Ex vivo activity of cytotoxic drugs and targeted agents in Small Intestinal NETs

• Introduction: Small Intestinal Neuroendocrine Tumours (SI-NET) are considered to be generally resistant to systemic treatment. To date predictive markers for drug activity are lacking.Patients and Methods: Tumour samples from 27 patients with SI-NET were analyzed ex vivo for sensitivity to a panel of cytotoxic drugs and targeted agents using a short-term total cell kill assay. Samples of renal cancer, colorectal cancer (CRC), ovarian cancer, and chronic lymphocytic leukemia (CLL) were included for comparison. For the SI-NET subset, drug sensitivity was analyzed in relation to clinico-pathological variables and pre-treatment biomarkers.Results: For standard cytotoxic drugs, SI-NETs demonstrated similar or higher sensitivity to 5-FU, platinums, gemcitabine and doxorubicin compared with CRC. For targeted kinase inhibitors, SI-NET was among the most sensitive diagnoses. CLL and ovarian cancer were generally the most sensitive diagnoses to both cytotoxic drugs and protein kinase inhibitors. The mTOR inhibitor sirolimus exhibited modest cytotoxic activity.Individual SI-NET samples demonstrated great variability in ex vivo sensitivity for most drugs. Cross-resistance between different drugs also varied considerably, being higher among protein kinase inhibitors.Age, stage, grade, peritoneal carcinomatosis and extra-abdominal metastases as well as serum chromogranin A and urine 5-HIAA concentrations at diagnosis did not correlate to drug sensitivity ex vivo.Conclusions: SI-NETs exhibit variable but generally intermediate sensitivity ex vivo to cytotoxic and targeted drugs. Clinico-pathological factors and currently used biomarkers were not clearly associated to ex vivo sensitivity, challenging these criteria for treatment decisions in SI-NETs. The great variability in drug sensitivity calls for individualized selection of therapy.

Subject headings

MEDICIN OCH HÄLSOVETENSKAP  -- Klinisk medicin -- Cancer och onkologi (hsv//swe)

MEDICAL AND HEALTH SCIENCES  -- Clinical Medicine -- Cancer and Oncology (hsv//eng)

MEDICIN OCH HÄLSOVETENSKAP  -- Klinisk medicin -- Kirurgi (hsv//swe)

MEDICAL AND HEALTH SCIENCES  -- Clinical Medicine -- Surgery (hsv//eng)

Keyword

Small Intestinal NETs

Ex vivo sensitivity

cytotoxic drugs

targeted agents

Oncology

Onkologi

Kirurgi

Surgery

Publication and Content Type

vet (subject category)

ovr (subject category)