Delta-like ligand 3-targeted radioimmunotherapy for neuroendocrine prostate cancer.

Neuroendocrine prostate cancer (NEPC) is a lethal subtype of prostate cancer with limited meaningful treatment options. NEPC lesions uniquely express delta-like ligand 3 (DLL3) on their cell surface. Taking advantage of DLL3 overexpression, we developed and evaluated lutetium-177 (177Lu)-labeled DLL3-targeting antibody SC16 (177Lu-DTPA-SC16) as a treatment for NEPC. SC16 was functionalized with DTPA-CHX-A" chelator and radiolabeled with 177Lu to produce 177Lu-DTPA-SC16. Specificity and selectivity of 177Lu-DTPA-SC16 were evaluated in vitro and in vivo using NCI-H660 (NEPC, DLL3-positive) and DU145 (adenocarcinoma, DLL3-negative) cells and xenografts. Dose-dependent treatment efficacy and specificity of 177Lu-DTPA-SC16 radionuclide therapy were evaluated in H660 and DU145 xenograft-bearing mice. Safety of the agent was assessed by monitoring hematologic parameters. 177Lu-DTPA-SC16 showed high tumor uptake and specificity in H660 xenografts, with minimal uptake in DU145 xenografts. At all three tested doses of 177Lu-DTPA-SC16 (4.63, 9.25, and 27.75 MBq/mouse), complete responses were observed in H660-bearing mice; 9.25 and 27.75 MBq/mouse doses were curative. Even the lowest tested dose proved curative in five (63%) of eight mice, and recurring tumors could be successfully re-treated at the same dose to achieve complete responses. In DU145 xenografts, 177Lu-DTPA-SC16 therapy did not inhibit tumor growth. Platelets and hematocrit transiently dropped, reaching nadir at 2 to 3 wk. This was out of range only in the highest-dose cohort and quickly recovered to normal range by week 4. Weight loss was observed only in the highest-dose cohort. Therefore, our data demonstrate that 177Lu-DTPA-SC16 is a potent and safe radioimmunotherapeutic agent for testing in humans with NEPC.

[Value of postoperative radiotherapy and analysis of prognostic factors in early-stage neuroendocrine carcinoma of cervix].

Objective: To evaluate the effect of postoperative radiotherapy and high-risk pathological factors on the prognosis of early-stage neuroendocrine carcinoma of cervix (NECC). Methods: A single-center retrospective cohort study of early-stage NECC in Peking Union Medical College Hospital from January 2011 to April 2022 were enrolled. The patients were treated with radical hysterectomy±adjuvant treatment. They were divided into postoperative non-radiation group and postoperative radiation group. The possible postoperative recurrence risk factors identified by univariate analysis were assessed using multivariate logistic regression. The Kaplan-Meier method was used to analyze the progression free survival (PFS), overall survival (OS), recurrence rate, and mortality rate. Results: (1) Sixty-two cases were included in the study, including 33 cases in postoperative non-radiation group and 29 cases in postoperative radiation group. (2) The median follow-up time was 37 months (ranged 12-116 months), with 23 cases (37%) experienced recurrences. There were 7 cases (11%) pelvic recurrences and 20 cases (32%) distant recurrences, in which including 4 cases (6%) both pelvic and distant recurrences. Compared with postoperative non-radiation group, the postoperative radiation group had a lower pelvic recurrence rate (18% vs 3%; P=0.074) but without statistic difference, a slightly elevated distant recurrence rate (24% vs 41%; P=0.150) and overall recurrence rate (33% vs 41%; P=0.513) without statistically significances. Univariate analysis showed that lymph-vascular space invasion and the depth of cervical stromal invasion≥1/2 were risk factors for postoperative recurrence (all P<0.05). Multivariate analysis showed lymph-vascular space invasion was an independent predictor for postoperative recurrence (OR=23.03, 95%CI: 3.55-149.39, P=0.001). (3) During the follow-up period, 18 cases (29%, 18/62) died with tumor, with 10 cases (30%, 10/33) in postoperative non-radiation group and 8 cases (28%, 8/29) in postoperative radiation group, without significant difference (P=0.814). The postoperative 3-year and 5-year survival rate was 79.2%, 60.8%. The depth of cervical stromal invasion≥1/2 was more common in postoperative radiation group (27% vs 64%; P=0.011), and postoperative radiation in such patients showed an extended trend in PFS (32.3 vs 53.9 months) and OS (39.4 vs 73.4 months) but without statistic differences (P=0.704, P=0.371). Compared with postoperative non-radiation group, the postoperative radiation did not improve PFS (54.5 vs 37.3 months; P=0.860) and OS (56.2 vs 62.4 months; P=0.550) in patients with lymph-vascular space invasion. Conclusions: Postoperative radiation in early-stage NECC patients has a trend to reduce pelvic recurrence but not appear to decrease distant recurrence and overall recurrence, and has not improved mortality. For patients with the depth of cervical stromal invasion≥1/2, postoperative radiation has a trend of prolonging OS and PFS but without statistic difference. Lymph-vascular space invasion is an independent predictor for postoperative recurrence, but postoperative radiation in such patients does not seem to have any survival benefits.

Evaluation of Survival and Postoperative Radiation Among Patients with Advanced Medullary Thyroid Carcinoma: An Analysis of the National Cancer Database.

BACKGROUND: This study compared survival between patients who had medullary thyroid cancer (MTC) treated with surgery alone and patients who underwent surgery and radiation (SRT). METHODS: Patients from the National Cancer Database (NCDB) with a diagnosis of stage 3 or 4 MTC, lymph node disease, and no distant metastases between 2008 and 2016 were studied. Kaplan-Meier analyses and log-rank statistics were used to estimate and compare overall survival between patients treated with surgery alone and those treated with SRT. Mutlivariable Cox proportional hazards models and propensity-matching were used to adjust for confounding and selection bias. RESULTS: Among 1370 patients, 1112 (81%) received surgery alone, and 258 (19%) received SRT. The hazard ratio for mortality in the SRT group was 1.784 (95% confidence interval [CI] 1.313-2.43) after multivariable adjustment for confounding variables. Furthermore, SRT remained associated with a higher mortality rate (p < 0.008) after propensity-matching in an effort to adjust for selection bias. CONCLUSIONS: This analysis of NCDB patients showed that SRT is associated with a significantly higher mortality rate among patients treated for stage 3 or 4 IV MTC with positive lymph node disease. Although this observation can be attributed to unmeasured confounders or selection bias, the cause for the profound survival differences deserves prospective evaluation, especially as adjuvant therapies for this disease continue to evolve.

Successful salvage of recurrent leptomeningeal disease in large cell neuroendocrine lung cancer with stereotactic radiotherapy.

A 70-year old male with stage I large cell neuroendocrine carcinoma (LCNEC) of the lung underwent resection of a metachronous 5 cm brain metastasis and received postoperative hypofractionated stereotactic radiotherapy (hfSRT). Five sequential nodular leptomeningeal metastases up to 5.3 cm in diameter were diagnosed on MRI within 10 months and were treated with SRT. Currently the patient has no evidence of intracranial disease 24 months after last irradiation without chemotherapy or whole brain radiotherapy. This is the first report of sustained complete remission of multiple large leptomeningeal metastases achieved with hfSRT, highlighting this brain-sparing approach in selected patients with LCNEC lung cancer.

Efficacy and safety of peptide receptor radionuclide therapy in advanced radioiodine-refractory differentiated thyroid cancer and metastatic medullary thyroid cancer: a systematic review.

BACKGROUND: It has been shown that a subgroup of patients with differentiated thyroid cancer (DTC) and medullary thyroid carcinoma (MTC) would progress to advanced stages of thyroid cancer. Therefore, the present study was done to systematically review available evidence in order to investigate efficacy and safety of peptide receptor radionuclide therapy (PRRT) in the patients with advanced radioiodine refractory differentiated thyroid cancer (RR-DTC) and metastatic MTC. METHODS: For this purpose, relevant studies investigated safety and efficacy of PRRT in the patients with advanced RR-DTC and metastatic MTC were identified by searching Medline (Pubmed, Ovid, and Ebsco), Scopus, Embase, Web of Science, and Cochrane Library databases (from database inception to March 24, 2021). The review was performed according to the preferred reporting items for systematic reviews and meta-analyses (PRISMA) statement. Searching was done independently by two investigators. Two researchers independently extracted the data and any disagreement was adjudicated by consensus. Quality of the studies was assessed using the tool of case reports/series in systematic reviews. RESULTS: Among 2284 related papers, 41 papers met the inclusion criteria. A total of 157 patients with RR-DTC were treated with PPRT. Biochemical and objective responses (partial and complete) were observed in 25.3 and 10.5% of patients, respectively. Among 220 patients with metastatic MTC, biochemical and objective responses were observed in 37.2 and 10.6% of the patients, respectively. Forty-six deaths were reported in 95 patients with advanced RR-DTC. In addition, 63 deaths were observed in 144 patients with metastatic MTC. Major side effects were reported in 124 patients treated with 90Y -based agent. In the patients treated with 177Lu-DOTA-TATE and 111In-Octreotide, mild and transient hematologic or renal complications were reported. CONCLUSION: Findings of the study revealed that in the absence of the established treatment for the patients with RR-DTC and metastatic MTC, PRRT could be effective with few adverse events. TRIAL REGISTRATION: PROSPERO registration number: CRD42019125245 .

Unexpected response to palliative radiotherapy for subcutaneous metastases of an advanced small cell pancreatic neuroendocrine carcinoma: a case report of two different radiation schedules.

BACKGROUND: Skin metastases from pancreatic neuroendocrine carcinoma (PNEC) are rare and their palliative treatment is challenging. We report our experience in the multimodal management of one of the few reported cases of metastatic PNEC with multiple visceral and subcutaneous secondary lesions, focusing on the effectiveness of palliative radiotherapy for skin metastases. CASE PRESENTATION: A 61-years old woman affected by a metastatic PNEC - with subcutaneous growing and bleeding secondary lesions (at the scalp, right scapular region and at the back of the left thoracic wall, respectively) - obtained a successful control of visceral metastases with the use of chemotherapy and an unexpected local response of her skin metastases with palliative radiotherapy. In particular, two subsequent radiation treatments were performed using different fractionation schedules (30 Gy in 10 fractions and 20 Gy in 5 fractions, respectively). Both radiation treatments were well-tolerated and patient's quality of life was improved. Local response was maintained until patient's death - that occurred due to cachexia. CONCLUSIONS: The presented case highlights the effectiveness and the good tolerance of radiotherapy in the treatment of subcutaneous metastases; nevertheless, further knowledge of the optimal local palliative approach for PNEC metastatic sites is necessary. The experience gained in this work is the occasion to encourage a routine integrated multidisciplinary team management of metastatic PNECs because of their clinical complexity. The aim is to guarantee the optimization of the care with personalized and more effective systemic and local treatments - also including supportive cares and treatment-related side effects management.

A retrospective study of definitive chemoradiotherapy in patients with resectable small cell neuroendocrine carcinoma of the esophagus.

BACKGROUND: Standard treatment for resectable small cell neuroendocrine carcinoma of the esophagus (SCNEC-E) remains to be established. METHODS: We retrospectively studied 7 consecutive patients with resectable SCNEC-E who received definitive chemoradiotherapy (dCRT) to evaluate the safety and efficacy. Treatment consisted of two courses of chemotherapy with cisplatin (80 mg/m2 on day 1) and etoposide (100 mg/m2 on days 1-3) or carboplatin (AUC 5 on day 1) and etoposide (80 mg/m2 on days 1-3) given every 4 weeks during dCRT. The total radiation dose was 50.4 Gy (28 fractions). RESULTS: The clinical stage was IA in 1 patient, IB in 2 patients, IIA in 3 patients, and IIB in 1 patient. Definitive CRT was completed in all patients. The median overall treatment time of radiotherapy was 44 days. The chemotherapy regimen included in dCRT was cisplatin and etoposide in 3 patients and carboplatin and etoposide in 4 patients. Acute adverse events of grade 3 or 4 were neutropenia 100%, thrombocytopenia 43%, febrile neutropenia 43%, and nausea 14%. There were no late grade 3 or 4 adverse events. The median survival time was 32 months. The complete response rate was 100%. The recurrence rate was 43%. The median survival of the 4 patients without recurrence was 56 months. CONCLUSIONS: Definitive CRT with cisplatin and etoposide or carboplatin and etoposide is a feasible treatment for the resectable SCNEC-E, and long-term survival can be achieved in some patients.

Peptide receptor radionuclide therapy in patients with medullary thyroid carcinoma: predictors and pitfalls.

BACKGROUND: For progressive metastatic medullary thyroid carcinoma (MTC), the available treatment options with tyrosine kinase inhibitors result in grade 3-4 adverse events in a large number of patients. Peptide Receptor Radionuclide Therapy (PRRT), which has also been suggested to be a useful treatment for MTC, is usually well tolerated, but evidence on its effectivity is very limited. METHODS: Retrospective evaluation of treatment effects of PRRT in a highly selected group of MTC patients, with progressive disease or refractory symptoms. In addition, a retrospective evaluation of uptake on historical 111In-DTPA-octreotide scans was performed in patients with detectable tumor size > 1 cm. RESULTS: Over the last 17 years, 10 MTC patients were treated with PRRT. Four out of 10 patients showed stable disease at first follow-up (8 months after start of therapy) whereas the other 6 were progressive. Patients with stable disease were characterized by a combination of both a high uptake on 111In-DTPA-octreotide scan (uptake grade ≥ 3) and a positive somatostatin receptor type 2a (SSTR2a) expression of the tumor by immunohistochemistry. Retrospective evaluation of historical 111In-DTPA-octreotide scans of 35 non-treated MTC patients revealed low uptake (uptake grade 1) in the vast majority of patients 31/35 (89%) with intermediate uptake (uptake grade 2) in the remaining 4/35 (11%). CONCLUSIONS: PRRT using 177Lu-octreotate could be considered as a treatment in those patients with high uptake on 111In-DTPA-octreotide scan (uptake grade 3) and positive SSTR2a expression in tumor histology. Since this high uptake was present in a very limited number of patients, this treatment is only suitable in a selected group of MTC patients.

Exceptional Response to Nivolumab and Stereotactic Body Radiation Therapy (SBRT) in Neuroendocrine Cervical Carcinoma with High Tumor Mutational Burden: Management Considerations from the Center For Personalized Cancer Therapy at UC San Diego Moores Cancer Center.

Neuroendocrine carcinoma of the cervix is an ultra-rare malignancy with a poor prognosis and limited treatment options. Checkpoint blockade immunotherapy has rapidly developed into an emerging standard of care for several common disease types. Interestingly, in preclinical and retrospective clinical data, radiation therapy has been demonstrated to synergize with checkpoint inhibitors. Here we report a patient with metastatic, chemotherapy-refractory neuroendocrine carcinoma who presented with partial bowel obstruction due to a large tumor burden. Genomic analysis demonstrated a high number of alterations on liquid biopsy (circulating tumor DNA [ctDNA]), which prompted treatment with stereotactic body radiation therapy (SBRT) combined with anti-programmed cell death protein 1 antibody. Tissue rebiopsy and comprehensive genomic profiling confirmed high tumor mutational burden and a mismatch repair gene defect. The patient manifested near-complete systemic resolution of disease, ongoing at 10+ months. We discuss the novel treatment modality of SBRT combined with a checkpoint inhibitor and the implications of molecular profiling and tumor mutational burden as potential predictors of response. KEY POINTS: High-grade, large-cell neuroendocrine carcinoma of the cervix is an ultra-rare malignancy that carries a grim prognosis.Next-generation sequencing may reveal key mutations in MSH2 genes amongst others. MSH2 mutations target the DNA mismatch repair process and can predispose patients to malignancies with high mutational burdens.Immunotherapy combined with radiation therapy can elicit a significant response, both within and outside the field of radiation. The latter is termed the "abscopal" effect, perhaps mediated by radiation-induced cross presentation of tumor antigens resulting in immune activation.Sequencing of blood-derived ctDNA showed a high number of alterations, and tissue sequencing confirmed a high tumor mutational burden as a consequence of a mismatch repair gene defect. This observation led to a therapeutic "match" with an anti- programmed cell death protein 1 antibody combined with SBRT, resulting in a durable (10+ months), near-complete remission in a patient with advanced chemotherapy-refractory disease.

Progress in the treatment of esophageal neuroendocrine carcinoma.

Esophageal neuroendocrine neoplasms are rare. With the improvement and popularization of diagnostic methods, the morbidity statistics have increased annually in recent years. There are currently no treatment guidelines for esophageal neuroendocrine neoplasms, and surgery is the only cure. This usually involves radical surgery when the tumor is limited to the primary site or when only regional lymph node metastasis occurs. Surgical treatment is key to treating esophageal neuroendocrine neoplasms, but combined treatment with chemotherapy and radiotherapy can significantly improve patient survival. The effect of radiotherapy alone on this disease is poor. However, targeted endocrine therapy can improve endocrine hormone symptoms. The prognosis of patients with esophageal neuroendocrine neoplasms is mainly determined by the pathological stage. With the development of molecular biology techniques, the combination of targeted drugs and traditional chemotherapy is expected to provide novel ideas and directions for the treatment of esophageal neuroendocrine neoplasms in the coming years. In this article, the status of esophageal neuroendocrine tumor treatments was reviewed in detail.

Discrepant salivary gland response after radioiodine and MIBG therapies.

BACKGROUND: A retrospective study using PET/CT imaging with 124I-labeled metaiodobenzylguanidine (124I-MIBG) was performed to estimate the (radiation) absorbed dose to the salivary glands in neuroendocrine cancer patients undergoing 131I-MIBG therapy and to compare these results with those in radioiodine (131I-iodide) therapy. METHODS: Twenty-seven patients received individual 124I-MIBG-PET/CT dosimetries, among whom 18 had not previously undergone any MIBG therapies (patient group before treatment) and 9 had already received MIBG therapies prior to the tracer dosimetries (patient group after treatment). For each patient, three or four 124I-MIBG PET/CT scans were performed at approximately 4 and 24 hours, as well as at approximately 48 or/and ≥96 hours after tracer injection. The absorbed doses per administered 131I-MIBG activity to the submandibular and parotid glands were calculated based on the MIRD concept, with its assumption of a uniform glandular activity distribution. RESULTS: The mean±standard deviation of the (self-)absorbed dose per activity averaged over both patient groups and salivary gland types was 0.53±0.24 Gy/GBq (median, 0.49 Gy/GBq; range, 0.17-1.38 Gy/GBq). The absorbed doses per activity of the patient group before treatment did not significantly deviate from those of the patient group after treatment (P=0.67). In the patient group after treatment, the mean±standard deviation of the cumulative 131I-MIBG activity was 20±12 GBq (median, 16 GBq; range, 10-50 GBq). Among the patient groups, no significant absorbed dose difference was found between the submandibular and parotid glands (P>0.24). In comparison to radioiodine therapy, the estimated absorbed dose per activity in MIBG was significantly higher (P<0.001), on average twice as high, contradicting the relationship between the absorbed dose and clinical observation of glandular side effects. CONCLUSIONS: The discrepant salivary gland responses in MIBG and radioiodine therapies suggest a different radiotherapeutical distribution on microscopic scale within the glandular tissue and prove the clinical relevance of a microdosimetric analysis.

Long-term results of PRRT in advanced bronchopulmonary carcinoid.

PURPOSE: Peptide receptor radionuclide therapy (PRRT) for the treatment of neuroendocrine tumours (NET) has been explored for almost two decades, but there are still few trials that have exclusively investigated well-differentiated and moderately differentiated NET arising from the respiratory tree. Thus, the aim of this study was to explore the outcome in patients affected by bronchopulmonary carcinoid (BPC) following PRRT. METHODS: We retrospectively analysed 114 patients with advanced stage BPC consecutively treated with PRRT at the European Institute of Oncology, Milan, from 1997 to 2012 and followed until October 2014. The objective responses, overall survival (OS) and progression-free survival (PFS) were rated, and three different PRRT protocols ((90)Y-DOTATOC vs. (177)Lu-DOTATATE vs. (90)Y-DOTATOC + (177)Lu-DOTATATE) were compared with regard to their efficacy and tolerability. RESULTS: The median OS (evaluated in 94 of the 114 patients) was 58.8 months. The median PFS was 28.0 months. The (177)Lu-DOTATATE protocol resulted in the highest 5-year OS (61.4%). Morphological responses (partial responses + minor responses) were obtained in 26.5% of the cohort and were associated with longer OS and PFS. The (90)Y-DOTATOC + (177)Lu-DOTATATE protocol provided the highest response rate (38.1%). Adverse events were mild in the majority of patients. However, haematological toxicity negatively affected survival. No severe (grade 3/4) serum creatinine increase was observed. Patients treated with (90)Y-DOTATOC alone more frequently showed a mild/moderate decrease in renal function. In patients treated with chemotherapy before PRRT had a shorter OS and PFS, and a higher risk of developing nephrotoxicity. CONCLUSION: In a large cohort of patients with advanced BPC treated in a "real-world" scenario and followed up for a median of 45.1 months (range 2-191 months), PRRT proved to be promising in prolonging survival and delaying disease progression. Despite the potential selection biases, considering the risk-benefit ratio, (177)Lu-DOTATATE monotherapy seems the best option for PRRT. Our results indicate that the use of PRRT in earlier stages of the disease could provide a more favorable outcome.

Nonsurgical Management of Neuroendocrine Cancer of the Cervix: Brief Report.

OBJECTIVES: The aim of this study was to evaluate disease progression and overall survival in patients diagnosed with neuroendocrine carcinoma of the cervix treated with chemotherapy and radiation without surgical intervention; we hypothesize similar overall survival to the surgical intervened cases. METHODS: This study used a retrospective analysis of patients with neuroendocrine carcinoma of the cervix who were not surgically managed. Review was performed from 1990 to 2014. The data collected included demographics, stage of disease, and outcomes after each treatment. Specific chemotherapy regimen given and radiation dosage were reviewed. Overall survival and recurrence rates were calculated. RESULTS: A total of 16 patients met inclusion criteria. Six patients were diagnosed with stage I; these patients had 83.3% 2-year overall survival, 83.3% 5-year overall survival, and a recurrence rate of 16.6%. Three patients were diagnosed with stage II; these patients had 66.6% 2-year overall survival, 0% 5-year overall survival, and a recurrence rate of 100%. Seven patients were diagnosed with stage IV; these patients had 14.3% 2-year overall survival and 0% 5-year overall survival and never underwent remission. CONCLUSIONS: Our findings noted a comparable overall survival with lower rates of recurrence in patients with early-stage disease using chemotherapy and radiation therapy alone as primary means of treatment. Nonsurgical management of neuroendocrine carcinoma of the cervix may be of benefit in early-stage disease.

[A case of gastric endocrine cell carcinoma which was significantly reduced in size by radiotherapy].

In 2010, the World Health Organization classified gastric neuroendocrine tumors (NETs) into three types: NET grade (G) 1, NET G2 and neuroendocrine carcinoma (NEC). NECs are associated with a very poor prognosis. The patient was an 84-year-old female who was initially diagnosed by gastrointestinal endoscope with type 3 advanced gastric cancer with stenosis of the gastric cardia. Her overall status and performance status did not allow for operations or intensive chemotherapy. Palliative radiotherapy was performed and resulted in a significant reduction in the size of the tumor as well as the improvement of the obstructive symptoms. She died 9 months after radiotherapy. An autopsy provided a definitive diagnosis of gastric endocrine cell carcinoma, and the effectiveness of radiotherapy was pathologically-confirmed. Palliative radiotherapy may be a useful treatment option for providing symptom relief, especially for old patients with unresectable advanced gastric neuroendocrine carcinoma.

Synchronous two distinct neuroendocrine lung cancer lesions.

The synchronous primary lung tumors is a rare condition and presented patient is the first reported case of simultaneous two distinct neuroendocrine lung cancer lesions in the same lobe. We present the case of a 55-year-old woman with synchronous two distinct neuroendocrine lung cancer lesions in the right upper lobe. Initially she showed no signs or symptoms related to lung lesions and was admitted to Thoracic Surgery Ward for the investigation of two oval, solitary pulmonary nodules (11 and 19 mm in diameter) detected on a chest X-ray performed three months earlier. The radiological imaging showed a variability of growth of both lesions (smaller tumor has enlarged while the larger one remained unchanged). After the CT-guided lung biopsy, patient underwent right upper lobectomy. Histological examination revealed a small cell carcinoma in one of the tumors and a large cell neuroendocrine carcinoma in the other one. The patient was discharged in good condition and lung inflation in chest X-ray and qualified for adjuvant chemotherapy with a combination of cisplatin and etoposide and the prophylactic cranial irradiation. Very important issues, having impact on outcome of patients with multiple lung tumours is differentiation whether the lesions are metastases or synchronous primary lung tumors and the optimal management of these patients.

[A case of intracranial invasion from sinonasal small cell neuroendocrine carcinoma].

Sinonasal neuroendocrine carcinomas (NECs) are rare tumors. We present a rare case of intracranial invasion of sinonasal small-cell NEC. A 61-year-old woman with nasal obstruction and bleeding was referred to our hospital. Computed tomography showed a polyp-like tumor occupying her left nasal cavity and extending to the paranasal sinuses and anterior cranial fossa. The tumor was removed using a transfacial approach by otolaryngologists and a bifrontal cranial approach by neurosurgeons. In histopathological analyses, we found that the tumor presented with both an epithelial and neuroendocrine nature, and was diagnosed as a small-cell NEC. Post-surgery, she received localized radiation therapy and chemotherapy, and is alive, 18 months after diagnosis. In cases where it is difficult to perform a differential diagnosis of tumors arising from the frontal cranial base and extending to the nasal and cranial sides, NEC should be considered as a possibility.

Decreasing utilization for postoperative radiation therapy in locoregionally advanced medullary thyroid cancer.

BACKGROUND: Use of postoperative radiation therapy (PORT) in locoregionally advanced medullary thyroid cancer (MTC) remains controversial. The objective was to evaluate the effect of PORT on locoregional control (LRC) and overall survival (OS). METHODS: Retrospective cohort study of 346 MTC patients separated into PORT and no-PORT cohorts. Relative indications for PORT, as well as changes in patterns of treatment, were recorded. RESULTS: 49/346 (14%) received PORT. PORT was associated with worse OS; adjusted HR = 2.0 (95%CI 1.3-3.3). PORT was not associated with improved LRC, even when adjusting for advanced stage (Stage III p = 0.892; Stage IV p = 0.101). PORT and targeted therapy were not associated with improved OS compared to targeted therapy alone; adjusted HR = 1.2 (95%CI 0.3-4.1). CONCLUSIONS: Use of PORT in MTC has decreased and its indications have become more selective, coinciding with the advent of effective targeted therapies. Overall, PORT was not associated with improved LRC or OS.

Transformation of G1-G2 neuroendocrine tumors to neuroendocrine carcinomas following peptide receptor radionuclide therapy.

We observed that some patients with well-differentiated neuroendocrine tumors (NET) who received peptide receptor radionuclide therapy (PRRT) with Lutetium-177 (177Lu) DOTATATE developed rapid disease progression with biopsy-proven histologic transformation to neuroendocrine carcinoma (NEC), an outcome that has not been previously described. Therefore, we conducted a retrospective review of all patients with well-differentiated G1-G2 NET who received at least one cycle of PRRT with (177Lu) DOTATATE at our center from January 2019 to December 2020. Among 152 patients, we identified 7 patients whose NET transformed to NEC. Median time from start of PRRT to transformation was 8.2 months (range: 2.6-14.4 months). All patients whose tumors underwent transformation had pancreatic tail as the primary site and had prior chemotherapy with temozolomide. No differences in the incidence of transformation were observed according to gender, race, original tumor grade, or number of prior therapies. Six patients received treatment with platinum and etoposide after transformation with two patients having partial response as best response. All patients with transformation died from progressive disease with median overall survival (OS) after transformation of 3.3 months (95% CI 2.1-4.4). Molecular testing of transformed NEC identified mutation(s) in TP53 and/or ATM in all cases. Transformation of NET to NEC following PRRT is associated with aggressive course and dismal prognosis. Patients with pancreatic tail as the primary site who had prior therapy with temozolomide may be at a higher risk. Further investigation is necessary to determine the best treatment sequence in this patient population.