Role of radiotherapy for pancreatobiliary neuroendocrine tumors

Case reports: chemoradiotherapy for locally advanced neuroendocrine carcinoma of the gallbladder

Neuroendocrine carcinoma (NEC) is a rare subtype of malignant gallbladder tumor. Although surgical resection is the only potentially curative therapy for gallbladder NEC, most cases are surgically unresectable because of advanced stage disease and/or biologically aggressive behavior. The standard palliative treatment for malignant gallbladder tumors is chemotherapy; however, the efficacy of chemoradiotherapy in the treatment of gallbladder tumors is controversial. Here, we report a case of gallbladder NEC that showed a durable response to chemoradiotherapy. A 68-year-old Japanese man presented with a huge gallbladder tumor with liver and duodenal invasion. Pathological findings revealed poorly differentiated NEC of the gallbladder. After seven cycles of chemotherapy comprising cisplatin and irinotecan, computed tomography (CT) revealed remarkable tumor shrinkage, but an enlarged portal lymph node. The patient was treated with 50.4 Gy in 28 fractions with two cycles of cisplatin and etoposide. After chemoradiotherapy, the enlarged lymph node also decreased in size. Maximum standardized uptake value of fluorodeoxyglucose-positron emission tomography/CT(FDG-PET/CT) changed from 8.2 to physiological accumulation. We defined this condition as a complete response on both enhanced CT and FDG-PET/CT; therefore, we did not perform systemic treatment and only observed his condition. This patient remained healthy with no recurrence at 3 years after chemoradiotherapy.

Outcomes after high-dose radiation in the management of neuroendocrine neoplasms

BACKGROUND

Neuroendocrine neoplasms (NENs) comprise a rare and heterogenous group of cancers, for which the role of radiation therapy continues to evolve. The purpose of this study is to analyze oncologic outcomes after the use of high-dose radiation in management of NENs at a tertiary hospital.

MATERIALS AND METHODS

We performed a retrospective review of patients who received high-dose radiation with intent to cure or provide durable local control (defined as biologically effective dose (BED) ≥40, α/β = 10) for a localized or metastatic NEN from 2006 to 2019. Evaluation of disease status after radiation was performed according to Response Evaluation Criteria in Solid Tumors (RECIST) criteria when possible. Patients were grouped by differentiation (well-differentiated (WD) or poorly-differentiated (PD)) and stage (localized/locally advanced disease (L) or metastatic (M)) in analysis of probabilities of progression after radiation.

RESULTS

45 patients completed a radiation course with BED ≥40 for a NEN (median BED 72). With a median follow-up of 24 months after radiation, the 2-year actuarial rates of local relapse-free survival, new metastasis-free survival, progression-free survival, and overall survival after radiation were 98%, 45%, 41%, and 69%, respectively. 25 patients (56%) developed new metastases after completion of radiation, including 33% (n = 3) of patients with WD-L disease, 44% (n = 8) of WD-M, 77% (n = 10) of PD-L, and 80% (n = 4) of PD-M, with progressively shorter median times to progression (26, 9, 8, and 3 months, respectively; p = 0.093). Of the 25 patients evaluable by RECIST, 68% (n = 17) achieved either a complete or partial best response in the irradiated lesion.

CONCLUSIONS

These data suggest that focal, high-dose radiation has a role in the management of selected patients with NENs. Local failure is rare in patients with both well-differentiated and poorly-differentiated disease, although the predominant pattern of failure remains development of new metastases.

Early post-surgical recurrence of metastatic vertebral neuro-endocrine tumour treated effectively with chemo-radiotherapy

Spinal metastasis of neuro-endocrine tumours (NETs) usually arise from a primary in the lung. We encountered such a patient with NET metastasis to T6 vertebra causing severe cord compression. Considering the neurological status, immediate decompression surgery along with T3-T8 posterior stabilization was done. Early recurrence of the tumour causing near total obliteration of the spinal canal leading to significant neurological compromise was noted within one month of surgery. A second surgery at this stage was avoided due to the risk involved and concurrent chemo-radiotherapy was initiated. The tumour was sensitive to chemo-radiotherapy and rapid resolution was noted on subsequent follow-up visits. With appropriate rehabilitation, patient regained full power to become ambulant with support. This case report highlights a rare, early and aggressive recurrence of metastatic vertebral NET following index surgery which was effectively managed with chemo-radiotherapy.

External Beam Radiotherapy in the Treatment of Gastroenteropancreatic Neuroendocrine Tumours: A Systematic Review

AIMS

External beam radiotherapy (EBRT) is infrequently used to treat gastroenteropancreatic neuroendocrine tumours (GEPNETS), with little published data to date. We carried out a systematic review to assess the activity of EBRT for GEPNETS.

MATERIALS AND METHODS

Major databases were searched for papers including at least five patients treated with contemporary EBRT techniques. Eligible studies underwent dual independent review. The primary end points were response rate for lesions treated with definitive intent and recurrence-free survival for primary lesions treated with neoadjuvant or adjuvant intent.

RESULTS

Of 11 included studies (all retrospective), seven investigated pancreatic neuroendocrine tumours (PNETs, 100 patients, 14% grade 3) and four studies investigated extra-pancreatic neuroendocrine tumours (84 patients, 14% grade 3). Trials investigating PNETs administered a median of 50.4 Gy via three-dimensional conformal radiotherapy and intensity-modulated radiotherapy. EBRT was given with neoadjuvant or adjuvant intent in 56 patients, with a recurrence rate of 15%. For the 44 patients not undergoing surgery, the radiological response rate was 46%. Grade 3 + toxicity rates were 11% (acute) and 4% (late). Twelve patients with anorectal neuroendocrine carcinoma received 58 Gy to the primary tumour. Seventy-two patients were treated to sites of metastatic disease (34 bone, 27 brain, 11 soft tissue). Local and distant control were poorly reported. Overall survival ranged from 9 to 19 months. No studies in this group reported toxicity outcomes.

CONCLUSIONS

There are limited, retrospective data on the overall activity and safety of EBRT in GEPNETS. EBRT generally seems to be well tolerated in selected PNET patients with encouraging activity. Well-designed prospective studies in clearly defined populations are required to clarify the role of EBRT in neuroendocrine tumours.

Efficacy of radiotherapy for primary tumor in patients with unresectable pancreatic neuroendocrine tumors

Background

Detailed information regarding the clinical efficacy of radiotherapy (RT) for primary tumor in patients with unresectable pancreatic neuroendocrine tumors (pNETs) is unknown. We therefore performed a retrospective study to evaluate the efficacy and safety of RT for primary pancreatic tumors in patients with pNETs.

Methods

We investigated 11 patients with pNETs who received RT to the primary site between January 1997 and June 2015. Seven patients had Grade 2 neuroendocrine tumors (NET-G2) and four had neuroendocrine carcinoma (NEC) according to the 2010 WHO histopathological classification.

Results

The tumor response and control rates were 27.2% and 100%, respectively (3: partial response, 8: stable disease). Among patients with NET-G2 tumors, the response rate was 28.5% (2/7 patients) and symptomatic improvement was noted in 33.3% of the patients (1/3 patients). The response rate for patients with NEC were 25% (1/4), one NEC patients with symptoms exhibited symptomatic improvement. The median overall survival and median progression-free survival were 35.9 months and 5.5 months, respectively. Grade 3 diarrhea as an acute toxicity and Grade 3 gastrointestinal hemorrhage as a late toxicity were observed.

Conclusions

RT to the primary cancer site in patients with pNETs was an effective modality for local disease control and the treated patients had good outcomes. If metastatic tumors are under control, RT to the primary site may be beneficial for patients with pNETs.

May we challenge the ENETS guidelines in pancreatic neuroendocrine neoplasms? A quiz for French experts

INTRODUCTION

Recent guidelines have been published by a consensus of international experts (2016 ENETS (European NeuroEndocrine Tumor Society) guidelines). Nevertheless, in case of pancreatic neuroendocrine neoplasms (panNEN) the ENETS guidelines fail to propose a unique strategy in some situations, due to the lack of high-level of evidence and the absence of formal agreement between the experts drawing up the guidelines.

MATERIAL AND METHODS

A survey of 25 questions on panNEN was sent to 104 French experts challenging the guidelines. Questions focused on clinical situations in localized G-1/2 panNEN, localized G-3 panNEN, metastatic G-1/2 panNEN, and metastatic G-3 panNEN for which multiple options were proposed by the ENETS guidelines.

RESULTS

Fifty-seven experts (55%) have answered the survey. 18/25 questions obtained at least 50% similar responses, allowing a "consensus" or a "position statement". Among the results, surgery of small panNEN is preferred to surveillance in young patients; the temozolomide-capecitabine combination is favored instead of streptozotocin-based chemotherapy for G-1/2 metastatic panNEN.

CONCLUSION

French experts are mostly in line with the European guidelines, but some differences do exist. Whilst waiting for prospective studies, this survey helps physicians to propose standardized procedures and identifies situations where a step forward has been enabled by French experts. This questionnaire paves the way for a simplified therapeutic algorithm of panNEN.

A case of pancreatic neuroendocrine tumors

Pancreatic neuroendocrine tumors (pNETs) are an uncommon malignancy arising from the neuroendocrine cells of pancreas. Most cases of pNETs present with metastatic disease, but there are few reports in the literature describing pNETs metastasis to the lung and mediastinal lymph nodes [1]. Moreover, although a multimodal treatment including surgical resection and chemotherapy is acceptable for management of pNETs, advanced pNETs still remain a difficult therapeutic challenge [2, 3]. Radiotherapy or combined chemoradiotherapy has not been standard in the treatment of pNETs. An 80-year-old female was admitted to our hospital with cough and anorexia. She had been diagnosed and resected pNETs 8 years ago. Mass shadow was pointed out with chest X-ray, and endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) was performed. Pathological examination revealed neuroendocrine tumors, so the lung mass was considered as metastasis of pNETs. Then, we discussed her treatment at Cancer Board, and radiotherapy was chosen. We hope this case suggests that radiotherapy will be one of the treatment options for metastatic pNETs.