Abstract 1727: CD8+ T cells in the invasive margin combined with FOXP3+ T cells in the tumor center significantly associate with survival in resectable gastric cancer, a post-hoc analysis of the Dutch D1/D2 trial

Introduction: In gastric cancer, studies of tumor infiltrating lymphocytes as a prognostic biomarker show contradictory results. These results may be caused by use of variable immunohistochemistry (IHC) quantification techniques, different marker selections and particularly inconsistency in the evaluated tumor regions. To overcome these issues, we performed a comprehensive digital image analysis of 5 immune cell markers for their prognostic value in a cohort of gastric cancer patients who were treated with surgery only in the Dutch D1/D2 trial.

Methods: All available surgical resection specimens of gastric cancer patients were included in this study (N=251). IHC for T-cell markers CD3, CD45RO, CD8, FOXP3 and Granzyme B was performed on serial slides. After manual annotation of the tumor area, an invasive margin was defined as 0.5 mm into the tumor still containing tumor cells (inner margin, IM) and 0.5 mm outside of the tumor not containing tumor cells (outer margin, OM). The density of positive immune cells (cells/mm2) was digitally quantified using QuPath for each 0.5x0.5 mm2 square across tumor center (TC), IM and OM, separately. A classification and regression tree (CART) model was employed to identify an optimal combination of prognostic markers from the continuous immune cell density variables with cancer specific survival (CSS) as outcome.

Results: The CART decision tree identified CD8 OM (≥798 cells/mm2) as most dominant prognostic factor, followed by FOXP3 TC (≥20 cells/mm2) in the CD8 OM low subset. This resulted in 3 CART branches in the decision tree: CD8 OM high with best prognosis, CD8 OM low/FOXP3 TC high with intermediate prognosis, and CD8 OM low/FOXP3 TC low with worst prognosis (Log-rank P-value <0.0001). The CD8 OM high branch was enriched in EBV+ (38.2%) and MSI-high (17.6%) tumors, compared to the other two branches with poorer prognosis (4.2% and 3.4% for EBV+, 7.9% and 8.4% for MSI-high). The CART model was an independent predictor of CSS in a multivariable cox-regression (HR branch 2 vs 1: 4.87, 95% CI 1.96-12.07 and HR branch 3 vs 1: 7.97, 95% CI 3.20-19.86), which included T stage, N stage, Lauren subtype, EBV-status and MSI-status. The performance of the CART model was assessed by 5-fold cross-validation, where 4 out of 5 models reached a P-value < 0.05 (Likelihood-Ratio test).

Conclusions: The OM in gastric cancer contains previously overlooked important prognostic information valuable for immune biomarker studies. The combination of CD8 OM and FOXP3 TC is identified as strongest prognostic factor in the risk stratification of resectable gastric cancer, and is independent of T stage, N stage, EBV-status, MSI-status and Lauren subtype. Moreover, high T-cell densities found in a proportion of EBV-/MSS tumors support further investigation of response to immunotherapy in these subgroups.

Citation Format: Tanya T. Soeratram, Hedde D. Biesma, Jacqueline M. Egthuijsen, Elma Meershoek-Klein Kranenbarg, Henk H. Hartgrink, Cornelis J. van de Velde, Erik van Dijk, Yongsoo Kim, Bauke Ylstra, Hanneke W. van Laarhoven, Nicole C. van Grieken. CD8+ T cells in the invasive margin combined with FOXP3+ T cells in the tumor center significantly associate with survival in resectable gastric cancer, a post-hoc analysis of the Dutch D1/D2 trial [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 1727.

Selection of optimal molecular targets for tumor-specific imaging in pancreatic ductal adenocarcinoma

Discrimination of pancreatic ductal adenocarcinoma (PDAC) from chronic pancreatitis (CP) or peritumoral inflammation is challenging, both at preoperative imaging and during surgery, but it is crucial for proper therapy selection. Tumor-specific molecular imaging aims to enhance this discrimination and to help select and stratify patients for resection. We evaluated various biomarkers for the specific identification of PDAC and associated lymph node metastases. Using immunohistochemistry (IHC), expression levels and patterns were investigated of integrin αvβ6, carcinoembryonic antigen-related cell adhesion molecule 5 (CEACAM5), Cathepsin E (Cath E), epidermal growth factor receptor (EGFR), hepatocyte growth factor receptor (c-MET), thymocyte differentiation antigen 1 (Thy1), and urokinase-type plasminogen activator receptor (uPAR). In a first cohort, multiple types of pancreatic tissue were evaluated (n=62); normal pancreatic tissue (n=8), CP (n=7), PDAC (n=9), tumor associated lymph nodes (n=32), and PDAC after neoadjuvant radiochemotherapy (n=6). In a second cohort, tissues were investigated (n=55) with IHC and immunofluorescence (IF) for concordance of biomarker expression in all tissue types, obtained from an individual patient. Integrin αvβ6 and CEACAM5 showed significantly higher expression levels in PDAC versus normal pancreatic tissue (P=0.001 and P<0.001, respectively) and CP (P=0.003 and P<0.001, respectively). Avβ6 and CEACAM5 expression identified tumor-positive lymph nodes correctly in 84% and 68%, respectively, and in 100% of tumor-negative nodes for both biomarkers. In conclusion, αvβ6 and CEACAM5 are excellent biomarkers to differentiate PDAC from surrounding tissue and to identify lymph node metastases. Individually or combined, these biomarkers are promising targets for tumor-specific molecular imaging of PDAC.

An International Collaborative Standardizing a Comprehensive Patient-Centered Outcomes Measurement Set for Colorectal Cancer

IMPORTANCE

Global health systems are shifting toward value-based care in an effort to drive better outcomes in the setting of rising health care costs. This shift requires a common definition of value, starting with the outcomes that matter most to patients.

OBJECTIVE

The International Consortium for Health Outcomes Measurement (ICHOM), a nonprofit initiative, was formed to define standard sets of outcomes by medical condition. In this article, we report the efforts of ICHOM's working group in colorectal cancer.

EVIDENCE REVIEW

The working group was composed of multidisciplinary oncology specialists in medicine, surgery, radiation therapy, palliative care, nursing, and pathology, along with patient representatives. Through a modified Delphi process during 8 months (July 8, 2015 to February 29, 2016), ICHOM led the working group to a consensus on a final recommended standard set. The process was supported by a systematic PubMed literature review (1042 randomized clinical trials and guidelines from June 3, 2005, to June 3, 2015), a patient focus group (11 patients with early and metastatic colorectal cancer convened during a teleconference in August 2015), and a patient validation survey (among 276 patients with and survivors of colorectal cancer between October 15, 2015, and November 4, 2015).

FINDINGS

After consolidating findings of the literature review and focus group meeting, a list of 40 outcomes was presented to the WG and underwent voting. The final recommendation includes outcomes in the following categories: survival and disease control, disutility of care, degree of health, and quality of death. Selected case-mix factors were recommended to be collected at baseline to facilitate comparison of results across treatments and health care professionals.

CONCLUSIONS

A standardized set of patient-centered outcome measures to inform value-based health care in colorectal cancer was developed. Pilot efforts are under way to measure the standard set among members of the working group.

Highlights from the seventh European Multidisciplinary Colorectal Cancer Congress (EMCCC) 2014

It is widely recognised that colorectal cancer has become a complex disease and involves many medical disciplines. The mission of the European Multidisciplinary Colorectal Cancer Congress (EMCCC), which is an initiative of the Dutch Colorectal Cancer Group (DCCG), is to facilitate the interaction between relevant disciplines on current issues of research. The three-day meeting in Amsterdam in November 2014 assembled approximately 450 participants with nine different disciplines from 38 countries worldwide. On day one, workshops on imaging, surgery, medical oncology/pathology, radiotherapy, and genetics were followed by the keynote lecture of the congress. On day two and three, a total of 35 established international opinion leaders presented lectures in plenary sessions on prevention and screening of early colorectal cancer, genetics, translational research, biomarkers, organ-saving treatment in rectal cancer, current controversies, and multidisciplinary management. Posters from submitted abstracts were displayed, with selected abstracts being orally presented.

Modern Treatment of Rectal Cancer Closes the Gap Between Common Adenocarcinoma and Mucinous Carcinoma

BACKGROUND

Mucinous carcinoma (MC) is a distinct form of rectal cancer (RC) comprising 10 % of all cases and has been associated with an impaired prognosis compared with non-mucinous adenocarcinoma (AC). The benefit of today's modern treatment for MC patients is unknown but a prospective randomized trial to answer this does not seem feasible. This study provides an analysis of the modern treatment of rectal MC and efficacy of preoperative therapies for MC patients.

METHODS

Data from three large (trial) cohorts were used. Data from the Netherlands Cancer Registry (NCR) were used to analyze the prognosis of RC patients over time (N = 38,035). To study the benefit of preoperative short-term radiotherapy, patients from the total mesorectal excision (TME) trial (N = 1,530) were selected, and the benefit from preoperative chemoradiotherapy was analyzed with data on 540 locally advanced RC (LARC) patients from two hospitals.

RESULTS

Data from the NCR confirmed that 5-year overall survival for MC was significantly worse from 1989 to 1998, but no longer different from AC from 1999 onwards. MC patients had a higher rate of positive circumferential resection margin than AC patients (TME trial 27.2 vs. 16.5 %, p = 0.006; LARC cohort 34.5 vs. 9.8 %, p < 0.0001), but there was no difference in outcome between MC and AC patients after preoperative short-term radiotherapy or chemoradiotherapy.

CONCLUSIONS

Modern treatment of RC has benefited MC patients, leading to equal survival for MC and AC patients. Enhancements in the fields of imaging and quality of surgery have improved outcome and preoperative therapies should be recommended for both histological subtypes.

Detailed examination of lymph nodes improves prognostication in colorectal cancer

Up to 30% of stage II patients with curatively resected colorectal cancer (CRC) will develop disease recurrence. We evaluated whether examination of lymph nodes by multilevel sectioning and immunohistochemical staining can improve prognostication. Lymph nodes (n = 780) from 36 CRC patients who had developed disease recurrence (cases) and 72 patients who showed no recurrence of disease for at least 5 years (controls) were analyzed. Sections of 4 levels at 200-microm interval were immunohistochemically stained for cytokeratin expression. The first level was analyzed by conventional and automated microscopy, and the 3 following levels were analyzed by automated microscopy for the presence of tumor cells. Overall, cases showed more micrometastases (3 patients) than controls (1 patient). Analysis of a second level led to the additional detection of 1 patient with micrometastases (case) and 1 patient with macrometastasis (case). Examining more levels only led to additional isolated tumor cells, which were equally divided between cases and controls. Likewise, automated microscopy resulted only in detection of additional isolated tumor cells when compared with conventional microscopy. In multivariate analysis, micrometastases [odds ratio (OR) 26.3, 95% confidence interval (CI) 1.9-364.8, p = 0.015], T4 stage (OR 4.8, 95% CI 1.4-16.7, p = 0.013) and number of lymph nodes (OR 0.9, 95% CI 0.8-1.0, p = 0.028) were independent predictors for disease recurrence. Lymph node analysis of 2 levels and immunohistochemical staining add to the detection of macrometastases and micrometastases in CRC. Micrometastases were found to be an independent predictor of disease recurrence. Isolated tumor cells were of no prognostic significance.

Cost-effectiveness of a short stay admission programme for breast cancer surgery

BACKGROUND

Short stay (admission, surgery, and discharge the same day or within 24 hours) following breast cancer surgery is part of an established care protocol but as yet not well implemented in Europe. Alongside a before-after multi-centre implementation study, an economic evaluation was performed exploring the cost-effectiveness of a short stay programme (SSP) versus care as usual (CAU).

MATERIAL AND METHODS

In the implementation study, 324 patients were included. In the economic evaluation a societal perspective was applied with a six week time horizon. Cost data were obtained from Case Record Forms and cost diaries. Effectiveness was assessed by calculating Quality Adjusted Life Years (QALYs), using the EuroQol-5D. Cost-effectiveness was expressed as the incremental costs per QALY.

RESULTS

Mean societal costs decreased by euro955,- (95% CI euro - 2104,- to euro157,-) for patients in SSP (n=127) compared with CAU (n=135). Mean healthcare costs differed euro883,- (95% CI euro - 1560,- to euro870,-) in favour of SSP. The incremental cost-effectiveness ratio could not be calculated due to similar effectiveness for both groups, i.e. the difference in QALYs was zero. The cost-effectiveness acceptability curves showed that the probability that SSP was more cost-effective than CAU was over 90% in the base-case analysis.

DISCUSSION

A short stay programme as implemented is cost-effective compared with care as usual. In achieving good and more efficient quality of care, larger scale implementation is warranted.

Effects of tamoxifen and exemestane on cognitive functioning of postmenopausal patients with breast cancer: results from the neuropsychological side study of the tamoxifen and exemestane adjuvant multinational trial

PURPOSE

To evaluate the influence of adjuvant tamoxifen and exemestane on cognitive functioning in postmenopausal patients with breast cancer (BC).

PATIENTS AND METHODS

Neuropsychological assessments were performed before the start (T1) and after 1 year of adjuvant endocrine treatment (T2) in Dutch postmenopausal patients with BC, who did not receive chemotherapy. Patients participated in the international Tamoxifen and Exemestane Adjuvant Multinational trial, a prospective randomized study investigating tamoxifen versus exemestane as adjuvant therapy for hormone-sensitive BC.

RESULTS

Participants included 80 tamoxifen users (mean age, 68.7 years; range 51 to 84), 99 exemestane users (mean age, 68.3 years; range, 50 to 82), and 120 healthy controls (mean age, 66.2 years; range, 49 to 86). At T2, after adjustment for T1 performance, exemestane users did not perform statistically significantly worse than healthy controls on any cognitive domain. In contrast, tamoxifen users performed statistically significantly worse than healthy controls on verbal memory (P < .01; Cohen's d = .43) and executive functioning (P = .01; Cohen's d = .40), and statistically significantly worse than exemestane users on information processing speed (P = .02; Cohen's d = .36). With respect to visual memory, working memory, verbal fluency, reaction speed, and motor speed, no significant differences between the three groups were found.

CONCLUSION

After 1 year of adjuvant therapy, tamoxifen use is associated with statistically significant lower functioning in verbal memory and executive functioning, whereas exemestane use is not associated with statistically significant lower cognitive functioning in postmenopausal patients with BC. Our results accentuate the need to include assessments of cognitive effects of adjuvant endocrine treatment in long-term safety studies.

Integrating chromosomal aberrations and gene expression profiles to dissect rectal tumorigenesis

Background

Accurate staging of rectal tumors is essential for making the correct treatment choice. In a previous study, we found that loss of 17p, 18q and gain of 8q, 13q and 20q could distinguish adenoma from carcinoma tissue and that gain of 1q was related to lymph node metastasis. In order to find markers for tumor staging, we searched for candidate genes on these specific chromosomes.

Methods

We performed gene expression microarray analysis on 79 rectal tumors and integrated these data with genomic data from the same sample series. We performed supervised analysis to find candidate genes on affected chromosomes and validated the results with qRT-PCR and immunohistochemistry.

Results

Integration of gene expression and chromosomal instability data revealed similarity between these two data types. Supervised analysis identified up-regulation of EFNA1 in cases with 1q gain, and EFNA1 expression was correlated with the expression of a target gene (VEGF). The BOP1 gene, involved in ribosome biogenesis and related to chromosomal instability, was over-expressed in cases with 8q gain. SMAD2 was the most down-regulated gene on 18q, and on 20q, STMN3 and TGIF2 were highly up-regulated. Immunohistochemistry for SMAD4 correlated with SMAD2 gene expression and 18q loss.

Conclusion

On basis of integrative analysis this study identified one well known CRC gene (SMAD2) and several other genes (EFNA1, BOP1, TGIF2 and STMN3) that possibly could be used for rectal cancer characterization.