The second week of January 2026 brings together a distinctly translational and practice-shaping set of discussions in GI oncology, spanning fundamental cancer biology, biomarker-driven decision-making, real-world evidence, and evolving multidisciplinary strategies. This week’s selected posts reflect how progress in GI oncology increasingly depends on contextual understanding—of tumor biology, patient fitness, disease dynamics, and timing—rather than on single markers or isolated interventions.
Across pancreatic, colorectal, gastric, biliary, and esophageal cancers, contributors highlight the limits of reductionist thinking: KRAS mutations without context do not define malignancy; immune activation alone does not guarantee response; and aggressive local or systemic strategies require careful biological and temporal selection. From neoadjuvant immunotherapy in pMMR colon cancer and ctDNA-guided adjuvant decisions, to organ-sparing concepts in gastric cancer, liver transplantation for colorectal liver metastases, and nutrition as a determinant of chemotherapy delivery in PDAC, these posts emphasize stratification, feasibility, and patient-centered judgment.
Together, this week’s voices underscore a shared message as 2026 begins: meaningful advances in GI oncology will come not only from new drugs or technologies, but from integrating biology, biomarkers, multidisciplinary coordination, and real-world constraints into coherent, rational treatment strategies tailored to the right patient at the right time.
Nelson Dusetti – Research Director, INSERM | Pancreatic Cancer & Translational Oncology | Co-founder of Predicting Med, developing transcriptomic tools for precision oncology
“I’m sharing our recently published review addressing a long-standing question in pancreatic cancer research: why an oncogenic KRAS mutation is not sufficient, on its own, to induce and sustain malignant transformation.
In PDAC, KRAS mutations are almost universal, yet tumor initiation and progression depend on the biological and genetic context in which KRAS operates. This review brings together mechanistic, experimental and translational studies showing how cooperative alterations (tumor suppressors, telomerase, MYC, microenvironmental cues) are required to overcome senescence and enable malignancy.
We hope this work contributes to a clearer framework for understanding KRAS-driven cancers and helps support ongoing discussion around more rational, context-aware therapeutic strategies in translational research.”
Gertjan Rasschaert – MD, Consultant GI Oncology, UZ Leuven | Colorectal Cancer Research, Tejpar Lab KU Leuven | Clinical Trials
“Today was a good day! Thank you American Society of Clinical Oncology (ASCO) for the opportunity to present our research with an oral communication at ASCO GI26 in San Francisco.
Liver transplantation (LTx) for unresectable colorectal liver metastases (uCLM).
Pooled real-world data from all Belgian liver transplant centers:29 patients
- Median duration of chemotherapy before LTx: 13 months
- Median follow-up: 20.5 months
- 11 recurrences, mainly pulmonary
- Median time to recurrence: 6.3 months
- 2-year OS: 90.1% (95% CI 74.4–100)
- 2-year RFS: 54.8% (95% CI 37.3–80.1)
- Median OS after recurrence: 26.5 months
2 pMMR, BRAF V600E mt patients with more than 4 years of follow-up without recurrence
We need harmonized and strict selection protocols in order to improve these outcomes!
Our newly established Belgian protocol is the first LTx indication where there is national consensus on selection criteria across all 6 accredited LTx centers.
We created a national independent validation committee as per TransMet.
Two main criteria:
- Unresectable CLM as per expert surgeon agreement.
- No (history) of metastatic disease beyond the liver.
Two strict requirements:
- Minimum 6 months of partial response and/or stable disease on the same treatment line.
- Mandatory 8-week therapeutic pause with no progression beyond the liver. This period may be used to resect the primary tumor.
With a stricter ‘test of time’, we believe the nasty biologies will be filtered out naturally. Thus, no need for discrimination based only on point mutations or histology. Time will tell.
Belgium, a country of only 11 million people, has more than 300 LTx patients per year (and increasing). We anticipate transplanting 15 uCLM cases per year across Belgium with these criteria, through both patient offer and center offer, DBD and DCD. When listed, 28 MELD points are granted. We anticipate transplantation within 1–2 months after listing.
With a mortality of around 12% on the Belgian waiting list for LTx, we do take these cases seriously and respect other (mostly benign) treatment indications.”
Myriam Chalabi – Medical Oncologist / Clinical Group Leader, Netherlands Cancer Institute
“Excited, happy and proud to share our Nature publication on the effects of neoadjuvant immune checkpoint blockade in MMR-proficient colon cancer Nature Magazine; part of the NICHE platform! In this paper, we provide validation of previous clinical results, plus extensive and comprehensive analyses of the tumor microenvironment of pMMR tumors.
Below a few highlights.We show that the combination of nivolumab plus ipilimumab led to a 26% response rate, including deep pathologic responses. Circulating tumor DNA concentrations were also associated with clinical staging Natera Oncology. Importantly, responses were seen across clinical stages, and responses were also strongly associated with ctDNA clearance.
Using whole exome sequencing, imaging mass cytometry, bulk RNA sequencing and single-cell RNA sequencing, we investigated features associated with response, providing novel insights into pMMR colon neoadjuvant ICB response.
While all patients had a low TMB, responders had higher chromosomal instability and whole genome duplications, pointing to distinct genomic vulnerabilities. Responders were enriched for TP53 mutations, while KRAS G12 mutations were associated with non-response. For the first time, we provide genomic features of pMMR colon cancers that are easily attainable and may be useful in selecting patients for future trials.On a transcriptomics level, we found that responders had significantly higher proliferation signatures, while baseline inflammation signatures were not significantly different between responders and nonr-responders. On a cellular level, IMC showed higher proliferation in both cancer cells and lymphoid cells in responders compared to non-responders. Using both IMC and scRNAseq we also found a higher proportion of Ki67+ and CD103+ CD8 T cells in responders, and these populations were enriched for dysfunctional tumor reactive phenotypes, indicating likely involvement in tumor control.
Importantly, immune activation was observed in both responders and non-responders post-treatment, indicating this is not the predominant mechanism for resistance.
Altogether, our work sheds light on features associated with response in pMMR colon cancer and warrant further investigation of neoadjuvant combination ICB.The landscape for patients with MMR-deficient tumors has changed globally since the NICHE(-2) trial. And now it’s time to improve outcomes for patients with pMMR colon cancer. Our work is far from done!”
Omnia Korani – Passionate Medical Oncologist | Lecturer at National Cancer Institute | ESMO Certified | ESCO Graduate | ESGO member | ASCO Member | ESO Ambassador | Dedicated to Improving Patient QOL and Outcomes
” Precision oncology in action: ctDNA guiding benefit from adjuvant therapy
Only 18.4% of patients were ctDNA-positive, yet this subgroup experienced significantly worse outcomes, with ctDNA positivity strongly associated with inferior survival:
- Disease-free survival: aHR = 6.12 (95% CI 4.66–8.03)
- Overall survival: aHR = 5.86 (95% CI 4.19–8.19)
Interestingly, within this high-risk ctDNA-positive group, celecoxib use was associated with meaningful survival benefit compared with placebo:
- Improved DFS: aHR = 0.61 (95% CI 0.42–0.89)
- Improved OS: aHR = 0.62 (95% CI 0.40–0.96)
In contrast, ctDNA-negative patients did not derive benefit from celecoxib, with no significant improvement in:
- DFS (aHR = 0.76; 95% CI 0.53–1.09; P = 0.41)
- OS (aHR = 0.85; 95% CI 0.54–1.36; P = 0.33)
Notably, this pattern remained consistent even after stratification by microsatellite instability and PIK3CA mutation status, reinforcing the potential role of ctDNA as a predictive biomarker rather than merely prognostic.”
Lucjan Wyrwicz – Professor, Narodowy Instytut Onkologii im. Marii Skłodowskiej-Curie – Państwowy Instytut Badawczy
“True pleasure to visit San Francisco to attend ASCO GI Congress, the major US meeting devoted to research and treatment of gastrointestinal malignancies. Giving a lecture here during the educational session is associated with some stress, even for a lecturer giving 50+ scientific or educational talks per year. I would like to thank ASCO and the scientific faculty for their kind invitation to share our European view on organ-sparing treatment of subtypes of gastric cancer. This was a challenging task since such approach is not yet a standard of care neither in Narodowy Instytut Onkologii im. Marii Skłodowskiej-Curie – Państwowy Instytut Badawczy nor US-based hospitals.”
Gabriele Capurso – Associate Professor of Gastroenterology, Deputy Director Pancreas Center, IRCCS San Raffaele; General Secretary, European Pancreatic Club (EPC)
“I am very proud of our new study published on Clinical Nutrition!
Impact of Nutritional Status on Chemotherapy Delivery and Outcomes in Advanced Pancreatic CancerIt is the first prospective multicenter study focused on the impact of nutrition on the possibility to deliver chemotherapy in advanced pancreatic cancer.
Key findings:
- 140 patients with advanced PDAC underwent baseline nutritional and QoL assessments, including the Mini Nutritional Assessment (MNA), EORTC-PAN26, and Functional Assessment of Anorexia/Cachexia Therapy subscale (FAACT-A/CS).
- Poor nutritional status is common in advanced pancreatic cancer (33.6% malnourished).
- Malnutrition negatively affects chemotherapy delivery, as higher MNA and EORTC-PAN26 scores were associated with better relative dose intensity of chemotherapy.
- Worse nutritional status was also associated with poorer clinical outcomes, as FAACT-A/CS < 28 was independently associated with shorter OS with an HR = 1.90.
Take Home:
Nutritional assessment with several specific tools should be an integral part of routine care. Next step, nutritional intervention in patients at higher risk?I am proud and truly thankful to share this work with my colleagues at the Pancreas Center HSR that coordinated the study and with the awesome Pancreas 2000 group within EPC – European Pancreatic Club. Teamwork makes the difference.”
Anthony Turpin – MD, PhD, GI Oncologist, Lille University Hospital
“Very happy to have presented the results of the ALTOPANC study during the ASCO-Gastro-intestinal Cancer #GI26 Symposium in the Mini-Oral Session.
Patients with oligometastatic pancreatic adenocarcinoma may benefit from metastases-directed therapies, particularly radiofrequency.
This study is the largest real-world cohort (155 patients) focusing on this topic.
We propose the ALTOPANC score based on CA19-9, number of oligometastases and their site, to better select the patients.A great collaborative work between medical oncologists and surgeons in France and Belgium.
A special thank to Pauline Parent, Victoria Pacquement, Sara El Kurdi, Prof Pascal Hammel, Stephanie Truant, and Giraud in Lille and Paris.”
Gagan Brar – GI Medical Oncologist with a research focus in biliary tract cancer and colorectal cancer, City of Hope
“Better than BILCAP?
Adjuvant anti-PD-1 + capecitabine in resected iCCA mRFS similar to per protocol analysis of adj. cape monotx, mOS NR
not better, perhaps related to micromets at dx Should we be pushing neoadj tx strategies instead?”
Arndt Vogel – Clinician-Scientist, ESMO Ambassador, focused on Liver Cancer and Precision Oncology, Toronto General Hospital / Princess Margaret Cancer Center (Canada) and MHH (Germany)
“First-line tiragolumab plus atezolizumab & CTx in pts with previously untreated, locally advanced unresectable or metastatic oesophageal cancer
- MORPHEUS-EC ph1b/2 trial
- mOS 10·9 vs 11·4 vs 8·7 mo
support the benefit of tiragolumab in combi with atezolizumab & CTx”
Erman Akkus – Medical Oncologist, Gastrointestinal Oncology
“Nivolumab with definitive chemoradiotherapy for oesophageal squamous cell carcinoma (NOBEL): a multicentre, single-arm, phase 2 feasibility trial – eClinicalMedicine”
Find out 10 Must-Read Posts in GI Oncology from the First week of December on OncoDaily.