BackgroundSeveral studies have demonstrated a prognostic impact of tumor-infiltrating T lymphocytes and natural killer (NK) cells in esophageal and gastric adenocarcinoma, but whether these associations differ by the density of tumor-infiltrating immune cells of the B cell lineage remains largely unknown.ResultsHigh infiltration of any T and NK lymphocytes investigated was in general associated with a favorable prognosis, but the strongest beneficial prognostic impact was seen in combination with high B lymphocyte infiltration. These findings were most evident in gastric cancer, where significant interactions in relation to OS were observed for CD3+, CD8+ and FoxP3+ with CD20+ cells (pinteraction =0.012, 0.009 and 0.007, respectively) and for FoxP3+ with IGKC+ cells (pinteraction =0.034). In esophageal tumors, there was only a significant interaction for CD3+ and CD20 + cells (pinteraction =0.028).MethodsImmunohistochemistry and automated image analysis was applied to assess the density of T lymphocytes (CD3+, CD8+, FoxP3+) and NK cells (NKp46+) in chemoradiotherapy-naïve tumors from a consecutive cohort of 174 patients with resected esophageal or gastric adenocarcinoma. The density of B lymphocytes (CD20+) and plasma cells (IGKC+) had been assessed previously. Kaplan-Meier analysis and Cox proportional hazard's modelling was applied to examine the impact of the investigated markers on time to recurrence (TTR) and overall survival (OS).ConclusionsThese data support that the antitumoral effects of tumor-infiltrating T lymphocytes in esophageal and gastric adenocarcinoma may be largely dependent on a functional interplay between T and B lymphocytes or plasma cells.

Tumor dosimetry was performed for 177 Lu-DOTA-TATE with the aims of better understanding i) the range and variation of the tumor absorbed doses (ADs), ii) how different dosimetric quantities evolve over the treatment cycles, and iii) whether this evolution differs depending on the tumor grade. Such information is important for radiobiological interpretation and may inform the design of alternative administration schemes. Methods: Data come from 41 patients with neuroendocrine tumors (NETs) of grade 1 (n=23) or 2 (n=18), that had received between 2 and 9 treatment cycles. Dosimetry was performed for 182 individual lesions, giving in total 880 individual AD assessments across all cycles. Hybrid planar-SPECT/CT imaging was used, including quantitative SPECT reconstruction, voxel-based absorbed-dose-rate calculation, semiautomatic image segmentation, and partial-volume correction. Linear mixed-effect models were used to analyze changes over cycles in tumor ADs, absorbed-dose rates and activity concentrations at day-1, effective half-times, and tumor volumes. Tumors smaller than 8 ml were excluded from analyses. Results:Tumor ADs ranged between 2 and 77 Gy per cycle. On average the AD decreased over the cycles, with significantly different rates (p < 0.05) for grade 1 and 2 NETs of 6% and 14% per cycle, respectively. The absorbed-dose rates and activity concentrations at day-1 decreased by similar amounts. The effective halftimes were less variable but shorter for grade 2 than grade 1 (p < 0.001). For grade 2 NETS the tumor volumes decreased, with a similar tendency in grade 1. Conclusions: The tumor AD, absorbed-dose rate and activity uptake decrease, in parallel with tumor volumes, between 177 Lu-DOTA-TATE treatment cycles, particularly for grade 2 NETs. The effective half-times vary less but are lower for grade 2 than grade 1 NETs. These results may indicate the development of radiation-induced fibrosis and could have implications for the design of future treatment and dosimetry protocols.

Purpose Radionuclide therapy with 177Lu-DOTATATE is well established for patients with advanced somatostatin receptor–positive neuroendocrine tumors with a standard schedule of 7.4 GBq at four occasions. However, this approach does not consider individual variability affecting the tumor radiation dose or dose to organs at risk. Therefore, it is important to assess more personalized strategies. The aim of this phase II trial was to evaluate individualized 177Lu-DOTATATE for which the number of cycles varied based on renal dosimetry. Methods Patients were eligible if they had a progressive, somatostatin receptor–positive neuroendocrine tumor with a Ki 67 labeling index < 20%. They received cycles of 7.4 GBq of 177Lu-DOTATATE at 10 ± 2-week intervals until a predefined radiation dose to the kidneys was reached. The primary endpoint was objective tumor response (RECIST v 1.1). Secondary endpoints included progression-free survival (PFS), overall survival (OS), and toxicity (CTCAE v. 4.0). Results Ninety-six patients who had received a median of 5 cycles (range 1–9) were evaluable for efficacy. The objective tumor response was 16% partial response, 66% stable disease, and 19% progressive disease. The median PFS and OS were 29 months and 47 months, respectively, and were significantly associated with kidney dose, performance status, and Ki 67 levels but not with tumor origin. The overall toxicity was mild, and the most common events were grade 1–2 anemia, thrombocytopenia, fatigue, nausea, and diarrhea. Grade 3–4 toxicity occurred in < 10% of patients and was mostly hematological, with no grade 3–4 renal toxicity. Conclusion Individualized treatment with 177Lu-DOTATATE based on renal dosimetry is clearly feasible with low toxicity and promising efficacy, showing the potential to further improve outcome beyond the standard approach, and should be further assessed in randomized trials. Trial registration EudraCT 2011–000,240-16. NCT01456078. https://clinicaltrials.gov/ct2/show/NCT01456078

Periampullary adenocarcinoma, including pancreatic cancer, is a heterogeneous group of tumours with dismal prognosis, for which there is an urgent need to identify novel treatment strategies. The human epithelial growth factor receptors EGFR, HER2 and HER3 have been studied in several tumour types, and HER-targeting drugs have a beneficial effect on survival in selected types of cancer. However, these effects have not been evident in pancreatic cancer, and remain unexplored in other types of periampullary cancer. The prognostic impact of HER-expression in these cancers also remains unclear. The aim of this study was therefore to examine the expression and prognostic value of EGFR, HER2 and HER3 in periampullary cancer, with particular reference to histological subtype. To this end, protein expression of EGFR, HER2 and HER3, and HER2 gene amplification was assessed by immunohistochemistry and silver in situ hybridization, respectively, on tissue microarrays with tumours from 175 periampullary adenocarcinomas, with follow-up data on recurrence-free survival (RFS) and overall survival (OS) for up to 5 years. EGFR expression was similar in pancreatobiliary (PB) and intestinal (I) type tumours, but high HER2 and HER3 expression was significantly more common in I-type tumours. In PB-type cases receiving adjuvant gemcitabine, but not in untreated cases, high EGFR expression was significantly associated with a shorter OS and RFS, with a significant treatment interaction in relation to OS (pinteraction = 0.042). In I-type cases, high EGFR expression was associated with a shorter OS and RFS in univariable, but not in multivariable, analysis. High HER3 expression was associated with a prolonged RFS in univariable, but not in multivariable, analysis. Neither HER2 protein expression nor gene amplification was prognostic. The finding of a potential interaction between the expression of EGFR and response to adjuvant chemotherapy in PB-type tumours needs validation, and merits further study.