by next generation sequencing for mutations in 50 genes. The most frequently mutated genes were TP53 in left-sided tumors compared to right-sided tumors and BRAF in right-sided tumors compared to left-sided tumors. Mutations in KRAS, NRAS, and BRAF were not detected in 45% of patients with left-sided tumors and in 28.6% of patients with right-sided tumors. Liver metastases were more common in patients with left-sided tumors. Tumors on the right side were larger at diagnosis and had a higher grade (G3) than tumors on the left. Rectal tumors exhibit distinctive biological characteristics when compared to left-sided tumors, including a higher absence rate of KRAS, NRAS, and BRAF mutations (47.4% in rectal versus 42.8% in left-sided tumors). These rectal tumors are also unique in their primary metastasis site, which is predominantly the lungs, and they have varying mutation rates, particularly in genes such as BRAF, FBXW7, and TP53, that distinguish them from tumors found in other locations. Primary tumor location has implications for the potential treatment of CRC with anti-EGFR therapy.

Genomic Characterization and Clinical Outcomes of Patients with Peritoneal Metastases from the AACR GENIE Biopharma Collaborative Colorectal Cancer Registry.

Utilizing the GENIE BPC registry, this study found that PM in patients with colorectal cancer occur more frequently in females and right-sided primary tumors and are associated with worse OS. In addition, we found a lower frequency of APC alterations and a higher frequency in MED12 alterations in patients with PM.

Baseline ctDNA gene alterations as a biomarker of survival after panitumumab and chemotherapy in metastatic colorectal cancer.

Certain genetic alterations and right-sided primary tumor location are associated with resistance to anti-epidermal growth factor (EGFR) treatment in metastatic colorectal cancer (mCRC). The phase 3 PARADIGM trial (n = 802) demonstrated longer overall survival with first-line anti-EGFR (panitumumab) versus antivascular endothelial growth factor (bevacizumab) plus modified FOLFOX6 in patients with RAS wild-type mCRC with left-sided primary tumors. This prespecified exploratory biomarker analysis of PARADIGM (n = 733) evaluated the association between circulating tumor DNA (ctDNA) gene alterations and efficacy outcomes, focusing on a broad panel of gene alterations associated with resistance to EGFR inhibition, including KRAS, NRAS, PTEN and extracellular domain EGFR mutations, HER2 and MET amplifications, and ALK, RET and NTRK1 fusions. Overall survival was prolonged with panitumumab plus modified FOLFOX6 versus bevacizumab plus modified FOLFOX6 in patients with ctDNA that lacked gene alterations in the panel (that is, negative hyperselected; median in the overall population: 40.7 versus 34.4 months; hazard ratio, 0.76; 95% confidence interval, 0.62-0.92) but was similar or inferior with panitumumab in patients with ctDNA that contained any gene alteration in the panel (19.2 versus 22.2 months; hazard ratio, 1.13; 95% confidence interval, 0.83-1.53), regardless of tumor sidedness. Negative hyperselection using ctDNA may guide optimal treatment selection in patients with mCRC. ClinicalTrials.gov registrations: NCT02394834 and NCT02394795 .

Association of KRAS G12C Status with Age at Onset of Metastatic Colorectal Cancer.

The association of age at the onset of CRC and the prevalence of a KRAS G12C mutation is unclear. A retrospective, multicenter study evaluating metastatic CRC patients from January 2019 to July 2023, treated at the Oncoclinicas units and tested for tissue based KRAS/NRAS and BRAF mutations in a centralized genomics lab. A mismatch repair (MMR) status was retrieved from different labs and electronic medical records, as were patient demographics (age, gender) and tumor sidedness. The chi-square test was used to examine the association between clinical and molecular variables, with p value < 0.05 being statistically significant. A total of 858 cases were included. The median age was 63.7 years (range 22-95) and 17.4% were less than 50 years old at the diagnosis of metastatic CRC. Male patients represented 50.3% of the population. The sidedness distribution was as follows: left side 59.2%, right side 36.8% and not specified 4%. The prevalence of the KRAS mutation was 49.4% and the NRAS mutation was 3.9%. Among KRAS mutated tumors, the most common variants were G12V (27.6%) and G12D (23.5%), while KRAS G12C was less frequent (6.4%), which represented 3.1% of the overall population. The BRAF mutant cases were 7.3% and most commonly V600E. Only five (<1%) non-V600E mutations were detected. MSI-high or dMMR was present in 14 cases (1.6%). In the age-stratified analysis, left-sidedness (p < 0.001) and a KRAS G12C mutation (p = 0.046) were associated with a younger age (<50 years). In the sidedness-stratified analysis, a BRAF mutation (p = 0.001) and MSI-high/dMMR status (p = 0.009) were more common in right-sided tumors. Our data suggest that KRAS G12C mutations are more frequent in early-onset metastatic CRC. To the best of our knowledge, this is the largest cohort in the Latin American population with metastatic CRC reporting RAS, BRAF and MSI/MMR status.

Wilms tumour in a two day old neonate: A rare and challenging case

Wilms tumor or nephroblastoma is the second most common renal tumor occurring in the neonatal age group next to congenital mesoblastic nephroma. The most common age group of presentation of Wilms tumor is between 3 and 4 years of age. Here, we report a case of right-sided Wilms tumor in a 2-day-old neonate. A term-born female baby presented on day 2 of birth with abdominal distension and physical examination revealed a large palpable mass in the right lumbar region crossing the midline. Imaging features were suggestive of a retroperitoneal mass of probable right renal origin. The patient was taken up for right radical nephroureterectomy and Per-operatively, there was anticipated tumor spillage. Post-operative histopathological examination was suggestive of a triphasic Wilms tumor with no anaplasia and favorable histology. The patient was diagnosed with Wilms tumor of the right kidney, COG stage III, SIOP (“International Society of Pediatric Oncology”) intermediate risk loss of heterozygosity testing for 1p and 16q was negative. She was started on chemotherapy with a DDA4 regimen. She completed whole abdominal radiotherapy and tolerated treatment well. The child is disease free and is under regular follow-up. This case of neonatal Wilms tumor was indeed a challenge to the pediatric surgeons and the oncologists but the final results were worth the challenge that was faced.

Disease characteristics and prognostic factors of colorectal cancer patients with bone metastasis: A real-world data from Turkey.

Bone metastasis is rarely seen in colorectal cancer (CRC) patients, and there is insufficient data available regarding such cases. The study aimed to identify the prognostic factors and characteristics associated with overall survival in patients with bone metastatic CRC. Data from bone metastatic CRC patients referred to a high-volume tertiary cancer center in Turkey, between January 2018 and April 2021, were retrospectively collected. The records of 150 consecutive patients treated for bone metastases due to CRC were reviewed. Overall survival curves were generated by the Kaplan-Meier method and analyzed using the log-rank test. Median age was 55 years (19-86 years). Bone metastases were more common in men and those with metachronous metastases. The axial skeleton was the most commonly involved site, and patients were frequently presented with single bone metastasis. Peritoneal metastases were significantly correlated with extra-axial metastases (P = 0.002), and radiotherapy was applied to axial metastases significantly, more frequently (P = 0.02). Lung metastasis was also more prevalent in K-RAS mutated patients (P = 0.008). The median survival time from diagnosis of bone metastasis was 8.3 months (95% confidence interval (CI), 5.5-10.6), and the three-year survival rate was 76.9% (95% CI, 69.8-84.0). Multivariate analysis revealed that brain metastases, right-sided colon tumor, high serum ALP, and Ca 19-9 levels were independent poor prognostic factors (P = 0.01, 0.02, <0.001, and 0.04, respectively). The location of CRC correlates significantly with the site of bone metastasis; the prognosis of CRC patients with bone metastasis is very poor, and the significant poor prognostic factors are brain metastases, right-sidedness, high serum ALP, and Ca 19-9 levels. More attention should be paid to bone metastasis in CRC patients.

Real-world data of TAS-102 therapy in refractory metastatic colorectal cancer (mCRC): The experience of the University Hospital of Montreal (CHUM).

137 Background: Colorectal cancer poses a substantial healthcare burden due to its elevated rates of diagnosis and mortality. Managing refractory metastatic cases remains a challenge in our practice due to the paucity of therapeutic options. Treatment with Trifluridine-Tipiracil (TAS-102) prolonged overall survival among patients (pts) with mCRC. This study investigates the efficacy of TAS-102 therapy in this patient population and explores various prognostic factors influencing clinical outcomes. Methods: We retrospectively reviewed the data of 53 patients with refractory mCRC treated with at least 1 cycle of TAS-102 at CHUM between March 2018 and January 2023. Multivariate and univariate analyses were employed to evaluate the impact of age, number of prior treatments, presence of KRAS mutation, gender, tumor origin, and Eastern Cooperative Oncology Group (ECOG) performance status on progression-free survival (PFS) and overall survival (OS). Survival analysis was conducted using the Kaplan-Meier method, and Cox regression analysis assessed prognostic factors. Results: The median age was 61 years (23-82), and 27 pts (50.9%) were females. Twenty-two pts (41.5%) had their primary tumor located in the left colon, 17 pts (32.1%) had right-sided tumors, and 14 pts (26.4%) with rectal tumors. 52% of pts received TAS-102 after 2 lines of therapy and 43% beyond third line. The performance status was: ECOG 0/1 in 46 pts (86.8%), and ECOG 2 in 7 pts (13.2%). In our refractory mCRC pts, median PFS was 3 months and median OS 7 months. Univariate analysis demonstrated no significant differences in PFS or OS based on patient sex, KRAS mutation status, tumor sidedness, or the number of prior treatments. In univariate and multivariate analysis ECOG 0/1 pts compared to ECOG 2 pts had a significant improvement in both PFS (HR = 0.33; p = 0.0511) and OS (HR = 0.21; p = 0.0086). Conclusions: In our real-world experience, clinical outcomes were comparable to the findings from the RECOURSE trial, suggesting improved PFS and OS with TAS-102 in heavily pre-treated mCRC patients. ECOG performance status remains a significant prognostic factor and underscores its importance in treatment decisions for this patient population.