Cetuximab is a monoclonal antibody that targets the human epidermal growth factor receptor (EGFR). Although approved for use in EGFR-overexpressing advanced colorectal cancer, recent studies have shown a lack of association between EGFR overexpression and cetuximab response, requiring the identification of novel biomarkers predictive of response to this agent. To do so, 22 colon cancer cell lines were screened for cetuximab response in vitro and sensitive and resistant lines were identified. In sensitive cell lines, cetuximab induced a G 0 -G 1 arrest without inducing apoptosis. Notably, cetuximabsensitive but not cetuximab-resistant cell lines were preferentially responsive to EGF-stimulated growth. Whereas neither EGFR protein/mRNA expression nor gene copy number correlated with cetuximab response, examination of the mutation status of signaling components downstream of EGFR showed that cell lines with activating PIK3CA mutations or loss of PTEN expression (PTEN null) were more resistant to cetuximab than PIK3CA wild type (WT)/PTENexpressing cell lines (14 F 5.0% versus 38.5 F 6.4% growth inhibition, mean F SE; P = 0.008). Consistently, PIK3CA mutant isogenic HCT116 cells showed increased resistance to cetuximab compared with PIK3CA WT controls. Furthermore, cell lines that were PIK3CA mutant/PTEN null and Ras/BRAF mutant were highly resistant to cetuximab compared with those without dual mutations/PTEN loss (10.8 F 4.3% versus 38.8 F 5.9% growth inhibition, respectively; P = 0.002), indicating that constitutive and simultaneous activation of the Ras and PIK3CA pathways confers maximal resistance to this agent. A priori screening of colon tumors for PTEN expression status and PIK3CA and Ras/BRAF mutation status could help stratify patients likely to benefit from this therapy.

PURPOSE To develop an evidence-based clinical practice guideline to assist in clinical decision making for patients with advanced hepatocellular carcinoma (HCC). METHODS ASCO convened an Expert Panel to conduct a systematic review of published phase III randomized controlled trials (2007-2020) on systemic therapy for advanced HCC and provide recommended care options for this patient population. RESULTS Nine phase III randomized controlled trials met the inclusion criteria. RECOMMENDATIONS Atezolizumab + bevacizumab (atezo + bev) may be offered as first-line treatment of most patients with advanced HCC, Child-Pugh class A liver disease, Eastern Cooperative Oncology Group Performance Status (ECOG PS) 0-1, and following management of esophageal varices, when present, according to institutional guidelines. Where there are contraindications to atezolizumab and/or bevacizumab, tyrosine kinase inhibitors sorafenib or lenvatinib may be offered as first-line treatment of patients with advanced HCC, Child-Pugh class A liver disease, and ECOG PS 0-1. Following first-line treatment with atezo + bev, and until better data are available, second-line therapy with a tyrosine kinase inhibitor may be recommended for appropriate candidates. Following first-line therapy with sorafenib or lenvatinib, second-line therapy options for appropriate candidates include cabozantinib, regorafenib for patients who previously tolerated sorafenib, or ramucirumab (for patients with α-fetoprotein ≥ 400 ng/mL), or atezo + bev where patients did not have access to this option as first-line therapy. Pembrolizumab or nivolumab are also reasonable options for appropriate patients following sorafenib or lenvatinib. Consideration of nivolumab + ipilimumab as an option for second-line therapy and third-line therapy is discussed. Further guidance on choosing between therapy options is included within the guideline. Additional information is available at www.asco.org/gastrointestinal-cancer-guidelines .

Histone deacetylase inhibitors (HDACi) induce growth arrest and apoptosis in colon cancer cells and are being considered for colon cancer therapy. The underlying mechanism of action of these effects is poorly defined with both transcription-dependent and -independent mechanisms implicated. We screened a panel of 30 colon cancer cell lines for sensitivity to HDACi-induced apoptosis and correlated the differences with gene expression patterns induced by HDACi in the five most sensitive and resistant lines. A robust and reproducible transcriptional response involving coordinate induction of multiple immediate-early (fos, jun, egr1, egr3, atf3, arc, nr4a1) and stress response genes (Ndrg4, Mt1B, Mt1E, Mt1F, Mt1H) was selectively induced in HDACi sensitive cells. Notably, a significant percentage of these genes were basally repressed in colon tumors. Bioinformatics analysis revealed that the promoter regions of the HDACi-induced genes were enriched for KLF4/Sp1/Sp3 transcription factor binding sites. Altering KLF4 levels failed to modulate apoptosis or transcriptional responses to HDACi treatment. In contrast, HDACi preferentially stimulated the activity of Spl/Sp3 and blocking their action attenuated both the transcriptional and apoptotic responses to HDACi treatment. Our findings link HDACi-induced apoptosis to activation of a Spl/Sp3-mediated response that involves derepression of a transcriptional network basally repressed in colon cancer.

A B S T R A C T PurposeTo evaluate the safety and efficacy of a modified administration schedule of docetaxel, cisplatin, and fluorouracil (mDCF) with bevacizumab in patients with advanced gastroesophageal malignancies. Patients and MethodsPreviously untreated patients with metastatic gastroesophageal adenocarcinoma received bevacizumab 10 mg/kg, docetaxel 40 mg/m 2 , fluorouracil 400 mg/m 2 , leucovorin 400 mg/m 2 on day 1, fluorouracil 1,000 mg/m 2 /d ϫ 2 days intravenous continuous infusion beginning on day 1, and cisplatin 40 mg/m 2 on day 3. The primary objective was to improve 6-month progression-free survival (PFS) from 43% (historical DCF control) to 63% with the addition of bevacizumab. The target accrual was 44 patients to have 10% type I and II error rates. ResultsIn total, 44 eligible patients with cancer were enrolled from October 2006 to October 2008: 22 gastric, 20 gastroesophageal junction (GEJ), and two esophagus. In 39 patients with measurable disease, the confirmed response rate was 67% (95% CI, 50% to 81%). Six-month PFS was 79% (95% CI, 63% to 88%), and median PFS was 12 months (95% CI, 8.8 to 18.2 months). With 26-month follow-up, median overall survival (OS) was 16.8 months (95% CI, 12.1 to 26.1 months), and 2-year survival was 37%. Treatment-related grade 3 to 4 toxicity was as follows: neutropenia without fever (50%), fatigue (25%), venous thromboembolism (39%), and nausea, vomiting, mucositis, neuropathy, and febrile neutropenia less than 10% each. In subset analysis, diffuse gastric cancer had significantly worse PFS and OS, and the response rate in proximal/GEJ tumors was 85% (95% CI, 62% to 97%). ConclusionmDCF with bevacizumab appears tolerable and has notable patient outcomes in patients with advanced gastroesophageal adenocarcinoma. Six-month PFS was 79%, surpassing our predefined efficacy end point, and median and 2-year OS were 16.8 months and 37%, respectively. J Clin

Colorectal cancers (CRC) with microsatellite instability (MSI) have clinical, pathologic, genetic, and epigenetic features distinct from microsatellite-stable CRC. Examination of epidermal growth factor receptor (EGFR) mRNA and protein expression levels in a panel of colon cancer cell lines identified strong expression of EGFR in multiple cell lines with MSI. Although no relationship between EGFR overexpression and the length of a CA dinucleotide repeat in intron 1 was observed, a variant A13/A14 repeat sequence within the 3 ¶-untranslated region (3 ¶-UTR) of the EGFR gene was identified, which was mutated by either mononucleotide or dinucleotide adenosine deletions in 64% of MSI cell lines and 69% of MSI colon tumors. Using a Tet-Off system, we show that this mutation increases EGFR mRNA stability in colon cancer cells, providing a mechanistic basis for EGFR overexpression in MSI colon cancer cell lines. To determine whether this mutation is a driver or a bystander event in MSI colon cancer, we examined the effect of pharmacologic and molecular inhibition of EGFR in EGFR 3 ¶-UTR mutant MSI cell lines. Cell lines with an EGFR 3 ¶-UTR mutation and that were wild-type (WT) for downstream signaling mediators in the Ras/BRAF and PIK3CA/PTEN pathways were sensitive to EGFR inhibition, whereas those harboring mutations in these signaling mediators were not. Furthermore, in cell lines WT for downstream signaling mediators, those with EGFR 3 ¶-UTR mutations were more sensitive to EGFR inhibition than EGFR 3 ¶-UTR WT cells, suggesting that this mutation provides a growth advantage to this subset of MSI colon tumors.

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Metastatic anal cancer is a rare disease in the Western hemisphere and current treatment modalities are not effective. In this study, patients with advanced epithelial cancer of the anal canal received MAP followed by Bleomycin and CCNU upon progression of disease. Twelve out of twenty eligible patients had a partial response 60%, (95% CI {36% -81%}). No complete responses were observed. The median survival was 15 months (95% CI {6-20} months). The median time to progression or death was 8 months (95% CI {4-9 months}). Toxicities were moderate and tolerable with routine supportive care; there were 2 cases of grade 3 vomiting, 2 cases of respiratory distress (one grade 1 and one grade 3), one case each of grade 3 leg cramps and cardiac arrhythmia. Of particular note were 7 cases of grade 3 hematologic toxicity. Two patients had grade 4 leukopenia and thrombocytopenia, respectively, that resolved without sequelae. The combination therapy of MAP followed by Bleomycin and CCNU for patients with advanced anal cancer, not amenable to radiotherapy or surgery, results in a moderate objective response but with moderate toxicities. This regimen and sequence is worthy of further study especially in combination with colony stimulating factors, however, its tolerability may be most applicable for patients who have had minimal prior therapy.

PURPOSE To update the ASCO guideline (2018) on the practical assessment and management of age-associated vulnerabilities in older patients undergoing systemic cancer therapy. METHODS An Expert Panel conducted a systematic review to identify relevant randomized clinical trials (RCTs), systematic reviews, and meta-analyses from January 2016 to December 2022. RESULTS A total of 26 publications met eligibility criteria and form the evidentiary basis for the update. RECOMMENDATIONS The Expert Panel reiterates its overarching recommendation from the prior guideline that geriatric assessment (GA), including all essential domains, should be used to identify vulnerabilities or impairments that are not routinely captured in oncology assessments for all patients over 65 years old with cancer. Based on recently published RCTs demonstrating significantly improved clinical outcomes, all older adults with cancer (65+ years old) receiving systemic therapy with GA-identified deficits should have GA-guided management (GAM) included in their care plan. GAM includes using GA findings to inform cancer treatment decision-making as well as to address impairments through appropriate interventions, counseling, and/or referrals. A GA should include high priority aging-related domains known to be associated with outcomes in older adults with cancer: physical and cognitive function, emotional health, comorbid conditions, polypharmacy, nutrition, and social support. Clinical adaptation of the GA based on patient population, resources, and time is appropriate. The Panel recommends the Practical Geriatric Assessment as one option for this purpose ( https://old-prod.asco.org/sites/new-www.asco.org/files/content-files/practice-patients/documents/2023-PGA-Final.pdf ; https://youtu.be/jnaQIjOz2Dw ; https://youtu.be/nZXtwaGh0Z0 ). Additional information is available at www.asco.org/supportive-care-guidelines .