Primary tumor site is a useful predictor of cetuximab efficacy in the third-line or salvage treatment of KRAS wild-type (exon 2 non-mutant) metastatic colorectal cancer: a nationwide cohort study

Efficacy, safety and genomic analysis of SCT200, an anti-EGFR monoclonal antibody, in patients with fluorouracil, irinotecan and oxaliplatin refractory RAS and BRAF wild-type metastatic colorectal cancer: a phase Ⅱ study

BACKGROUND

Limited therapeutic options are available for metastatic colorectal cancer (mCRC) patients after failure of first- and second-line therapies, representing an unmet medical need for novel therapies.

METHODS

This is an open-label, single arm, multicenter, phase Ⅱ study aiming to perform the efficacy, safety and genomic analysis of SCT200, a noval fully humanized IgG1 anti-epidermal growth factor receptor (EGFR) monoclonal antibody, in patients with fluorouracil, irinotecan and oxaliplatin refractory RAS and BRAF wild-type mCRC. SCT200 (6 mg/kg) was given weekly for the first six weeks, followed by a higher dose of 8 mg/kg every two weeks until disease progression or unacceptable toxicity. Primary endpoint was independent review committee (IRC)-assessed objective response rate (ORR) and secondary endpoints included ORR in patients with left-sided tumor, disease control rate (DCR), duration of response (DoR), time to response (TTR), progression-free survival (PFS), overall survival (OS) and safety.

FINDINGS

From February 12, 2018 to December 1, 2019, a total of 110 patients aged between 26 and 77 years (median: 55; interquartile range [IQR]: 47-63) with fluorouracil, oxaliplatin, and irinotecan refractory RAS and BRAF wild-type mCRC were enrolled from 22 hospitals in China. As the data cut-off date on May 15, 2020, the IRC-assessed ORR and DCR was 31% (34/110, 95% confidence interval [CI] 22-40%) and 75% (82/110, 95% CI 65-82%), respectively. Thirty one percent (34/110) patients achieved confirmed partial response (PR). The median PFS and median OS were 5.1 months (95% CI 3.4-5.2) and 16.2 months (95% CI 11.1-not available [NA]), respectively. The most common ≥ grade 3 treatment-related adverse events (TRAEs) were hypomagnesemia (17%, 19/110) and acneiform dermatitis (11%, 12/110). No deaths occurred. Genomic analysis suggested positive association between MYC amplification and patients' response (P = 0.0058). RAS/RAF mutation and MET amplification were the most frequently detected resistance mechanisms. Patients with high circulating tumor DNA (ctDNA) at baseline or without ctDNA clearance at the 7th week after the first dose of SCT200 administration before receiving SCT200 had worse PFS and OS.

INTERPRETATION

SCT200 exhibited promising clinical efficacy and manageable safety profiles in RAS and BRAF wild-type mCRC patients progressed on fluorouracil, irinotecan and oxaliplatin treatment. The baseline ctDNA and ctDNA clearance status at the 7th week after the first dose of SCT200 administration before receiving SCT200 could be a potential prognostic biomarker for RAS and BRAF wild-type mCRC patients with SCT200 therapy.

FUNDING

This study was sponsored by Sinocelltech Ltd., Beijing, China and partly supported by the National Science and Technology Major Project for Key New Drug Development (2019ZX09732001-006, 2017ZX09304015).

Prevalence of KRAS G12C Mutation and Co-mutations and Associated Clinical Outcomes in Patients With Colorectal Cancer: A Systematic Literature Review

PURPOSE

A systematic literature review was conducted to estimate the global prevalence of Kirsten rat sarcoma virus gene (KRAS) mutations, with an emphasis on the clinically significant KRAS G12C mutation, and to estimate the prognostic significance of these mutations in patients with colorectal cancer (CRC).

DESIGN

Relevant English-language publications in the Embase, MEDLINE, and the Cochrane Library databases (from 2009 to 2021) and congress presentations (from 2016 to 2021) were reviewed. Eligible studies were those that reported the prevalence and clinical outcomes of the KRAS G12C mutation in patients with CRC.

RESULTS

A total of 137 studies (interventional [n = 8], post hoc analyses of randomized clinical trials [n = 6], observational [n = 122], and longitudinal [n =1]) were reviewed. Sixty-eight studies reported the prevalence of KRAS mutations (KRASm) in 42 810 patients with CRC. The median global prevalence of KRASm was 38% (range, 13.3%-58.9%) and that of the KRAS G12C mutation (KRAS G12C) 3.1% (range, 0.7%-14%). Available evidence suggests that KRASm are possibly more common in tumors that develop on the right side of the colon. Limited evidence suggests a lower objective response rate and inferior disease-free/relapse-free survival in patients with KRAS G12C compared with patients with KRASwt or other KRASm.

CONCLUSION

Our analysis reveals that KRAS G12C is prevalent in 3% of patients with CRC. Available evidence suggests a poor prognosis for patients with KRAS G12C. Right-sided tumors were more likely to harbor KRASm; however, their role in determining clinical outcomes needs to be investigated further.

Current Status of Angiogenesis Inhibitors as Second-Line Treatment for Unresectable Colorectal Cancer

Colorectal cancer is the third most common disease and the second most common cause of death around the world. The drug for second-line treatment depends on the drugs used in first-line treatment and the biomarker status. As biomarkers, the RAS gene, BRAF gene, and dMMR/MSI-H, TMB-H, and HER2 statuses have been established in clinical practice, and the corresponding molecularly targeted therapeutic agents are selected based on the biomarker status. Given the frequency of biomarkers, it is assumed that when patients move on to second-line treatment, an angiogenesis inhibitor is selected in many cases. For second-line treatment, three angiogenesis inhibitors, bevacizumab (BEV), ramucirumab (RAM), and aflibercept (AFL), are available, and one of them is combined with cytotoxic agents. These three angiogenesis inhibitors are known to inhibit angiogenesis through different mechanisms of action. Although no useful biomarkers have been established for the selection of angiogenesis inhibitors, previous biomarker studies have suggested that angiogenesis-related factors such as VEGF-A and VEGF-D might be predictors of the therapeutic efficacy of angiogenesis inhibitors. These biomarkers are measured as protein levels in plasma and are considered to be promising biomarkers. We consider that the rationale for selecting among these three angiogenesis inhibitors should be clarified to benefit patients.

Final results of DESTINY-CRC01 investigating trastuzumab deruxtecan in patients with HER2-expressing metastatic colorectal cancer

DESTINY-CRC01 (NCT03384940) was a multicenter, open-label, phase 2 trial assessing the efficacy and safety of trastuzumab deruxtecan (T-DXd) in patients with HER2-expressing metastatic colorectal cancer (mCRC) that progressed after ≥2 prior regimens; results of the primary analysis are published. Patients received T-DXd 6.4 mg/kg every 3 weeks and were assigned to either: cohort A (HER2-positive, immunohistochemistry [IHC] 3+ or IHC 2+/in situ hybridization [ISH]+), cohort B (IHC 2+/ISH-), or cohort C (IHC 1+). Primary endpoint was objective response rate (ORR) by independent central review in cohort A. Secondary endpoints included ORR (cohorts B and C), duration of response, disease control rate, progression-free survival, overall survival, pharmacokinetics, and safety of T-DXd. 86 patients were enrolled (53 in cohort A, 15 in cohort B, and 18 in cohort C). Results of the primary analysis are published, reporting an ORR of 45.3% in cohort A. Here, we report the final results. No responses occurred in cohorts B or C. Median progression-free survival, overall survival, and duration of response were 6.9, 15.5, and 7.0 months, respectively. Overall serum exposure (cycle 1) of T-DXd, total anti-HER2 antibody, and DXd were similar regardless of HER2 status. Most common grade ≥3 treatment-emergent adverse events were decreased neutrophil count and anemia. Adjudicated drug-related interstitial lung disease/pneumonitis occurred in 8 patients (9.3%). These findings support the continued exploration of T-DXd in HER2-positive mCRC.

Efficacy of third-line anti-EGFR-based treatment versus regorafenib or trifluridine/tipiracil according to primary tumor site in RAS/BRAF wild-type metastatic colorectal cancer patients

Background

Right- (R) and left-sided (L) metastatic colorectal cancer (mCRC) exhibit different clinical and molecular features. Several retrospective analyses showed that survival benefit of anti-EGFR-based therapy is limited to RAS/BRAF wt L-sided mCRC patients. Few data are available about third-line anti-EGFR efficacy according to primary tumor site.

Methods

RAS/BRAF wt patients mCRC treated with third-line anti-EGFR-based therapy versus regorafenib or trifluridine/tipiracil (R/T) were retrospectively collected. The objective of the analysis was to compare treatment efficacy according to tumor site. The primary endpoint was progression-free survival (PFS); secondary endpoints were overall survival (OS), response rate (RR) and toxicity.

Results

A total of 76 RAS/BRAF wt mCRC patients, treated with third-line anti-EGFR-based therapy or R/T, were enrolled. Of those, 19 (25%) patients had a R-sided tumor (9 patients received anti-EGFR treatment and 10 patients R/T) and 57 (75%) patients had a L-sided tumor (30 patients received anti-EGFR treatment and 27 patients R/T). A significant PFS [7.2 vs 3.6 months, HR 0.43 (95% CI 0.2-0.76), p= 0.004] and OS benefit [14.9 vs 10.9 months, HR 0.52 (95% CI 0.28-0.98), p= 0.045] in favor of anti-EGFR therapy vs R/T was observed in the L-sided tumor group. No difference in PFS and OS was observed in the R-sided tumor group. A significant interaction according to primary tumor site and third-line regimen was observed for PFS (p= 0.05). RR was significantly higher in L-sided patients treated with anti-EGFR vs R/T (43% vs. 0%; p <0.0001), no difference was observed in R-sided patients. At the multivariate analysis, third-line regimen was independently associated with PFS in L-sided patients.

Conclusions

Our results demonstrated a different benefit from third-line anti-EGFR-based therapy according to primary tumor site, confirming the role of L-sided tumor in predicting benefit from third-line anti-EGFR vs R/T. At the same time, no difference was observed in R-sided tumor.

TRIM29 is differentially expressed in colorectal cancers of different primary locations and affects survival by regulating tumor immunity based on retrospective study and bioinformatics analysis

Background

In colorectal cancer (CRC) patients, different primary tumor locations caused distinct prognosis and clinicopathological features. It is necessary to identify specific tumor markers according tumor site. Our previous work has identified differentially expressed genes between CRC and adjacent normal tissues, in which only TRIM29 was differently expressed between right colon cancer (RCC) and left colon cancer (LCC) patients. Rectal cancer (RECC) was not included in this latter study and the effects of TRIM29 on the survival with RCC and LCC patients were not investigated. This study further verified TRIM29 expression through Gene Expression Omnibus (GEO) database and our retrospective study. The role of TRIM29 on survival according tumor sites was also explored. Furthermore, the molecular mechanisms of TRIM29 were explored.

Methods

The GEO dataset was used to confirm the differential expression of TRIM29 in proximal and distal cancers. Moreover, TRIM29 were assess using immunohistochemistry (IHC) in 227 cases to observe the correlation between TRIM29 and tumor site. The relationship between TRIM29 and the clinicopathologic features was investigated according tumor sites. Furthermore, the disease-free survival (DFS) and overall survival (OS) was analyzed using the Kaplan-Meier method to assess the prognostic value of TRIM29. Finally, bioinformatics analysis was used to explore the molecular mechanisms. The Tumor-Immune System Interactions and Drug Bank database (TISIDB) was used to analyze the correlations between TRIM29 expression and tumor immune functions. The correlation of TRIM29 with tumor infiltrating lymphocytes or mismatch-repair-proficient/mismatch-repair-deficient (pMMR/dMMR) status was also investigated.

Results

TRIM29 expression was significantly higher in patients with RCC (P<0.001). RCC patients with high TRIM29 tended to be older, male, in stage III-IV, with N+ staging, and intestinal obstruction (P<0.001, P<0.001, P<0.001, P<0.001, and P=0.010, respectively). High TRIM29 expression was associated with an increased risk of recurrence/metastasis and death, only in RCC patients (P=0.020 and P<0.001). Functional annotations and immune activity analysis showed that TRIM29 is related to tumor infiltrating lymphocytes and immune dysfunction.

Conclusions

TRIM29 plays varying roles in patients with different tumor sites. TRIM29 is correlated with the clinicopathological features and prognosis in RCC patients. Indeed, TRIM29 may serve as a new biomarker for RCC patients.

Mid-transverse Location in Primary Colon Tumor: A Poor Prognostic Factor?

BACKGROUND

The location of colonic tumors has been linked to different clinical and oncologic outcomes. Transverse colon cancers are generally included as right colon cancers. Furthermore, hepatic and splenic flexure tumors are usually included as components of the transverse colon.

OBJECTIVE

This study was aimed at comparing the clinicopathologic characteristics and long-term outcomes between mid-transverse and right and left colon cancers and determining the prognostic impact of the primary tumor location in the mid-transverse colon.

DESIGN

This was a retrospective study.

SETTINGS

Two specialized colorectal centers were included.

PATIENTS

Patients who underwent curative surgery for colon cancer were analyzed. Tumors located in the transverse colon, excluding the flexures, were defined as mid-transverse colon cancers.

MAIN OUTCOME MEASURES

Demographic characteristics, operative outcomes, pathologic results, and long-term outcomes were the primary outcome measures.

RESULTS

Of the 487 patients, 41 (8.4%) had mid-transverse, 191 (39.2%) had right, and 255 (52.4%) had left colon cancers. For mid-transverse colon cancers, the mean length of hospital stay, mean length of the resected specimen, and the mean number of harvested lymph nodes were significantly higher. For patients with stage I to III cancer, the 5-year overall and disease-free survival rates were significantly worse in the mid-transverse colon cancers than in the right and left colon cancers (overall survival: 55.5% vs 82.8% vs 85.9%, p = 0.004, and disease-free survival; 47.7% vs 72.4% vs 79.5%, p = 0.003). After adjustment for other clinicopathologic factors, mid-transverse colon cancers were significantly associated with a poor prognosis (HR = 2.19 [95% CI, 1.25-3.83]; p = 0.006).

LIMITATIONS

Molecular and genetic information were unavailable in this retrospective study.

CONCLUSIONS

In our case series, colon cancers located in the mid-transverse colon showed poorer prognosis than cancers in other locations. The impact of tumor location in the mid-transverse colon on prognosis, including molecular and genetic markers, should be investigated further in prospective studies. See Video Abstract at http://links.lww.com/DCR/B631.

LOCALIZACIN TRANSVERSA MEDIA EN EL TUMOR DE COLON PRIMARIO UN FACTOR DE MAL PRONSTICO

ANTECEDENTES:La ubicación de los tumores de colon se ha relacionado con diferentes resultados clínicos y oncológicos. Los cánceres de colon transverso se incluyen generalmente como cánceres de colon derecho. Además, los tumores del ángulo hepático y esplénico suelen incluirse como un componente del colon transverso.OBJETIVO:Este estudio tuvo como objetivo comparar las características clínico-patológicas y los resultados a largo plazo entre los cánceres de colon transverso medio y derecho e izquierdo y determinar el impacto pronóstico de la ubicación del tumor primario en el colon transverso medio.DISEÑO:Este fue un estudio retrospectivo.AJUSTE ENTORNO CLINICO:Se incluyeron dos centros colorrectales especializados.PACIENTES:Se analizaron los pacientes que fueron sometidos a cirugía curativa por cáncer de colon. Los tumores ubicados en el colon transverso, excluidos los ángulos, se definieron como "cánceres de colon transverso medio".PRINCIPALES MEDIDAS DE RESULTADO VOLARACION:Las características demográficas, los resultados quirúrgicos, los resultados patológicos y los resultados a largo plazo fueron las principales medidas de resultado valoracion.RESULTADOS:De los 487 pacientes, 41 (8,4%) tenían cáncer de colon transverso medio, 191 (39,2%) derecho y 255 (52,4%) cáncer de colon izquierdo. Para los cánceres de colon transverso medio, la duración media de la estancia hospitalaria, la duración de la muestra resecada y el número medio de ganglios linfáticos extraídos fueron significativamente mayores. Para los pacientes en estadio I-III, las tasas de supervivencia general y sin enfermedad a 5 años fueron significativamente peores en los cánceres de colon transverso medio que en los cánceres de colon derecho e izquierdo (supervivencia general: 55,5% frente versus a 82,8% frente versus a 85,9%, p = 0,004 y supervivencia libre de enfermedad; 47,7% frente a 72,4% frente a 79,5%, p = 0,003, respectivamente). Después del ajuste por otros factores clínico-patológicos, los cánceres de colon transverso medio se asociaron significativamente con un pronóstico desfavorable (Razón de riesgo: 2,19; intervalo de confianza del 95%: 1,25-3,83; p = 0,006).LIMITACIONES:La información molecular y genética no estuvo disponible en este estudio retrospectivo.CONCLUSIONES:En nuestra serie de casos, los cánceres de colon localizados en el colon transverso medio mostraron un peor pronóstico que los cánceres en otras localizaciones. El impacto de la ubicación del tumor en el colon transverso medio sobre el pronóstico, incluidos los marcadores moleculares y genéticos, debe investigarse más a fondo en estudios prospectivos. Consulte Video Resumen en http://links.lww.com/DCR/B631. (Traducción-Dr Adrián Ortega).

Serum-based measurements of stromal activation through ADAM12 associate with poor prognosis in colorectal cancer

Background

Recently it has been recognized that stromal markers could be used as a clinically relevant biomarker for therapy response and prognosis. Here, we report on a serum marker for stromal activation, A Disintegrin and Metalloprotease 12 (ADAM12) in colorectal cancer (CRC).

Methods

Using gene expression databases we investigated ADAM12 expression in CRC and delineated the source of ADAM12 expression. The clinical value of ADAM12 was retrospectively assessed in the CAIRO2 trial in metastatic CRC with 235 patients (31% of total cohort), and an independent rectal cancer cohort (n = 20).

Results

ADAM12 is expressed by activated CRC associated fibroblasts. In the CAIRO2 trial cohort, ADAM12 serum levels were prognostic (ADAM12 low versus ADAM12 high; median OS 25.3 vs. 17.1 months, HR 1.48 [95% CI 1.11–1.96], P = 0.007). The prognostic potential was specifically high for metastatic rectal cancer (HR 1.78 [95% CI 1.06–3.00], P = 0.030) and mesenchymal subtype tumors (HR 2.12 [95% CI 1.25–3.60], P = 0.004). ADAM12 also showed potential for predicting recurrence in an exploratory analysis of non-metastatic rectal cancers.

Conclusions

Here we describe a non-invasive marker for activated stroma in CRC which associates with poor outcome, especially for primary cancers located in the rectum.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-022-09436-0.

Differences in T cell immune-related lncRNA and mRNA expression patterns between right- and left-sided colorectal cancers

BACKGROUND

Right-sided colorectal cancer (RCRC) and left-sided colorectal cancer (LCRC) harbor different genetic alterations associated with immune response.

OBJECTIVE

This study aimed to analyze the differences in T cell immune-related RNA expression patterns between RCRC and LCRC.

METHODS

The differentially expressed genes (DEGs) and lncRNAs (DElncRNAs) between LCRC and RCRC were screened from the Cancer Genome Atlas (TCGA) database. A correlation analysis between DEGs or DElncRNAs and differential T cells was also performed to obtain T cell-related genes, followed by miRNA prediction. The mRNA-lncRNA network and the competitive endogenous RNA (ceRNA) network were subsequently constructed, and the expression level of mRNA in the ceRNA network was verified using GSE104645.

RESULTS

RCRC patients had a poorer prognosis and were older than LCRC patients. In total, 923 DEGs and 328 DElncRNAs were screened between LCRC and RCRC patients. Compared to RCRC patients, LCRC patients showed a decrease in CD8⁺ T cells. In addition, 26 miRNAs, 8 mRNAs, and 10 lncRNAs were included in the ceRNA network. Finally, the validation analysis revealed that CDHR1 and PRLR were significantly downregulated, while TRIB2 was upregulated in RCRC patients compared to LCRC patients.

CONCLUSION

The analysis of T cell immune-related RNA expression might provide new insights into the underlying molecular mechanisms of the differences between LCRC and RCRC.

Treatment sequencing of metastatic colorectal cancer based on primary tumor location

Colorectal cancer is a heterogeneous disease with various clinical, molecular, and embryological differences related to the origin of the tumor from the right or left colon. Recent studies have demonstrated that tumor sidedness has both a prognostic and predictive value in metastatic colorectal cancer . Patients whose primary tumor originates from the left side of the colon and whose tumor's genome encodes wild-type RAS and BRAF should be offered cetuximab or panitumumab in the first-line treatment of metastatic disease or in subsequent lines. For tumors originating from the right side of the colon, anti-angiogenic treatment, particularly bevacizumab, is an option for this poor prognostic group until better options become available. Specifically, an aggressive initial approach with FOLFOXIRI plus bevacizumab is a treatment option in right-sided tumors under investigation. This report reviews the available data for the treatment of metastatic colorectal cancer according to the location of the primary tumor and proposes the optimal treatment sequencing strategy incorporating the site of origin of the tumor and molecular information into the decision-making process.

Colon Cancer, Version 2.2021, NCCN Clinical Practice Guidelines in Oncology

This selection from the NCCN Clinical Practice Guidelines in Oncology (NCCN Guidelines) for Colon Cancer focuses on systemic therapy options for the treatment of metastatic colorectal cancer (mCRC), because important updates have recently been made to this section. These updates include recommendations for first-line use of checkpoint inhibitors for mCRC, that is deficient mismatch repair/microsatellite instability-high, recommendations related to the use of biosimilars, and expanded recommendations for biomarker testing. The systemic therapy recommendations now include targeted therapy options for patients with mCRC that is HER2-amplified, or BRAF V600E mutation-positive. Treatment and management of nonmetastatic or resectable/ablatable metastatic disease are discussed in the complete version of the NCCN Guidelines for Colon Cancer available at NCCN.org. Additional topics covered in the complete version include risk assessment, staging, pathology, posttreatment surveillance, and survivorship.

Effect of Primary Tumor Location on Postmetastasectomy Survival in Patients with Colorectal Cancer Liver Metastasis

BACKGROUND

The effects of primary tumor location on colorectal liver metastasis (CRLM) and post-hepatic-metastasectomy overall survival (OS) are controversial. This study evaluated the difference in post-hepatic-metastasectomy OS among right-sided colon, left-sided colon, and rectal cancer groups.

METHODS

In total, 381 patients who underwent curative-intent CRLM resection were enrolled. Patients were grouped based on the primary tumor location (right-sided, left-sided, and rectum). The Kaplan-Meier analysis and log-rank test were performed for survival analysis. The univariate and multivariate analyses of clinical and pathological factors were performed using the Cox proportional hazards model.

RESULTS

Significant OS difference was noted among the three groups (log-rank, p = 0.014). The multivariate analysis revealed a 32% lower death risk in left-sided colon cancer compared with right-sided colon cancer (hazard ratio [HR] 0.68, p = 0.042), whereas no OS difference was noted between the rectal cancer and right-sided colon cancer groups. The left- versus right-sided OS advantage was noted only in the KRAS wild-type subgroup (HR 0.46, p = 0.002), and a rectal versus right-sided OS disadvantage was noted in the KRAS mutant subgroup (HR 1.78, p = 0.03).

CONCLUSIONS

The CRLM post-hepatic-metastasectomy OS was superior in left-sided colon cancer than in right-sided colon cancer and was similar in rectal and right-sided colon cancer. The OS difference in different primary tumor locations is dependent on KRAS mutation status, with a decreased left- versus right-sided death risk noted only in KRAS wild-type colon cancer and an increased rectal versus right-sided death risk noted only in KRAS mutant colon cancer.

Primary Tumor Location and Outcomes After Cytoreductive Surgery and Intraperitoneal Chemotherapy for Peritoneal Metastases of Colorectal Origin

BACKGROUND

The aim of this study is to evaluate outcomes in patients with peritoneal metastasis of colorectal cancer (pmCRC) who underwent cytoreductive surgery and intraperitoneal chemotherapy (CRS/IPC) in relation to the location of the primary tumor. Regional therapy, including cytoreductive surgery and intraperitoneal chemotherapy, has been associated with improved survival in patients with pmCRC. Location of the primary tumor has been shown to be prognostic in patients with metastasis.

PATIENTS AND METHODS

A retrospective review was performed for all patients who underwent complete cytoreduction and intraperitoneal chemotherapy from 2010 to 2017, examining patient and tumor characteristics, overall and recurrence-free survival, recurrence patterns, and tumor mutational profiles.

RESULTS

Ninety-three patients were included in the study: 49 (53%) with a right-sided and 44 (47%) with a left-sided primary tumor. Patients with a right-sided tumor had significantly shorter recurrence-free survival (median, 6.3 months; 95% CI, 4.7-8.1 months vs 12.3 months; 95% CI, 3.6-21.7 months; P = 0.02) and overall survival (median, 36.6 months; 95% CI, 26.4-46.9 months vs 83.3 months; 95% CI 44.2-122.4 months; P = 0.03). BRAF and KRAS mutations were more frequent in right-sided tumors, and APC and TP53 mutations were more frequent in left-sided tumors, which were more chromosomally instable. BRAF mutations were associated with early recurrence.

CONCLUSIONS

Tumor sidedness is a predictor of oncological outcomes after CRS/IPC. Tumor sidedness and molecular characteristics should be considered when counseling patients regarding expected outcomes and when selecting or stratifying pmCRC patients for clinical trials of regional therapy.

First-line cetuximab improves the efficacy of subsequent bevacizumab for RAS wild-type left-sided metastatic colorectal cancer: an observational retrospective study

The optimal targeted therapy sequence in patients of RAS wild-type left-sided metastatic colorectal cancer (mCRC) remains controversial, and few studies focus on the impact of first-line targeted agents on second-line ones. We enrolled 101 left-sided mCRC patients with RAS wild-type status, of which 50 cases received bevacizumab plus chemotherapy in both first-line and second-line therapies (Group A) and 51 cases received first-line cetuximab plus chemotherapy followed by second-line bevacizumab-containing regimens (Group B). The progression free survival (PFS) and overall survival (OS) from start of first-line (PFS 1nd and OS 1nd) and second-line (PFS 2nd and OS 2nd) therapy were compared between the two groups. PFS 1nd was comparable (10.0 vs 10.4 months; p = 0.402), while PFS 2nd (4.6 vs 7.9 months; p = 0.002), OS 1nd (26.8 vs 40.0 months; p = 0.011), and OS 2nd (15.2 vs 22.3 months; p = 0.006) were all poorer in group A compared with group B. Our study in combination with previous clinical data suggest that first-line application of cetuximab may provide a favorable condition for promoting the effect of subsequent bevacizumab, thus representing the optimal targeted therapy sequence in patients of RAS wild-type left-sided mCRC.

Cost-effectiveness of FOLFIRI + cetuximab vs FOLFIRI + bevacizumab in the first-line treatment of RAS wild-type metastatic colorectal cancer in Germany: data from the FIRE-3 (AIO KRK-0306) study

Aims: This analysis evaluates the cost-effectiveness of first-line treatment with FOLFIRI + cetuximab vs FOLFIRI + bevacizumab for patients with RAS wild-type (wt) metastatic colorectal cancer (mCRC) in Germany based on the randomized phase 3 FIRE-3 trial. For patients with RAS wt mCRC, FOLFIRI + cetuximab yielded statistically significant median overall survival gains over FOLFIRI + bevacizumab.Materials and methods: A standard 3-state partitioned survival cost-utility model was developed to compare the health benefits and costs of treatment from a German social health insurance perspective using individual patient-level trial data. Health outcomes were reported in life-years (LYs) and quality-adjusted life-years (QALYs) gained. Survival was estimated based on Kaplan-Meier (KM) curves supplemented with best-fitting parametric survival model extrapolations. Subgroup analyses of patients with a left-sided primary tumor location or patients with metastases confined to the liver were performed.Results: In the modified intention-to-treat analysis, FOLFIRI + cetuximab, providing 0.68 additional LYs (0.53 QALYs), yielded incremental cost-effectiveness ratios (ICERs) of €36,360/LY and €47,250/QALY. In subgroup analyses, patients experienced improved survival gains without a corresponding increase in costs, resulting in lower ICERs. Our model was most sensitive to changes in treatment duration across all lines of therapy, utility of progressive disease, as well as patients' weight and body surface area.Limitations: This cost-effectiveness analysis was based on patient-level data from the FIRE-3 trial. Trial outcomes may not adequately reflect those in the real-world setting. Additionally, resource use and costs were obtained from tariff lists, which do not account for differences in treatment practice. These considerations limit generalizability of outcomes to other countries, or within the German healthcare setting.Conclusions: Based on our analyses, FOLFIRI + cetuximab is cost-effective compared with FOLFIRI + bevacizumab in patients with RAS wt mCRC, with ICERs well below willingness-to-pay thresholds for diseases with a high burden.

Incidence and prognosis of pulmonary metastasis in colorectal cancer: a population-based study

PURPOSE

It is unclear how primary tumor location affects the pulmonary metastasis in colorectal cancer patients with different primary tumor locations. We aim to explore the relationship between primary tumor location and the incidence and prognosis of colorectal cancer patients with pulmonary metastasis at diagnosis.

METHODS

From Surveillance, Epidemiology, and End Results (SEER) database, 9920 out of 192,969 CRC patients were identified with pulmonary metastasis at diagnosis between 2010 and 2015. Patients were classified into three subsets according to primary tumor location. The incidence of pulmonary metastasis and median survival were calculated. Multivariable logistic and Cox regression were performed to identify the risk factors of pulmonary metastasis and prognosis.

RESULTS

The incidence of pulmonary metastasis was 5.14% in the entire colorectal cancer cohort and 25.66% in metastatic colorectal cancer patients. The median survival of those patients was 10 months. Rectal cancer patients exhibited the highest incidence of pulmonary metastasis, while they had the longest median survival (15 months). The right-sided colon cancer patients had the lowest incidence of pulmonary metastasis, but the shortest median survival (8 months). 61 to 80 years old, over 80, black, two or three extrapulmonary metastatic sites and CEA-positive had a negative influence both on the incidence and prognosis.

CONCLUSIONS

The importance of primary tumor location in affecting the incidence of pulmonary metastasis and prognosis of colorectal cancer patients was highlighted in this study. Primary tumor location should be considered in clinical interference and personalized treatment for colorectal cancer patients with pulmonary metastasis.

PD-1/PD-L1-dependent immune response in colorectal cancer

Colorectal cancer (CRC) is still considered as the third most frequent cancer in the world. Microsatellite instability (MSI), inflammation, and microRNAs have been demonstrated as the main contributing factors in CRC. Subtype 1 CRC is defined by NK cells infiltration, induction of Th1 lymphocyte and cytotoxic T cell responses as well as upregulation of immune checkpoint proteins including programmed cell death-1 (PD-1). Based on the diverse features of CRC, such as the stage and localization of the tumor, several treatment approaches are available. However, the efficiency of these treatments may be decreased due to the development of diverse resistance mechanisms. It has been proven that monoclonal antibodies (mAbs) can increase the effectiveness of CRC treatments. Nowadays, several mAbs including nivolumab and pembrolizumab have been approved for the treatment of CRC. Immune checkpoint receptors including PD-1 can be inhibited by these antibodies. Combination therapy gives an opportunity for advanced treatment for CRC patients. In this review, an update has been provided on the molecular mechanisms involved in MSI colorectal cancer immune microenvironment by focusing on PD-ligand 1 (PD-L1) and treatment of patients with advanced immunotherapy, which were examined in the different clinical trial phases. Considering induced expression of PD-L1 by conventional chemotherapeutics, we have summarized the role of PD-L1 in CRC, the chemotherapy effects on the PD-1/PD-L1 axis and novel combined approaches to enhance immunotherapy of CRC by focusing on PD-L1.

Impact of Delayed Addition of Anti-EGFR Monoclonal Antibodies on the Outcome of First-Line Therapy in Metastatic Colorectal Cancer Patients: a Retrospective Registry-Based Analysis

BACKGROUND

The addition of monoclonal antibodies targeting the epidermal growth factor receptor (anti-EGFR Abs) to chemotherapy for metastatic colorectal carcinoma (mCRC) is commonly delayed in the real-world clinical practice, usually because of late RAS testing results.

OBJECTIVE

To determine whether delayed addition of anti-EGFR mAbs up to the fourth cycle of backbone chemotherapy adversely affected outcomes of mCRC patients treated with first-line regimens.

PATIENTS AND METHODS

Clinical data of patients with histologically verified, RAS wild-type mCRC treated with first-line systemic therapy regimens containing anti-EGFR mAbs were retrospectively analysed from a national database. Patients were divided into three groups according to the timing of anti-EGFR mAbs addition to the chemotherapy backbone. Cohort A (n = 401) included patients in whom anti-EGFR mAbs were added to chemotherapy from the first cycle, cohort B (n = 71) patients with anti-EGFR mAbs added to chemotherapy from the second cycle, and cohort C (n = 101) patients who had anti-EGFR mAbs added to chemotherapy from the third or fourth cycle.

RESULTS

Three hundred and thirty-six (58.6%) patients received panitumumab and 237 (41.4%) patients received cetuximab. The median progression-free survival (PFS) of the whole cohort was 12.2 months (95% confidence interval [CI] 10.9-13.5), and the median overall survival (OS) was 33.5 months (95% CI 27.6-39.4). The median PFS and OS for patients treated with anti-EGFR mAbs added to chemotherapy were 12.9 (95% CI 11.5-14.3) and 30.6 months (95% CI 25.2-36.1) for cohort A, 9.7 (95% CI 9.1-10.3) and not reached for cohort B, compared to 11.5 (95% CI 9.8-13.2) and 37.9 months (95% CI 28.6-47.3) for cohort C, respectively.

CONCLUSIONS

Delayed addition of anti-EGFR mAbs to first-line chemotherapy was not associated with inferior survival or response rates.

Association of Primary Tumor Site With Mortality in Patients Receiving Bevacizumab and Cetuximab for Metastatic Colorectal Cancer

Importance

Biologic therapy (BT) (eg, bevacizumab or cetuximab) is increasingly used to treat metastatic colorectal cancer (mCRC). Recent investigations have suggested that right- or left-sided primary tumor origin affects survival and response to BT.

Objective

To evaluate the association of tumor origin with mortality in a diverse population-based data set of patients receiving systemic chemotherapy (SC) and bevacizumab or cetuximab for mCRC.

Design, Setting, and Participants

This population-based nonconcurrent cohort study of statewide California Cancer Registry data included all patients aged 40 to 85 years diagnosed with mCRC and treated with SC only or SC plus bevacizumab or cetuximab from January 1, 2004, through December 31, 2014. Patients were stratified by tumor origin in the left vs right sides.

Interventions

Treatment with SC or SC plus bevacizumab or cetuximab.

Main Outcomes and Measures

Mortality hazards by tumor origin (right vs left sides) were assessed for patients receiving SC alone or SC plus bevacizumab or cetuximab. Subgroup analysis for patients with wild-type KRAS tumors was also performed.

Results

A total of 11 905 patients with mCRC (6713 men [56.4%] and 5192 women [43.6%]; mean [SD] age, 60.0 [10.9] years) were eligible for the study. Among these, 4632 patients received SC and BT. Compared with SC alone, SC plus bevacizumab reduced mortality among patients with right- and left-sided mCRC, whereas SC plus cetuximab reduced mortality only among patients with left-sided tumors and was associated with significantly higher mortality for right-sided tumors (hazard ratio [HR], 1.31; 95% CI, 1.14-1.51; P < .001). Among patients treated with SC plus BT, right-sided tumor origin was associated with higher mortality among patients receiving bevacizumab (HR, 1.31; 95% CI, 1.25-1.36; P < .001) and cetuximab (HR, 1.88; 95% CI, 1.68-2.12; P < .001) BT, compared with left-sided tumor origin. In patients with wild-type KRAS tumors (n = 668), cetuximab was associated with reduced mortality among only patients with left-sided mCRC compared with bevacizumab (HR, 0.75; 95% CI, 0.63-0.90; P = .002), whereas patients with right-sided mCRC had more than double the mortality compared with those with left-sided mCRC (HR, 2.44; 95% CI, 1.83-3.25, P < .001).

Conclusions and Relevance

Primary tumor site is associated with response to BT in mCRC. Right-sided primary tumor location is associated with higher mortality regardless of BT type. In patients with wild-type KRAS tumors, treatment with cetuximab benefited only those with left-sided mCRC and was associated with significantly poorer survival among those with right-sided mCRC. Our results underscore the importance of stratification by tumor site for current treatment guidelines and future clinical trials.

A phase 2 study of panitumumab with irinotecan as salvage therapy in chemorefractory KRAS exon 2 wild-type metastatic colorectal cancer patients

BACKGROUND

Targeted agents are standard treatment for RAS wild-type metastatic colorectal cancer in the first- and second-line settings. This phase 2 study determined the benefit of targeting the epidermal growth factor receptor (EGFR) with panitumumab plus irinotecan in irinotecan-refractory patients.

METHODS

KRAS exon-2 wild-type patients failing prior irinotecan received panitumumab (6 mg/kg) and irinotecan (180 mg/m²) every 2 weeks. The primary endpoint was the overall response rate (ORR). Secondary endpoints included safety, progression-free survival (PFS) and overall survival (OS). KRAS exon-2 status was evaluated centrally, along with NRAS, BRAF mutations, epiregulin, amphiregulin, PTEN and EGFR copy number status, and correlated with efficacy.

RESULTS

Sixty-one patients were treated. Among the 46 wild-type RAS patients, the ORR was 15.2% (seven partial responses), with median PFS of 3.8 months (95% CI 2.7-4.3) and median OS of 12.5 months (95% CI 6.7-15.9). Wild-type BRAF patients showed a 13.0% response rate. No significant correlations between response and baseline biomarker expression were identified. Common grade 3-4 adverse events were diarrhoea and rash (18.0% each), hypomagnesaemia and asthenia (8.2% each).

CONCLUSIONS

The addition of panitumumab to irinotecan as salvage therapy is feasible but has limited activity in irinotecan-refractory metastatic colorectal cancer. No biomarkers predictive of response were identified.

The Impact of Primary Tumor Sidedness on the Effect of Regorafenib in Refractory Metastatic Colorectal Cancer

Recently, the sidedness of the primary tumor (right versus left) has been investigated for its ability to prognosticate and predict outcomes. We evaluated the effect of regorafenib based on KRAS mutation status and the sidedness of the primary tumor in patients with metastatic colorectal cancer (mCRC). We analyzed 135 patients with refractory metastatic colorectal cancer (mCRC) being treated with regorafenib at Samsung Medical Center, between January 2014 and January 2018. Primary tumors originating in the splenic flexure, descending colon, sigmoid colon, rectum, or proximal third of the transverse colon were defined as left-sided CRC (LC). Primary tumors originating in the appendix, cecum, ascending colon, hepatic flexure, or distal two-thirds of the transverse colon were defined as right-sided CRC (RC). Among all 135 patients, 100 (74.1%) had left sided colon cancer and 35 (25.9%) had right-sided colon cancer. No patients achieved a complete response, but four achieved a partial response, revealing a response rate (RR) of 3.0%. Thirty-seven patients had stable disease, yielding a disease control rate (DCR) of 30.4%. There was no difference in RR or DCR according to the location of the primary tumor (LC vs. RC). A significant difference in progression free survival (PFS) with regorafenib was observed between the LC and RC groups (2.6 months; 95% CI, 2.0 to 3.1 vs. 1.9 months; 95% CI, 1.6 to 2.3; P = 0.04, respectively). In a subpopulation with wild type KRAS, PFS with regorafenib was also significantly different between the LC and RC groups (2.9 months; 95% CI, 1.5 to 4.3 vs. 2.1 months; 95% CI, 0.6 to 3.6; P = 0.04). On multivariate analysis, the sidedness of the primary tumor (LC vs. RC) and the number of metastatic sites (≤1 vs. 2>) had a prognostic effect on PFS (P = 0.01 and P = 0.01, respectively). Regorafenib is a current standard treatment for CRC, but treatment outcomes may be improved if regorafenib is administered based on the appropriate biomarker.

Survival comparison of right and left side non-small cell lung cancer in stage I-IIIA patients: A Surveillance Epidemiology and End Results (SEER) analysis

Background

Primary tumors located in the right and left side have distinctive prognoses, but the details have not been fully identified in non‐small cell lung cancer (NSCLC). This study investigated the impact of primary tumor side on long‐term survival in NSCLC patients.

Methods

Data of 90 407 patients from the Surveillance, Epidemiology, and End Results (SEER) Program were analyzed. To avoid bias between groups, we used innovative propensity score matching (PSM) analysis.

Results

There was no significant distinction in overall survival (OS) between right (n = 53 496) and left (n = 36 911) side tumors (hazard ratio [HR] 0.993, 95% confidence interval [CI] 0.9756–1.011; P = 0.432). Left side was associated with superior five‐year cancer‐specific survival (CSS) compared to right side NSCLC (HR 0.977, 95% CI 0.9574–0.9969; P = 0.024). No significant difference was observed in OS (P = 0.689) or CSS (P = 0.288) after PSM analysis. In the 51 319 patients who underwent surgery, left side (n = 21 245) was associated with poor OS compared to right side (n = 30 074) NSCLC (HR 1.039, 95% CI 1.011–1.067; P = 0.006), while CSS was similar (HR 1.031, 95% CI 0.997–1.065; P = 0.069). In patients who underwent surgery, there was also no significant difference in OS (P = 0.986) or CSS (P = 0.979) after PSM analysis.

Conclusion

The prognosis between right and left side NSCLC in stage I–IIIA was similar regardless of whether patients underwent surgery. Primary tumor side cannot be considered a prognostic factor when choosing appropriate treatment.

Sequential therapy with bevacizumab and EGFR inhibitors for metastatic colorectal carcinoma: a national registry-based analysis

Purpose

Although inhibitors of vascular endothelial growth factor and inhibitors of epidermal growth factor receptor (EGFRi) are commonly used for the treatment of metastatic colorectal cancer (mCRC), the optimal sequencing of these agents is currently unclear.

Methods

A national registry of targeted therapies was used to analyze baseline characteristics and outcomes of patients with mCRC and wild-type KRAS exon 2 status who received bevacizumab and EGFRi (cetuximab or panitumumab) as a part of first- and second-line treatment in either sequence.

Results

The cohort included 490 patients (181 patients treated with first-line EGFRi and second-line bevacizumab and 309 patients treated with first-line bevacizumab and second-line EGFRi). Median overall survival (OS) from the initiation on first-line therapy was similar for patients treated with either sequence, reaching 31.8 (95% CI 27.5-36.1) vs 31.4 months (95% CI 27.8-35.0) for EGFRi → bevacizumab vs bevacizumab → EGFRi cohort, respectively. Time from first-line initiation to progression on the second-line therapy [progression-free survival (PFS)] was 21.1 (95% CI 19.3-23.0) vs 19.3 months (95% CI 17.3-21.3) for bevacizumab → EGFRi vs EGFRi → bevacizumab cohort, respectively (P=0.016).

Conclusion

This retrospective analysis of real-world data of patients with wild-type KRAS exon 2 mCRC showed no differences in OS between cohorts treated with bevacizumab → EGFRi vs the reverse sequence while combined PFS favored the bevacizumab → EGFRi sequence.

Patients with RAS wild-type right-sided unresectable liver-confined mCRC also benefit from cetuximab plus chemotherapy in first-line treatment

Growing evidence indicates that primary tumor location of metastatic colorectal cancer (mCRC) can affect response to specific therapy. This study aimed to assess the impact of primary tumor location on efficacy of cetuximab in Chinese patients with mCRC. We included patients with RAS wild-type liver-limited mCRC treated with first-line cetuximab plus chemotherapy or chemotherapy alone between June 2008 and December 2016. All patients were categorized as having left-sided tumors or right-sided tumors. Progression free survival (PFS), overall survival (OS), objective response rate (ORR) and conversion rate of surgery for liver metastases was analyzed according to tumor location and treatment. Right-sided tumors were characterized with larger primary tumor, poorer differentiation, more lymph node metastases and larger and more liver metastases. For patients with left-sided tumors (N=233), addition of cetuximab to chemotherapy significantly improved ORR (68.9% vs. 30.6%, OR=5.01, P < 0.001), conversion rate of liver surgery (33.5% vs. 10.8%, OR=4.18, P < 0.001), PFS (12.1 months vs. 6.1 months, HR=0.42, P < 0.001), and OS (not evaluable vs. 23.1 months, HR=0.31, P < 0.001). Among patients with right-sided tumors (N=85), cetuximab plus chemotherapy, compared with chemotherapy alone, also significantly improved ORR (56.8% vs. 29.3%, OR=3.18, P=0.010), PFS (9.3 months vs. 5.1 months, OR=0.57, P=0.012) and OS (25.3 months vs. 16.8 months, HR=0.56, P=0.032) but conversion rate of liver surgery (20.5% vs. 9.8%, HR=2.38, P=0.171). Our results demonstrated differential effect of cetuximab on efficacy outcomes based on tumor sidedness. Also, we found that patients with right-sided tumors also benefit from cetuximab plus chemotherapy but not as great as left-sided tumors and in general, did worse. In conclusion, findings of previous studies about differential effect of anti-EGFR therapy based on tumor sidedness are applicable to an Asian population.

Clinicopathological Associations of K-RAS and N-RAS Mutations in Indonesian Colorectal Cancer Cohort

BACKGROUND

K-RAS and recently N-RAS gene mutation testing are mandatory requirements prior to anti-epidermal growth factor receptor (EGFR) monoclonal antibody treatment of metastatic CRC. Mutation prevalence and distribution in Indonesian colorectal cancer (CRC) are not known.

METHODS

Combined methods of PCR high-resolution melt (HRM), restriction fragment length polymorphism (RFLP), and direct DNA sequencing were used to genotype exons 2, 3, and 4 of both K-RAS and N-RAS genes for routine clinical testing of CRC patients. Descriptive analytical review of 595 consecutive CRC patients (years 2013 to 2016) was performed to find associations between gene mutations and clinicopathologic features.

RESULTS

This retrospective study revealed overall K-RAS gene mutation in exon 2 (codon 12 and 13) rates being 34.9%. Women (42.5%), stages I and II (43.4%), and well and moderate differentiations (37.7%) had higher frequency of K-RAS exon 2 mutations than men (29%, p = 0.006), stages (III and IV 31.9%, p = 0.05), and poor differentiation (11.8%, p = 0.002), respectively. At later period (2015-2016), 121 of 595 patients were genotyped for the remaining exons 3 and 4 of K-RAS as well as exons 2, 3, and 4 of N-RAS mutations resulting in overall RAS mutation prevalence of 41%. Mucinous histology had highest frequency of N-RAS mutation.

CONCLUSIONS

Combination of PCR HRM with either RFLP or direct DNA sequencing was useful to detect K-RAS exon 2 and extended RAS mutations, respectively. Frequency of all RAS mutations in stage IV Indonesian (41%) was similar among Asians (41-49%), which tend to be lower than western (55%) CRC.

Prognostic and predictive value of primary tumour side in patients with RAS wild-type metastatic colorectal cancer treated with chemotherapy and EGFR directed antibodies in six randomized trials

Background

There is increasing evidence that metastatic colorectal cancer (mCRC) is a genetically heterogeneous disease and that tumours arising from different sides of the colon (left versus right) have different clinical outcomes. Furthermore, previous analyses comparing the activity of different classes of targeted agents in patients with KRAS wild-type (wt) or RAS wt mCRC suggest that primary tumour location (side), might be both prognostic and predictive for clinical outcome.

Methods

This retrospective analysis investigated the prognostic and predictive influence of the localization of the primary tumour in patients with unresectable RAS wt mCRC included in six randomized trials (CRYSTAL, FIRE-3, CALGB 80405, PRIME, PEAK and 20050181), comparing chemotherapy plus EGFR antibody therapy (experimental arm) with chemotherapy or chemotherapy and bevacizumab (control arms). Hazard ratios (HRs) and 95% confidence intervals (CIs) for overall survival (OS) and progression-free survival (PFS) for patients with left-sided versus right-sided tumours, and odds ratios (ORs) for objective response rate (ORR) were estimated by pooling individual study HRs/ORs. The predictive value was evaluated by pooling study interaction between treatment effect and tumour side.

Results

Primary tumour location and RAS mutation status were available for 2159 of the 5760 patients (37.5%) randomized across the 6 trials, 515 right-sided and 1644 left-sided. A significantly worse prognosis was observed for patients with right-sided tumours compared with those with left-sided tumours in both the pooled control and experimental arms for OS [HRs = 2.03 (95% CI: 1.69-2.42) and 1.38 (1.17-1.63), respectively], PFS [HRs = 1.59 (1.34-1.88) and 1.25 (1.06-1.47)], and ORR [ORs = 0.38 (0.28-0.50) and 0.56 (0.43-0.73)]. In terms of a predictive effect, a significant benefit for chemotherapy plus EGFR antibody therapy was observed in patients with left-sided tumours [HRs = 0.75 (0.67-0.84) and 0.78 (0.70-0.87) for OS and PFS, respectively] compared with no significant benefit for those with right-sided tumours [HRs = 1.12 (0.87-1.45) and 1.12 (0.87-1.44) for OS and PFS, respectively; P value for interaction <0.001 and 0.002, respectively]. For ORR, there was a trend (P value for interaction = 0.07) towards a greater benefit for chemotherapy plus EGFR antibody therapy in the patients with left-sided tumours [OR = 2.12 (1.77-2.55)] compared with those with right-sided tumours [OR = 1.47 (0.94-2.29)]. Exclusion of the unique phase II trial or the unique second-line trial had no impact on the results. The predictive effect on PFS may depend of the type of EGFR antibody therapy and on the presence or absence of bevacizumab in the control arm.

Conclusion

This pooled analysis showed a worse prognosis for OS, PFS and ORR for patients with right-sided tumours compared with those with left-sided tumours in patients with RAS wt mCRC and a predictive effect of tumour side, with a greater effect of chemotherapy plus EGFR antibody therapy compared with chemotherapy or chemotherapy and bevacizumab, the effect being greatest in patients with left-sided tumours. These predictive results should be interpreted with caution due to the retrospective nature of the analysis, which was carried out on subpopulations of patients included in these trials, and because none of these studies contemplated a full treatment sequence strategy.

Strategy to targeting the immune resistance and novel therapy in colorectal cancer

Assessing the CRC subtypes that can predict the outcome of colorectal cancer (CRC) in patients with immunogenicity seems to be a promising strategy to develop new drugs that target the antitumoral immune response. In particular, the disinhibition of the antitumoral T‐cell response by immune checkpoint blockade has shown remarkable therapeutic promise for patients with mismatch repair (MMR) deficient CRC. In this review, the authors provide the update of the molecular features and immunogenicity of CRC, discuss the role of possible predictive biomarkers, illustrate the modern immunotherapeutic approaches, and introduce the most relevant ongoing preclinical study and clinical trials such as the use of the combination therapy with immunotherapy. Furthermore, this work is further to understand the complex interactions between the immune surveillance and develop resistance in tumor cells. As expected, if the promise of these developments is fulfilled, it could develop the effective therapeutic strategies and novel combinations to overcome immune resistance and enhance effector responses, which guide clinicians toward a more “personalized” treatment for advanced CRC patients.

Tumor location impact in stage II and III colon cancer: epidemiological and outcome evaluation

Background

We aimed to describe clinico-pathological characteristics and differences between right-sided (RCC) and left-sided colon cancer (LCC) in Tunisian population. We also analyzed outcome to determine whether location is of prognostic significance.

Methods

Clinico-pathological characteristics and Kaplan Meier survival were compared between two groups of LCC [150] and RCC [53] patients with stage II and III adenocarcinoma treated with curative intent between 2003-2014.

Results

RCC patients were significantly more likely to be female, (56.6% vs. 39.3%, P=0.029) and to have undifferentiated tumor (87.1% vs. 8.4%, P=0.014), then LCC. After a median follow up of 49 months, 5-year overall survival (OS) was significantly worse in RCC vs. LCC [42% vs. 78%; hazard ratio (HR) =2.07; 95% CI: 1.05-4.09; P=0.03], no difference in relapse free survival (RFS) was observed. Median time to relapse was significantly shorter in RCC (15 months) vs. LCC (24 months), P=0.005. Tumor location significantly impacted survival in stage III, 5-year OS was 45% in RCC, and 63% in LCC, (HR =2.28; 95% CI: 1.01-5.24; P=0.04), there was no impact of tumor location in stage II, (HR =1.94; 95% CI: 0.54-6.93; P=0.29).

Conclusions

Prognostic impact of tumor location should be considered as a stratification factor in the future clinical trials.

Is the Location of the Tumor Another Prognostic Factor for Patients With Colon Cancer?

Purpose

In this study, we investigated both the characteristics of right colon cancer (RTCC) in comparison with those of left colon cancer (LTCC) and the impact of the location of the colon cancer on the prognosis.

Methods

We retrospectively analyzed the cases of 974 patients with nonmetastatic colon cancer who had undergone surgery with a curative intent from January 2001 to December 2011. RTCC was defined as a tumor located proximal to the splenic flexure. The characteristics of RTCC cancer were investigated by using descriptive analyses, and their impacts on the prognosis were assessed by using a Cox multivariate regression.

Results

Compared to LTCC, RTCC showed a female-dominant feature, and an undifferentiated pathology was more frequently observed. The number of lymph nodes retrieved from patients with RTCC was significantly higher than that retrieved from patients with LTCC. During 75 months of follow-up, peritoneal recurrence was more common in patients with RTCC than it was in patients with LTCC, and among the patients with stage III colon cancer, the disease-free and the overall survival rates were significantly worse in patients with RTCC. After adjustments with the other prognostic factors associated with colon cancer had been made, a tumor located at the right colon was found to be independently associated with poor prognosis.

Conclusion

RTCC showed unique clinicopathologic features and was associated with a poorer prognosis.

Pre-treatment inflammatory indexes as predictors of survival and cetuximab efficacy in metastatic colorectal cancer patients with wild-type RAS

This study aims at evaluating the prognostic significance of neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), lymphocyte-to-monocyte ratio (LMR), and systemic immune-inflammation indexes (SII) in metastatic colorectal cancer (mCRC) patients treated with cetuximab. Ninety-five patients receiving cetuximab for mCRC were categorized into the high or low NLR, PLR, LMR, and SII groups based on their median index values. Univariate and multivariate survival analysis were performed to identify the indexes’ correlation with progression-free survival (PFS) and overall survival (OS). In the univariate analysis, ECOG performance status, neutrphil counts, lymphocyte counts, monocyte counts, NLR, PLR, and LDH were associated with survival. Multivariate analysis showed that ECOG performance status of 0 (hazard ratio [HR] 3.608, p < 0.001; HR 5.030, p < 0.001, respectively), high absolute neutrophil counts (HR 2.837, p < 0.001; HR 1.922, p = 0.026, respectively), low lymphocyte counts (HR 0.352, p < 0.001; HR 0.440, p = 0.001, respectively), elevated NLR (HR 3.837, p < 0.001; HR 2.467, p = 0.006) were independent predictors of shorter PFS and OS. In conclusion, pre-treatment inflammatory indexes, especially NLR were potential biomarkers to predict the survival of mCRC patients with cetuximab therapy.

Left-sided primary tumor is a favorable prognostic factor for metastatic colorectal cancer patients receiving surgery

OBJECTIVE

The role of surgery in metastatic colorectal cancer (mCRC) remains controversial. This study was performed to assess the impact of surgery on survival in metastatic colorectal cancer.

MATERIALS AND METHODS

Information of mCRC patients diagnosed between January 1, 2004, and December 31, 2013, was retrieved from the Surveillance, Epidemiology, and End Results Program database. Patients were classified in three groups: patients undergoing resection of both primary and distant metastatic tumors (group 'PMTR'), patients receiving primary tumor resection alone (group 'PTR') and patients not undergoing any surgery (group 'No resection'). Kaplan-Meier method and multivariate Cox proportional hazard regression analysis were applied to estimate disease specific survival time (DSS) and determine prognostic factors.

RESULTS

A total of 38,591 mCRC patients were eligible. Overall, median DSS of group 'PMTR' was significantly longer compared with group 'PTR' and group 'No resection' (28.0 vs 21.0 vs 11.0 months, P < 0.001). Stratified analysis observed that primary tumor in left-sided colorectal cancer (LCRC) was a favorable prognostic factor compared with right-sided colorectal cancer (RCRC) (median DSS of LCRC: PMTR, 34 months, PTR, 25 months, No resection, 13 months; median DSS of RCRC: PMTR, 20 months, PTR, 16 months, No resection, 8 months; P < 0.001). Multivariate analysis demonstrated that surgery was an independent prognostic factor for better survival (PMTR, HR = 0.403, 95% CI 0.384-0.423, P < 0.001; PTR, HR = 0.515, 95% CI 0.496-0.534, P < 0.001). Furthermore, in patients undergoing surgery, patients with younger age, female, married status, LCRC and lower CEA level were prone to receiving PMTR.

CONCLUSIONS

This analysis demonstrated that surgery was an independent prognostic factor for improved survival in mCRC. Patients with LCRC had better survival than patients with RCRC after surgery.

KRAS/BRAF基因与结肠癌糖代谢研究现状

正电子发射断层成像术(positron emission tomography, PET)/计算机断层扫描(computed tomography, CT)显像可用于结肠癌的诊断、监测疗效和预后评估. ¹⁸F标记葡萄糖(2-fluorine-18-fluoro-2-deeoxy-D-glucose, ¹⁸F-FDG)是PET/CT常用显像剂, 可以反映结肠癌活体组织葡萄糖代谢. KRAS/BRAF基因检测常用于结肠癌靶向治疗方案的选择及评估其治疗效果. 文献报道¹⁸F-FDG-PET/CT显像可预测结肠癌KRAS/BRAF基因状态, 能以无创的方式预测结肠癌抗表皮生长因子受体靶向治疗效果. 目前国内有关KRAS/BRAF基因与结肠癌糖代谢的研究相对较少, 本文结合近期的相关文献进行概述.

Prognostic and predictive value of primary tumour side in patients with RAS wild-type metastatic colorectal cancer treated with chemotherapy and EGFR directed antibodies in six randomized trials

BACKGROUND

There is increasing evidence that metastatic colorectal cancer (mCRC) is a genetically heterogeneous disease and that tumours arising from different sides of the colon (left versus right) have different clinical outcomes. Furthermore, previous analyses comparing the activity of different classes of targeted agents in patients with KRAS wild-type (wt) or RAS wt mCRC suggest that primary tumour location (side), might be both prognostic and predictive for clinical outcome.

METHODS

This retrospective analysis investigated the prognostic and predictive influence of the localization of the primary tumour in patients with unresectable RAS wt mCRC included in six randomized trials (CRYSTAL, FIRE-3, CALGB 80405, PRIME, PEAK and 20050181), comparing chemotherapy plus EGFR antibody therapy (experimental arm) with chemotherapy or chemotherapy and bevacizumab (control arms). Hazard ratios (HRs) and 95% confidence intervals (CIs) for overall survival (OS) and progression-free survival (PFS) for patients with left-sided versus right-sided tumours, and odds ratios (ORs) for objective response rate (ORR) were estimated by pooling individual study HRs/ORs. The predictive value was evaluated by pooling study interaction between treatment effect and tumour side.

RESULTS

Primary tumour location and RAS mutation status were available for 2159 of the 5760 patients (37.5%) randomized across the 6 trials, 515 right-sided and 1644 left-sided. A significantly worse prognosis was observed for patients with right-sided tumours compared with those with left-sided tumours in both the pooled control and experimental arms for OS [HRs = 2.03 (95% CI: 1.69-2.42) and 1.38 (1.17-1.63), respectively], PFS [HRs = 1.59 (1.34-1.88) and 1.25 (1.06-1.47)], and ORR [ORs = 0.38 (0.28-0.50) and 0.56 (0.43-0.73)]. In terms of a predictive effect, a significant benefit for chemotherapy plus EGFR antibody therapy was observed in patients with left-sided tumours [HRs = 0.75 (0.67-0.84) and 0.78 (0.70-0.87) for OS and PFS, respectively] compared with no significant benefit for those with right-sided tumours [HRs = 1.12 (0.87-1.45) and 1.12 (0.87-1.44) for OS and PFS, respectively; P value for interaction <0.001 and 0.002, respectively]. For ORR, there was a trend (P value for interaction = 0.07) towards a greater benefit for chemotherapy plus EGFR antibody therapy in the patients with left-sided tumours [OR = 2.12 (1.77-2.55)] compared with those with right-sided tumours [OR = 1.47 (0.94-2.29)]. Exclusion of the unique phase II trial or the unique second-line trial had no impact on the results. The predictive effect on PFS may depend of the type of EGFR antibody therapy and on the presence or absence of bevacizumab in the control arm.

CONCLUSION

This pooled analysis showed a worse prognosis for OS, PFS and ORR for patients with right-sided tumours compared with those with left-sided tumours in patients with RAS wt mCRC and a predictive effect of tumour side, with a greater effect of chemotherapy plus EGFR antibody therapy compared with chemotherapy or chemotherapy and bevacizumab, the effect being greatest in patients with left-sided tumours. These predictive results should be interpreted with caution due to the retrospective nature of the analysis, which was carried out on subpopulations of patients included in these trials, and because none of these studies contemplated a full treatment sequence strategy.

The impact of primary tumor location on efficacy of cetuximab in metastatic colorectal cancer patients with different Kras status: a systematic review and meta-analysis

OBJECTIVE

To assess the prognostic role of primary tumor location along with Kras status in metastatic colorectal cancer (mCRCs) treated with cetuximab.

MATERIALS AND METHODS

Databases of EMBASE, Pubmed, the Cochrane library, China National Knowledge Infrastructure and other databases from inception to July 2016 were searched. Randomized controlled trial (RCT) and/or retrospective studies of influence of primary tumor location on efficacy of cetuximab in patients with mCRC were identified. The primary endpoint was progression-free survival (PFS), and the secondary endpoints were overall survival (OS), overall response rate (ORR) and disease control rate (DCR).

RESULTS

Ten studies including 2977 cases were finally included. The results of meta-analysis were in favor of cetuximab to patients with left-sided colorectal cancer in terms of OS (HR = 0.52, 95% CI: 0.40-0.66; p < 0.01), PFS (HR = 0.64, 95% CI: 0.58-0.70; p < 0.01), and ORR (OR = 2.17, 95% CI: 1.57-2.99; p < 0.01). Patients with right-sided CRC gained less benefit from cetuximab in terms of OS (HR = 1.89, 95% CI: 1.43-2.50; p < 0.01), compared with left-sided CRC. Regarding Kras status, left-sided mCRC with wild type Kras had better PFS (HR = 0.61, 95% CI: 0.51-0.74; p < 0.01) and OS (HR = 0.49, 95% CI: 0.35-0.69; p < 0.01) than right-sided cases when treated with cetuximab. We also found that cetuximab was both significantly effective in different treatment lines and regions when comparing by primary tumor locations (p < 0.01).

CONCLUSIONS

mCRC Patients with left-sided, wild type Kras have a better prognosis than those with right-sided diseases when treated with cetuximab. The clinical application of cetuximab should be determined by the primary tumor location and molecular gene mutation status.

Right- vs. Left-Sided Metastatic Colorectal Cancer: Differences in Tumor Biology and Bevacizumab Efficacy

There is evidence of a different response to treatment with regard to the primary tumor localization (right-sided or left-sided) in patients with metastatic colorectal cancer (mCRC). We analyzed the different outcomes and biomolecular characteristics in relation to tumor localization in 122 of the 370 patients with metastatic colorectal cancer enrolled onto the phase III prospective multicenter “Italian Trial in Advanced Colorectal Cancer (ITACa)”, randomized to receive first-line chemotherapy (CT) or CT plus bevacizumab (CT + B). RAS and BRAF mutations; baseline expression levels of circulating vascular endothelial growth factor (VEGF), endothelial nitric oxide synthase (eNOS), cyclooxygenase-2 (COX2), ephrin type-B receptor 4 (EPHB4), hypoxia-inducible factor 1-alpha (HIF-1α), lactate dehydrogenase (LDH), and high-sensitivity C reactive protein (hs-CRP); and inflammatory indexes such as the neutrophil-to-lymphocyte ratio, platelet-lymphocyte rate and systemic immune-inflammation index were evaluated. Patients with right-sided tumors showed a longer median progression-free survival in the CT + B arm than in the CT group (12.6 vs. 9.0 months, respectively, p = 0.017). Baseline inflammatory indexes were significantly higher in left-sided tumors, whereas eNOS and EPHB4 expression was significantly higher and BRAF mutation more frequent in right-sided tumors. Our data suggest a greater efficacy of the CT + B combination in right-sided mCRC, which might be attributable to the lower inflammatory status and higher expression of pro-angiogenic factors that appear to characterize these tumors.

Primary tumor site and anti-EGFR monoclonal antibody benefit in metastatic colorectal cancer: a meta-analysis

AIM

This meta-analysis aimed to document the impact of primary tumor site on anti-EGFR monoclonal antibody (mAb) benefit in metastatic colorectal cancer.

MATERIALS & METHODS

Tumors with metastatic left-sided colorectal cancer (LCC) were compared with tumors with metastatic right-sided colon cancer (RCC) with respect to anti-EGFR mAb objective response rate (ORR), overall survival (OS) and progression-free survival (PFS) benefit.

RESULTS

Comparing LCC with RCC, LCC was found to have significantly superior anti-EGFR mAb ORR (p < 0.00001), OS (p < 0.00001) and PFS (p < 0.00001) benefit. Additionally, anti-EGFR mAb therapy significantly improved both OS and PFS for LCC compared with no anti-EGFR mAb therapy, but not for RCC. The test of interaction was also apparent for OS (p = 0.0002) and PFS (p = 0.0002).

CONCLUSION

This meta-analysis demonstrated that LCC had markedly superior anti-EGFR mAb treatment benefit compared with RCC.

Characteristics of Differently Located Colorectal Cancers Support Proximal and Distal Classification: A Population-Based Study of 57,847 Patients

Background

It has been suggested that colorectal cancer be regarded as several subgroups defined according to tumor location rather than as a single entity. The current study aimed to identify the most useful method for grouping colorectal cancer by tumor location according to both baseline and survival characteristics.

Methods

Cases of pathologically confirmed colorectal adenocarcinoma diagnosed from 2000 to 2012 were identified from the Surveillance, Epidemiology, and End Results database and categorized into three groups: right colon cancer (RCC), left colon cancer (LCC), and rectal cancer (ReC). Adjusted hazard ratios for known predictors of disease-specific survival (DSS) in colorectal cancer were obtained using a Cox proportional hazards regression model.

Results

The study included 57847 patients: 43.5% with RCC, 37.7% with LCC, and 18.8% with ReC. Compared with LCC and ReC, RCC was more likely to affect old patients and women, and to be at advanced stage, poorly differentiated or un-differentiated, and mucinous. Patients with LCC or ReC had better DSS than those with RCC in subgroups including stage III or IV disease, age ≤70 years and non-mucinous adenocarcinoma. Conversely, patients with LCC or ReC had worse DSS than those with RCC in subgroups including age ˃70 years and mucinous adenocarcinoma.

Conclusions

RCC differed from both LCC and ReC in several clinicopathologic characteristics and in DSS. It seems reasonable to group colorectal cancer into right-sided (i.e., proximal) and left-sided (i.e., distal) ones.

The relevance of primary tumour location in patients with metastatic colorectal cancer: A meta-analysis of first-line clinical trials

BACKGROUND

Retrospective subgroup analyses suggest that primary tumour location (PTL) has a prognostic importance and relates to response to targeted therapy.

METHODS

We conducted a meta-analysis of first-line clinical trials available up to October 2016, which assessed the relevance of PTL in patients with metastatic colorectal cancer (mCRC). Right- and left-sided colorectal cancers were differentiated (RC and LC).

RESULTS

In 13 first-line randomised controlled trials and one prospective pharmacogenetic study, RC was associated with a significantly worse prognosis compared with LC (hazard ratio [HR] for overall survival: 1.56; 95% confidence interval [CI]: 1.43-1.70; P < 0.0001). A meta-analysis of PRIME and CRYSTAL study suggests that PTL was predictive of survival benefit from addition of anti-EGFR antibody to standard chemotherapy in patients with RAS wild-type tumour (overall survival, HR for LC: 0.69; 95% CI: 0.58-0.83; P < 0.0001 and HR for RC: 0.96; 95% CI: 0.68-1.35; P = 0.802). A meta-analysis of FIRE-3/AIO KRK0306, CALGB/SWOG 80405 and PEAK study indicates that patients with RAS wild-type LC had a significantly greater survival benefit from anti-EGFR treatment compared with anti-VEGF treatment when added to standard chemotherapy (HR 0.71; 95% CI: 0.58-0.85; P = 0.0003). By contrast, in patients with RC, benefit from standard therapy was poor and bevacizumab-based treatment was numerically associated with longer survival (HR 1.3; 95% CI: 0.97-1.74; P = 0.081).

CONCLUSIONS

The present meta-analysis demonstrates that PTL is prognostic in mCRC. Further, it supports the conclusion that patients with left-sided RAS wild-type mCRC should be preferentially treated with an anti-EGFR antibody. In right-sided mCRC, chemotherapy plus bevacizumab is a treatment option, but optimal treatment has yet to be defined.