Evidence of low-dose hyper-radiosensitivity in normal cells of cervix cancer patients?

The aim of the present study was to examine the low-dose radiation response of human normal cells using the micronucleus assay. Skin fibroblasts and keratinocytes derived from 40 cervix cancer patients were studied. After in vitro gamma irradiation with single doses ranging from 0.05 to 4 Gy, the fraction of binucleated cells with micronuclei was assessed. For each patient, the Linear-Quadratic (LQ) model and the Induced-Repair (IR) model were fitted over the whole data set (0.05-4 Gy). In conclusion, the present study showed some evidence of low-dose hypersensitivity in the fibroblasts of two patients and in the keratinocytes of four of the forty patients studied.

A ratio of apoptosis to mitosis, proliferation pattern and prediction of radiotherapy response in cervical carcinoma.

The prognostic significance of apoptotic (AI) and mitotic (MI) indices, and the ratio of these parameters (AI/MI), MIB-1 labeling index (MIB-1LI) and proliferation pattern was studied in 130 (FIGO stage IB-IIIB) squamous cervical cancer patients before radiotherapy. Also the influence of the patients age and tumors pathological features (stage, grade, degree of keratinization) and DNA ploidy on the biological parameters were analysed. AI and MI were assessed on histological sections stained with hematoxylin and eosin, and the MIB-1LI on specimens stained with rabbit anti-human Ki-67 antibody (DAKO Ltd). Sections stained with MIB-1 antibody were used for assessment of the tumor proliferation pattern. The median age of the patients was 55 years (29-80). The median values for MIB-1LI, AI, MI, AI/MI, were: 52.3%, 1.1%, 1.5, and 0.9, respectively. In the univariate analysis median values for cut-off points were used for MIB-1LI, and AI, however, for other parameters significant cut-off points have been chosen. For MI it was 2.6 and for the AI/MI ratio 0.7. The median time of follow-up was 29 months, with a range of 2-145 months. The univariate analysis showed that tumor stage (p=0.7009), grade (p=0.6660) and AI (p=0.9378) had negligible influence on patients survival. However, MI >2.6 (p=0.0442), AI/MI

Tumour cell kinetics as a prognostic factor in squamous cell carcinoma of the cervix treated with radiotherapy.

PURPOSE: Proliferative rate and DNA ploidy status were evaluated by flow cytometry in cervical cancer patients, prior to radiotherapy, to assess their importance as prognostic factors to predict survival rates. MATERIAL AND METHODS: Between 1987 and 1995, a total of 260 patients with squamous cell carcinoma (SCC) of the cervix, FIGO stages IB-IIIB were analysed. Tumour samples were incubated with bromodeoxyuridine (BrdUrd) in vitro to measure their total labelling index (totLI) and LI (totLI for diploid and anLI for aneuploid tumours). Proliferation was also assessed by S-phase fraction (SPF) analysis of the DNA profile. Patients had intracavitary therapy (three applications, each of 16 Gy to point A) and XRT of 40-50 Gy given over 4-5 weeks. RESULTS: The cervical tumours were characterized by a high proliferation rate which varied within each clinical stage of disease. The totLI ranged from 1.1 to 33.1% with median value of 9.6% whilst the LI ranged from 1.1 to 37.1% with a median value of 10.9%. Univariate analysis identified patient's age (cut-offpoint < or = 50&greater; years) and to a lesser extent proliferation (cut-off point, median totLI=9.6%) as significant prognostic factors for 5-year survival. The median survival time for younger patients ( < or = 50 years) with tumours of low proliferation (totLI < or = 9.6%) tumours was 17.5 months compared with 56 months in the faster proliferating tumours (P=0.0354). In the older patient sub-group, proliferation rate had no influence on survival. The median LI value was not a useful parameter in survival. Cox multivariate analysis showed that patient age ( < or = 50 years) and low proliferation of the tumour cells (totLI < or = 9.6) were unfavourable prognostic factors for cervical cancers treated with radiotherapy. DNA ploidy was not significant in this series. CONCLUSIONS: These data suggest that further improvements in therapy might be gained by selection of alternative treatments strategies such as neoadjuvant chemotherapy or radiation sensitizers in younger patients with more slowly proliferating tumours.

Flow cytometric analysis of DNA ploidy and proliferative potential in brain tumours.

The proliferative potential and DNA ploidy in 203 brain tumours (27 astrocytomas grade I, 37 grade II, 80 grade III, and 59 grade IV) were investigated using bromodeoxyuridine (BrdUrd) incorporation and flow cytometry. One to three tumour samples from each patient were incubated in vitro for one hour at 37 degrees C with bromodeoxyuridine (BrdUrd) using the high preasure oxygen method. After incubation, fixation and staining, the cell preparations were analysed by flow cytometry. The percentage of BrdUrd-labelled cells (BrdUrd Labelling Index, BrdUrdLI), the predicted potential doubling time (predTpot) and the total DNA content were evaluated. The percentage of unlabelled S-phase cells (SPF) and proliferative index (PI, the percentage of cells in S + G2 phases) were also estimated. DNA aneuploidy was found in 61.1% of high-grade (III-IV) and 50.0% of low-grade (I-II) astrocytomas. The tumours showed variability in the BrdUrdLI values which ranged from 0.2 to 15.8%. Significantly higher mean value for BrdUrdLI was shown in grade III-IV astrocytomas (3.4%), than in grade I-II astrocytomas (1.5%), p = 0.0068. Also significantly shorter mean predTpot was shown in high grade III-IV astrocytomas (28 days) than in low grade I-II tumours (51 days), p = 0.0096. However, no relationship was shown between other cell proliferation parameters and histological grade. The mean intratumoral variability calculated on the basis of BrdUrdLI values on 2-3 samples from each tumour amounted to 31.2% +/- SD 15.9%.

Tumour cell kinetics as prognostic factor in surgically-treated-non-small cell lung cancer.

The proliferative rate of tumour cells were studied in 80 non-small cell lung cancers (NSCLC) treated surgically at the Centre of Oncology in Kraków, between 1990 and 1996. There were 56 squamous cell carcinoma (SqLC) and 24 non-SqLC (18 adenocarcinoma (AcLC), three large cell carcinomas (LcLC), three mixed tumours). The proliferative potential of the tumour cells was studied on the basis of percentage of cells in the S-phase (S-phase fraction, SPF), proliferative index (PI, number of cells in S+ G2/M phases), bromodeoxyuridine labelling index (BrdUrdLI), and predictive potential doubling time (pred Tpot). Significant differences in the proliferating rate between histological groups of tumours were shown by the BrdUrdLI. The 5-year survival time for patients with higher proliferating tumours (BrdUrdLI > 4.1%, optimal cutoff level) was significantly higher (median survival time of > 60 months) than those with lower proliferative potential (BrdUrdLI < or = 4.1%) (median survival time of 19 months, P = 0.0091). SqLC patients had significantly better 5-year survival (median survival time of 47.5 months) than those with non-SqLC (median survival time of 18.5 months). Cox multivariate analysis showed that only higher proliferation of the tumour cells (BrdUrdLI > 4.1%), and lower clinical stage (I and II) were favourable prognostic factors in respect to patients' survival.

Measurement of DNA ploidy and proliferation rate in lung tumours by bromodeoxyuridine labelling index, S-phase fraction and AgNOR technique.

Proliferative rate and DNA ploidy in 23 squamous cell carcinoma of the lung (SCCL), 10 adenocarcinomas (ACL) and 4 metastatic tumours (MT) were studied. The proliferative potential of the tumours was assessed with the use of three methods: bromodeoxyuridine labelling index (BrdUrd LI), S-phase fraction (SPF) and argyrophilic organizer regions (AgNOR) technique. Differences in the proliferating rate between different histological groups of tumours and within groups were shown by the BrdUrdLI and AgNOR technique. However, for the BrdUrdLI only these differences were statistically significant. No correlation was found between the values for all examined tests and the clinical stage of the tumours. The broadest range of the BrdUrdLI values was for SCCL and the mean BrdUrdLI was highest in this histological group. The number of SPF cells in metastatic tumours was lower than that in two other histological groups, however it was not a significant difference. The highest number of AgNORs and tot AgNOR area per cell was noticed again in SCCL, however, these values were not significantly different (p = 0.189) from other histological groups. Also the mean size of AgNOR particle area did not differ between groups (p = 0.279). Twenty six of thirty seven (70%) tumours were aneuploid. The highest percentage was recorded for SCCL (81%), while the lowest (25%) for MT. In the aneuploid tumours no significantly higher proliferation rate was observed as assessed by the BrdUrdLI and SPF. However, higher AgNOR numbers (p = 0.0472) and higher tot AgNOR area per cell (p = 0.0128) in aneuploid than in diploid tumours were observed. There was no correlation between BrdUrdLI, SPF and AgNOR counts.