Small cell lung cancer: The new biology

Over the past 30 years, the application of new techniques has lead to many advances in our knowledge of small cell lung cancer (SCLC). It was Barnard in 19261 who first described "oat cell sarcoma" of the mediastium as a tumor originating in the bronchi and already- characterized this tumor as giving rise to widespread metastases. Using electron microscopy-, Bensch et M, in 1968, 2 described the presence of dense-core granules in SCLC, similar to those found in endocrine cells elsewhere. Endocrine cells were identified in the respiratory epithelium in I938 and subsequently" were shown to be argyro~ philic. 3 In 1937, HamperP described the similarity of these cells to the Kulchitsky ceils of the gastrointestinal tract. The presence of neurosecretot T granules and later biochemical evidence led to the linkage of SCLC with the epithelial neurendocrine cells of the bronchi. 5 In 1967, SCLC was recognized as a distinct entity of lung cancer by the World Health Organization classification. In 1971, the first SCLC cell lines were described. 6 Since the 1980s, a wealth of information about the biological characteristics of SCLC has been obtained from advanced cell culture methods leading to the establishment of a large number of small cell lung carcinoma cell lines] ,8 Several investigators have examined the possible correlation of the ability to establish a cell line with the clinical prognosis of the patient. In SCLC patients with extensive disease, a retrospective study found a correlation of the ability to estabfish a cell line with poor prognosis. 9 However, a subsequent prospective study failed to confirm these results. 10