Pro-Gastrin-Releasing Peptide as a Biomarker in Lung Neuroendocrine Neoplasm

There is a lack of effective biomarkers for diagnosing lung neuroendocrine neoplasms (LNENs). A known small cell lung cancer (SCLC) biomarker is a pro-gastrin-releasing peptide (ProGRP), but not for all LNENs, especially for bronchopulmonary carcinoids. This study aimed to evaluate the diagnostic value of ProGRP and chromogranin A (CgA) in diagnosing LNENs. The ProGRP and CgA levels in 290 cases of LNENs and 54 healthy controls (HCs) were measured. The median ProGRP concentration in the group of LNEN patients was 136.4 pg/mL, higher than that of HCs at 6.5 pg/mL. Most of the LNEN cohort was well-differentiated tumors (typical and atypical carcinoids, n = 262, 91.7% of all LNENs). The sensitivity, specificity, and area under the curve (AUC) of ProGRP when distinguishing LNENs vs. HCs were 94.8%, 100%, and 0.995. CgA (AUC = 0.375) could not determine LNENs vs. HCs. Therefore, based on these results, ProGRP may be considered as an effective marker for diagnosing LNENs.

Renal Disturbances during and after Radioligand Therapy of Neuroendocrine Tumors-Extended Analysis of Potential Acute and Chronic Complications

Neuroendocrine tumors (NEN) are a group of neoplasms that arise from hormonal and neural cells. Despite a common origin, their clinical symptoms and outcomes are varied. They are most commonly localized in the gastrointestinal tract. Targeted radioligand therapy (RLT) is a treatment option which has proven to be successful in recent studies. However, the possible outcomes and true safety profile of the treatment need to be fully determined, especially by new, more sensitive methods. Our study aimed to present an extended analysis of acute and chronic renal complications during and after radioligand therapy using, for the first time in the literature, innovative and complex renal parameters. Forty patients with neuroendocrine tumors underwent four courses of radioligand therapy with [¹⁷⁷Lu]Lu-DOTATATE or [¹⁷⁷Lu]Lu/[⁹⁰Y]Y-DOTATATE. Radioisotopes were administrated in intervals of 8-12 weeks, with concurrent intravenous nephroprotection. New detailed and sensitive renal parameters were used to determine the renal safety profile during and after radioisotope therapy for standard treatment of NEN. During the first and fourth courses of RLT, no change in the glomerular filtration rate (GFR) was observed. However, long-term observations one year after the treatment showed a 10% reduction in the GFR. During the first course of treatment, the fractional urea and calcium excretions increased, while the fractional potassium concentration decreased. The fractional calcium excretion remained highly increased in long-term observations. Decreases in urine IL-18, KIM-1 and albumin concentrations were observed during RLT. The concentrations of IL-18 and KIM-1 remained low even a year after therapy. The ultrasound parameters of renal perfusion changed during treatment, before partially returning to the baseline one year after therapy, and were correlated with the biochemical parameters of renal function. A permanent increase in diastolic blood pressure was correlated with the decrease in the GFR observed during the study. In this innovative and complex renal assessment during and after RLT, we found a permanent 10% per year decrease in the GFR and noticeable disturbances in renal tubule function. The diastolic blood pressure also increased.

Adaptive Tomotherapy for locally advanced unresectable pancreatic neuroendocrine tumor: Case report and literature review

BACKGROUND

Pancreatic neuroendocrine tumor (NET) is rare, and the majority presents late in their clinical course. Here, we present a huge locally advanced pancreatic NET having Hi-Art helical Tomotherapy that resulted in a 68% reduction in target volume during adaptive image-guided radiotherapy (IGRT).

CASE SUMMARY

A 63-year-old man without any history of systemic disease developed voiding difficulty for several months. Associated symptoms included poor appetite, nausea, distended abdomen, and body weight loss. Further magnetic resonance imaging showed a large multilobulated tumor in the left upper abdomen. Tumor biopsy revealed well-differentiated, grade 2, neuroendocrine tumor. Complete resection was unattainable. Therefore, Lanreotide was prescribed initially. However, tumor progression up to the greatest diameter of 18 cm was noted on computed tomography 5 months later. Thus, he stopped Lanreotide and commenced on concurrent chemoradiotherapy (CCRT). With a total dose of 70 Gy in 35 fractions, we generated two adaptive treatment plans during the whole course. Laparoscopic subtotal pancreatectomy with spleen preservation was performed after neoadjuvant CCRT. It has been more than 3 years after IGRT, and he remains cancer free and reports no side effects during regular follow-ups.

CONCLUSION

Tomotherapy caused tumor size reduction and hence facilitated surgical possibility for this originally unresectable pancreatic NET. Neoadjuvant IGRT incorporated with adaptive treatment planning enhanced delivery accuracy. In this case of pancreatic NET resistant to Lanreotide, inter-fractional tumor regression from 1910 to 605 cc (68%) was documented.

PD-L1 expression and patient outcomes in gastrointestinal neuroendocrine neoplasm: a meta-analysis

BACKGROUND

Programmed cell death ligand 1 (PD-L1) is a known prognostic and therapeutic marker in malignant tumors. This meta-analysis aimed to investigate the association of PD-L1 expression with the clinicopathological parameters and survival outcomes of gastrointestinal neuroendocrine neoplasms (NENs).

METHODS

PubMed, EMBASE, Web of Science, OVID Medline, the Cochrane Library, and Google Scholar were searched for relevant studies June 30, 2020. Studies reporting PD-L1 immunohistochemistry of gastrointestinal NEN with associated survival data or clinicopathological parameters were included.

RESULTS

In total, 10 studies were included. Odd ratios (ORs) were combined to evaluate association between PD-L1 expression and clinicopathological parameters. Hazard ratios (HR) and standard errors were combined to evaluate the association between PD-L1 expression and overall survival. PD-L1 expression was significantly associated with higher tumor grade [OR: 3.42; 95% confidence interval (CI): 2.00-5.85, P<0.05] and lymph node metastasis (OR: 1.94; 95% CI: 1.13-3.34, P=0.02). However, PD-L1 expression was not associated with age, sex, and tumor stage. The pooled hazard ratio (HR: 2.45, 95% CI: 1.20-4.98, P<0.05) showed a significant association between PD-L1 expression and shorter overall survival.

DISCUSSION

The results of this meta-analysis show that PD-L1 expression in tumor cells of gastrointestinal NEN can be used as a biomarker of worse survival and important clinicopathological parameters. Further, it can also be used as a therapeutic biomarker for developing novel treatment modalities that can improve prognosis. Although the results of this meta-analysis are more robust than those of the individual studies analyzed, this study also has several limitations. Further studies with a larger study population and consistent method for evaluating PD-L1 expression are needed to validate our results.

Grade G2 Rectal Neuroendocrine Tumor Is Much More Invasive Compared With G1 Tumor

Background

To compare clinicopathologic feature of rectal neuroendocrine tumor (NET) grade G1 with G2 NET.

Methods

Six hundred-one cases of rectal G1 and G2 NETs diagnosed in our center were analyzed.

Results

Of 601 cases of rectal NET, 515 cases were with grade G1 and 86 cases were with grade G2. Median tumor size was 0.7 cm. Compared with G1 NET, G2 tumors were with significantly larger tumor size (0.8 vs 2.2 cm, p < 0.001), less percentages of patients with tumors confined to submucosa (92.6 vs 42.8%, p < 0.001), more frequent presence of microvascular invasion (MVI) (3.6 vs 16.9%, p < 0.001) or peri-neural invasion (PNI) (2.0 vs 24.1%, p < 0.001). Incidence of lymph node and distant metastasis was 5.2 and 2.1% in G1 NET compared with 44.2 and 31.4% in G2 tumor, respectively (p < 0.001). For tumors sized 1–2 cm and confined to submucosa, incidence of lymph node metastasis was 6.1% for G1 NET compared with 21.1% for G2 NET. Status of MVI/PNI was predictive of lymph node metastasis for G2 tumor rather than G1 NET in this subgroup.

Conclusions

Rectal G2 NET was much more invasive with significantly elevated prevalence of lymph node metastasis compared with G1 tumor.