ADRENOCORTICAL FUNCTION IN BRONCHOGENIC CARCINOMA: STUDY OF 100 PATIENTS

Endocrine function in small cell undifferentiated carcinoma of the lung

The endocrine status of 106 patients with undifferentiated small cell carcinoma of the lung was evaluated before treatment was begun. Almost one half of the patients had evidence of abnormal control of the secretion of adrenal cortical steroids, manifested by loss of diurnal rhythmicity or dexamethasone suppressibility. Only two had the clinical syndrome of ectopic ACTH secretion. Evidence of inappropriate secretion of vasopressin was found in 38% of the patients, most of whom also had abnormalities of corticosteroid secretory pattern. About one half of the patients had evidence of abnormal glucose tolerance, and many also had a paradoxical rise of plasma growth hormone concentration after glucose administration. The levels of the other hormones studies were normal. The pattern of hormone abnormality observed in these patients appears to be relatively specific for small cell undifferentiated carcinoma, and is different from that observed in other pulmonary tumors. Patients with abnormal control of plasma cortisol had a worse prognosis than those with normal adrenal function, largely because of decreased response rates to chemotherapy. Other endocrine abnormalities were of no prognostic significance.

Diagnostic and therapeutic implications of ectopic hormone production in small cell carcinoma of the lung

In 75 unselected and untreated patients with small cell carcinoma of the lung, plasma ACTH, serum calcitonin, and antidiuretic hormone (ADH) in plasma and urine were related to corresponding clinical symptoms and biochemical findings at the time of diagnosis. The significance of elevated concentrations of these substances in relation to treatment was also investigated. Plasma ACTH concentrations were increased in 22 patients (29%), and 25 patients (33%) were considered to have inappropriate ADH secretion. Only one patient had definite hypokalaemic alkalosis, and one patient pronounced hyponatraemia, with associated clinical syndromes of ectopic ACTH and ADH secretion. Serum calcitonin concentrations were increased in 48 patients (65%). No related clinical symptoms were disclosed, and all these patients had normal serum calcium concentrations. Thirty-three of 66 patients (50%) had raised levels of free cortisol in a 24-hour urine and these levels were significantly related to plasma ACTH concentrations. The median survival was slightly shorter in patients with increased values of the three substances, but this was not related to increased plasma ACTH concentrations and was not statistically significant. Survival rates and results of treatment were independent of the pretreatment levels of the three substances.

Lung tumours and ACTH production

ACTH levels measured by N- and C-terminal immunoassays and cytochemical bioassay, were measured in fourteen lung tumours not associated with the ectopic ACTH syndrome and in macroscopically normal lung tissue taken from the same patients at thoracotomy. Significant concentrations of immunocative (greater than 3 ng/g wet weight) and bioactive (greater than 0.2 ng/g wet weight) ACTH were found in all the carcinoid and oat cell tumours (n=9), a combined tumour (poorly differentiated adenocarcinoma with large cell carcinoid elements), and a poorly differentiated squamous cell tumour. All the carcinoid tumours contained more C- than N-terminal ACTH immunoactivity. The squamous cell tumours (n=2), anaplastic tumours (n=2) and adenocarcinoma contained insignificant ACTH levels. There was a good correlation between the ACTH levels and the presence of secretory granules in the tumours examined ultrastructually. All the macroscopically normal samples of lung tissue contained immuno and bioactive ACTH-like material, the levels of which correlated well with ACTH levels in the tumour tissue. It is suggested that all lung tumours of carcinoid or oat cell type synthesize ACTH-like materials although clinical evidence of the ectopic ACTH syndrome may be absent. The presence of ACTH-like materials in non-tumorous lung tissue in patients with lung cancer may indicate a low level of ACTH production throughout the lung or sequestration of ACTH containing granules secreted by the tumour.

Serial measurement of plasma cortisol in lung cancer

Serial plasma cortisol estimations were carried out in 81 male lung cancer patients and in a control group of 50 male subjects with conditions other than lung cancer. It was found that group mean plasma cortisol levels, both in the morning and in the afternoon, were greater in the lung cancer patients than in the no-cancer control group. However, long-term assessment four years after the beginning of the study showed that high plasma cortisol levels were found predominantly in cancer patients within six months of death. If such patients are excluded from the study, there is no significant difference in group mean plasma cortisol levels between male lung cancer patients and a male control group.

Incidence of paramalignant disorders in bronchogenic carcinoma

The incidence of paramalignant disorders was studied in 280 consecutive patients with early lung cancer confirmed histologically. The commonest disorders were weight loss exceeding 6.4 kg (30.7 percent of the series), finger clubbing (29 percent), fever (21.1 percent), and endocrinopathies (12.1 percent). Paramalignant diseases are common even in early lung cancer and all patients should have investigations for their detection.

Metabolic studies following thoracotomy for lung cancer with particular reference to postoperative atrial fibrillation

Atrial fibrillation has proved to be a frequent complication after thoracotomy for lung cancer. In order to study the possibility that metabolic changes are the trigger mechanism of these arrhythmias, free fatty acids (FFA), glycerol, triglycerides, serum insulin and glucose were determined pre- and postoperatively in patients both with and without this postoperative complication. In the primary series of patients, FFA were found to be increased immediately after the start of the atrial fibrillation, partly in relation to the morning values and partly to the 24-hour curve. This is a possible expression of an increased lipolysis in a causal relationship to the arrhythmia. In another series of patients, the degree of lypolysis was demonstrated using the glycerol values. With this method, no signs of increased lipolysis were found in connection with the onset of atrial fibrillation. Thus, changes in the lipoid metabolism were not found to be the trigger mechanism of the postoperative atrial fibrillation. Reduced values of serum insulin and glucose were not demonstrated either during the uncomplicated postoperative period or at the start of atrial fibrillation.