Chylous Ascites Associated with Advanced Pancreatic Cancer That Improved with Appropriate Treatment: A Case Report

Chylous ascites is a rare form of ascites with high triglyceride content arising from the thoracoabdominal lymph nodes in the peritoneal cavity due to various benign or malignant etiologies, including pancreatic cancer. During cancer chemotherapy, the accumulation of ascites can lead to the deterioration of the patient's general condition, making chemotherapy administration difficult, and resulting in a poor prognosis. We encountered a rare case of chylous ascites complicated by advanced pancreatic cancer. The patient presented with a discrepancy between the shrinkage of the pancreatic cancer and the accumulation of ascites. Therefore, we were able to promptly diagnose chylous ascites by performing biochemical tests. The patient was treated with octreotide, reportedly effective in treating chylous ascites, which rapidly improved the chylous ascites and general condition of the patient, allowing the patient to continue chemotherapy for pancreatic cancer. Therefore, physicians should consider the possibility of chylous ascites when clinically unexplained ascites are observed in patients with advanced cancer. The investigation and treatment of chylous ascites should be initiated as soon as possible.

Nivolumab-induced Thrombotic Thrombocytopenic Purpura in Patients with Gastric Tube Cancer

Recently, immune checkpoint inhibitors (ICIs) have been used to treat several cancer types. ICIs have been reported to cause a wide variety of immune-related adverse events, including endocrine, neurologic, gastrointestinal, and cutaneous disorders. Thrombotic thrombocytopenic purpura (TTP) is an autoimmune hematologic disorder characterized by the presence of autoantibodies against a disintegrin and metalloprotease with thrombospondin-1, member 13. Several previous cases of TTP were thought to have been caused by ICI treatment. We herein report a rare case of TTP that developed after long-term treatment with an ICI (nivolumab) for gastric tube cancer.

Cancer Pain Management in Patients Receiving Inpatient Specialized Palliative Care Services

CONTEXT

Cancer pain is a common complication that is frequently undertreated in patients with cancer.

OBJECTIVES

This study is aimed at assessing the time needed to achieve cancer pain management goals through specialized palliative care (SPC).

METHODS

This was a multicenter, prospective, longitudinal study of inpatients with cancer pain who received SPC. Patients were continuously followed up until they considered cancer pain management successful, and we estimated this duration using the Kaplan-Meier method. We investigated the effectiveness of pain management using multiple patient-reported outcomes (PROs) and quantitative measures, including pain intensity change in the Brief Pain Inventory. A paired-sample t-test was used to compare the pain intensity at the beginning and end of the observation period.

RESULTS

Cancer pain management based on the PROs was achieved in 87.9% (385/438) of all cases. In 94.5% (364/385) of these cases, cancer pain management was achieved within 1 week, and the median time to pain management was 3 days (95% confidence interval [CI], 2-3). The mean worst pain intensity in the last 24 h at the start and end of observation were 6.9 ± 2.2 and 4.0 ± 2.3, respectively, with a difference of -2.9 (95% CI, -3.2 to -2.6; p < 0.01). Overall, 81.6% of the patients reported satisfaction with cancer pain management, and 62 adverse events occurred.

CONCLUSION

SPC achieved cancer pain management over a short period with a high level of patient satisfaction resulting in significant pain reduction and few documented adverse events.

FOLFIRI Chemotherapy for Patients With Metastatic Urachal Carcinoma

BACKGROUND/AIM

Urachal carcinoma is a rare cancer, with limited evidence regarding systemic chemotherapy for metastatic urachal carcinoma. This study aimed to evaluate the efficacy and safety of a combination therapy of 5-fluorouracil and irinotecan (FOLFIRI) in patients with metastatic urachal carcinoma.

PATIENTS AND METHODS

Patients with metastatic urachal carcinoma treated with FOLFIRI between March 2008 and April 2023 at the Department of Medical Oncology, Tohoku University Hospital, were retrospectively analyzed using medical records.

RESULTS

Six patients with urachal carcinoma received FOLFIRI. The histological type was adenocarcinoma in all patients. The metastatic or recurrent sites were the peritoneum, lungs, lymph nodes, and local relapse sites. Three patients received FOLFIRI as first-line chemotherapy, and the other three received FOLFIRI as second-line chemotherapy. Two patients had only non-measurable lesions as the targets of tumor response. The best response was the stable disease or non-complete response/non-progressive disease in four patients, with a disease control rate of 67%. The median progression-free survival was 7.5 months. In two patients with ascites only as the site of metastasis, the amount of ascites and serum tumor marker levels decreased after FOLFIRI was initiated. Grade 3/4 toxicities included grade 3 neutropenia in one patient and grade 3 diarrhea in one patient.

CONCLUSION

FOLFIRI has modest efficacy and good tolerability for the treatment of metastatic urachal carcinoma.

Intractable Ventricular Tachycardia Prior to an Overt Cardiac Tumor Mass of Metastatic Cardiac Rhabdomyosarcoma (Spindle-cell Type)

We herein report a 37-year-old man who experienced recurrence of metastatic cardiac rhabdomyosarcoma along with intractable ventricular tachycardia (VT) 7 years after resection of rhabdomyosarcoma in his right elbow. At 36 years old, he developed VT unresponsive to radiofrequency catheter ablation (RFCA). Initially, the cardiac tumor was not detected, but it gradually grew in size at the RFCA site. A surgical biopsy confirmed the diagnosis of metastatic cardiac rhabdomyosarcoma. Despite radiation therapy, cardiac tumor progression and VT instability could not be prevented. Ultimately, the patient died 27 months after the initial documentation of VT.

Comparison of Efficacy and Safety between Carboplatin-Etoposide and Cisplatin-Etoposide Combination Therapy in Patients with Advanced Neuroendocrine Carcinoma: A Retrospective Study

INTRODUCTION

Neuroendocrine carcinoma (NEC) is characterized by a poor prognosis and is generally treated with platinum and etoposide combination therapy as first-line chemotherapy. However, it remains uncertain whether carboplatin and etoposide combination therapy (CE) and cisplatin and etoposide combination therapy (PE) have comparable treatment efficacy. In this retrospective analysis, we compared the efficacy and safety of CE and PE in patients with NEC.

METHODS

We retrospectively reviewed the patient's clinical record from 2005 to 2022 at the Department of Medical Oncology, Tohoku University Hospital. Patients who received either CE or PE were included in the study. Statistical analyses were performed using JMP Pro 16.0 (SAS Institute Inc., Cary, NC, USA).

RESULTS

A total of 104 patients were enrolled, with 73 patients assigned to the CE group and 31 patients assigned to the PE group. Statistically, the response rate, progression-free survival time and overall survival time were 42.6%, 5.1 months (95% CI: 3.5-6.3) and 13.6 months (95% CI: 8.9-17.4), respectively, in the CE groups and 44.4%, 5.6 months (95% CI: 3.1-7.0) and 12.5 months (95% CI: 11.2-14.6), respectively, in the PE groups. There was no significant difference in treatment efficacy between the CE and the PE groups. However, the number of patients with elevated creatinine (3.35 mg/dL and 3.88 mg/dL in 2 patients, respectively) was significantly higher in the PE group than in the CE group.

CONCLUSION

The efficacy of CE and PE in patients with NEC is comparable. However, the incidence of renal dysfunction was found to be significantly higher in the PE group than in the CE group.

Prevalence of opioid-induced adverse events across opioids commonly used for analgesic treatment in Japan: a multicenter prospective longitudinal study

PURPOSE

Although opioids have been shown to be effective for cancer pain, opioid-induced adverse events (AEs) are common. To date, little is known about the differences in risks of AEs by opioid type. This study was performed to compare the prevalence of AEs across opioids commonly used for analgesic treatment in Japan.

METHODS

This study was conducted as a preplanned secondary analysis of a multicenter prospective longitudinal study of inpatients with cancer pain who received specialized palliative care for cancer pain relief. We assessed daily AEs until termination of follow-up. We rated the severity of AEs based on the Common Terminology Criteria for Adverse Events version 5.0. We computed adjusted odds ratios for each AE (constipation, nausea and vomiting, delirium, and drowsiness) with the following variables: opioid, age, sex, renal dysfunction, and primary cancer site.

RESULTS

In total, 465 patients were analyzed. Based on the descriptive analysis, the top four most commonly used opioids were included in the analysis: oxycodone, hydromorphone, fentanyl, and tramadol. With respect to the prevalence of AEs among all analyzed patients, delirium (n = 25, 6.3%) was the most frequent, followed by drowsiness (n = 21, 5.3%), nausea and vomiting (n = 19, 4.8%), and constipation (n = 28, 4.6%). The multivariate logistic analysis showed that no single opioid was identified as a statistically significant independent predictor of any AE.

CONCLUSION

There was no significant difference in the prevalence of AEs among oxycodone, fentanyl, hydromorphone, and tramadol, which are commonly used for analgesic treatment in Japan.

Antibiotics May Interfere with Nivolumab Efficacy in Patients with Head and Neck Squamous Cell Carcinoma

INTRODUCTION

Patients with the head and neck squamous cell carcinoma (SCC) are often treated with immune checkpoint inhibitors (ICIs). Recently, antibiotic intake was reported to lower the efficacy of ICIs in patients with several types of cancers. However, it is unclear if antibiotics affect the efficacy of ICIs in patients with head and neck SCC. We retrospectively assessed the influence of antibiotics on the treatment efficacy of nivolumab, an ICI, in patients with head and neck SCC.

METHODS

We reviewed the medical records of patients with head and neck SCC treated with nivolumab at the Department of Medical Oncology, Tohoku University Hospital, between 2017 and 2021. Patients who received oral or intravenous antibiotics from a month before the day of nivolumab initiation to the day of the first imaging evaluation of ICI efficacy were assigned to the antibiotic-treated group. The remaining patients were assigned to the antibiotic-untreated group. The response rate (RR), progression-free survival (PFS), and overall survival time (OS) of both groups were compared.

RESULTS

Forty-five patients were assigned to the antibiotic-treated group and 19 to the antibiotic-untreated group. The RR, median PFS, and median OS of the antibiotic-treated group were 23.7%, 3.2 months (95% confidential interval [CI]: 2.0-4.1), and 8.4 months (95% CI: 5.3-15.1) and those of the antibiotic-untreated group were 42.1%, 5.8 months (95% CI: 2.3-16.7), and 18.4 months (95% CI: 6.2-23.1), respectively. The PFS of the antibiotic-untreated group was significantly longer than that of the antibiotic-treated group.

CONCLUSION

Our findings indicate that antibiotic treatment significantly shortens the PFS with nivolumab therapy in patients with head and neck SCC.

TP53 Gain-of-Function Mutation is a Poor Prognostic Factor in High-Methylated Metastatic Colorectal Cancer

BACKGROUND

Neither TP53 mutation nor DNA methylation status has been established as a biomarker alone of metastatic colorectal cancer. We analyzed the association between TP53 mutation functional subtypes and genome-wide DNA methylation status (GWMS) as combined prognostic markers.

METHODS

Patient clinical data were obtained from the TRICOLORE study, a randomized phase III trial. The TP53 mutations were classified into wild-type, gain-of-function (GOF) mutations, and non-gain-of-function (non-GOF) mutations. GWMS of the tumor tissues classified them into high-methylated colorectal cancer (HMCC) and low-methylated colorectal cancer (LMCC). Overall survival (OS) was compared based on these subgroups.

RESULTS

Of the 209 patients, 60 (28.7%) were HMCC and 149 (71.3%) were LMCC, 35 (16.7%) were TP53 wild-type and 174 (83.3%) were TP53 mutants including 79 (45.4%) GOF mutations and 95 (54.6%) non-GOF mutations. The OS of the HMCC group was shorter than that of the LMCC group (median 25.3 vs. 40.3 months, P < .001, hazard ratio 1.87) in the total cohort. The combined subgroup analyses of GWMS and TP53 mutation subtypes showed that the HMCC/GOF group had significantly shorter OS than the HMCC/non-GOF group, the LMCC/GOF group, and the LMCC/non-GOF group (median 17.7; 35.3, 40.3, and 41.2 months, P = .007, P < .001, and P < .001, respectively), regardless of the primary tumor location. By the multivariate analysis, only HMCC (P = .009) was a poor prognostic factor in the GOF mutation group.

CONCLUSIONS

TP53 GOF with HMCC is a newly identified poorest prognostic molecular subset in metastatic colorectal cancer.

Depth of response may predict clinical outcome in patients with recurrent/metastatic head and neck cancer treated with pembrolizumab-containing regimens

Background

Pembrolizumab-containing regimens are standards of care for recurrent and metastatic head and neck squamous cell carcinoma (R/M HNSCC). The depth of response (DpR) predicts the survival of patients with several types of solid cancers; however, its association with the survival outcomes of patients with R/M HNSCC treated with pembrolizumab-containing regimens remains unclear.

Methods

This study included 66 patients with R/M HNSCC who received a pemblolizumab-containing regimen as a first-line therapy at Tohoku University Hospital, Sendai, Japan. The patients' characteristics, combined positive score, baseline tumor size, tumor response, DpR, overall survival (OS), progression-free survival (PFS), PFS2, and adverse events were reviewed. The associations between DpR and survival outcomes were analyzed.

Results

The 1 year-OS and 1 year-PFS rates of pembrolizumab-containing regimens were 69.4% and 24.4%, respectively. The response rate was 28.8%. The mean and median values of tumor change from baseline were 5.1% and -9.0%. In the correlation analysis, a significant negative correlation was observed between tumor change rate from baseline and survival outcomes (OS: r= -0.41, p=0.0017; PFS: r=-0.49, p<0.001). In the multivariate analysis, DpR with tumor change of ≤-45 was associated with better OS and PFS.

Conclusion

DpR induced by pembrolizumab-containing regimens may be a predictive factor for OS and PFS in patients with R/M HNSCC.

A multi-institutional observational study evaluating the incidence and the clinicopathological characteristics of NeoRAS wild-type metastatic colorectal cancer

PURPOSE

As circulating tumor DNA (ctDNA) measurement becomes more widespread, the "NeoRAS" phenomenon, where tissue rat sarcoma viral oncogene homolog (RAS) status converts from mutant (MT) to wild-type (WT) after treatment in metastatic colorectal cancer (mCRC), is gaining attention because ineffective epidermal growth factor receptor (EGFR) inhibitors may made effective. This study investigated its incidence and clinicopathological characteristics.

PATIENTS AND METHODS

In total, 107 mCRC patients (refractory or intolerant to previous chemotherapies) with tissue RAS MT were enrolled in four institutions from June 2021 to August 2022. The RAS status in ctDNA was assessed using OncoBEAM™ RAS CRC assay. Clinicopathologic features were compared between patients according to their RAS status in ctDNA, whether WT conversion was noted or not.

RESULTS

The incidence rate of NeoRAS WT mCRC was 21.5% (23/107). According to tissue RAS mutation sites, NeoRAS WT frequency in patients with KRAS mutation in exon 2 was significantly lower than those in exon 3 and 4 or NRAS (18.2% [18/99] vs 62.5% [5/8], P = 0.011). Regarding clinical background, there were significant differences in NeoRAS WT frequency between male vs female patients (30.6% [19/62] vs 8.9% [4/45], P = 0.008), and absence vs presence of liver metastasis (38.6% [17/44] vs 9.5% [6/63], P < 0.001). Comparing the two groups divided by the median value, NeoRAS WT was associated with smaller tumor diameter (>60.9 mm vs ≤, 3.8% [2/53] vs 38.9% [21/54], P < 0.001), lower carcinoembryonic antigen level (>38.2 ng/ml vs ≤, 11.3% [6/53] vs 31.5% [17/54], P = 0.018), and lower carbohydrate antigen 19-9 level (>158.0 U/ml vs ≤, 9.4% [5/53] vs 33.3% [18/54], P = 0.004). In the logistic regression multivariate analysis, liver metastasis absence (Odds ratio [OR], 4.62; P = 0.019), smaller tumor diameter (OR, 7.92; P = 0.012), and tissue RAS MT in other than KRAS exon 2 (OR, 9.04; P = 0.026) were significantly related to the conversion to NeoRAS WT in ctDNA.

CONCLUSIONS

Original RAS variants in tissue, tumor diameter, and liver metastasis are related to conversion to NeoRAS WT mCRC in ctDNA.

Different impacts of TP53 mutations on cell cycle-related gene expression among cancer types

Functional properties caused by TP53 mutations are involved in cancer development and progression. Although most of the mutations lose normal p53 functions, some of them, gain-of-function (GOF) mutations, exhibiting novel oncogenic functions. No reports have analyzed the impact of TP53 mutations on the gene expression profile of the p53 signaling pathway across cancer types. This study is a cross-cancer type analysis of the effects of TP53 mutations on gene expression. A hierarchical cluster analysis of the expression profile of the p53 signaling pathway classified 21 cancer types into two clusters (A1 and A2). Changes in the expression of cell cycle-related genes and MKI67 by TP53 mutations were greater in cluster A1 than in cluster A2. There was no distinct difference in the effects between GOF and non-GOF mutations on the gene expression profile of the p53 signaling pathway.

A multicenter, single-arm, phase II study of nivolumab in patients with biliary tract cancer with a PD-L1 combined positive score ≥ 1

533

Background: Patients with advanced biliary tract cancer (BTC) have a poor prognosis, and high unmet medical needs still exist for the treatment of this disease. Nivolumab has shown its effectiveness against multiple cancer types, especially those with PD-L1 expression. This study assessed the efficacy and safety of nivolumab in BTC patients with a combined positive score (CPS) ≥ 1 who were refractory or intolerant to the standard of care (SOC): gemcitabine, cisplatin and tegafur/gimeracil/oteracil (S-1). Methods: This was a single-arm, multicenter, open-label, prospective phase II study. Key eligibility criteria were as follows: having unresectable or recurrent BTC (intrahepatic bile duct cancer, extrahepatic bile duct cancer, gallbladder cancer, or ampullary cancer); being refractory or intolerant to SOC; having adequate hepatic, renal and hematological function; and having a CPS ≥ 1 in central assessment. Patients received nivolumab (480 mg, every 4 weeks) until disease progression, clinical deterioration, or unacceptable toxicity. The primary endpoint was objective response rate (ORR) assessed by the central review according to RECIST 1.1. The secondary endpoints included overall survival (OS), progression-free survival (PFS), and safety. Results: A total of 84 patients were enrolled between Mar 11, 2020 and Mar 15, 2021, of them 12 received one regimen and 72 received two or more regimens. The median follow-up period was 6.90 months. ORR per central assessment was 10.7% (CR: 3.6%, PR: 7.1%), and ORR per investigator assessment was 15.5% (CR: 2.4%, PR: 13.1%). The median PFS per central and investigator assessment was 1.02 (95% CI 0.95–1.77) months and 2.48 (95% CI 1.87–2.83) months, respectively. The median OS was 6.90 (95% CI 5.26–9.20) months. The median duration of response per central and investigator assessment was not reached (range 2.8–13.0+) and 10.15 (range 2.0–12.8+) months, respectively. The 1-year survival rate was 25.3% (95% CI 15.4–36.4). The most frequent treatment-related adverse events were pyrexia (19.0%), pruritus (16.7%), and decreased appetite (13.1%). Conclusions: Nivolumab may have some activity with a durable response and a manageable safety profile in heavily treated BTC patients with CPS ≥ 1. Clinical trial information: JapicCTI-205097 .

A multi-institutional observational study evaluating the incidence and the clinicopathological characteristics of NeoRAS wild-type metastatic colorectal cancer

206

Background: The ’’Neo RAS’’ phenomenon, in which tissue rat sarcoma viral oncogene homolog ( RAS) status converts from mutant (MT) to wild-type (WT) after treatment in metastatic colorectal cancer (mCRC), is gaining attention because epidermal growth factor receptor (EGFR) inhibitors, which were originally considered to be ineffective, may converted to be effective. This multi-center study investigated its incidence and clinicopathological characteristics that are still unclear. Methods: 107 mCRC patients with tissue RAS MT, confirmed using MEBGEN RASKET-B, who were refractory or intolerant to previous chemotherapies, including fluoropyrimidines, oxaliplatin, or irinotecan were enrolled in 4 institutions from June 2021 to August 2022. The RAS status in ctDNA was investigated after prior chemotherapy using ONCOBEAMTM RAC CRC. Clinicopathological characteristics were compared between patients with RAS MT and RAS WT (Neo RAS) in ctDNA. Results: The incidence of Neo RAS WT mCRC was 21.5% (23/107). The frequency of Neo RAS in KRAS exon 2 was significantly lower than that in other alleles such as exon 3 and 4 or NRAS (18.2% [18/99] vs 62.5% [5/8], P = 0.011). There were significant differences in frequency of Neo RAS between male vs female (30.6% [19/62] vs 8.9% [4/45], P = 0.008), absence vs presence of liver metastasis (38.6% [17/44] vs 9.5% [6/63], P < 0.001), and between two groups divided at the median: tumor diameter (> 60.9 mm vs ≤, 3.8% [2/53] vs 38.9% [21/54], P < 0.001), carcinoembryonic antigen level (> 38.2 ng/ml vs ≤, 11.3% [6/53] vs 31.5% [17/54], P = 0.018), carbohydrate antigen 19-9 level (> 158.0 U/ml vs ≤, 9.4% [5/53] vs 33.3% [18/54], P = 0.004). Logistic regression multivariate analysis, absence of liver metastasis (Odds ratio [OR], 4.62; P = 0.019), smaller tumor diameter (OR, 7.92; P = 0.012) and tissue RAS MT in other than KRAS exon 2 (OR, 9.04; P = 0.026) were significantly related to the appearance of Neo RAS WT mCRC. Conclusions: Original RAS status in tissue, tumor diameter and liver metastasis are related to conversion to Neo RAS WT mCRC.

TP53 gain of function mutation as a prognostic factor in high-methylated metastatic colorectal cancer: Translational research of TRICOLORE study

179

Background: TP53 tumor suppressor gene is frequently inactivated by loss-of-function mutations. Some of the mutations gain additional oncogenic functions and are known as gain-of-function (GOF) mutations. This study analyzed the association among primary tumor site (PS), genome-wide DNA methylation status (GWMS), and TP53 mutation subtypes about prognosis in metastatic colorectal cancer (mCRC). Methods: Tumor tissues of mCRC patients registered in the TRICOLORE Study (clinical trial number) were analyzed for GWMS and TP53 mutation as translational research and were classified into high-methylated colorectal cancer (HMCC) and low-methylated colorectal cancer (LMCC) for GWMS, and wild-type , GOF mutation and non-GOF mutation for TP53 mutation. Overall survival (OS) was compared between single or combined subgroups, and Cox regression analysis was performed to identify factors contributing to OS. Results: A total of 209 patients were analyzed, HMCC and LMCC were 60 (28.7%) and 149 (71.3%), respectively. TP53 wild-type , GOF mutation and non-GOF mutation were 35 (16.7%), 79 (37.8%) and 95 (45.5%), respectively. HMCC showed a significantly worse prognosis than LMCC (median OS 25.3 vs. 40.3 months, P < 0.01, hazard ratio 1.87). Combining GWMS and TP53 mutation subtypes about prognosis, the HMCC/GOF (n = 26) group had a significantly poorer prognosis than the other three groups including HMCC/non-GOF (n = 22), LMCC/GOF (n = 53), and LMCC/non-GOF groups (n = 73) (median OS 17.7, 35.3, 40.3, 41.2 months, p = 0.007, p < 0.001, p < 0.001, respectively). The HMCC/GOF group had a poorer prognosis than the other 3 groups regardless of the PS. In the multivariate analysis in the GOF mutation subgroup, HMCC (p < 0.01) was the only poor prognostic factor, while right-sided colon cancer (p = 0.03) and RAS mutations (p = 0.01) were significant poor prognostic factors in the multivariate analysis in the non-GOF mutation subgroup. Conclusions: TP53 gain of function mutations are independent poor prognostic factors in high-methylated metastatic colorectal cancer.

Multicentre single-arm phase II trial evaluating the safety and effiCacy of Panitumumab and iRinOtecan in NeoRAS Wild-type mEtaStatic colorectal cancer patientS (C-PROWESS trial): study protocol

INTRODUCTION

A new concept of 'NeoRAS wild-type (WT)', which means conversion of RAS status from RAS mutant to RAS WT after treatment, has been reported. Previous observational and proof-of-concept studies have demonstrated the efficacy of epidermal growth factor receptor inhibitors in patients with NeoRAS WT metastatic colorectal cancer (mCRC). Moreover, posthoc biomarker analyses of these studies have suggested that not only the RAS status in the circulating tumour DNA (ctDNA) but also other gene mutational status may be useful as biomarkers of epidermal growth factor receptor inhibitors for NeoRAS WT mCRC.

METHODS AND ANALYSIS

This trial is a multicentre, single-arm, phase II trial to assess the efficacy and safety of panitumumab plus irinotecan therapy for patients with NeoRAS mCRC. The key eligibility criteria include RAS mutant mCRC initially proven in tumour tissue refractory or intolerant to fluoropyrimidine, oxaliplatin and irinotecan; RAS WT in ctDNA (defined as plasma mutant allele frequencies of all RAS ≤0.1%) within 28 days before enrolment and Eastern Cooperative Oncology Group performance status ≤2. The primary endpoint is the response rate. The target sample size is 30 patients. Biomarker analyses are planned to be performed using next-generation sequencing-based ctDNA analysis.

ETHICS AND DISSEMINATION

This study was approved by the certified review board of National Cancer Center Hospital. The main results of the trial will be presented in international meetings and in medical journals.

TRIAL REGISTRATION NUMBER

s031210565.

BRAF and MEK Inhibitor Treatment for Metastatic Undifferentiated Sarcoma of the Spermatic Cord with BRAF V600E Mutation

An 18-year-old Japanese man was diagnosed with an undifferentiated sarcoma of the spermatic cord, with multiple distant metastases to the lungs and bones. The patient received doxorubicin-based standard chemotherapy. Although the chemotherapy was effective, it induced severe adverse events, which led to treatment discontinuation. A comprehensive genomic profiling test using resected tumor tissue revealed the BRAF V600E mutation. Based on the result, the patient received combination therapy with dabrafenib and trametinib. The combination therapy achieved a good response with few adverse events. However, 6.5 months later, pleural metastases and meningeal dissemination had emerged. A liquid comprehensive genomic profiling test was performed after the progression to identify the resistance mechanism, which resulted in the detection of no actionable gene alterations other than BRAF V600E. This report shows that the BRAF V600E mutation may be a promising therapeutic target and that resistance to the targeted therapy could also occur in soft tissue sarcoma. The significance of BRAF mutations across different types of cancer should be validated, and it is necessary to apply targeted therapies and develop methods to overcome resistance based on the optimal use of comprehensive genomic profiling tests.

[Biomarkers of Anti-EGFR Antibodies in the Treatment of Metastatic Colorectal Cancer]

Anti-EGFR antibodies(cetuximab and panitumumab)are molecular targeted agents that exert their antitumor effects by binding directly to the epidermal growth factor receptor(EGFR)and inhibiting its downstream signaling. Anti-EGFR antibodies have become one of the most important agents in the treatment of metastatic colorectal cancer(CRC), showing efficacy in combination with cytotoxic chemotherapeutic agents and as single agents in first-line and second-line treatment or later. Molecular targeted agents show more potent therapeutic effects than conventional chemotherapeutic agents, but their cost-effectiveness is often an issue due to their high drug costs. Predictive biomarkers of therapeutic efficacy that enable appropriate patient selection have an important role not only in improving the cost-effectiveness of molecular targeted agents, but also from the perspective of avoiding side effects in invalid patients. In addition to RAS and BRAF genotypes as molecular biological factors, anatomical factors such as the site of primary tumor(sidedness)are described in guidelines as important biomarkers for anti-EGFR treatment in the treatment of metastatic CRC. Recently, an association between HER2 gene amplification and anti-EGFR antibody resistance in RAS/BRAF wild-type metastatic CRC was reported. Furthermore, an epigenetic factor, DNA methylation status, was reported to be associated with the therapeutic effect of anti-EGFR treatments, and our subsequent studies have suggested that DNA methylation status is predictive of therapeutic efficacy of anti- EGFR antibodies regardless of the site of the primary tumor. Novel biomarkers will continue to be developed from a variety of approaches to provide more optimal cancer treatment for each individual patient.

Inhibition of stearoyl-CoA desaturase 1 (SCD1) enhances the antitumor T cell response through regulating β-catenin signaling in cancer cells and ER stress in T cells and synergizes with anti-PD-1 antibody

Background

Understanding the mechanisms of non-T cell inflamed tumor microenvironment (TME) and their modulation are important to improve cancer immunotherapies such as immune checkpoint inhibitors. The involvement of various immunometabolisms has recently been indicated in the formation of immunosuppressive TME. In this study, we investigated the immunological roles of stearoyl-CoA desaturase 1 (SCD1), which is essential for fatty acid metabolism, in the cancer immune response.

Methods

We investigated the roles of SCD1 by inhibition with the chemical inhibitor or genetic manipulation in antitumor T cell responses and the therapeutic effect of anti-programmed cell death protein 1 (anti-PD-1) antibody using various mouse tumor models, and their cellular and molecular mechanisms. The roles of SCD1 in human cancers were also investigated by gene expression analyses of colon cancer tissues and by evaluating the related free fatty acids in sera obtained from patients with non-small cell lung cancer who were treated with anti-PD-1 antibody.

Results

Systemic administration of a SCD1 inhibitor in mouse tumor models enhanced production of CCL4 by cancer cells through reduction of Wnt/β-catenin signaling and by CD8⁺ effector T cells through reduction of endoplasmic reticulum stress. It in turn promoted recruitment of dendritic cells (DCs) into the tumors and enhanced the subsequent induction and tumor accumulation of antitumor CD8⁺ T cells. SCD1 inhibitor was also found to directly stimulate DCs and CD8⁺ T cells. Administration of SCD1 inhibitor or SCD1 knockout in mice synergized with an anti-PD-1 antibody for its antitumor effects in mouse tumor models. High SCD1 expression was observed in one of the non-T cell-inflamed subtypes in human colon cancer, and serum SCD1 related fatty acids were correlated with response rates and prognosis of patients with non-small lung cancer following anti-PD-1 antibody treatment.

Conclusions

SCD1 expressed in cancer cells and immune cells causes immunoresistant conditions, and its inhibition augments antitumor T cells and therapeutic effects of anti-PD-1 antibody. Therefore, SCD1 is an attractive target for the development of new diagnostic and therapeutic strategies to improve current cancer immunotherapies including immune checkpoint inhibitors.

Clinical impact of DNA methylation status on first-line antiepidermal growth factor receptor treatment in patients with metastatic colorectal cancer

3528

Background: The CpG island methylator phenotype (CIMP), important for carcinogenesis, is a predictor of prognosis and chemotherapy sensitivity in colorectal cancer. However, there is a lack of consensus of CIMP markers, and thus, more comprehensive methylation markers are required to reliably predict the clinical outcomes. Previously, we reported that genome-wide DNAmethylation statuscould predict the effect of epidermal growth factor receptor (EGFR) inhibitors more accurately than previously reported methylation classifications (Ouchi et al. Cancer Sci 2015). Moreover, we had developed a DNA methylation assay based on MethyLight to reflect genome-wide DNA methylation status and reported its usefulness in predicting prognosis in patients with metastatic colorectal cancer (mCRC) treated with EGFR inhibitors as a third-line chemotherapy (Ouchi et al. Cancer Sci 2022). This study aimed to clarify the effects of genome-wide DNA methylation status on clinical outcomes in patients with mCRC treated with first-line EGFR inhibitors. Methods: We enrolled 241 patients with mCRC, who received chemotherapy plus EGFR inhibitors as a first-line treatment, and analyzed the associations between genome-wide DNA methylation status using a novel comprehensive methylation marker panel and clinical outcomes and evaluated the predictive power and value of the methylation status. Results: Total 169 patients were included in the final analyses. The frequency of highly methylated CRC (HMCC) was 8.9% (15/169). The characteristics of patients with HMCC included right-sided primary tumor location (P = 0.042), undifferentiated histology (P = 0.047), and BRAFV600E mutation (P < 0.001). Patients with HMCC showed worse clinical outcomes than those with low methylated CRC in terms of response rate (P = 0.017), progression-free survival (PFS; P = 0.004), and overall survival (P = 0.019). In the multivariate analysis, peritoneal metastasis (Hazard ratio (HR): 2.24, P = 0.017), methylation status (HR: 3.04, P = 0.037), and BRAFV600E mutations (HR: 5.83, P = 0.0001) were independent factors for shorter PFS. Conclusions: Genome-wide DNA methylation status may be an independent predictor of first-line EGFR inhibitors in patients with mCRC.

Altered gene expression due to aberrant DNA methylation correlates with responsiveness to anti-EGFR antibody treatment

The cetuximab gene expression signature and DNA methylation status of colorectal cancer (CRC) are predictive of the therapeutic effects of anti‐epidermal growth factor receptor (EGFR) antibody therapy. As DNA methylation is a means of regulating gene expression, it may play an important role in the expression of cetuximab signature genes. This study aims to determine the effects of aberrant DNA methylation on the regulation of cetuximab signature gene expression. Comprehensive DNA methylation and gene expression data were retrieved from CRC patients in three tumor tissue (TT) cohorts and three normal colorectal mucosa/tumor tissue paired (NCM‐TT) cohorts. Of the 231 cetuximab signature genes, 57 exhibited an inverse correlation between the methylation of promoter CpG sites and gene expression level in multiple cohorts. About two‐thirds of the promoter CpG sites associated with the 57 genes exhibited this correlation. In all 57 gene promoter regions, the methylation levels in NCMs did not differ according to comparisons based on cetuximab signature or DNA methylation status classification of matched TTs. Thus, the altered expression of 57 genes was caused by aberrant DNA methylation during carcinogenesis. Analysis of the association between cetuximab signature or DNA methylation status and progression‐free survival (PFS) of anti‐EGFR antibody agents in the same cohort showed that DNA methylation status was most associated with PFS. In conclusion, we found that aberrant DNA methylation regulates specific gene expression in cetuximab signature during carcinogenesis, suggesting that it is one of the important determinants of sensitivity to anti‐EGFR antibody agents.

A modified MethyLight assay predicts the clinical outcomes of anti-EGFR treatment in metastatic colorectal cancer

DNA methylation status correlates with clinical outcomes of anti‐epidermal growth factor receptor (EGFR) treatment. There is a strong need to develop a simple assay for measuring DNA methylation status for the clinical application of drug selection based on it. In this study, we collected data from 186 patients with metastatic colorectal cancer (mCRC) who had previously received anti‐EGFR treatment. We modified MethyLite to develop a novel assay to classify patients as having highly methylated colorectal cancer (HMCC) or low‐methylated colorectal cancer (LMCC) based on the methylation status of 16 CpG sites of tumor‐derived genomic DNA in the development cohort (n = 30). Clinical outcomes were then compared between the HMCC and LMCC groups in the validation cohort (n = 156). The results showed that HMCC had a significantly worse response rate (4.2% vs 33.3%; P = .004), progression‐free survival (median: 2.5 vs 6.6 mo, P < .001, hazard ratio [HR] = 0.22), and overall survival (median: 5.6 vs 15.5 mo, P < .001, HR = 0.23) than did LMCC in patients with RAS wild‐type mCRC who were refractory or intolerable to oxaliplatin‐ and irinotecan‐based chemotherapy (n = 101). The DNA methylation status was an independent predictive factor and a more accurate biomarker than was the primary site of anti‐EGFR treatment. In conclusion, our novel DNA methylation measurement assay based on MethyLight was simple and useful, suggesting its implementation as a complementary diagnostic tool in a clinical setting.