Stromal localization of inactive CD8+ T cells in metastatic mismatch repair deficient colorectal cancer

BACKGROUND

The determinants of metastasis in mismatch repair deficiency with high levels of microsatellite instability (MSI-H) in colorectal cancer (CRC) are poorly understood. Here, we hypothesized that distinct immune and stromal microenvironments in primary tumors may discriminate between non-metastatic MSI-H CRC and metastatic MSI-H CRC.

METHODS

We profiled 46,727 single cells using high-plex imaging mass cytometry and analyzed both differential cell type abundance, and spatial distribution of fibroblasts and immune cells in primary CRC tumors with or without metastatic capacity. We validated our findings in a second independent cohort using immunohistochemistry.

RESULTS

High-plex imaging mass cytometry and hierarchical clustering based on microenvironmental markers separated primary MSI-H CRC tumors with and without metastatic capacity. Primary tumors with metastatic capacity displayed a high stromal content and low influx of CD8+ T cells, which expressed significantly lower levels of markers reflecting proliferation (Ki67) and antigen-experience (CD45RO) compared to CD8+ T cells in non-metastatic tumors. CD8+ T cells showed intra-epithelial localization in non-metastatic tumors, but stromal localization in metastatic tumors, which was validated in a second cohort.

CONCLUSION

We conclude that localization of phenotypically distinct CD8+ T cells within stroma may predict metastasis formation in MSI-H CRC.

Comparison of NTRK fusion detection methods in microsatellite-instability-high metastatic colorectal cancer

Tropomyosin receptor kinase (TRK) inhibitors have been approved for metastatic solid tumors harboring NTRK fusions, but the detection of NTRK fusions is challenging. International guidelines recommend pan-TRK immunohistochemistry (IHC) screening followed by next generation sequencing (NGS) in tumor types with low prevalence of NTRK fusions, including metastatic colorectal cancer (mCRC). RNA-based NGS is preferred, but is expensive, time-consuming, and extracting good-quality RNA from FFPE tissue is challenging. Alternatives in daily clinical practice are warranted. We assessed the diagnostic performance of RNA-NGS, FFPE-targeted locus capture (FFPE-TLC), fluorescence in situ hybridization (FISH), and the 5'/3' imbalance quantitative RT-PCR (qRT-PCR) after IHC screening in 268 patients with microsatellite-instability-high mCRC, the subgroup in which NTRK fusions are most prevalent (1-5%). A consensus result was determined after review of all assay results. In 16 IHC positive tumors, 10 NTRK fusions were detected. In 33 IHC negative samples, no additional transcribed NTRK fusions were found, underscoring the high sensitivity of IHC. Sensitivity of RNA-NGS, FFPE-TLC, FISH, and qRT-PCR was 90%, 90%, 78%, and 100%, respectively. Specificity was 100% for all assays. Robustness, defined as the percentage of samples that provided an interpretable result in the first run, was 100% for FFPE-TLC, yet more limited for RNA-NGS (85%), FISH (70%), and qRT-PCR (70%). Overall, we do not recommend FISH for the detection of NTRK fusions in mCRC due to its low sensitivity and limited robustness. We conclude that RNA-NGS, FFPE-TLC, and qRT-PCR are appropriate assays for NTRK fusion detection, after enrichment with pan-TRK IHC, in routine clinical practice.

Abstract 3358: PLCRC-PROVENC3: assessing the prognostic value of post-surgery liquid biopsy cell-free circulating tumor DNA in stage III colon cancer patients

Introduction: Surgery followed by adjuvant chemotherapy (ACT) is standard of care in stage III colon cancer. However, 50% of the patients would be cured by surgery alone and are being overtreated, while 30-35% will experience a recurrence despite adjuvant treatment, resulting in only 15-20% of the patients benefitting from ACT. Therefore, there is a need for prognostic biomarkers to better stratify this group of patients for ACT decisions. Recent observational and interventional studies in non-metastatic colon cancer have shown that detection of cell-free circulating tumor DNA (ctDNA) in blood after surgery is highly prognostic for development of recurrence. Hence, ctDNA analysis is a promising approach to guide treatment decisions in stage III colon cancer, but studies with large well-defined patient cohorts are needed to prove clinical utility.

Aim: Determine the prognostic value of ctDNA in stage III colon cancer patients treated with ACT to reduce futile treatment.

Methods: 241 stage III colon cancer patients treated with ACT were included in the prospective observational study “PROVENC3” (PROgnostic Value of Early Notification by Ctdna in Colon Cancer stage 3), a substudy of the Prospective Dutch Colorectal Cancer cohort (PLCRC). The PLCRC infrastructure accrued patients with colorectal cancer in 23 participating hospitals in the Netherlands. After informed consent, blood was collected pre-surgery, post-surgery, post-ACT and every six months up to 3 years. Tumor-informed detection of ctDNA was performed through integrated whole genome sequencing (WGS) analyses of formalin-fixed paraffin-embedded tumor tissue DNA (80x), germline DNA (40x), and plasma cell-free DNA (30x).

Results: Patient accrual was completed in 2021, with a median follow-up of 35.6 months. In total, 1090 blood samples have been collected to date. Analytical studies demonstrated a limit of detection of the test of 0.005% ctDNA utilizing contrived reference models derived from six independent cell lines, with a specificity of 99.6% across 119 noncancerous donor plasma specimens. From the PROVENC3 study, ctDNA analyses are ongoing for pre-surgery (n=68) and post-surgery (n=241 patients) blood samples. Preliminary results demonstrated a ctDNA detection rate of 93.4% pre-surgery and 17.1% post-surgery, which was associated with disease recurrence. Final analysis will enable determination of: 1) the proportion of ctDNA-positive/negative patients after surgery and the corresponding recurrence rates; 2) the prognostic value of post-surgery ctDNA; and 3) the lead time between post-surgery ctDNA detection and recurrence.

Future Perspective: Ultimately, the results of this study will be used to model and design a ctDNA-guided interventional trial in stage III colon cancer patients, to reduce futile ACT and its associated side-effects.

Citation Format: Carmen Rubio-Alarcon, Steven L. Ketelaars, Ingrid A. Franken, Sietske C. van Nassau, Dave E. van der Kruijssen, Suzanna J. Schraa, Theodora C. Linders, Pien Delis-van Diemen, Maartje Alkemade, Anne Bolijn, Marianne Tijssen, Margriet Lemmens, Miranda van Dongen, Mirthe Lanfermeijer, Annegien Broeks, Lana Meiqari, Linda J. Bosch, Victor E. Velculescu, Amy Greer, Samuel V. Angiuoli, Andrew Georgiadis, David Riley, James R. White, Christopher Greco, Liam Cox, Daan van den Broek, Cornelis J. Punt, Veerle M. Coupé, Miriam Koopman, Jeanine Roodhart, Gerrit A. Meijer, Mark Sausen, Geraldine R. Vink, Remond J. Fijneman. PLCRC-PROVENC3: assessing the prognostic value of post-surgery liquid biopsy cell-free circulating tumor DNA in stage III colon cancer patients [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 3358.

Cell-Free Circulating (Tumor) DNA before Surgery as a Prognostic Factor in Non-Metastatic Colorectal Cancer: A Systematic Review

Identification of non-metastatic colorectal cancer (CRC) patients with a high risk of recurrence after tumor resection is important to select patients who might benefit from adjuvant treatment. Cell-free DNA (cfDNA) and circulating tumor DNA (ctDNA) analyses after surgery are promising biomarkers to predict recurrence in these patients. However, these analyses face several challenges and do not allow guidance of neoadjuvant treatment, which might become a novel standard option in colon cancer treatment. The prognostic value of cfDNA/ctDNA before surgery is unclear. This systematic review aims to provide an overview of publications in which the prognostic value of presurgery cfDNA/ctDNA in non-metastatic CRC patients was studied and is performed according to PRISMA guidelines. A total of 29 out of 1233 articles were included and categorized into three groups that reflect the type of approach: measurement of cfDNA, ctDNA somatic alterations, and ctDNA methylation. Overall, a clear association between presurgery cfDNA/ctDNA and the outcome was not observed, but large studies that primarily focus on the prognostic value of presurgery cfDNA/ctDNA are lacking. Designing and performing studies that focus on the value of presurgery cfDNA/ctDNA is needed, in addition to standardization in the reporting of cfDNA/ctDNA results according to existing guidelines to improve comparability and interpretation among studies.

Abstract CT251: MEDOCC-CrEATE trial in progress: effectiveness of adjuvant chemotherapy in stage II colon cancer patients with positive circulating tumor DNA

Background Accurate detection of patients with minimal residual disease (MRD) after resection of localized colon cancer remains an unmet clinical need as these patients might benefit from adjuvant chemotherapy (ACT). For stage II colon cancer, ACT is only indicated in patients with a pT4 tumor without a deficient mismatch repair system (dMMR), according to Dutch guidelines. However, recurrence rate (RR) in stage II colon cancer is still 15-20%. Circulating tumor DNA (ctDNA), consisting of small fragments of DNA containing tumor-specific mutations, has been shown to be a promising biomarker for MRD and a strong predictor for recurrent disease when detectable after resection. The MEDOCC-CrEATE trial investigates how many stage II colon cancer patients with detectable ctDNA after surgery will accept ACT and whether ACT reduces RR in these patients.

Methods The MEDOCC-CrEATE study follows the ‘trials within cohorts' (TwiCs) design. Patients with colorectal cancer are included in the Prospective Dutch ColoRectal Cancer (PLCRC) cohort study and give informed consent for collection of clinical data and biomaterials, including tissue and blood samples. Additionally, patients are invited to give their consent for future randomization without being informed when allocated to the control group receiving standard of care. In MEDOCC-CrEATE 1320 stage II colon cancer patients without an indication for ACT will be included and randomized 1:1 into an experimental and a control arm. In the experimental arm, tissue and blood samples are analyzed after surgery for tissue-informed detection of plasma ctDNA, using the PGDx elio™ Platform. Patients with detectable ctDNA after surgery will be offered ACT consisting of 8 cycles of capecitabine plus oxaliplatin. Patients in the experimental arm without detectable ctDNA and patients in the control arm receive standard follow-up. The primary endpoint is the proportion of patients accepting ACT when ctDNA is detectable after resection. Most important secondary endpoint is 2-year RR, but also includes 5-year RR, disease free and overall survival, time to recurrence, quality of life and cost-effectiveness of the ctDNA-based treatment strategy. Data will be analyzed by intention to treat. To our knowledge, MEDOCC-CrEATE is the first trial in which a ctDNA guided strategy for adjuvant chemotherapy in colon cancer is investigated. The first patient was enrolled in August 2020. MEDOCC-CrEATE is now open for inclusion in 8 hospitals in the Netherlands. So far, 9 patients have been randomized. The number of participating hospitals will be expanded to 20-25 hospitals to include all 1320 patients within 3 years. MEDOCC-CrEATE has been registered in the Netherlands Trial Register: NL6281/NTR6455.

Citation Format: Suzanna J. Schraa, Karlijn L. Van Rooijen, Dave E. Van Der Kruijssen, Carmen Rubio Alarcón, Jillian Phallen, John Simmons, Sam Angiuoli, Amy E. Greer, Veerle M. Coupé, Helma M. Van Grevenstein, Sjoerd Elias, Helena M. Verkooijen, Miranda M. Van Dongen, Linda J. Bosch, Daan Van Den Broek, Gerrit A. Meijer, Victor E. Velculescu, Remond J. Fijneman, Geraldine R. Vink, Miriam Koopman. MEDOCC-CrEATE trial in progress: effectiveness of adjuvant chemotherapy in stage II colon cancer patients with positive circulating tumor DNA [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr CT251.

Circulating tumor DNA guided adjuvant chemotherapy in stage II colon cancer (MEDOCC-CrEATE): study protocol for a trial within a cohort study

BACKGROUND

Accurate detection of patients with minimal residual disease (MRD) after surgery for stage II colon cancer (CC) remains an urgent unmet clinical need to improve selection of patients who might benefit form adjuvant chemotherapy (ACT). Presence of circulating tumor DNA (ctDNA) is indicative for MRD and has high predictive value for recurrent disease. The MEDOCC-CrEATE trial investigates how many stage II CC patients with detectable ctDNA after surgery will accept ACT and whether ACT reduces the risk of recurrence in these patients.

METHODS/DESIGN

MEDOCC-CrEATE follows the 'trial within cohorts' (TwiCs) design. Patients with colorectal cancer (CRC) are included in the Prospective Dutch ColoRectal Cancer cohort (PLCRC) and give informed consent for collection of clinical data, tissue and blood samples, and consent for future randomization. MEDOCC-CrEATE is a subcohort within PLCRC consisting of 1320 stage II CC patients without indication for ACT according to current guidelines, who are randomized 1:1 into an experimental and a control arm. In the experimental arm, post-surgery blood samples and tissue are analyzed for tissue-informed detection of plasma ctDNA, using the PGDx elio™ platform. Patients with detectable ctDNA will be offered ACT consisting of 8 cycles of capecitabine plus oxaliplatin while patients without detectable ctDNA and patients in the control group will standard follow-up according to guideline. The primary endpoint is the proportion of patients receiving ACT when ctDNA is detectable after resection. The main secondary outcome is 2-year recurrence rate (RR), but also includes 5-year RR, disease free survival, overall survival, time to recurrence, quality of life and cost-effectiveness. Data will be analyzed by intention to treat.

DISCUSSION

The MEDOCC-CrEATE trial will provide insight into the willingness of stage II CC patients to be treated with ACT guided by ctDNA biomarker testing and whether ACT will prevent recurrences in a high-risk population. Use of the TwiCs design provides the opportunity to randomize patients before ctDNA measurement, avoiding ethical dilemmas of ctDNA status disclosure in the control group.

TRIAL REGISTRATION

Netherlands Trial Register: NL6281/NTR6455 . Registered 18 May 2017, https://www.trialregister.nl/trial/6281.

Relative dose intensity as a proxy measure of quality and prognosis in adjuvant chemotherapy for breast cancer in daily clinical practice

AIM

Adjuvant chemotherapy treatment of women with breast cancer is frequently complicated by toxic side-effects, resulting in dose reduction and delay. In Dutch guidelines, a relative dose intensity (RDI) of at least 85% is recommended for optimal treatment. The aim was to investigate predictors of low RDI and its effect on prognosis.

METHODS

All patients treated in the St. Antonius Hospital with adjuvant chemotherapy for breast cancer between 2008 and 2013 were included (N = 605). RDI was calculated for each single chemotherapeutic agent and for chemotherapy regimens in total. Incidence and causes of RDI <85% were studied, as well as the effect of RDI on prognosis.

RESULTS

About 10% of 605 patients had RDIs <85%. Predictive factors included age, episodes of febrile neutropenia and grade III or IV hypersensitivity reaction to taxanes. Other adverse events, such as peripheral neuropathy, did not affect RDI. The incidence of febrile neutropenia in the 5-fluorouracil, epirubicin, cyclofosfamide, docetaxel (FEC-D) protocol was 24% and therefore was above the threshold set by the European Organisation for Research and Treatment of Cancer for primary granulocyte colony-stimulating factor (G-CSF) prophylaxis. No relationship between RDI and (disease-free) survival was found with a median follow-up of 38 months. Apart from the stage of disease, obesity is a predictor of poor outcome.

CONCLUSIONS

RDI <85% is predicted by patients' age, febrile neutropenia and hypersensitivity reactions to taxanes. The incidence of febrile neutropenia in FEC-D treatment indicates primary prophylaxis with G-CSF following docetaxel treatment. No relationship was found between RDI and (disease-free) survival, but longer follow-up is needed.