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PubMed This is a summary of 19 peer-reviewed journal articles Updated
Oncology

Living with NENs: Monitoring and Survivorship

At a Glance

Many neuroendocrine neoplasms (NENs) are slow-growing and managed as chronic conditions. Long-term survivorship requires regular surveillance scans to monitor tumor status, proactive management of symptoms like carcinoid syndrome, and nutritional screenings to prevent vitamin deficiencies.

For many people, a neuroendocrine neoplasm (NEN) diagnosis is the start of a long-term relationship with the medical system. Because many NENs are slow-growing, the focus often shifts from “curing” the disease to managing it as a chronic condition [1]. This transition into survivorship requires a dual focus: regular monitoring to watch for changes and proactive management of your daily quality of life (QoL).

The Rhythm of Surveillance

Surveillance is the process of using scans and tests to “keep an eye” on the cancer over time. Your schedule will be highly individualized based on your tumor’s primary site, its grade, and how it has behaved in the past [2][3].

  • Imaging: Contrast-enhanced CT scans are the standard tool for monitoring the size and number of tumors [4]. In some cases, MRI or SSTR-PET/CT (like DOTATATE) may be used to provide a more detailed look [5].
  • Frequency: In the beginning, you may have scans every 3 to 6 months. If the disease remains stable, your doctor may eventually move these to once a year [6][7].
  • Biomarkers: While blood tests like Chromogranin A (CgA) were once routine, newer guidelines emphasize that they are not always reliable for monitoring and should be used cautiously alongside imaging [8].

Managing Chronic Symptoms: Beyond the Basics

If you have carcinoid syndrome, managing symptoms like chronic diarrhea is critical for maintaining your quality of life and preventing malnutrition [9].

  • Telotristat Ethyl (Xermelo): If monthly injections (SSAs) are not enough to control your diarrhea, your doctor may add a medication called telotristat ethyl [10]. This oral drug blocks the enzyme that makes serotonin, directly reducing the “chemical engine” behind the diarrhea [11][12]. Clinical trials have shown it can significantly reduce daily bowel movements and improve overall well-being [13][14].
  • The “Mimics” of Diarrhea: Not all diarrhea in NEN patients is caused by carcinoid syndrome. It can also be caused by bile acid malabsorption (BAM) (especially if you have had intestinal surgery) or pancreatic exocrine insufficiency (PEI) (if the tumor is in the pancreas or if you are on SSAs) [15][16]. Identifying the correct cause is essential. If PEI is the cause, it can often be effectively managed by taking pancreatic enzyme replacement pills with your meals.

Nutritional Health and Deficiencies

Living with a functional NEN can alter how your body processes nutrients. Up to 40% of NEN patients face a risk of malnutrition or specific vitamin deficiencies, which can sap your energy and affect your mood [9][17].

  • Pellagra (Vitamin B3 Deficiency): Patients with Carcinoid Syndrome are at a unique risk for Niacin (Vitamin B3) deficiency. Because the tumor steals an amino acid called tryptophan to overproduce serotonin, your body cannot make enough niacin. Symptoms include skin rashes, confusion, and worsened diarrhea. Routine nutritional screening should be a standard part of your care [9][18].

The Psychological Toll: “Scanxiety”

Living with a chronic cancer takes a significant psychological toll. Many patients experience “scanxiety”—the intense anxiety and distress that occurs in the days or weeks leading up to a surveillance scan and while waiting for results.

  • A Chronic Mindset: Unlike more common cancers that are treated with a “one-and-done” approach, NENs often require a long-term “watch and wait” or “treat and monitor” mindset. This can feel like living with a “waiting game” [19].

Empowering yourself with a specialized care team—including an oncologist who understands NENs, a dietitian, and psychological support—can help you move from simply surviving to truly living with this condition.

Common questions in this guide

How often do I need imaging scans for a neuroendocrine neoplasm?
Surveillance schedules are personalized based on your tumor's primary site, grade, and history. Initially, you may need scans every 3 to 6 months, which may be extended to once a year if your disease remains stable over time.
What are my options if my carcinoid syndrome diarrhea isn't controlled by injections?
If standard monthly SSA injections are not providing enough relief, your doctor might prescribe an oral medication called telotristat ethyl. This drug blocks the enzyme that produces serotonin, which directly reduces the chemical cause of the diarrhea.
Could something other than carcinoid syndrome be causing my diarrhea?
Yes. While carcinoid syndrome is a common cause, diarrhea can also be triggered by bile acid malabsorption or pancreatic exocrine insufficiency, especially if you have had intestinal surgery or take certain medications. Your care team can help pinpoint the exact cause to provide the right treatment.
Why am I at risk for a vitamin B3 (niacin) deficiency?
Tumors associated with carcinoid syndrome overproduce serotonin by stealing an amino acid called tryptophan from your body. Because tryptophan is needed to make niacin, this process can lead to a severe vitamin B3 deficiency known as pellagra.
What is scanxiety and how can I manage it?
Scanxiety is the common feeling of intense distress or nervousness that happens in the days leading up to a medical scan or while waiting for results. Building a specialized care team, working with a therapist, and joining patient support groups are highly recommended ways to cope with this chronic stress.

Questions to Ask Your Doctor

Curated prompts to bring to your next appointment.

  1. 1.How frequently will I need imaging (scans) and blood tests during my surveillance?
  2. 2.If my diarrhea isn't fully controlled by my monthly injection, is telotristat ethyl an option for me?
  3. 3.Are my digestive issues caused by carcinoid syndrome, or could they be related to bile acid malabsorption or pancreatic insufficiency?
  4. 4.Should I be working with a specialized dietitian to monitor for malnutrition or vitamin deficiencies like Niacin (B3)?
  5. 5.What psychological support or resources do you recommend for managing the anxiety that comes with regular scans?

Questions For You

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References

References (19)
  1. 1

    Better Management for Neuroendocrine Neoplasms: A Complex Task Ahead.

    Coriat R

    Journal of clinical medicine 2021; (10(9)) doi:10.3390/jcm10091859.

    PMID: 33922910
  2. 2

    Updates on Diagnostic and Therapeutic Management of Gastrointestinal and Pancreatic NET.

    Krug S, Schrader J, Rinke A

    Cancers 2022; (14(11)) doi:10.3390/cancers14112628.

    PMID: 35681608
  3. 3

    [Gastroenteropancreatic neuroendocrine neoplasms-Heterogeneity, management and perspectives of treatment and research].

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    Der Internist 2020; (61(8)):875-890 doi:10.1007/s00108-020-00832-x.

    PMID: 32676723
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    ENETS Consensus Guidelines for the Standards of Care in Neuroendocrine Tumors: Radiological, Nuclear Medicine & Hybrid Imaging.

    Sundin A, Arnold R, Baudin E, et al.

    Neuroendocrinology 2017; (105(3)):212-244 doi:10.1159/000471879.

    PMID: 28355596
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    Gastroenteropancreatic Neuroendocrine Tumor Diagnosis: DOTATATE PET/CT.

    Kandathil A, Subramaniam RM

    PET clinics 2023; (18(2)):189-200 doi:10.1016/j.cpet.2022.11.001.

    PMID: 36585339
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    Tumour grade and primary site predict patterns of recurrence and survival in patients with resected gastroenteropancreatic neuroendocrine tumors.

    Watanabe A, Yip L, Hamilton TD, et al.

    American journal of surgery 2021; (221(6)):1141-1149 doi:10.1016/j.amjsurg.2021.03.027.

    PMID: 33795127
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    Association between somatostatin analogues and diabetes mellitus in gastroenteropancreatic neuroendocrine tumor patients: A Surveillance, Epidemiology, and End Results-Medicare analysis of 5235 patients.

    Ni K, Yang JY, Baeg K, et al.

    Cancer reports (Hoboken, N.J.) 2021; (4(5)):e1387 doi:10.1002/cnr2.1387.

    PMID: 33835729
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    Critical updates in neuroendocrine tumors: Version 9 American Joint Committee on Cancer staging system for gastroenteropancreatic neuroendocrine tumors.

    Chauhan A, Chan K, Halfdanarson TR, et al.

    CA: a cancer journal for clinicians 2024; (74(4)):359-367 doi:10.3322/caac.21840.

    PMID: 38685134
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    Nutritional and vitamin status in patients with neuroendocrine neoplasms.

    Clement DS, Tesselaar ME, van Leerdam ME, et al.

    World journal of gastroenterology 2019; (25(10)):1171-1184 doi:10.3748/wjg.v25.i10.1171.

    PMID: 30886501
  10. 10

    Telotristat Ethyl for Patients With Carcinoid Syndrome Associated With Chest Pain and Hypertension.

    Kasi PM

    Pancreas 2018; (47(1)):e2 doi:10.1097/MPA.0000000000000971.

    PMID: 29232344
  11. 11

    Telotristat ethyl: a novel agent for the therapy of carcinoid syndrome diarrhea.

    Dillon JS, Chandrasekharan C

    Future oncology (London, England) 2018; (14(12)):1155-1164 doi:10.2217/fon-2017-0340.

    PMID: 29350062
  12. 12

    Inhibition of Peripheral Synthesis of Serotonin as a New Target in Neuroendocrine Tumors.

    Molina-Cerrillo J, Alonso-Gordoa T, Martínez-Sáez O, Grande E

    The oncologist 2016; (21(6)):701-7 doi:10.1634/theoncologist.2015-0455.

    PMID: 27107003
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    Telotristat Ethyl: A Review in Carcinoid Syndrome Diarrhoea.

    Lyseng-Williamson KA

    Drugs 2018; (78(9)):941-950 doi:10.1007/s40265-018-0935-1.

    PMID: 29931594
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    Long-Term Treatment with Telotristat Ethyl in Patients with Carcinoid Syndrome Symptoms: Results from the TELEPATH Study.

    Hörsch D, Anthony L, Gross DJ, et al.

    Neuroendocrinology 2022; (112(3)):298-310 doi:10.1159/000516958.

    PMID: 33940581
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    Bile Acid Malabsorption in Patients with Neuroendocrine Tumors.

    Khanna L, Halfdanarson TR, Sonbol MB, et al.

    Digestive diseases and sciences 2022; (67(6)):2517-2525 doi:10.1007/s10620-021-07189-7.

    PMID: 34365537
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    Differential diagnosis of diarrhoea in patients with neuroendocrine tumours: A systematic review.

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    World journal of gastroenterology 2020; (26(30)):4537-4556 doi:10.3748/wjg.v26.i30.4537.

    PMID: 32874063
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    Vitamin D deficiency and tumor aggressiveness in gastroenteropancreatic neuroendocrine tumors.

    Altieri B, Barrea L, Modica R, et al.

    Endocrine 2022; (75(2)):623-634 doi:10.1007/s12020-021-02869-w.

    PMID: 34533768
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    Nutritional status and gastroenteropancreatic neuroendocrine neoplasms: lights and shadows with a clinical guide from the NIKE Group.

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    Patient reported experience of the burden of neuroendocrine tumors and impact of eSHINE Patient Support Program on patient quality of life.

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    PMID: 33145888

This page provides informational resources on managing and monitoring neuroendocrine neoplasms. It does not replace professional medical advice. Always consult your oncology team about your specific surveillance plan and symptom management.

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