title: Diploid predominance and prognostic significance of S-phase cells in malignant mesothelioma.
abstract: 70 histologically verified, malignant mesotheliomas were analysed by flow cytometry for DNA content and S-phase fraction (SPF) of tumour cells. 60% (42/70) were DNA diploid. 18 of the 28 aneuploid tumours were near-diploid with DNA indices of 1.3 or less. SPF could be calculated in 51 cases. SPF was significantly higher in aneuploid (median 16.0%) than in diploid tumours (median 5.6%). DNA ploidy was not a prognostic determinant; survival was the same for both aneuploid and diploid tumours. SPF, however, was significantly correlated (P = 0.039) with prognosis. Patients who had tumours with a low SPF survived almost twice as long as those with a high SPF. Thus malignant mesothelioma has a peculiar DNA ploidy pattern compared with many other solid tumours, with a predominance of diploid or near-diploid type cells. As in many other tumours, SPF may be used as a clinically relevant prognostic indicator.
authors.affiliation: Department of Radiotherapy and Oncology, Helsinki University Central Hospital, Finland.
authors.forename: S
authors.initials: S
authors.lastname: Pyrhönen
authors.forename: A
authors.initials: A
authors.lastname: Laasonen
authors.forename: L
authors.initials: L
authors.lastname: Tammilehto
authors.forename: J
authors.initials: J
authors.lastname: Rautonen
authors.forename: S
authors.initials: S
authors.lastname: Anttila
authors.forename: K
authors.initials: K
authors.lastname: Mattson
authors.forename: L R
authors.initials: LR
authors.lastname: Holsti
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D004171:Diploidy; D005260:Female; D006801:Humans; D008297:Male; D008654:Mesothelioma / Q000235:genetics* / Q000401:mortality / Q000473:pathology; D008875:Middle Aged; D010997:Pleural Neoplasms / Q000235:genetics* / Q000401:mortality / Q000473:pathology; D011379:Prognosis; D016196:S Phase / Q000502:physiology*