Validation of the Prognostic Performance of Breast Cancer Index in Hormone Receptor-Positive Postmenopausal Breast Cancer Patients in the TEAM Trial

PURPOSE

Patients with early-stage hormone receptor-positive (HR+) breast cancer face a prolonged risk of recurrence even after adjuvant endocrine therapy. The Breast Cancer Index (BCI) is significantly prognostic for overall (0-10 years) and late (5-10 years) distant recurrence (DR) risk in N0 and N1 patients. Here, BCI prognostic performance was evaluated in HR+ postmenopausal women from the Tamoxifen and Exemestane Adjuvant Multinational (TEAM) trial.

EXPERIMENTAL DESIGN

3,544 patients were included in the analysis (N = 1,519 N0, N = 2,025 N+). BCI risk groups were calculated using pre-specified cutoff points. Kaplan-Meier analyses and log-rank tests were used to assess the prognostic significance of BCI risk groups based on DR. Hazard ratios (HR) and confidence intervals (CI) were calculated using Cox models with and without clinical covariates.

RESULTS

For overall 10-year DR, BCI was significantly prognostic in Ni0 (N = 1,196) and N1 (N = 1,234) patients who did not receive prior chemotherapy (P < 0.001). In patients who were DR-free for 5 years, 10-year late DR rates for low- and high-risk groups were 5.4% and 9.3% (N0 cohort, N = 1,285) and 4.8% and 12.2% (N1 cohort, N = 1,625) with multivariate HRs of 2.25 (95% CI, 1.30-3.88; P = 0.004) and 2.67 (95% CI, 1.53-4.63; P < 0.001), respectively. Late DR performance was substantially improved using previously optimized cutoff points, identifying BCI low-risk groups with even lower 10-year late DR rates of 3.8% and 2.7% in N0 and N1 patients, respectively.

CONCLUSIONS

The TEAM trial represents the largest prognostic validation study for BCI to date and provides a more representative assessment of late DR risk to guide individualized treatment decision-making for HR+ patients with early-stage breast cancer.

Locoregional Failure During and After Short-course Radiotherapy Followed by Chemotherapy and Surgery Compared With Long-course Chemoradiotherapy and Surgery: A 5-Year Follow-up of the RAPIDO Trial

OBJECTIVE

To analyze risk and patterns of locoregional failure (LRF) in patients of the RAPIDO trial at 5 years.

BACKGROUND

Multimodality treatment improves local control in rectal cancer. Total neoadjuvant treatment (TNT) aims to improve systemic control while local control is maintained. At 3 years, LRF rate was comparable between TNT and chemoradiotherapy in the RAPIDO trial.

METHODS

A total of 920 patients were randomized between an experimental (EXP, short-course radiotherapy, chemotherapy, and surgery) and a standard-care group (STD, chemoradiotherapy, surgery, and optional postoperative chemotherapy). LRFs, including early LRF (no resection except for organ preservation/R2 resection) and locoregional recurrence (LRR) after an R0/R1 resection, were analyzed.

RESULTS

Totally, 460 EXP and 446 STD patients were eligible. At 5.6 years (median follow-up), LRF was detected in 54/460 (12%) and 36/446 (8%) patients in the EXP and STD groups, respectively ( P =0.07), in which EXP patients were more often treated with 3-dimensional-conformed radiotherapy ( P =0.029). In the EXP group, LRR was detected more often [44/431 (10%) vs. 26/428 (6%); P =0.027], with more often a breached mesorectum (9/44 (21%) vs. 1/26 (4); P =0.048). The EXP treatment, enlarged lateral lymph nodes, positive circumferential resection margin, tumor deposits, and node positivity at pathology were the significant predictors for developing LRR. Location of the LRRs was similar between groups. Overall survival after LRF was comparable [hazard ratio: 0.76 (95% CI, 0.46-1.26); P =0.29].

CONCLUSIONS

The EXP treatment was associated with an increased risk of LRR, whereas the reduction in disease-related treatment failure and distant metastases remained after 5 years. Further refinement of the TNT in rectal cancer is mandated.

Abstract P2-11-10: Validation of the Breast Cancer Index (BCI) prognostic models optimized for late distant recurrence in postmenopausal women with early-stage HR+ breast cancer in the TEAM trial

Background: Women with HR+ breast cancer experience a persistent risk of distant recurrence (DR) even after completion of 5 years of adjuvant endocrine therapy, with more than 50% of DR occurring after 5 years (late DR). The prognostic genomic signatures currently being used in the clinic were not developed or optimized specifically for late DR. We have previously shown that the Breast Cancer Index (BCI) and BCIN+ prognostic models were significantly prognostic for risk of overall (0-10y) and late (5-10y) distant recurrence (DR) in N0 and N1 HR+ patients in the Tamoxifen and Exemestane Adjuvant Multinational (TEAM) trial. Here, the prognostic performance of the BCI and BCIN+ models with alternative cut-points optimized for late DR were evaluated in patients from the TEAM trial, who were free from DR for at least 5 years.

Methods: BCI testing was performed blinded to clinical outcome. The pre-specified alternative cut-points 4.4 and 1.8 for BCI and BCIN+ models were determined previously from Trans-aTTom and IDEAL studies, respectively (ESMO 2021). Kaplan-Meier analysis and log-rank test were used to evaluate the prognostic significance of BCI/BCIN+ risk groups based on DR. Univariate and multivariate Cox models were used to estimate hazard ratios (HRs) and the associated 95% confidence intervals (CIs).

Results: 1285 HR+ N0 (median age 69.2, 54.2% T1, 92.5% G2-3, 21.3% chemotherapy) and 1762 N1 (median age 68.5, 49.7% T1, 80.8% G2-3, 42.6% chemotherapy) patients who remained free from DR at 5 years post randomization were included in the current analysis. For N0 patients, BCI identified 439 (34%) and 846 (66%) patients as low and high-risk with late 10-year DR rates of 3.8% (95% CI: 1.5-6.0%) and 9.1% (95% CI: 6.8-11.4%), respectively (HR: 2.6, 95% CI: 1.4-5.0; p=0.0025). For N1 patients, BCIN+ identified 287 (16%) and 1475 (84%) patients as low and high-risk with late 10-year DR rates of 3.4% (95% CI: 1.2-5.5%) and 12.3% (95% CI: 10.4-14.2%), respectively (HR: 3.5, 95% CI: 1.8-6.9; p&lt; 0.0001). Similar results were observed in the HER2- patients. Notably, BCI/BCIN+ remained a statistically significant prognostic factor in the multivariate analysis after controlling for age, tumor size, grade, treatment. (Table).

Conclusions: Compared to the original BCI/BCIN+ models, the optimized BCI and BCIN+ models showed improved prognostic performance for identifying low-risk patients with a very low risk of late DR (&lt; 4%), for both N0 and N1 patients. These results provide further validation of BCI clinical utility as an aid in the decision-making for extended endocrine therapies for HR+ breast cancer, particularly in patients with N1 disease that may be spared extended endocrine treatment.

Table

Citation Format: John MS Bartlett, Keying Xu, Jenna Wong, Gregory R. Pond, Yi Zhang, Melanie Spears, Ranelle Salunga, Elizabeth Mallon, Karen J. Taylor, Annette Hasenburg, Christos Markopoulos, Luc Dirix, Caroline Seynaeve, Cornelis J.H. van de Velde, Daniel Rea, Catherine A. Schnabel, Kai Treuner, Jane Bayani. Validation of the Breast Cancer Index (BCI) prognostic models optimized for late distant recurrence in postmenopausal women with early-stage HR+ breast cancer in the TEAM trial [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr P2-11-10.

Risk and location of distant metastases in patients with locally advanced rectal cancer after total neoadjuvant treatment or chemoradiotherapy in the RAPIDO trial

INTRODUCTION

Although optimising rectal cancer treatment has reduced local recurrence rates, many patients develop distant metastases (DM). The current study investigated whether a total neoadjuvant treatment strategy influences the development, location, and timing of metastases in patients diagnosed with high-risk locally advanced rectal cancer included in the Rectal cancer And Pre-operative Induction therapy followed by Dedicated Operation (RAPIDO) trial.

MATERIAL AND METHODS

Patients were randomly assigned to short-course radiotherapy followed by 18 weeks of CAPOX or FOLFOX4 before surgery (EXP), or long-course chemoradiotherapy with optional postoperative chemotherapy (SC-G). Assessments for metastatic disease were performed pre- and post-treatment, during surgery, and 6, 12, 24, 36, and 60 months postoperatively. From randomisation, differences in the occurrence of DM and first site of metastasis were evaluated.

RESULTS

In total, 462 patients were evaluated in the EXP and 450 patients in the SC-G groups. The cumulative probability of DM at 5 years after randomisation was 23% [95% CI 19-27] and 30% [95% CI 26-35] (HR 0.72 [95% CI 0.56-0.93]; P = 0.011) in the EXP and SC-G, respectively. The median time to DM was 1.4 (EXP) and 1.3 years (SC-G). After diagnosis of DM, median survival was 2.6 years [95% CI 2.0-3.1] in the EXP and 3.2 years [95% CI 2.3-4.1] in the SC-G groups (HR 1.39 [95% CI 1.01-1.92]; P = 0.04). First occurrence of DM was most often in the lungs (60/462 [13%] EXP and 55/450 [12%] SC-G) or the liver (40/462 [9%] EXP and 69/450 [15%] SC-G). A hospital policy of postoperative chemotherapy did not influence the development of DM.

CONCLUSIONS

Compared to long-course chemoradiotherapy, total neoadjuvant treatment with short-course radiotherapy and chemotherapy significantly decreased the occurrence of metastases, particularly liver metastases.

Abstract GS5-10: Utility of the 70-gene MammaPrint test for prediction of extended endocrine therapy benefit in patients with early-stage breast cancer in the IDEAL Trial

Background: The IDEAL trial showed no significant benefit of 5 years extended endocrine therapy (EET) using letrozole in postmenopausal patients with hormone receptor positive (HR+) breast cancer (BC) versus 2.5 years. Genomic classifiers may assist with treatment decisions by predicting EET benefit. The 70-gene MammaPrint (MP) test classifies tumors as having a higher or lower risk of distant metastasis in HR+ early-stage BC. A MP lower risk result can be further classified as either Ultra-Low risk or Low risk of distant metastasis. In the NSABP B42 trial, MP predicted a statistically significant absolute benefit from EET in patients with a MP Low Risk result. Here, we aimed to determine the utility of MP in identifying a subgroup of patients enrolled in the IDEAL trial for which 5 years of EET is beneficial compared to 2.5 years.

Methods: A total of 869 patients had available primary tumor tissue for testing. MP results were available for 545/869 patients, of which 515 did not have an event at 2.5 year after randomization and were used for our analyses. The MP result for each patient was calculated by Agendia while blinded to patient clinical outcomes. The primary endpoint was distant recurrence (DR). Secondary endpoints were recurrence free interval (RFI) and breast cancer free interval (BCFI) as defined by STEEP criteria. Patients were classified as higher risk (score -1.000 - 0) or lower risk (score 0.001 - 1.000). Lower risk tumors were further classified as either MP Ultra-Low (score &gt; 0.355) or MP Low Risk (score ≥ 0.001, ≤ 0.355). Likelihood ratio test based on stratified Cox proportional hazards (PH) model were used to evaluate treatment by risk group interaction. Differences in endpoints between treatment groups were assessed by stratified log-rank tests. Hazard ratios (HR) and 95% Confidence Intervals (CI) were computed based on the stratified Cox PH model.

Results: The clinical characteristics of the 515 IDEAL samples with a MP result were comparable to the whole IDEAL cohort (n=1820). Within the 2.5 year EET group, 50.6% (n=134) were MP higher risk and 49.4% (n=131) MP lower risk, of which 14.5% (n=19/131) were MP Ultra-Low. Within the 5 year EET group, 50.0% (n=125) were MP higher risk and 50.0% (n=125) MP lower risk, of which 11.2% (n=14/125) were MP Ultra-Low. Among patients with MP lower risk tumors, 5 years vs. 2.5 years of EET resulted in a significant absolute benefit of 9.8% for DR (HR=0.42, [95% CI 0.174-0.996]), 9.8% for RFI (HR=0.43, [95% CI 0.198-0.934]), and 8.8% (HR=0.53, [95% CI 0.264-1.055]) for BCFI, whereas patients with MP higher risk tumors did not derive significant benefit (Table 1). Within the MP lower risk group, 5 year vs 2.5 year EET benefit was more pronounced in MP Low tumors, which exhibited a significant benefit of 10.1% for DR (HR=0.32, [95% CI 0.116-0.866]), 11.7% for RFI (HR=0.35, [95% CI 0.147-0.824]), and 9.7% for BCFI (HR=0.48, [95% CI 0.225-1.015]); MP Ultra Low tumors did not derive significant benefit. Treatment-by-risk group interaction was statistically significant for RFI.

Conclusion: A significant EET benefit was observed for MammaPrint lower risk tumors but not for MP higher risk tumors. MammaPrint Low tumors exhibited the largest absolute benefit of 5 years of EET compared to 2.5 years. Consistent with the findings in the NSABP B42 trial, the results from this second randomized trial provide clinically meaningful implications in patient selection for extended endocrine therapy.

Table 1. IDEAL: 10-year outcome analysis comparing 5 years vs. 2.5 years of EET using letrozole stratified by MP risk. **MammaPrint Lower Risk & Higher Risk (n=515) and *** MammaPrint Low Risk & High Risk (n=482)

Citation Format: Gerrit-Jan Liefers, Elma Meershoek-Klein Kranenbarg, Marjolijn Duijm-de Carpentier, Cornelis J.H. van de Velde, Miranda Kleijn, Christa Dreezen, Andrea Menicucci, Laura van’t Veer, William Audeh. Utility of the 70-gene MammaPrint test for prediction of extended endocrine therapy benefit in patients with early-stage breast cancer in the IDEAL Trial [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr GS5-10.

Radiotherapy or Surgery of the Axilla After a Positive Sentinel Node in Breast Cancer: 10-Year Results of the Randomized Controlled EORTC 10981-22023 AMAROS Trial

Clinical trials frequently include multiple end points that mature at different times. The initial report, typically based on the primary end point, may be published when key planned co-primary or secondary analyses are not yet available. Clinical Trial Updates provide an opportunity to disseminate additional results from studies, published in JCO or elsewhere, for which the primary end point has already been reported.

PURPOSE

The European Organisation for Research and Treatment of Cancer 10981-22023 AMAROS trial evaluated axillary lymph node dissection (ALND) versus axillary radiotherapy (ART) in patients with cT1-2, node-negative breast cancer and a positive sentinel node (SN) biopsy. At 5 years, both modalities showed excellent and comparable axillary control, with significantly less morbidity after ART. We now report the preplanned 10-year analysis of the axillary recurrence rate (ARR), overall survival (OS), and disease-free survival (DFS), and an updated 5-year analysis of morbidity and quality of life.

METHODS

In this open-label multicenter phase III noninferiority trial, 4,806 patients underwent SN biopsy; 1,425 were node-positive and randomly assigned to either ALND (n = 744) or ART (n = 681).

RESULTS

Per intention-to-treat analysis, 10-year ARR cumulative incidence was 0.93% (95% CI, 0.18 to 1.68; seven events) after ALND and 1.82% (95% CI, 0.74 to 2.94; 11 events) after ART (hazard ratio [HR], 1.71; 95% CI, 0.67 to 4.39). There were no differences in OS (HR, 1.17; 95% CI, 0.89 to 1.52) or DFS (HR, 1.19; 95% CI, 0.97 to 1.46). ALND was associated with a higher lymphedema rate in updated 5-year analyses (24.5% v 11.9%; P < .001). Quality-of-life scales did not differ by treatment through 5 years. Exploratory analysis showed a 10-year cumulative incidence of second primary cancers of 12.1% (95% CI, 9.6 to 14.9) after ART and 8.3% (95% CI, 6.3 to 10.7) after ALND.

CONCLUSION

This 10-year analysis confirms a low ARR after both ART and ALND with no difference in OS, DFS, and locoregional control. Considering less arm morbidity, ART is preferred over ALND for patients with SN-positive cT1-2 breast cancer.

Decreasing resection rates for nonmetastatic gastric cancer in Europe and the United States

BACKGROUND

Resection is the cornerstone of curative treatment for many nonmetastatic gastric cancers (GCs), but the population treatment patterns remains largely unknown. This large international population-based study aimed at investigating the treatment patterns and trends for nonmetastatic GC in Europe and the United States and at exploring factors associated with resection.

METHODS

Data of patients with microscopically confirmed primary invasive GC without distant metastasis from the national cancer registries of the Netherlands, Belgium, Sweden, Norway, Slovenia, and Estonia and the US Surveillance, Epidemiology, and End Results (SEER)-18 Program were retrieved. Age-standardized treatment rates were computed and trends were evaluated using linear regression. Associations of resection with patient and tumor characteristics were analyzed using multivariable-adjusted log-binomial regression. Analysis was performed in each country respectively without pooling.

RESULTS

Together 65 707 nonmetastatic GC patients diagnosed in 2003-2016 were analyzed. Age-standardized resection rates significantly decreased over years in all countries (by 4-24%). In 2013-2014, rates varied greatly from 54 to 75%. Patients with increasing ages, cardia cancers, or cancers invading adjacent structure were significantly less frequently resected. Resection was further associated with sex, performance status, comorbidities, tumor histology, tumor size, hospital type, and hospital volume. Association patterns and strengths varied across countries. After multivariable adjustment, resection rates remained decreasing (prevalence ratio = 0.97-0.995 per year), with decreasing trends consistently seen in various subgroups.

CONCLUSIONS

Nonmetastatic GCs were less frequently resected in Europe and the United States in the early 21st century. Resection rates varied greatly across countries and appeared not to be optimal. Various factors associated with resection were revealed. Our findings can help to identify differences and possibly modifiable places in clinical practice and provide important novel references for designing effective population-based GC management strategies. In Europe and the United States, nonmetastatic gastric cancers were less frequently resected in the early 21st century. Resection rates varied greatly across countries and appeared not optimal. Various factors associated with resection were revealed. Our findings identify differences and possibly modifiable places in clinical practice and provide important novel references for designing effective population-based management strategies.

The DULK (Dutch leakage) and modified DULK score compared: actively seek the leak

AIM

A standardized postoperative score, the DULK (Dutch leakage) score, has been demonstrated to be a useful clinical tool in the diagnosis of anastomotic leakage. It is complicated, however, and a simplification (the modified DULK score) based on fewer parameters derived from multiple logistic regression analyses has been developed. These include clinical condition, abdominal pain not localized at the wound, C-reactive protein level and respiratory rate. The accuracy of each was compared.

METHOD

Data of all patients from five Dutch centres operated on between 16 October 2007 and 1 November 2009 with an anastomosis in the colon or rectum were entered into a prospectively maintained database.

RESULTS

In total, 782 patients were included of whom 81 (10.4%) had a clinically relevant anastomotic leakage. The DULK score gave an overall sensitivity of 97% for anastomotic leakage, overall specificity of 53%, a positive predictive value (PPV) of 16% and a negative predictive value (NPV) of 99%. The modified DULK score used clinical condition, abdominal pain not localized at the wound, C-reactive protein level and respiratory rate. With at least one parameter present, overall sensitivity was 97%, overall specificity 57%, PPV 17% and NPV 99.5%. With at least two points PPV was 41% and with three points 57%.

CONCLUSION

Both the original and modified DULK scores are useful for the early diagnosis of clinically relevant anastomotic leakage. The modified DULK score offers the benefit of fewer parameters and so can easily be used in a clinical environment to estimate the likelihood of anastomotic leakage. However, the early diagnosis of anastomotic leakage remains difficult.

Abstract 668: DNA methylation of apoptosis-related genes as clinical biomarker in rectal cancer

Background: To prevent over- and undertreatment of rectal cancer patients, there is a need for the development of new biomarkers that can complement the current staging system. We have previously shown that apoptosis plays an important role in local tumor recurrence after TME surgery. We studied the epigenetic regulation of several key apoptosis genes in rectal cancer tissues, using methylation-sensitive restriction enzymes.

Materials and methods: DNA was obtained from frozen specimens of 138 patients representative for the non-irradiated arm of the Dutch Total Mesorectal Excision (TME) trial. Isoschizomers HpaII (CpG methylation sensitive) and MspI (not sensitive) were used for restriction enzyme digestion of tumor DNA, followed by real-time PCR for apoptosis genes Apaf1, Bcl2, TrailR2, Fas and p53. A pilot series consisted of 50 patients with tumor stages I-III and 10 normal rectal tissues. For the validation study stage III patients (n=88) and 18 normal rectal tissues were selected.

Results: Single marker analyses showed a significant correlation between methylation status and apoptotic status (measured by immunohistochemical staining of M30) of Fas (p=0.005) and Apaf1 (p=0.052). Combining intrinsic pathway markers Apaf1, Bcl2 and p53, significant differences were observed between the methylation groups in survival and recurrence analyses (log rank test), with overall survival (p=0.054), cancer specific survival (p=0.014) and distant recurrence free survival (p=0.006).

Conclusion: Methylation of apoptosis genes is representative for the apoptotic status of a tumor and is correlated to survival and recurrence in rectal cancer patients. The apoptotic status of a tumor may be used to guide treatment strategies for individual patients.

[A.B. and E.C.M.Z contributed equally to this work.]

Citation Format: Anne Benard, Eliane C.M. Zeestraten, Inès J. Goossens-Beumer, Hein Putter, Christine Kuo, Cornelis J.H. van de Velde, Peter J.K. Kuppen, Dave S.B. Hoon. DNA methylation of apoptosis-related genes as clinical biomarker in rectal cancer. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 668. doi:10.1158/1538-7445.AM2013-668

Optimization of near-infrared fluorescent sentinel lymph node mapping for vulvar cancer

OBJECTIVES

Near-infrared fluorescence imaging has the potential to improve sentinel lymph node mapping in vulvar cancer, which was assessed in the current study. Furthermore, dose optimization of indocyanine green adsorbed to human serum albumin was performed.

STUDY DESIGN

Nine vulvar cancer patients underwent the standard sentinel lymph node procedure using (99m)technetium-nancolloid and patent blue. In addition, intraoperative imaging was performed after peritumoral injection of 1.6 mL of 500, 750, or 1000 μM of indocyanine green adsorbed to human serum albumin.

RESULTS

Near-infrared fluorescence sentinel lymph node mapping was successful in all patients. A total of 14 sentinel lymph nodes (average, 1.6; range, 1-4) were detected: 14 radioactive (100%), 11 blue (79%), and 14 near-infrared fluorescent (100%).

CONCLUSION

This study demonstrates feasibility and accuracy of sentinel lymph node mapping using indocyanine green adsorbed to human serum albumin. Considering safety, cost, and pharmacy preferences, an indocyanine green adsorbed to human serum albumin concentration of 500 μM appears optimal for sentinel lymph node mapping in vulvar cancer.

Treatment of resectable gastric cancer

Stomach cancer is one of the most common cancers worldwide, despite its declining overall incidence. Although there are differences in incidence, etiology and pathological factors, most studies do not separately analyze cardia and noncardia gastric cancer. Surgery is the only potentially curative treatment for advanced, resectable gastric cancer, but locoregional relapse rate is high with a consequently poor prognosis. To improve survival, several preoperative and postoperative treatment strategies have been investigated. Whereas perioperative chemotherapy and postoperative chemoradiation (CRT) are considered standard therapy in the Western world, in Asia postoperative monochemotherapy with S-1 is often used. Several other therapeutic options, although generally not accepted as standard treatment, are postoperative combination chemotherapy, hyperthermic intraperitoneal chemotherapy and preoperative radiotherapy and CRT. Postoperative combination chemotherapy does show a statistically significant but clinically equivocal survival advantage in several meta-analyses. Hyperthermic intraperitoneal chemotherapy is mainly performed in Asia and is associated with a higher postoperative complication rate. Based on the currently available data, the use of postoperative radiotherapy alone and the use of intraoperative radiotherapy should not be advised in the treatment of resectable gastric cancer. Western randomized trials on gastric cancer are often hampered by slow or incomplete accrual. Reduction of toxicity for preoperative and especially postoperative treatment is essential for the ongoing improvement of gastric cancer care.

The clinical use of indocyanine green as a near-infrared fluorescent contrast agent for image-guided oncologic surgery

Optical imaging using near-infrared (NIR) fluorescence provides new prospects for general and oncologic surgery. ICG is currently utilised in NIR fluorescence cancer-related surgery for three indications: sentinel lymph node (SLN) mapping, intraoperative identification of solid tumours, and angiography during reconstructive surgery. Therefore, understanding its advantages and limitations is of significant importance. Although non-targeted and non-conjugatable, ICG appears to be laying the foundation for more widespread use of NIR fluorescence-guided surgery.

Abstract 4140: Preclinical optimization and clinical translation of near-infrared fluorescence imaging of colorectal liver metastases using indocyanine green

Background: Near-infrared (NIR) fluorescence imaging using indocyanine green (ICG) is a promising technique to obtain real-time assessment of the extent and number of colorectal liver metastases during liver surgery. The current study aims to optimize dosage and timing of ICG administration.

Materials and methods: The Mini-FLARE imaging system was used for real-time identification of liver tumors in 18 rats. Liver tumors were measured at 24, 48, 72 or 96 hours after administration of 0.04, 0.08, or 0.16 mg ICG (0.13, 0.26 or 0.53 mg / kg, respectively). Guided by these results, intraoperative identification of liver metastases was performed in 12 patients undergoing liver resection. NIR fluorescence imaging was performed 24 or 48 hours after administration of 10 or 20 mg ICG (0.13 or 0.26 mg / kg, respectively). After intraoperative imaging, resection specimens were sliced to examine internal fluorescent patterns using the Mini-FLARE imaging system. Subsequently, frozen tissue sections were measured for fluorescence using the Nuance multispectral imager.

Results: Using NIR fluorescence imaging and ICG, all colorectal liver metastases (N = 34), could be identified in all rats. Average tumor-to-liver (TLR) ratio over all groups was 3.0 ± 1.2. Liver signal was lower in the 72 h time group compared to other time points, resulting in a significantly higher TLR. ICG dose did not significantly influence TLR, but a trend was found favoring the 0.08 mg dose group. Clinically, during intraoperative NIR fluorescence imaging, all superficially located metastases (&lt; 1 cm beneath liver capsule) were identified (N = 18). Average TLR was 11.1 ± 5.1 and no significant differences between time-points or doses were found. Liver signal was comparable to pre-injection signal at 24 to 48 hours post-injection, eliminating the need to test other time-points. In all patients, a fluorescent rim around the tumor was found, as described in earlier studies. Using fluorescence microscopy, this clear fluorescent rim was localized in stromal tissue in the transition area between tumor and normal liver tissue in all liver metastases. In this area, multiple cell types that are involved in tissue inflammation (e.g. granulocytes, lymphocytes) were found. In two patients, additional small (2 – 8 mm) metastases were identified using NIR fluorescence that were otherwise missed preoperatively and intraoperatively using only visual inspection and ultrasound.

Conclusions: This study demonstrates that colorectal cancer liver metastases can be clearly identified during surgery using ICG and the Mini-FLARE imaging system. NIR fluorescence imaging has the potential to improve intraoperative detection of in particular small and superficially located liver metastases and can therefore be seen as an addition to the conventional imaging modalities.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 4140. doi:10.1158/1538-7445.AM2011-4140

Abstract 5184: Age interactions in the prognostic value of ALDH1 for clinical outcome in breast cancer

Introduction: Breast cancer is increasingly becoming a disease affecting older women. Clinicopathological characteristics, such as tumor size and hormone receptor expression, have been found to differ considerably between elderly and younger breast cancer patients, which suggests different underlying tumor biology between both populations. Cancer stem cells have been found to be a predictor of worse outcome in various breast cancer studies. However, these studies were all performed on populations of relative young patients. The aim of this study was to compare the frequency and the prognostic effect of ALDH1-positive tumors, representing the stem cell fraction, in elderly patients to younger patients.

Methods: Our study population (n=574) consisted of all early breast cancer patients primarily treated with surgery in our center between 1985 and 1994. Tissue micro array slides were immunohistochemically stained for expression of ALDH1. The percentage of ALDH1-positive tumors cells was microscopically assessed by two independent observers in a blinded manner.

Results: Complete lack of expression of ALDH1 was found in 40% of tumors. With increasing age more tumors showed complete absence of ALDH1 (logistic regression p-value &lt;0.001). For comparison of the prognostic effect of ALDH1 between elderly and young patients, a cut-off point of 65 years was taken for age stratification and only patients who did not receive systemic treatment were selected. A statistically significant worse outcome was found for relapse free period (RFP) and relative survival (RS) in younger patients with ALDH1 tumor presence (logrank p-value: RFP 0.009; RS 0.008). This prognostic effect of ALDH1 was independent of known clinicopathological parameters in multivariate analysis (RFP: Hazard Ratio (HR) 1.71, p-value 0.021; RS: HR: 2.36, p-value 0.016). In elderly patients no statistically significant differences in outcome were found for ALDH1 expression (logrank p-value: RFP 0.138; RS 0.354). Interactions between the effect of age and ALDH1 presence on outcome were tested and revealed that the diverse prognostic effect of ALDH1 between young and elderly patients as found in the stratified analyses was a statistically significant difference (p-value: 0.007).

Conclusion: ALDH1 presence is less frequently found in tumors of elderly breast cancer patients. In addition, presence of ALDH1 results in a worse outcome in young patients, but not elderly patients. This is the first study demonstrating that presence of ALDH1 activity and its prognostic effect is age-dependent. Our results support the hypothesis that breast cancer biology is different in elderly patients compared to their younger counterparts and emphasizes the importance of taking into consideration age-specific interactions in breast cancer research.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 5184. doi:10.1158/1538-7445.AM2011-5184

Nuclear localization of CXCR4 determines prognosis for colorectal cancer patients

Chemokines and their receptors are implicated in formation of colorectal cancer metastases. Especially CXCR4 is an important factor, determining migration, invasiveness, metastasis and proliferation of colorectal cancer cells. Object of this study was to determine expression of CXCR4 in tumor tissue of colorectal cancer patients and associate CXCR4 expression levels to clinicopathological parameters. Levels of CXCR4 expression of a random cohort of patients, who underwent primary curative resection of a colorectal carcinoma, were retrospectively determined by quantitative real-time RT-PCR and semi-quantitative analyses of immunohistochemical stained paraffin sections. Expression levels were associated to clinicopathological parameters. Using RT-PCR we found that a high expression of CXCR4 in the primary tumor was an independent prognostic factor for a poor disease free survival (p = 0.03, HR: 2.0, CI = 1.1-3.7). Immunohistochemical staining showed that nuclear distribution of CXCR4 in the tumor cells was inversely associated with disease free and overall survival (p = 0.04, HR: 2.6, CI = 1.0-6.2), while expression in the cytoplasm was not associated with prognosis. In conclusion, our study showed that a high expression of nuclear localized CXCR4 in tumor cells is an independent predictor for poor survival for colorectal cancer patients.

Causes of Fecal and Urinary Incontinence After Total Mesorectal Excision for Rectal Cancer Based on Cadaveric Surgery: A Study From the Cooperative Clinical Investigators of the Dutch Total Mesorectal Excision Trial

Purpose

Total mesorectal excision (TME) for rectal cancer may result in anorectal and urogenital dysfunction. We aimed to study possible nerve disruption during TME and its consequences for functional outcome. Because the levator ani muscle plays an important role in both urinary and fecal continence, an explanation could be peroperative damage of the nerve supply to the levator ani muscle.

Methods

TME was performed on cadaver pelves. Subsequently, the anatomy of the pelvic floor innervation and its relation to the pelvic autonomic innervation and the mesorectum were studied. Additionally, data from the Dutch TME trial were analyzed to relate anorectal and urinary dysfunction to possible nerve damage during TME procedure.

Results

Cadaver TME surgery demonstrated that, especially in low tumors, the pelvic floor innervation can be damaged. Furthermore, the origin of the levator ani nerve was located in close proximity of the origin of the pelvic splanchnic nerves. Analysis of the TME trial data showed that newly developed urinary and fecal incontinence was present in 33.7% and 38.8% of patients, respectively. Both types of incontinence were significantly associated with each other (P = .027). Low anastomosis was significantly associated with urinary incontinence (P = .049). One third of the patients with newly developed urinary and fecal incontinence also reported difficulty in bladder emptying, for which excessive perioperative blood loss was a significant risk factor.

Conclusion

Perioperative damage to the pelvic floor innervation could contribute to fecal and urinary incontinence after TME, especially in case of a low anastomosis or damage to the pelvic splanchnic nerves.

Quantitative Analysis of Methylation of Genomic Loci in Early-Stage Rectal Cancer Predicts Distant Recurrence

Purpose

There are no accurate prognostic biomarkers specific for rectal cancer. Epigenetic aberrations, in the form of DNA methylation, accumulate early during rectal tumor formation. In a preliminary study, we investigated absolute quantitative methylation changes associated with tumor progression of rectal tissue at multiple genomic methylated-in-tumor (MINT) loci sequences. We then explored in a different clinical patient group whether these epigenetic changes could be correlated with clinical outcome.

Patients and Methods

Absolute quantitative assessment of methylated alleles was used to assay methylation changes at MINT 1, 2, 3, 12, 17, 25, and 31 in sets of normal, adenomatous, and malignant tissues from 46 patients with rectal cancer. Methylation levels of these biomarkers were then assessed in operative specimens of 251 patients who underwent total mesorectal excision (TME) without neoadjuvant radiotherapy in a multicenter clinical trial.

Results

Methylation at MINT 2, 3, and 31 increased 11-fold (P = .005), 15-fold (P < .001), and two-fold (P = .02), respectively, during adenomatous transformation in normal rectal epithelium. Unsupervised grouping analyses of quantitative MINT methylation data of TME trial patients demonstrated two prognostic subclasses. In multivariate analysis of node-negative patients, this subclassification was the only predictor for distant recurrence (hazard ratio [HR], 4.17; 95% CI, 1.72 to 10.10; P = .002), cancer-specific survival (HR, 3.74; 95% CI, 1.4 to 9.43; P = .003), and overall survival (HR, 2.68; 95% CI, 1.41 to 5.11; P = .005).

Conclusion

Methylation levels of specific MINT loci can be used as prognostic variables in patients with American Joint Committee on Cancer stage I and II rectal cancer. Quantitative epigenetic classification of rectal cancer merits evaluation as a stratification factor for adjuvant treatment in early disease.