{
  "abstract": "Introduction The incidence of gastroenteropancreatic neuroendocrine tumours (GEP-NET) is increasing, with patients living many years after diagnosis. This raises concern about the presence of metachronous second primary (SP) malignancies. There is limited evidence on the incidence of SP of gastrointestinal and colorectal cancers in GEP-NET survivors. This study aimed to estimate the incidence and timing of SP malignancies, especially colorectal cancer, in patients with GEP-NET.Methods A total of 18,659 and 66,955 adult GEP-NET patients were extracted from the England National Cancer Registration and Analysis Service (NCRAS) 2012–2021 and the US Surveillance, Epidemiology, and End Results (SEER) 2000–2022 registries, respectively. Patients were categorised as those with SP malignancy (Group-1) and those without SP malignancy (Group-2). The annual incidence rates of SP colorectal malignancy and SP GEP malignancy were calculated for both NCRAS and SEER cohorts. Cumulative incidence and Kaplan-Meier (KM) curves were plotted.Results In the NCRAS cohort, Group-1 represented 1.02% of patients. The predominant site was colorectal (63.9%). Group-1 was older (mean age of 67.6 years), predominantly male (62.3%), and White (91%). There was no difference between the 2 groups in terms of deprivation status and rurality. The median time to SP colorectal or any SP malignancy was 54 months. The annual incidence of SP colorectal or any SP malignancy was 133/100,000 and 209/100,000 person-years, respectively.In the SEER cohort, Group-1 represented 2.6% of patients. The predominant site was colorectal (32.8%). Group-1 was older (mean age of 59.8 years), with a higher representation of non-White races (47%) and lower income. There was no difference between the 2 groups in terms of sex and rurality. The median time to SP colorectal or any SP malignancy was 48 months. The annual incidence of SP colorectal or any SP malignancy was 140/100,000 and 402/100,000 person-years, respectively.Conclusion There is a clinically relevant risk of metachronous second primary malignancies, especially colorectal cancer, in patients with GEP-NET. The incidence figures may support the use of faecal immunochemical testing (FIT) after GEP-NET diagnosis to screen for a second colorectal malignancy.",
  "authors": [
    {
      "affiliations": [
        "Hampshire Hospital NHS Trust, Basingstoke, United Kingdom"
      ],
      "name": "Ker Shiong Tan"
    },
    {
      "affiliations": [
        "Hampshire Hospital NHS Trust, Basingstoke, United Kingdom"
      ],
      "name": "Mohamed Mortagy"
    },
    {
      "affiliations": [
        "Hampshire Hospital NHS Trust, Basingstoke, United Kingdom"
      ],
      "name": "Aya Abdelhameed"
    },
    {
      "affiliations": [
        "Hampshire Hospital NHS Trust, Basingstoke, United Kingdom"
      ],
      "name": "Benjamin E White"
    },
    {
      "affiliations": [
        "Hampshire Hospital NHS Trust, Basingstoke, United Kingdom"
      ],
      "name": "John Ramage"
    }
  ],
  "title": "P158 Faecal immunochemical test surveillance after gastroenteropancreatic neuroendocrine tumour diagnosis: real-world incidence of metachronous colorectal cancer in two national registries",
  "uid": "87af3c64-3a92-533e-8aae-f60542440dbb"
}