Trending Topics in Gastroenterology | GastroAGI

New Perioperative Strategy in Gastric Cancer

The new perioperative strategy in gastric cancer involves incorporating immunotherapy into the existing chemotherapy regimen to improve outcomes for patients with resectable gastric and gastroesophageal junction cancers. These cancers are highly aggressive, with high recurrence rates even after surgery and chemotherapy. The current standard treatment, known as the FLOT regimen (fluorouracil, leucovorin, oxaliplatin, and docetaxel), has shown survival benefits but remains insufficient to address the high recurrence rates. To address this gap, the phase 3 MATTERHORN clinical trial investigated the addition of durvalumab, an immune checkpoint inhibitor targeting PD-L1 (programmed death-ligand 1), to the FLOT regimen. Durvalumab is designed to enhance the immune system's ability to recognize and attack cancer cells. Early results from the MATTERHORN trial have been promising, showing higher response rates and a potential survival benefit when durvalumab is added to the FLOT chemotherapy regimen. This suggests that immunotherapy, when combined with standard perioperative chemotherapy, could significantly improve outcomes for patients with resectable gastric and gastroesophageal junction cancers. In summary, the new perioperative strategy highlights the potential of integrating immunotherapy (durvalumab) with FLOT chemotherapy to reduce recurrence rates and improve survival in patients with these challenging cancers. This approach represents a significant advancement in the treatment landscape for gastric cancer.

CT Use and Future Cancer Risk

The rising use of CT (computed tomography) scans has sparked concerns about its potential long-term impact on cancer risk, as highlighted by a recent modeling study. Below is a detailed analysis of the findings and their implications: ### Key Findings: 1. **CT Scan Usage in 2023**: - In the U.S., approximately **62 million patients** underwent nearly **93 million CT scans** in 2023 alone. - This marks a significant reliance on CT imaging for diagnostic and medical purposes. 2. **Projected Cancer Cases**: - Researchers estimate that the radiation exposure from this level of CT use could result in about **103,000 future cancer cases**. - These cases could account for up to **5% of all annual cancer diagnoses**, a figure comparable to cancer risks associated with **alcohol consumption** or **excess body weight**. 3. **Age and Type of CT Scans**: - **Adults**: Abdomen and pelvis CT scans contributed the most to the projected cancer cases. - **Children**: Head CT scans were the largest contributor to projected cancers in this group. - **Highest Risk Per Scan**: Children under **1 year of age** face the highest risk per individual scan due to their greater sensitivity to radiation. - **Largest Number of Cases Overall**: Older adults had the highest number of projected cancer cases, primarily because they undergo CT scans more frequently. 4. **Cancer Types Linked to CT Radiation**: - **Adults**: Lung, colon, bladder cancers, and leukemia were the most commonly linked cancers. - **Children**: Thyroid, lung, and breast cancers were the most frequently associated with CT scan radiation. 5. **Lifetime Risk Increase**: - The overall lifetime risk of developing cancer increases slightly due to CT scan radiation exposure — from about **50% to 52.5%**. ### Implications: - **Balancing Risks and Benefits**: - While there is a small increase in lifetime cancer risk, experts emphasize that CT scans are often **essential and life-saving** tools in medical diagnosis and treatment. - The **diagnostic benefits** of CT imaging generally outweigh the **small added cancer risk**, especially in urgent or critical cases. - **Recommendations for Safer Use**: - **Reducing Unnecessary Imaging**: Avoiding CT scans that are not medically necessary can help lower overall radiation exposure. - **Minimizing Radiation Dose**: Using the **lowest radiation dose possible** for effective imaging can reduce long-term risks. - **Special Considerations for Children**: Pediatric patients, especially infants, should be given extra care in minimizing radiation exposure due to their higher sensitivity. ### Conclusion: CT scans are indispensable tools in modern medicine, but their increasing use raises valid concerns about long-term cancer risks. The study underscores the need for judicious use of CT imaging, particularly in vulnerable populations such as children and frequent users like older adults. By optimizing scanning practices and reducing unnecessary exposure, healthcare providers can continue to maximize the diagnostic benefits of CT scans while minimizing potential risks.

Four Key Genes Linked to Worse Gastric Cancer Outcomes

The four key genes linked to worse gastric cancer outcomes, as identified by new research from Brazil, are **BRCA2, CDH1, RHOA, and TP53**. Here’s a detailed breakdown of their significance: ### 1. **BRCA2** - **Role in Cancer**: BRCA2 is well-known for its involvement in breast and ovarian cancers. It plays a critical role in DNA repair, and mutations in this gene can lead to genomic instability, which promotes cancer development. - **Impact on Gastric Cancer**: In the context of gastric cancer, BRCA2 mutations are associated with higher chances of recurrence and death, contributing to worse disease-free and overall survival. ### 2. **CDH1** - **Role in Cancer**: CDH1 is linked to hereditary diffuse gastric cancer and encodes a protein called E-cadherin, which is important for cell adhesion. Mutations in CDH1 disrupt cell-to-cell communication, making it easier for cancer cells to invade and metastasize. - **Impact on Gastric Cancer**: CDH1 mutations are strongly associated with aggressive forms of gastric cancer, leading to poorer prognoses. ### 3. **RHOA** - **Role in Cancer**: RHOA is involved in regulating cell shape, movement, and the cytoskeleton. Alterations in this gene can promote cancer cell migration and invasion. - **Impact on Gastric Cancer**: Mutations in RHOA contribute to cancer progression by enhancing the ability of cancer cells to spread, worsening outcomes for patients. ### 4. **TP53** - **Role in Cancer**: TP53 is one of the most frequently mutated genes in all human cancers. It encodes the p53 protein, which acts as a tumor suppressor by regulating cell cycle arrest, DNA repair, and apoptosis. - **Impact on Gastric Cancer**: Mutations in TP53 disable its tumor-suppressing functions, allowing cancer cells to grow uncontrollably, leading to more aggressive disease and worse survival rates. ### Key Findings from the Research: - **Independent and Combined Effects**: Each of these genes is individually associated with a poorer prognosis in gastric cancer. However, the presence of mutations in multiple genes further increases the risk of recurrence and death. - **Prevalence**: About one-third of the patients in the study carried mutations in at least one of these genes. - **Treatment Implications**: Even with surgery, chemotherapy, and immunotherapy, patients with these mutations had worse disease-free and overall survival compared to those without them. ### Implications for Precision Oncology: - The study suggests that gastric cancer can arise through multiple pathways, and some cases are inherently more aggressive due to these genetic mutations. - **Personalized Treatment**: Identifying these mutations in patients can help guide precision oncology. High-risk patients with these mutations may benefit from more aggressive treatment strategies, while low-risk patients could avoid unnecessary side effects from intensive therapies. This research highlights the importance of genetic testing in gastric cancer to improve prognostic accuracy and tailor treatments to individual patients.

Catching Gastric Cancer early

Catching gastric cancer early is critically important for improving survival outcomes, especially given the poor prognosis associated with late-stage diagnosis. Early detection involves a structured, multidisciplinary approach that includes risk assessment, high-quality endoscopic techniques, and effective surveillance strategies. Below are the key steps and considerations for catching gastric cancer early: --- ### **1. Risk Assessment** - **Identify High-Risk Populations**: Certain groups are at significantly higher risk for gastric cancer. These include: - Individuals of Hispanic and Asian descent. - Immigrants from countries with high gastric cancer incidence (e.g., Japan, Korea, China, and parts of Latin America). - Patients with a family history of gastric cancer or hereditary cancer syndromes (e.g., hereditary diffuse gastric cancer). - Those with Helicobacter pylori infection, which is a major risk factor for gastric cancer development. - Patients with gastric premalignant conditions such as atrophic gastritis, gastric intestinal metaplasia, dysplasia, and epithelial polyps. - **Risk Stratification**: Clinicians should assess risk factors during pre-endoscopy evaluations and prioritize screening for high-risk individuals. --- ### **2. Early Detection Through Screening** - **Programmatic Screening**: Countries in Asia, such as Japan and Korea, have established nationwide gastric cancer screening programs that detect cancer at earlier stages. These programs rely heavily on endoscopy and have significantly improved survival rates. The U.S. does not have similar programs, but targeted screening for high-risk groups could yield similar benefits. - **Endoscopic Surveillance**: Patients with premalignant conditions (e.g., gastric intestinal metaplasia or dysplasia) should undergo regular surveillance with upper endoscopy to monitor for progression to gastric cancer. --- ### **3. High-Quality Endoscopy Techniques** - **Pre-Endoscopy Preparation**: - Use mucosal cleaning agents such as simethicone to enhance visualization. - Ensure adequate CO₂ insufflation for proper distension of the stomach. - **During Endoscopy**: - **Meticulous Technique**: Employ careful inspection of the gastric mucosa to identify subtle abnormalities. - **Photo Documentation**: Capture images of all areas, especially suspicious lesions, to facilitate accurate diagnosis and follow-up. - **Biopsy Protocol**: Use the Sydney biopsy protocol, which involves systematic sampling of the gastric mucosa to detect premalignant changes and early cancer. - **Withdrawal Time**: Ensure a withdrawal time of six to seven minutes, as shorter durations reduce detection rates. This allows for thorough examination of the gastric mucosa. --- ### **4. Post-Endoscopy Follow-Up** - **Pathology Collaboration**: - Work closely with skilled gastrointestinal pathologists to interpret biopsy results accurately. - Utilize validated histologic staging systems such as OLGA (Operative Link on Gastritis Assessment) and OLGIM (Operative Link on Gastric Intestinal Metaplasia) to stage premalignant conditions and guide surveillance intervals. - **Surveillance and Monitoring**: - Patients with premalignant conditions should be enrolled in regular surveillance programs to monitor for progression. - Follow-up intervals should be based on the severity of histologic findings (e.g., more frequent surveillance for high-grade dysplasia). --- ### **5. Addressing Disparities** - **Targeted Outreach**: High-risk populations, such as immigrants and ethnic minorities, often face barriers to care. Clinicians should focus on reducing disparities by increasing access to screening and surveillance programs for these groups. - **Education and Awareness**: Educating patients about the importance of early detection and the role of endoscopy can encourage adherence to recommended screening protocols. --- ### **6. Prevention Strategies** - **Eradication of Helicobacter pylori**: Treating H. pylori infection can significantly reduce the risk of gastric cancer in individuals with chronic gastritis or other risk factors. - **Lifestyle Modifications**: Encourage patients to adopt healthy dietary habits (e.g., reducing salt and processed food intake), avoid smoking, and limit alcohol consumption. --- ### **Impact of Early Detection** When gastric cancer is detected early: - Treatment options are more effective, often involving endoscopic resection or surgery with curative intent. - The 5-year survival rate improves dramatically, sometimes exceeding 90% for early-stage disease. - Patients avoid the challenges of managing advanced, metastatic disease, which has a much poorer prognosis. By adhering to structured guidelines, such as those emphasized by the American College of Gastroenterology (ACG) and the American Society for Gastrointestinal Endoscopy (ASGE), clinicians can improve early detection rates, reduce missed lesions, and ultimately improve survival outcomes for patients with gastric cancer.

ATOMIC Trial – PD-L1 pulse FOLFOX as adjuvant in CRC

The **ATOMIC trial** evaluated the efficacy of combining the PD-L1 inhibitor **atezolizumab** with standard adjuvant chemotherapy (**FOLFOX**) in patients with **stage III colon cancer** that is **mismatch repair-deficient (dMMR)** or **microsatellite instability-high (MSI-high)**. Below is a detailed breakdown of the trial and its findings: --- ### **Key Details of the ATOMIC Trial** #### **Study Design** - **Population:** 712 patients with **stage III colon cancer** that is **dMMR/MSI-high**. - **Intervention Groups:** - **Control arm:** FOLFOX alone for 6 months. - **Experimental arm:** FOLFOX + atezolizumab for 6 months, followed by **atezolizumab alone** for an additional 6 months. - **Primary Endpoint:** **Disease-Free Survival (DFS)** — the time patients remain free of cancer recurrence or progression. --- #### **Results** - **DFS Rates:** - Patients receiving **atezolizumab + FOLFOX** had a **DFS of 86.4%**. - Patients receiving **FOLFOX alone** had a **DFS of 76.6%**. - **Conclusion:** The addition of atezolizumab to FOLFOX significantly improved DFS, demonstrating a **strong survival benefit** for the immunotherapy combination. - **Hazard Ratio (HR):** The trial showed a robust HR favoring the combination therapy, indicating reduced risk of recurrence or progression with atezolizumab. --- ### **Implications** 1. **Potential New Standard of Care:** - The findings suggest that **atezolizumab + FOLFOX** could become the **new adjuvant standard** for patients with **stage III dMMR/MSI-high colon cancer**. - This is particularly relevant because **dMMR/MSI-high colon cancer** represents a subset (~10%) of all colon cancers. 2. **Practice-Changing Potential:** - The trial highlights the importance of **immune checkpoint inhibitors** like atezolizumab in the adjuvant setting for colon cancer patients with dMMR/MSI-high tumors, a group that is highly responsive to immunotherapy due to their immunogenic nature. --- ### **Remaining Questions** While the ATOMIC trial provides compelling evidence for the combination therapy, several questions remain unanswered: 1. **Duration of Chemotherapy:** - Is **6 months** of FOLFOX necessary, or could **3 months** (as increasingly common in practice) suffice? - Shorter chemotherapy durations might reduce toxicity without compromising efficacy. 2. **Role of Atezolizumab Alone:** - Could **atezolizumab alone** (without FOLFOX) be just as effective for these patients, given the strong immunogenicity of dMMR/MSI-high tumors? 3. **Optimal Duration of Atezolizumab:** - Should atezolizumab be administered for **6 months**, **12 months**, or even **24 months**? Longer durations might improve outcomes but raise concerns about toxicity and cost. 4. **Toxicity and Cost:** - What are the long-term side effects and financial implications of adding atezolizumab to standard chemotherapy? --- ### **Significance** Although only ~10% of colon cancers are **dMMR/MSI-high**, this trial has the potential to **change clinical practice** for this subgroup. The combination of immunotherapy with chemotherapy represents a promising strategy to improve outcomes in patients with this specific molecular profile.

Age and Oxaliplatin in CRC chemotherapeutic regime

The use of oxaliplatin in chemotherapy for colorectal cancer (CRC) varies in effectiveness depending on the stage of the disease and the age of the patient. Here's a detailed breakdown based on the findings: ### **Stage II Colorectal Cancer (CRC):** - **Effectiveness of Oxaliplatin:** Adding oxaliplatin to chemotherapy does **not improve survival** for patients with stage II CRC, regardless of age. - **Clinical Implication:** Oxaliplatin is not recommended for stage II CRC patients as it does not provide a survival benefit. ### **Stage III Colorectal Cancer (CRC):** - **Patients 70 Years or Younger:** - **Survival Benefit:** Oxaliplatin significantly improves survival in younger patients with stage III CRC. - **5-Year Survival Rates:** - With oxaliplatin: **85%** - Without oxaliplatin (chemotherapy alone): **78%** - **Clinical Implication:** Oxaliplatin is beneficial and should be considered as part of the chemotherapeutic regime for stage III CRC patients under 70. - **Patients Over 70 Years:** - **Survival Benefit:** Oxaliplatin provides **no clear survival benefit** for older patients with stage III CRC. - **5-Year Survival Rates:** - With oxaliplatin: **71%** - Without oxaliplatin (chemotherapy alone): **68%** - **Treatment Challenges:** Older patients are more likely to stop treatment early (37% vs 24% in younger patients), and early discontinuation is linked to worse survival outcomes. - **Clinical Implication:** Doctors should be cautious about prescribing oxaliplatin to patients over 70, as the benefits are limited and the risk of treatment discontinuation is higher. ### **Key Considerations for Older Patients:** - **Frailty:** The physical condition and resilience of the patient should be assessed before including oxaliplatin. - **Organ Health:** Liver, kidney, and other organ functions should be evaluated, as chemotherapy can be taxing on these systems. - **Support Systems:** The availability of caregivers or a robust support system can influence the patient's ability to complete treatment. - **Individualized Approach:** Age alone should not dictate treatment decisions. Physicians should weigh the risks and benefits based on the patient's overall health and circumstances. ### **Conclusion:** - **Stage II CRC:** Oxaliplatin is not recommended for any age group. - **Stage III CRC:** Oxaliplatin improves survival in patients aged 70 or younger but offers limited benefit for those over 70. Careful consideration of the patient's health status and likelihood of completing treatment is essential for older patients.