Risk of late recurrence and/or second lung cancer after treatment of patients with small cell lung cancer (SCLC).

The aim of this study was to illustrate some difficulties in distinguishing late recurrence of small cell lung cancer (SCLC), from second primary lung cancer. Three-hundred fourteen SCLC patients were observed at the Institute of Tuberculosis and Chest Diseases in Warsaw, during the period 1976-1985. All patients were treated with chemotherapy and 125 were also treated with radiotherapy on the tumour and mediastinum. Nineteen patients (6%) survived 3 years. This group consisted of eight females (9%) and 11 males (5%). In all of them a complete remission was obtained. In six patients from this group no progression of lung cancer was observed. Four of them are still living, 7.9-16.2 years after the start of treatment. Two patients died of heart infarct. In the remaining 13 patients, progression of SCLC or development of new cancer was noted in the course of observation. In seven of them, histological proof of the character of progression was obtained. In four cases non-small cell lung cancer (NSCLC) was diagnosed after 3-11 years of observation. In one of them SCLC metastases in the liver were unexpectedly found in the autopsy, although adenocarcinoma in the lung diagnosed during bronchoscopy was also confirmed in the autopsy. In three cases SCLC was diagnosed. In one case, 2.7 years from the beginning of treatment, only SCLC metastases were found during laparoscopy. SCLC was found in two other cases after a 7-year cancer-free period. In one of those patients, a new lesion was found in the other lung while the second patient developed a new lesion exactly in the place of the former cancer. In six other patients no histological proof of the character of progression was obtained. Two of the six are still living, 8.2 and 15.1 years later. In the first of these two, a new lesion developed very early in the course of treatment in the same place as the primary tumour and it was regarded as the progression of SCLC. In the second patient, who probably had NSCLC the lesion developed in the contralateral lung after 12.5 years of remission and disappeared after radiotherapy. Four patients died of cancer after 3.2-6.4 years of observation. The cumulative risk of a second primary lung cancer after a 3-year survival period oscillated in our SCLC patients between 4% and 6% for every patient/year of observation. It was concluded that prognosis in SCLC patients is still doubtful, nevertheless, some patients made a complete recovery.