Comparison of Clinicopathological Characteristics in the Patients with Cardiac Cancer with or without Esophagogastric Junctional Invasion: A Single-Center Retrospective Cohort Study

Selecting Targets for Molecular Imaging of Gastric Cancer: An Immunohistochemical Evaluation

PURPOSE

Tumor-targeted positron emission tomography (PET) and fluorescence-guided surgery (FGS) could address current challenges in pre- and intraoperative imaging of gastric cancer. Adequate selection of molecular imaging targets remains crucial for successful tumor visualization. This study evaluated the potential of integrin αvβ6, carcinoembryonic antigen-related cell adhesion molecule 5 (CEACAM5), epidermal growth factor receptor (EGFR), epithelial cell adhesion molecule (EpCAM) and human epidermal growth factor receptor-2 (HER2) for molecular imaging of primary gastric cancer, as well as lymph node and distant metastases.

METHODS

Expression of αvβ6, CEACAM5, EGFR, EpCAM and HER2 was determined using immunohistochemistry in human tissue specimens of primary gastric adenocarcinoma, healthy surrounding stomach, esophageal and duodenal tissue, tumor-positive and tumor-negative lymph nodes, and distant metastases, followed by quantification using the total immunostaining score (TIS).

RESULTS

Positive biomarker expression in primary gastric tumors was observed in 86% for αvβ6, 72% for CEACAM5, 77% for EGFR, 93% for EpCAM and 71% for HER2. Tumor expression of CEACAM5, EGFR and EpCAM was higher compared to healthy stomach tissue expression, while this was not the case for αvβ6 and HER2. Tumor-positive lymph nodes could be distinguished from tumor-negative lymph nodes, with accuracy ranging from 82 to 93% between biomarkers. CEACAM5, EGFR and EpCAM were abundantly expressed on distant metastases, with expression in 88-95% of tissue specimens.

CONCLUSION

Our findings show that CEACAM5, EGFR and EpCAM are promising targets for molecular imaging of primary gastric cancer, as well as visualization of both lymph node and distant metastases. Further clinical evaluation of PET and FGS tracers targeting these antigens is warranted.

Preoperative treatment with radiochemotherapy for locally advanced gastroesophageal junction cancer and unresectable locally advanced gastric cancer

Background.

To purpose of the study was to analyze the results of preoperative radiochemotherapy in patients with unresectable gastric or locoregionally advanced gastroesophageal junction (GEJ) cancer treated at a single institution.

Patients and methods.

Between 1/2004 and 6/2012, 90 patients with locoregionally advanced GEJ or unresectable gastric cancer were treated with preoperative radiochemotherapy at the Institute of Oncology Ljubljana. Planned treatment schedule consisted of induction chemotherapy with 5-fluorouracil and cisplatin, followed by concomitant radiochemotherapy four weeks later. Three-dimensional conformal external beam radiotherapy was delivered by dual energy (6 and 15 MV) linear accelerator in 25 daily fractions of 1.8 Gy in 5 weeks with two additional cycles of chemotherapy repeated every 28 days. Surgery was performed 4–6 weeks after completing radiochemotherapy. Following the surgery, multidisciplinary advisory team reassessed patients for the need of adjuvant chemotherapy. The primary endpoints were histopathological R0 resection rate and pathological response rate. The secondary endpoints were toxicity of preoperative radiochemotherapy and survival.

Results.

Treatment with preoperative radiochemotherapy was completed according to the protocol in 84 of 90 patients (93.3%). Twenty patients (22.2%) did not undergo the surgery because of the disease progression, serious comorbidity, poor performance status or still unresectable tumour. In 13 patients (14.4%) only exploration was performed because the tumour was assessed as unresectable or diffuse peritoneal carcinomatosis was established. Fifty-seven patients (63.4%) underwent surgery with the aim of complete removal of the tumour. Radical resection was achieved in 50 (55.6%) patients and the remaining seven (7.8%) patients underwent non-radical surgery (R1 in five and R2 in two patients). In this group of patients (n = 57), pathological complete response of tumour was achieved in five patients (5.6% of all treated patients or 8.8% of all operated patients). Down-staging was recorded in 49 patients (86%), in one patient (1.8%) the stage after radiochemotherapy was unchanged while in seven patients (12.3%) the pathological stage was higher than clinical, mainly due to higher pN stage. No death was recorded during preoperative radiochemotherapy. Most grade 3 and 4 toxicities were due to vomiting, nausea and bone marrow suppression (granulocytopenia). Twenty-six (45.6%) patients died due to GEJ or gastric carcinoma, one died because of septic shock following the surgery and a reason for two deaths was unknown. Twenty-eight patients (49.1%) were disease free at the time of analysis, while 29 patients (50.9%) developed the recurrence, mostly as distant metastases. At two years, locoregional control, disease-free survival, disease-specific survival and overall survival were 82.9%, 43.9%, 56.9% and 53.9%, respectively.

Conclusions.

Preoperative radiochemotherapy was feasible in our group of patients and had acceptable toxicity. Majority of patients achieved down-staging, allowing greater proportion of radical resections (R0), which are essential for patients’ cure.