Tumour fragment spheroids from human non-small-cell lung cancer maintained in organ culture.

Biopsy material from 17 human non-small-cell lung carcinomas (NSCLC) was maintained in agar overlay culture as tumour fragment spheroids for 40 days. A practical procedure for the formation of spheroids and organ culture is described. The mechanically dissociated tumour specimens showed a variation in their ability to generate spheroids that was not related to the ploidy or the histological differentiation of the biopsies. Light microscopic observations revealed a heterogeneous spheroid population with a mixture of tumour cells and stromal elements. Most of the histological elements normally found in human NSCLC could be seen in the spheroids. The cellular components in the spheroids varied between highly cellular to sparsely cellular, dominated by stromal elements. The squamous carcinomas were in general found to generate highly cellular spheroids more often than the adenocarcinomas. Spheroids with a different cellular content could be selected in vitro by using a morphometric technique. Diameter measurements showed a large variability in spheroid growth. Most of the spheroids decreased in size although bromodeoxyuridine labelling indicated active cell proliferation in the specimens. Frequent changes of medium did not affect spheroid growth. The culture system presented provides a model for studying the cellular heterogeneity as well as the biological characteristics of tumour tissue from individual patients in vitro.