Carcinoid syndrome: diagnosis and medical management

Gastro-intestinal carcinoids are slow growing tumors arising from enterochromaffin or Kulchitsky cells. Their clinical presentation depends on what combination of bioactive substances is secreted. Midgut carcinoid can present with the carcinoid syndrome in the presence of liver metastases. Its most typical clinical manifestations include cutaneous flushing and diarrhea. A nonspecific biochemical tumor marker for carcinoid tumors is serum chromogranin A and a specific marker for the carcinoid syndrome is the increased urinary excretion of 5-hydroxy indole acetic acid (5-HIAA). Localizing studies in carcinoid tumors/syndrome are: transabdominal ultrasonography (US), endoscopy, endoscopic US, videocapsule endoscopy, computerized tomography, magnetic resonance imaging, selective abdominal angiography, 111In-pentetreotide scintigraphy (and intraoperative radionuclide probe), 123I (131I)-metaiodobenzylguanidine (MIBG) scintigraphy, bone scintigraphy and 11C-5-HT positron emission tomography (PET). Therapies for carcinoid tumors/syndrome are: surgery, somatostatin analogs, interferon-alpha, radiotherapy, liver dearterialization, liver (chemo, or radio)-embolization, alcohol sclerotherapy of liver metastases, radiofrequency ablation of liver metastases, cryosurgery of liver metastases, occasionally liver transplantation, radiotherapy-coupled somatostatin analogs, 131I-MIBG and occasionally chemotherapy.

Detection of tumor cell contamination in peripheral blood by RT-PCR in gastrointestinal cancer patients

We analyzed the peripheral blood of patients with gastrointestinal tract cancer at different stages to assess the presence of carcinoembryonic antigen (CEA) mRNA by reverse transcriptase-polymerase chain reaction (RT-PCR), which we used as an indicator for micrometastatic malignant cells. A total of 35 gastric, 24 colorectal, 4 esophageal and 4 biliary tract cancer patients and nine normal healthy subjects were studied. No CEA mRNA was detected in the nine normal healthy volunteers. CEA mRNA was detected in 100% (10/10) of metastatic, 33.3% (3/9) of early gastric cancer (EGC), and 18.8% (3/16) resectable gastric cancer patients, respectively. In colorectal cancer, 55.6% (5/9) of metastatic cancers were positive for CEA mRNA, and 26.7% (4/15) Duke stage B/C showed positive. One patient with stage III gastric cancer who was negative CEA mRNA initially and turned positive during follow-up, developed multiple bone metastasis one month later. Another stage III patient, who was positive for CEA mRNA, preoperatively revealed early relapse in two months. These results suggest that the identification of circulating tumor cells using RT-PCR for the detection of CEA mRNA is feasible and this analysis may be a promising tool for early detection of micrometastatic circulating malignant cells in patients with gastrointestinal tract cancer.

Plasma selenium level in cancer patients.

Selenium has been shown to be a cancer preventive agent. A few studies have shown that increased selenium level is associated with decreased cancer incidence and decreased cancer mortality. The present study was carried out to find out the relationship of selenium level with site, extent of disease, recurrence of disease, histopathological diagnosis, anaemia and serum protein level of cancer patients. Plasma selenium level were studied in 100 patients and mean selenium level of 75.35 ng/ml in cancer patients was significantly less than control values (116.99 ng/ml) in normal healthy individuals (P < 0.003). The strongest association of plasma selenium level and cancer was found in cancer breast (70.50 ng/ml) and gastrointestinal tract (73.05 ng/ml) cancer. Selenium level decreased with the progress of disease and recurrence of disease. No significant association between histopathological diagnosis and selenium level was observed. Anaemia and hypoproteinemia was also not found to be related with selenium level.