Abstract Background A plant-based diet is associated with better survival among patients with nonmetastatic colorectal cancer (CRC), but its association in metastatic CRC is unknown. Methods Using an National Cancer Institute–sponsored trial (CALGB/SWOG 80405), we included 1284 patients who completed validated food frequency questionnaires at the initiation of metastatic CRC treatment. We calculated 3 indices: overall plant-based diet index (PDI), which emphasized consumption of all plant foods while reducing animal food intake; healthful plant-based diet index (hPDI), which emphasized consumption of healthful plant foods such as whole grains, fruits, and vegetables; and unhealthful plant-based diet index (uPDI), which emphasized consumption of less healthful plant foods such as fruit juices, refined grains, and sugar-sweetened beverages. We estimated the associations of 3 indices (quintiles) with overall survival (OS) and progression-free survival (PFS) using multivariable Cox proportional hazards regression. Results We observed 1100 deaths and 1204 progression events (median follow-up = 6.1 years). Compared with the lowest quintile, patients in the highest quintile of PDI had significantly better survival (hazard ratio [HR] for OS = 0.76 [0.62-0.94], Ptrend = .004; PFS = 0.81 [0.66-0.99], Ptrend = .09). Similar findings were observed for hPDI (HR for OS = 0.81 [0.65-1.01], Ptrend = .053; PFS = 0.80 [0.65-0.98], Ptrend = .04), whereas uPDI was not associated with worse survival (HR for OS = 1.16 [0.94-1.43], Ptrend = .21; PFS = 1.12 [0.92-1.36], Ptrend = .42). Conclusions Our study suggests that a plant-based diet, especially when rich in healthful plant foods, is associated with better survival among patients with metastatic CRC. The cause of survival benefits warrants further investigation.
Abstract 2200: Plant-based diet and survival among patients with metastatic colorectal cancer: Findings from CALGB/SWOG 80405 (Alliance)
Abstract Background: Plant-based diet is recommended by multiple cancer survivorship guidelines and was reported to be associated with better survival among patients with non-metastatic colorectal cancer. However, the association between plant-based diet and survival in metastatic colorectal cancer is unknown. Methods: Using an NCI-sponsored systemic therapy trial conducted from 2005 to 2015 (CALGB/SWOG 80405), we included 1,279 patients who completed validated food frequency questionnaires at the initiation of treatment for metastatic colorectal cancer. To emphasize different impact of healthful plant foods, less healthful plant foods, and animal foods, we used 18 food groups to calculate three plant-based indexes (ranges: 18-90 points): overall plant-based diet index (PDI), healthful plant-based diet index (hPDI), and unhealthful plant-based diet index (uPDI). The primary outcome was overall survival, and the secondary outcome was progression-free survival. We estimated the associations of three indexes (quintiles) with survival using multivariable Cox proportional hazards regression. Results: Of 1,279 patients (median follow-up: 6.1 years), mean (SD) age at diagnosis was 58.8 (11.7) years, 57.4% were men, 85.6% were White, and 1,096 deaths and 1,201 events of progression occurred. The mean (SD) points of three indexes were 51.2 (6.3) for PDI, 51.1 (6.7) for hPDI, and 51.2 (8.1) for uPDI. Compared to the lowest quintile (Q1), the highest quintile (Q5) of PDI was significantly associated with better overall survival (HR: 0.80 [0.65-0.99]) and progression-free survival (HR: 0.80 [0.65-0.98]). Similar findings were observed for hPDI, but uPDI was not significantly associated with worse survival. Conclusions: Our findings suggest that plant-based diet is associated with better survival among patients with metastatic colorectal cancer, and plant-based dietary interventions should be considered for future trials in metastatic colorectal cancer. Table. Adjusted Associations of Plant-Based Diet with Survival in Metastatic Colorectal Cancer Q1 Q2 Q3 Q4 Q5 P for trend Overall Survival PDI 1.00 0.96 (0.80-1.16) 0.93 (0.77-1.14) 0.82 (0.67-0.99) 0.80 (0.65-0.99) 0.01 hPDI 1.00 0.95 (0.78-1.14) 0.94 (0.77-1.15) 0.86 (0.70-1.04) 0.84 (0.68-1.03) 0.07 uPDI 1.00 1.14 (0.95-1.39) 1.07 (0.87-1.31) 1.18 (0.97-1.45) 1.17 (0.95-1.45) 0.15 Progression-free Survival PDI 1.00 0.84 (0.70-1.01) 0.94 (0.78-1.14) 0.93 (0.77-1.12) 0.80 (0.65-0.98) 0.10 hPDI 1.00 0.86 (0.72-1.03) 0.83 (0.69-1.01) 0.80 (0.67-0.97) 0.80 (0.66-0.97) 0.03 uPDI 1.00 1.12 (0.94-1.34) 1.11 (0.91-1.34) 1.10 (0.91-1.34) 1.15 (0.94-1.41) 0.23 Citation Format: En Cheng, Fang-Shu Ou, Chao Ma, Alan P. Venook, Heinz-Josef Lenz, Eileen M. O’Reilly, Peter T. Campbell, Chaoyuan Kuang, Bette J. Caan, Kimmie Ng, Jeffrey A. Meyerhardt. Plant-based diet and survival among patients with metastatic colorectal cancer: Findings from CALGB/SWOG 80405 (Alliance) [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 2200.
Association of Inflammatory Biomarkers With Survival Among Patients With Stage III Colon Cancer
ImportanceThe association of chronic inflammation with colorectal cancer recurrence and death is not well understood, and data from large well-designed prospective cohorts are limited.ObjectiveTo assess the associations of inflammatory biomarkers with survival among patients with stage III colon cancer.Design, Setting, and ParticipantsThis cohort study was derived from a National Cancer Institute–sponsored adjuvant chemotherapy trial Cancer and Leukemia Group B/Southwest Oncology Group 80702 (CALGB/SWOG 80702) conducted between June 22, 2010, and November 20, 2015, with follow-up ending on August 10, 2020. A total of 1494 patients with plasma samples available for inflammatory biomarker assays were included. Data were analyzed from July 29, 2021, to February 27, 2022.ExposuresPlasma inflammatory biomarkers (interleukin 6 [IL-6], soluble tumor necrosis factor α receptor 2 [sTNF-αR2], and high-sensitivity C-reactive protein [hsCRP]; quintiles) that were assayed 3 to 8 weeks after surgery but before chemotherapy randomization.Main Outcomes and MeasuresThe primary outcome was disease-free survival, defined as time from randomization to colon cancer recurrence or death from any cause. Secondary outcomes were recurrence-free survival and overall survival. Hazard ratios for the associations of inflammatory biomarkers and survival were estimated via Cox proportional hazards regression.ResultsOf 1494 patients (median follow-up, 5.9 years [IQR, 4.7-6.1 years]), the median age was 61.3 years (IQR, 54.0-68.8 years), 828 (55.4%) were male, and 327 recurrences, 244 deaths, and 387 events for disease-free survival were observed. Plasma samples were collected at a median of 6.9 weeks (IQR, 5.6-8.1 weeks) after surgery. The median plasma concentration was 3.8 pg/mL (IQR, 2.3-6.2 pg/mL) for IL-6, 2.9 × 103pg/mL (IQR, 2.3-3.6 × 103pg/mL) for sTNF-αR2, and 2.6 mg/L (IQR, 1.2-5.6 mg/L) for hsCRP. Compared with patients in the lowest quintile of inflammation, patients in the highest quintile of inflammation had a significantly increased risk of recurrence or death (adjusted hazard ratios for IL-6: 1.52 [95% CI, 1.07-2.14];P = .01 for trend; for sTNF-αR2: 1.77 [95% CI, 1.23-2.55];P < .001 for trend; and for hsCRP: 1.65 [95% CI, 1.17-2.34];P = .006 for trend). Additionally, a significant interaction was not observed between inflammatory biomarkers and celecoxib intervention for disease-free survival. Similar results were observed for recurrence-free survival and overall survival.Conclusions and RelevanceThis cohort study found that higher inflammation after diagnosis was significantly associated with worse survival outcomes among patients with stage III colon cancer. This finding warrants further investigation to evaluate whether anti-inflammatory interventions may improve colon cancer outcomes.Trial RegistrationClinicalTrials.gov Identifier:NCT01150045
Abstract 682: Associations of inflammatory biomarkers with survival among patients with stage III colon cancer (CALGB/SWOG 80702 [Alliance])
Abstract Chronic inflammation is a well-established carcinogenic pathway for colorectal cancer (CRC), but the role of inflammation in CRC prognosis is not well understood. Since cytokines are central in extensive biological networks to regulate inflammation, it is of great importance to investigate inflammatory cytokines and CRC survival. Among an NCI-sponsored adjuvant chemotherapy trial for patients with stage III colon cancer conducted between 2010 and 2015 (CALGB/SWOG 80702), we collected serum samples from 1,498 participants at a median of 1.6 months (interquartile [IQR]: 1.3-1.9 months) after surgery. IL-6, TNFR2, and hsCRP were assayed as biomarkers of chronic inflammation and were categorized into quintiles. The primary outcome was disease-free survival, defined as time from randomization to recurrence or death from any cause. Secondary outcomes included overall survival and time to recurrence. We estimated the associations of inflammatory biomarkers with survival using multivariable Cox proportional hazards regression. Of 1,498 participants (median follow-up: 5.9 years), mean age was 61.3 years, 82.2% were White, 55.5% were male, and 387 experienced recurrence or death. Medians (IQRs) of biomarkers were 2.6mg/L (1.2-5.6mg/L) for IL-6, 2.9×103pg/mL (2.3-3.6×103pg/mL) for TNFR2, and 2.6mg/L (1.2-5.6mg/L) for hsCRP. Compared to the lowest quintile (Q1), the highest quintile (Q5) in inflammatory biomarkers was significantly associated with worse disease-free survival (hazard ratios were 1.52 [95% CI, 1.08-2.15] for IL-6, 1.76 [95% CI, 1.22-2.54] for TNFR2, and 1.66 [95% CI, 1.17-2.35] for hsCRP). Similar patterns were observed for overall survival and time to recurrence. Our findings suggest that higher levels of inflammation after diagnosis were significantly associated with worse survival among those with stage III colon cancer, and reducing inflammation may be considered as a potential intervention to improve CRC survival. Associations of Inflammatory Biomarkers with Survival after Adjustment for Clinicopathologic Factors Q1 Q2 Q3 Q4 Q5 P for Trend Disease-free survival IL-6 1.00 1.14 (0.80-1.62) 1.37 (0.97-1.94) 1.44 (1.02-2.03) 1.52 (1.08-2.15) 0.02 TNFR2 1.00 1.21 (0.84-1.74) 1.43 (0.99-2.05) 1.56 (1.09-2.25) 1.76 (1.22-2.54) 0.002 hsCRP 1.00 1.34 (0.95-1.90) 1.62 (1.15-2.29) 1.26 (0.88-1.80) 1.66 (1.17-2.35) 0.04 Overall survival IL-6 1.00 1.44 (0.91-2.29) 1.56 (0.98-2.48) 1.48 (0.93-2.34) 1.68 (1.07-2.65) 0.09 TNFR2 1.00 1.57 (0.94-2.63) 1.88 (1.13-3.13) 1.92 (1.15-3.20) 2.31 (1.39-3.84) 0.003 hsCRP 1.00 1.27 (0.81-2.00) 1.72 (1.11-2.65) 1.22 (0.77-1.92) 1.73 (1.12-2.69) 0.06 Time to recurrence IL-6 1.00 1.34 (0.92-1.95) 1.48 (1.01-2.16) 1.55 (1.06-2.27) 1.54 (1.05-2.26) 0.07 TNFR2 1.00 1.14 (0.78-1.67) 1.28 (0.87-1.87) 1.48 (1.01-2.16) 1.54 (1.04-2.27) 0.02 hsCRP 1.00 1.27 (0.87-1.83) 1.64 (1.14-2.36) 1.21 (0.82-1.77) 1.55 (1.07-2.26) 0.12 Citation Format: En Cheng, Shi Qian, Anthony F. Shields, Elizabeth M. Cespedes Feliciano, Andrew B. Nixon, Ardaman P. Shergill, Katherine A. Guthrie, Felix Couture, Philip Kuebler, Pankaj Kumar, Dequincy Lewis, Benjamin Tan, Eileen M. O'Reilly, Justin C. Brown, Philip A. Philip, Bette J. Caan, Jeffrey A. Meyerhardt. Associations of inflammatory biomarkers with survival among patients with stage III colon cancer (CALGB/SWOG 80702 [Alliance]) [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 682.
Genetic architectures of proximal and distal colorectal cancer are partly distinct
Objective An understanding of the etiologic heterogeneity of colorectal cancer (CRC) is critical for improving precision prevention, including individualized screening recommendations and the discovery of novel drug targets and repurposable drug candidates for chemoprevention. Known differences in molecular characteristics and environmental risk factors among tumors arising in different locations of the colorectum suggest partly distinct mechanisms of carcinogenesis. The extent to which the contribution of inherited genetic risk factors for CRC differs by anatomical subsite of the primary tumor has not been examined. Design To identify new anatomical subsite-specific risk loci, we performed genome-wide association study (GWAS) meta-analyses including data of 48 214 CRC cases and 64 159 controls of European ancestry. We characterised effect heterogeneity at CRC risk loci using multinomial modelling. Results We identified 13 loci that reached genome-wide significance (p<5×10 −8 ) and that were not reported by previous GWASs for overall CRC risk. Multiple lines of evidence support candidate genes at several of these loci. We detected substantial heterogeneity between anatomical subsites. Just over half (61) of 109 known and new risk variants showed no evidence for heterogeneity. In contrast, 22 variants showed association with distal CRC (including rectal cancer), but no evidence for association or an attenuated association with proximal CRC. For two loci, there was strong evidence for effects confined to proximal colon cancer. Conclusion Genetic architectures of proximal and distal CRC are partly distinct. Studies of risk factors and mechanisms of carcinogenesis, and precision prevention strategies should take into consideration the anatomical subsite of the tumour.
Postdiagnosis Loss of Skeletal Muscle, but Not Adipose Tissue, Is Associated with Shorter Survival of Patients with Advanced Pancreatic Cancer
Abstract Background: Pancreatic cancer is associated with development of cachexia, a wasting syndrome thought to limit survival. Few studies have longitudinally quantified peripheral tissues or identified biomarkers predictive of future tissue wasting. Methods: Adipose and muscle tissue were measured by computed tomography (CT) at diagnosis and 50 to 120 days later in 164 patients with advanced pancreatic cancer. Tissue changes and survival were evaluated by Cox proportional hazards regression. Baseline levels of circulating markers were examined in relation to future tissue wasting. Results: Compared with patients in the bottom quartile of muscle change per 30 days (average gain of 0.8 ± 2.0 cm2), those in the top quartile (average loss of 12.9 ± 4.9 cm2) had a hazard ratio (HR) for death of 2.01 [95% confidence interval (CI), 1.12–3.62]. Patients in the top quartile of muscle attenuation change (average decrease of 4.9 ± 2.4 Hounsfield units) had an HR of 2.19 (95% CI, 1.18–4.04) compared with those in the bottom quartile (average increase of 2.4 ± 1.6 Hounsfield units). Changes in adipose tissue were not associated with survival. Higher plasma branched chain amino acids (BCAA; P = 0.004) and lower monocyte chemoattractant protein-1 (MCP-1; P = 0.005) at diagnosis were associated with greater future muscle loss. Conclusions: In patients with advanced pancreatic cancer, muscle loss and decrease in muscle density in 2 to 4 months after diagnosis were associated with reduced survival. BCAAs and MCP-1 levels at diagnosis were associated with subsequent muscle loss. Impact: BCAAs and MCP-1 levels at diagnosis could identify a high-risk group for future tissue wasting.
DNA repair and cancer in colon and rectum: Novel players in genetic susceptibility
Interindividual differences in DNA repair systems may play a role in modulating the individual risk of developing colorectal cancer. To better ascertain the role of DNA repair gene polymorphisms on colon and rectal cancer risk individually, we evaluated 15,419 single nucleotide polymorphisms (SNPs) within 185 DNA repair genes using GWAS data from the Colon Cancer Family Registry (CCFR) and the Genetics and Epidemiology of Colorectal Cancer Consortium (GECCO), which included 8,178 colon cancer, 2,936 rectum cancer cases and 14,659 controls. Rs1800734 (in MLH1 gene) was associated with colon cancer risk (p‐value = 3.5 × 10−6) and rs2189517 (in RAD51B) with rectal cancer risk (p‐value = 5.7 × 10−6). The results had statistical significance close to the Bonferroni corrected p‐value of 5.8 × 10−6. Ninety‐four SNPs were significantly associated with colorectal cancer risk after Binomial Sequential Goodness of Fit (BSGoF) procedure and confirmed the relevance of DNA mismatch repair (MMR) and homologous recombination pathways for colon and rectum cancer, respectively. Defects in MMR genes are known to be crucial for familial form of colorectal cancer but our findings suggest that specific genetic variations in MLH1 are important also in the individual predisposition to sporadic colon cancer. Other SNPs associated with the risk of colon cancer (e.g., rs16906252 in MGMT) were found to affect mRNA expression levels in colon transverse and therefore working as possible cis‐eQTL suggesting possible mechanisms of carcinogenesis.
Novel Common Genetic Susceptibility Loci for Colorectal Cancer
Abstract Background Previous genome-wide association studies (GWAS) have identified 42 loci (P < 5 × 10−8) associated with risk of colorectal cancer (CRC). Expanded consortium efforts facilitating the discovery of additional susceptibility loci may capture unexplained familial risk. Methods We conducted a GWAS in European descent CRC cases and control subjects using a discovery–replication design, followed by examination of novel findings in a multiethnic sample (cumulative n = 163 315). In the discovery stage (36 948 case subjects/30 864 control subjects), we identified genetic variants with a minor allele frequency of 1% or greater associated with risk of CRC using logistic regression followed by a fixed-effects inverse variance weighted meta-analysis. All novel independent variants reaching genome-wide statistical significance (two-sided P < 5 × 10−8) were tested for replication in separate European ancestry samples (12 952 case subjects/48 383 control subjects). Next, we examined the generalizability of discovered variants in East Asians, African Americans, and Hispanics (12 085 case subjects/22 083 control subjects). Finally, we examined the contributions of novel risk variants to familial relative risk and examined the prediction capabilities of a polygenic risk score. All statistical tests were two-sided. Results The discovery GWAS identified 11 variants associated with CRC at P < 5 × 10−8, of which nine (at 4q22.2/5p15.33/5p13.1/6p21.31/6p12.1/10q11.23/12q24.21/16q24.1/20q13.13) independently replicated at a P value of less than .05. Multiethnic follow-up supported the generalizability of discovery findings. These results demonstrated a 14.7% increase in familial relative risk explained by common risk alleles from 10.3% (95% confidence interval [CI] = 7.9% to 13.7%; known variants) to 11.9% (95% CI = 9.2% to 15.5%; known and novel variants). A polygenic risk score identified 4.3% of the population at an odds ratio for developing CRC of at least 2.0. Conclusions This study provides insight into the architecture of common genetic variation contributing to CRC etiology and improves risk prediction for individualized screening.
Mendelian Randomization Study of Body Mass Index and Colorectal Cancer Risk