Flow cytometric analysis of tumour DNA profile related to response to radiotherapy and survival in inoperable lung cancer

DNA flow cytometric analysis was done from 100 paraffin-embedded non-small cell (NSCLC) and 29 small cell lung carcinomas (SCLC). Most of the patients had locally advanced disease and all were considered inoperable and treated by radiotherapy. DNA aneuploidy was detected in 62 (62%) of the NSCLCs and in 20 (69%) of the SCLCs. Radiotherapy induced a slightly more extensive and prolonged tumour regression in DNA-aneuploid NSCLC with high S-phase fraction (SPF) than in those with low SPF and no evidence of aneuploidy. However, neither in NSCLC nor in SCLC were significant survival differences detected between DNA-diploid and DNA-aneuploid cases or between those with low ( 12%) S-phase fraction (SPF). Neither did the degree of differentiation have prognostic significance in this material.