[Skip to Navigation]
March 22, 1993

Ectopic Corticotropin Syndrome and Small-cell Carcinoma of the Lung: Clinical Features, Outcome, and Complications

Author Affiliations

From the Departments of Medicine (Drs Delisle, Boyer, Warr, and Feld) and Radiation Oncology (Drs Payne and Yeoh), Princess Margaret Hospital, Toronto, Ontario; and Department of Medicine, St Joseph's Health Center, London, Ontario (Dr Killinger).

Arch Intern Med. 1993;153(6):746-752. doi:10.1001/archinte.1993.00410060054009

Background:  Ectopic corticotropin syndrome is a rare complication of small-cell lung cancer (SCLC). There is little information concerning this syndrome available in the literature. We therefore reviewed all cases of ectopic corticotropin syndrome seen at our institution during a 20-year period.

Methods:  Cases were identified by searching a computerized database and reviewing the charts of all 840 patients with SCLC seen between 1971 and 1991. Patients were included if they met at least two of the following criteria: spontaneous hypokalemia (potassium level, <3.2 mmol/L); plasma cortisol level greater than 600 nmol/L; 24-hour urinary free cortisol level greater than 400 nmol/d; and plasma corticotropin level greater than 22 pmol/L. Data were abstracted from the patients' medical records.

Results:  Of 840 patients with SCLC, 14 (1.6%) had ectopic corticotropin production. This was diagnosed at the time of presentation with SCLC in seven patients and from 3 to 19 months later in the remainder. Five patients had limited disease and nine had extensive disease. One or more features of Cushing's syndrome were observed in 57% of patients, but the entire syndrome occurred rarely. Spontaneous hypokalemia was present in all patients, and 10 patients (71%) had hyperglycemia. There were two complete responses and one partial response to chemotherapy, giving an overall response rate of 21%, and the median survival was 5.5 months. Ten patients died of progressive growth of tumor, while three patients died of infections. In one other patient, infection probably contributed to death. A high rate of nonfatal infections was also seen.

Conclusions:  The occurrence of SCLC with ectopic corticotropin syndrome is associated with poor survival, and a high incidence of infective complications, in patients treated with chemotherapy.(Arch Intern Med. 1993;153:746-752)

Add or change institution