Konstantinos N. Syrigos

Autoantibodies against insulin and β-islet cells in pancreatic adenocarcinoma: A possible explanation for diabetes mellitus

To evaluate the prevalence of autoantibodies against the b‐islet cells (ICA) and the molecule of insulin (IAA) in the serum of patients with pancreatic adenocarcinoma (PA), we examined the sera of 36 newly diagnosed pancreatic adenocarcinoma patients for the presence of these antibodies, using an enzyme‐linked immuno‐assay method. These results were correlated with survival. Ten patients with insulin‐dependent diabetes mellitus (IDDM) and 21 healthy volunteers were evaluated as age‐matched controls. Twenty out of 36 (57%) PA patients were found to have detectable ICA autoantibodies and 17 (48%) PA patients had detectable IAA antibodies. Five out of 10 (50%) and 3 out of 10 (30%) IDDM patients had ICA and IAA antibodies, respectively. None of the healthy volunteers was positive for either of the autoantibodies examined. The difference was statistically very significant and the presence of high serum titers of both autoantibodies was associated with a worse outcome for these patients than for those without such autoantibodies. Our data suggest that the high incidence of diabetes mellitus in patients with PA may be attributed to the presence of these antibodies. Further clinical studies are needed to establish the above antibodies as prognostic markers of pancreatic cancer.

Prophylactic Cranial Irradiation in Patients with Small-Cell Lung Cancer

The meta-analysis performed by the Prophylactic Cranial Irradiation Overview Collaborative Group has provided clear evidence of the beneficial effects of this treatment in terms of survival and reduction of cerebral metastasis. Delivery of PCI results in a 5.4% improvement in overall survival at 3 years after the commencement of induction chemotherapy. PCI was also shown to yield a 54% proportional reduction in the incidence of cerebral metastases, from 59% to 33%, at 3 years. Subgroup analysis suggests a trend toward reduced incidence of cerebral metastasis with increased radiation dose and earlier introduction of PCI into the treatment regimen. Further studies will address the effect of different radiation doses and fractionation regimens (including twice-daily, hyperfractionated radiotherapy) and the optimal timing of PCI relative to induction chemotherapy. Evaluation of the data on the neuropsychiatric sequelae of PCI suggest that patients have significant abnormalities at baseline and that there is no demonstrable change after PCI. However, there is a suggestion that PCI delivered concomitantly with chemotherapy may be associated with a significant deterioration in cognitive function.

Management of Cerebral Metastasis in Patients with Non-Small-Cell Lung Cancer

The development of cerebral metastases represents a life-threatening condition in patients with NSCLC. The approach to management should be guided initially by consideration of the relevant prognostic factors. The RTOG RPA classification, which is based on age, the presence or absence of extracranial disease, and the Karnofsky performance status, functions as a useful means of dividing patients into groups with different outcomes. The RPA can be used to select patients for either aggressive management with potentially curative intent (for patients in RPA class 1), more palliative treatment (RPA class 2), or best supportive care (RPA class 3). Surgery, WBRT and radiosurgery may all have a role in treatment. There is a pressing need for appropriately controlled randomized trials to define more accurately the indications for each of these modalities.

Rare Tumors of the Chest

Non-bronchiogenic lung carcinomas, although rare, are of great importance for the clinician. Most of these tumors are asymptomatic or present with non-specific symptoms. As a result, the indication of disease is set incidentally in routine radiological examination, sometimes a long time after the onset of the disease. The X-ray findings are similar if not identical with those of a bronchiogenic malignancy, thus leading to incorrect diagnoses. Definite diagnosis in all cases is made by histopathological examination with additional information acquired by immunohistochemistry. Treatment strategies, involve surgical excision that may be followed by adjuvant chemotherapy and/or radiotherapy for non-metastatic disease, and chemotherapy (frequently combination regimens) for metastatic disease. Nevertheless, prognosis remains exceedingly dismal with the exceptions of low-grade PPL and carcinoid tumors.