Blood-based genomics of triple-negative breast cancer progression in patients treated with neoadjuvant chemotherapy.

BACKGROUND: As neoadjuvant chemotherapy (NAC) is increasingly used in triple-negative breast cancer (TNBC), we investigated the value of circulating tumor DNA (ctDNA) for patient monitoring prior, during, and after NAC, and circulating tumor cells (CTCs) for disease characterization at clinical progression. MATERIALS AND METHODS: Forty-two TNBC patients undergoing NAC were prospectively enrolled. Primary tumor mutations identified by targeted-gene sequencing were validated and tracked in 168 plasma samples longitudinally collected at multiple time-points by droplet digital polymerase chain reaction. At progression, plasma DNA underwent direct targeted-gene assay, and CTCs were collected and analyzed for copy number alterations (CNAs) by low-pass whole genome sequencing. RESULTS: ctDNA detection after NAC was associated with increased risk of relapse, with 2-year event-free survival estimates being 44.4% [95% confidence interval (CI) 21.4%-92.3%] versus 77.4% (95% CI 57.8%-100%). ctDNA prognostic value remained worthy even after adjusting for age, residual disease, systemic inflammatory indices, and Ki-67 [hazard ratio (HR) 1.91; 95% CI 0.51-7.08]. During follow-up, ctDNA was undetectable in non-recurrent cases with the unique exception of one showing a temporary peak over eight samples. Conversely, ctDNA was detected in 8/11 recurrent cases, and predated the clinical diagnosis up to 13 months. Notably, recurrent cases without ctDNA developed locoregional, contralateral, and bone-only disease. At clinical progression, CTCs presented chromosome 10 and 21q CNAs whose network analysis showed connected modules including HER/PI3K/Ras/JAK signaling and immune response. CONCLUSION: ctDNA is not only associated with but is also predictive of prognosis in TNBC patients receiving NAC, and represents an exploitable tool, either alone or with CTCs, for personalized TNBC management.

Hepcidin and ferritin blood level as noninvasive tools for predicting breast cancer.

BACKGROUND: Currently used CA15-3 and CEA have found their clinical application particularly in the follow-up of patients with advanced disease. Novel biomarkers are urgent, especially for improving early diagnosis as well as for discriminating between benign and malignant disease. PATIENTS AND METHODS: In the present study, we used a proteomic approach based on surface-enhanced laser desorption/ionization-time of flight-mass spectrometry screening with the aim of identifying differentially expressed 2-30 kDa proteins in plasma of patients with malignant (65 cases) and benign (88 cases) breast lesions with respect to 121 healthy controls. RESULTS: We found that the most promising SELDI peaks were those corresponding to hepcidin-25 and ferritin light chain. We evaluated the capability of these peaks in predicting malignant and benign breast lesions using the area under the receiver operating characteristic curve (AUC). The results showed a good capacity to predict malignant breast lesions for hepcidin-25 [AUC: 0.82; 95% confidence interval (CI) 0.75-0.90] and ferritin light chain (AUC: 0.86; 95% CI 0.79-0.92). Conversely, a weak and satisfactory capability to predict benign breast lesion was observed for hepcidin-25 (AUC: 0.63; 95% CI 0.41-0.85) and ferritin light chain (AUC: 0.73; 95% CI 0.49-0.97). A significant association between HER2 status and hepcidin-25 was observed and the distribution of transferrin and ferritin were found significantly different in patients with breast cancer when compared with that of controls. CONCLUSIONS: This study provides evidence that hepcidin and ferritin light chain level in plasma may be of clinical usefulness to predict malignant and benign disease with respect to healthy controls.

Vascular endothelial growth factor in node-positive breast cancer patients treated with adjuvant tamoxifen.

In 212 postmenopausal women with node-positive oestrogen receptor-positive (ER(LBA)) breast cancer subjected to radical surgery and adjuvant tamoxifen, the risk of 6-year relapse increased with increasing values of intratumoral vascular endothelial growth factor (VEGF) in patients whose tumours had a low/intermediate ER(LBA) content compared to patients with high-ER(LBA) tumours. These findings indicate that tumour progression, activated or sustained by high VEGF levels, may be counteracted in high-ER(LBA) cancers by tamoxifen, which in contrast fails to contrast the metastatic potential in low-ER(LBA) tumours.

Infiltrating ductal and lobular breast carcinomas are characterised by different interrelationships among markers related to angiogenesis and hormone dependence.

To obtain a more integrated understanding of the different breast cancer phenotypes and to investigate whether bio-molecular profiles can distinguish between specific histotypes, we explored the interrelations among several biologic variables indicative of, or related to, hormone dependence, proliferation and apoptosis control, and angiogenesis in ductal and lobular carcinomas, the most common histotypes. Oestrogen and progesterone receptors, tumour proliferative activity, the expression of cyclin A, p16(ink4A), p27(kip1), p21(waf1), p53, bcl-2, and levels of vascular endothelial growth factor and hypoxia-inducible factor-1alpha (HIF-1alpha) were evaluated in 190 in ductal and 67 lobular carcinomas. Our findings support the hypothesis that in ductal and lobular carcinomas are two distinct, partially phenotypically unrelated entities, the latter being characterised by the presence of features indicative of differentiation such as oestrogen receptors, low proliferation and lack of p53 expression and associated with low vascular endothelial growth factor content compared to angiogenesis in ductal carcinomas. Conversely, no significant difference was found between lobular carcinomas and in ductal carcinomas considering the frequency distribution of PgR-positive cases, cyclin-dependent kinase inhibitors acting at the G1/S boundary, bcl-2 and HIF-1alpha protein expression. Although both generally defined as hormone responsive, in ductal and lobular carcinomas are also characterised by biologic patterns in which proteins related to hormone responsiveness, cell-cycle control, apoptosis and angiogenesis were differently associated. This finding suggests the need to refine breast cancer characterisation in order to provide detailed information about individual tumours, or subsets of tumours, that will help in defining optimal treatment approaches.

A novel taxane active against an orthotopically growing human glioma xenograft.

BACKGROUND: The development of effective chemotherapy for central nervous system tumors is hampered by the blood-brain barrier and by limited drug diffusion in the brain tissue. BAY 59-8862 is a new taxane analog that was selected and developed for its activity against tumors with a P-glycoprotein-mediated, multidrug-resistant phenotype. Because P-glycoprotein is implicated in limiting the access of drugs to central nervous system tumor targets, the objective of this study was to evaluate the ability of intravenously administered BAY 59-8862 to affect the growth of central nervous system tumors. METHODS: The U-87 MG human glioma cell line was xenografted orthotopically (intracranially) in nude mice. Paclitaxel or BAY 59-8862 was delivered intravenously four times every fourth day, and antitumor efficacy was assessed by examining the effects on mouse survival time and by histologic examination of mouse brain. Drug levels in plasma and brain were determined according to a high-performance liquid chromatography method. RESULTS: The analog was as potent as paclitaxel in inhibiting the proliferation of three human glioma cell lines (U-87 MG, SW1783, and GBM) and was as effective as paclitaxel in inhibiting the heterotopic (subcutaneous) tumor growth in nude mice of U-87 MG cells (tumor weight inhibition, approximately 60%). In contrast, BAY 59-8862 was more active than paclitaxel (P < 0.05 in two of three experiments) in increasing the survival time of mice that were injected orthotopically with U-87 MG cells. The results were supported by the pharmacokinetic data, which indicated a much higher (about 15-fold) brain:plasma level ratio in BAY 59-8862-treated animals compared with paclitaxel-treated animals. CONCLUSIONS: The study provides evidence of an additional pharmacologic advantage of BAY 59-8862, i.e., the ability to affect the growth of intracranial tumors, probably due to the lack of recognition by the P-glycoprotein-mediated transport systems. The favorable behavior of BAY 59-8862 supports the potential interest in the analog for clinical studies in patients with brain tumors or metastases.

Biomarkers and outcome after tamoxifen treatment in node-positive breast cancers from elderly women.

The predictive role of tumour proliferative rate and expression of p53, bcl-2 and bax proteins, alone and in association with tumour size, nodal involvement and oestrogen receptors (ER), was analysed on 145 elderly patients (> or =70 years of age) with histologically assessed node-positive breast cancers treated with radical or conservative surgery plus radiotherapy followed by adjuvant tamoxifen for at least 1 year. The 7-year probability of relapse was significantly higher for patients with tumours rapidly proliferating (hazard ratio (HR) = 2.0, P = 0.01), overexpressing p53 (HR = 4.4, P = 0.0001), weakly or not exhibiting bcl-2 (HR = 1.9, P = 0.02), without ERs (HR = 3.4, P = 0.0001) or with > or = 4 positive lymph nodes (HR = 2.3, P = 0.003) than for patients with tumours expressing the opposite patho-biological profile. Conversely, tumour size and bax expression failed to influence relapse-free survival. Adjustment for the duration of tamoxifen treatment did not change these findings. Oestrogen receptors, cell proliferation, p53 accumulation and bcl-2 expression were also predictive for overall survival. Within ER-positive tumours, cell proliferation, p53 accumulation, bcl-2 expression and lymph node involvement provided significant and independent information for relapse and, in association, identified subgroups of patients with relapse probabilities of 20% (low-risk group, exhibiting only one unfavourable factor) to 90% (high-risk group, exhibiting three unfavourable factors). Such data could represent the initial framework for a biologically tailored therapy even for elderly patients and highlight the importance of a patho-biological characterization of their breast cancers.

Biological markers as indicators of response to primary and adjuvant chemotherapy in breast cancer.

Interest in translational studies on breast cancer is presently devoted to identify biological predictors of treatment response. In patients with operable breast cancer, subjected to primary and adjuvant chemotherapy, we analyzed the predictivity on objective clinical response and relapse-free survival of biological markers related to different cellular aspects and functions. Tumour proliferative rate (evaluated as the (3)H-thymidine-labelling index, TLI), oestrogen and progesterone receptors (ER and PgR, evaluated by the dextran-coated-charcoal method), nuclear DNA ploidy and the immunocytochemical expression of p53, bcl-2 and bax proteins were determined before primary treatment, at the time of diagnosis, and after primary chemotherapy, at surgery. Objective clinical response was significantly related only to pre-treatment p53 expression or PgR status, with a higher rate for tumours not expressing than for those expressing p53 (94% vs. 72%), as well as for PgR-negative (PgR(-)) than for PgR-positive (PgR(+)) tumours (86% vs. 68%). In the overall series, 8-year clinical outcome was significantly related only to post-treatment steroid receptors. In particular, higher 8-year relapse-free survival rate was observed for patients with ER(-) or PgR(-) than for those with ER(+) (64% vs. 38%) or PgR(+) (53% vs. 37%) tumours. Such findings held true even within the sub-set of patients who received adjuvant post-operative chemotherapy, i.e., those with node-positive (N(+)) or ER(-)/node-negative (N(-)) tumours, among whom also rapid proliferation or the presence of apoptosis-favouring markers (bcl-2(-) or bax(+), singly and in association) on surgical specimens identified a sub-set of women who benefited from systemic treatment. The different biological markers were variously indicative of clinical outcome, with a predictivity on tumour shrinkage for p53 and PgR, detected before primary chemotherapy, and on long-term follow-up for ER, PgR and, to a lesser extent, TLI and apoptosis-modulating markers. Int. J. Cancer (Pred. Oncol.) 84:580-586, 1999.

Clinical studies of Bcl-2 and treatment benefit in breast cancer patients.

Interest in translational studies aimed at investigating the role of biologic markers in predicting clinical outcome of breast cancer patients and, in particular, response to specific treatments, has progressively increased. Among biologic variables presently under investigation, apoptosis markers, in particular Bcl-2 and Bax expression, are receiving much attention for their relationship with the cellular response to genotoxic damage in experimental tumors. Retrospective, independent studies were carried out by several research groups on about 5000 patients with breast cancer at different stages and with an adequate follow-up. The outcome of separate analyses as a function of treatment generally demonstrated that Bcl-2 overexpression, which correlates with biologic features of a differentiated phenotype (slow proliferation, high steroid receptor levels, absence of p53 and c-erB-2 expression), is associated with a favorable outcome. Such a finding is mainly evident following surgery as well as endocrine treatment. Conversely, no or weak Bcl-2 expression, alone or in association with bax overexpression, appears indicative of a radiation response, and preliminary emerging evidence supports the involvement of such an association of apoptosis-related markers even as predictors of long-term response to neoadjuvant cytotoxic treatment. Although the findings of an involvement of Bcl-2 and Bax as determinants of treatment response should be confirmed within the context of randomized clinical trials, they indicate a combined consideration of proteins that negatively and positively regulate apoptosis in translational studies on the effect of chemical and physical agents at a cellular level.

Biological markers as indicators of pathological response to primary chemotherapy in oral-cavity cancers.

The predictive role in terms of pathological response and prognostic role of biomarkers such as GST-pi, p53, bcl-2 and bax expression, immuno-histochemically detected, and of the S-phase cell fraction, autoradiographically determined as thymidine labeling index (TLI), were investigated within a prospective randomized phase III clinical trial on squamous-cell carcinoma of the oral cavity, including surgery or primary chemotherapy (PCT), which foresaw the prospective determination of biological markers. Pathological response was defined as the achievement after PCT of a pathological complete remission or the presence of microresidual disease. The study was performed on tumors obtained from a series of 100 previously untreated patients with resectable T2-4N0-2M0 carcinoma. All biomarkers were unrelated, except for an inverse relation between TLI and GST-pi and a direct relation between bcl-2 and bax expression. In patients treated with surgery alone, 3-year disease-free survival (DFS) appeared to be weakly, but not significantly, related only to GST-pi and p53 expression. In patients treated with PCT, pathological response and DFS were independent of p53 expression and cell proliferation. Conversely, low GST-pi and bax expression were indicative of pathological response but lost relevance as predictors of DFS, whereas absence of bcl-2 was associated with high probability of 3-year DFS in the overall series as well as in non-responding patients. Within this latter sub-set, all patients with bcl-2-positive tumors relapsed within 1 year of surgery, whereas a 60% probability of 3-year DFS was observed for patients with bcl-2-negative tumors (p = 0.02). This interim analysis appears to indicate that some biofunctional markers can provide information on pathological response to PCT and could help in understanding treatment efficacy at a cellular level.

Bcl-2 protein and prognosis in patients with potentially curable non-small-cell lung cancer.

The bcl-2 proto-oncogene functions as a cell death suppressor, and its expression prolongs cell survival by blocking apoptosis. Data available on the clinical relevance of bcl-2 protein expression in patients with non-small-cell lung cancer (NSCLC) are controversial. We analysed the role of bcl-2 protein expression on 6-year relapse-free survival in 229 patients with stage I-IIIa NSCLC (101 squamous cell carcinomas and 128 adenocarcinomas) subjected to surgery, with curative intent. Immunohistochemical analysis was performed on archival material by using a monoclonal antibody anti-bcl-2 (clone 124). Bcl-2 protein expression, which was detected in 22% of the cases, was significantly related to stage, histology and grading, and was an indicator of clinical outcome. The probability of relapse-free survival at 6 years was longer for patients with bcl-2-positive tumours (74%) than for those with bcl-2-negative tumours (57%) (P=0.02). This finding was mainly evident for the subgroups of patients with stage IIIa tumours (P=0.05), squamous cell carcinoma (P=0.03) or moderately/poorly differentiated tumours (P=0.02). However, multivariate analysis by Weibull's regression model indicated that bcl-2 protein expression was not an independent prognostic risk factor in patients with curable NSCLC when the information provided by stage was available.

The clinical predictivity of biomarkers of stage III-IV epithelial ovarian cancer in a prospective randomized treatment protocol.

BACKGROUND: The aim of this study was to define the clinical relevance of functional biomarkers, prospectively assessed in a randomized clinical protocol, in patients with Stage III-IV epithelial ovarian cancer. The protocol compared cisplatin with polychemotherapy that included cisplatin and cyclophosphamide. METHODS: In a subset of 168 patients with invasive epithelial ovarian cancer cell proliferation was determined by the 3H-thymidine labeling index, DNA ploidy was assessed by flow cytometry, and the expression of p53, bcl-2, and glutathione S-transferase-pi (GST-pi) was evaluated by immunohistochemistry using the antibodies PAb1801, anti-bcl-2, and GST-pi, respectively. RESULTS: Cell proliferation, DNA ploidy, and the expression of p53, bcl-2, and GST-pi were generally unrelated to one another and unrelated to clinicopathologic features, except for an association between DNA ploidy and the rate of cell proliferation. All biologic variables except bcl-2 were slightly related to tumor grade. DNA ploidy emerged as a predictor of clinical complete response and 3-year overall survival, regardless of treatment type or residual disease. Conversely, except for a favorable outcome for patients with tumors not expressing bcl-2 who were treated with cisplatin, no definitive patterns of predictivity for short term or long term clinical outcomes were observed for the other biomarkers studied. CONCLUSIONS: DNA ploidy appears to be the most clinically relevant biomarker for epithelial ovarian cancer. More information is needed to understand the role of the other markers studied in this tumor type.

Expression of p53, glutathione S-transferase-pi, and Bcl-2 proteins and benefit from adjuvant radiotherapy in breast cancer.

BACKGROUND: In clinical breast cancer research, the utility of certain biomarkers as predictors of response to surgery, chemotherapy, or hormonal therapy has been studied intensively. Much less research has been done on the relevance of biologic predictors of response to radiotherapy, which represents an effective local-regional treatment for breast cancer. PURPOSE: The utility of biomarkers involved in DNA damage repair (p53 protein), control of programmed cell death (p53 and Bcl-2 proteins), and cellular detoxification (glutathione S-transferase-pi [GST-pi] enzyme) in predicting local breast cancer recurrence was analyzed retrospectively in two cohorts of breast cancer patients. These patients had had no detectable metastases in the axillary lymph nodes (i.e., node-negative) or in distant sites and had had similar distributions of clinicopathologic and biologic prognostic features. They had been treated by conservative surgery alone (139 case patients) or by conservative surgery followed by adjuvant radiotherapy (496 case patients) during the period from 1984 through 1990. METHODS: The expression of the p53, GST-pi, and Bcl-2 proteins in the specimens of primary breast tumor obtained from these patients was determined by use of immunohistochemistry; cell proliferation activity and levels of steroid receptors were determined by use of a [3H]thymidine-labeling index assay and the dextran-coated charcoal technique, respectively. The median time of follow-up of patients was 6 years. In the analyses of patient outcomes, only local failures that presented as first events were considered. RESULTS: After surgery alone, the risk of local recurrence at 6 years was higher for patients with tumors exhibiting elevated levels of p53 and GST-pi protein expression than for patients with low levels (hazard ratio [HR] = 3.1, 95% confidence interval [CI] = 1.3-7.7, two-sided P = .012; HR = 2.7, 95% CI = 1.1-6.4, two-sided P = .026, respectively). Weak or no observable expression of Bcl-2 protein was only suggestive of a higher frequency of local failures. Adjustment for patient age, tumor size, cell proliferation, and estrogen receptor status did not change these findings. Conversely, in the series of patients given conservative surgery followed by radiotherapy, there was no difference in local tumor recurrence between patients with tumors expressing or not expressing each of the three markers. CONCLUSIONS: Our study provides indirect evidence of a benefit from radiation therapy in preventing local breast cancer relapse, particularly among node-negative patients with tumors that express elevated levels of the p53 or GST-pi proteins or that express little or no Bcl-2 protein.

Comparative in vitro sensitivity of human cholangiocarcinoma and colon adenocarcinoma cells to anticancer agents.

We comparatively investigated the sensitivity of a human cholangiocarcinoma cell line (SG231) and an adenocarcinoma cell line (WiDr) to mitoxantrone (MX), taxol (TX), mitomycin C (MMC), doxorubicin (DX), cisplatin (CDDP) and 5-fluorouracil (5FU) by the sulforhodamine B assay. The lower susceptibility of SG231 to SFU, to CDDP, to DX and to MMC than WiDr was observed, whereas the sensitivity of the two cell lines to MX and TX was similar. We also investigated the ability of a chemical modulator, lonidomine (LND), and hyperthermia to enhance the cytotoxic activity of the different drugs in the SG231 cell line. No potentiation of MX or CDDP activity was observed after a 2 hours treatment in hyperthermic conditions (42 degrees C). Conversely, a slight potentiation of a 2 hours pretreatment with MX and DX was obtained by a 24 hours post treatment with LND.

Biological indicators of survival in patients treated by surgery for squamous cell carcinoma of the oral cavity and oropharynx.

Squamous cell carcinomas of the head and neck are a heterogeneous group of tumours with regard to anatomical site, natural history and response to various treatments. Assessment of the role of biomarkers as indicators of prognosis or response to treatment is thus complex. In the last decade, different biomarkers have been investigated in the search for objective and reproducible indicators of prognosis. In 69 squamous cell carcinomas of the oral cavity or oropharynx from patients treated with radical surgery alone, we determined cell kinetics, evaluated as in vitro 3H-thymidine labelling index (TLI), p53, bcl-2 and glutathione S-transferase pi (GST pi) expression, by using immunohistochemical methods. The biological variables were unrelated to one another or to established clinical and pathological prognostic factors. Univariate analysis showed that a low proliferative activity was associated to a significantly higher risk of death than that observed in patients with a high TLI, whereas p53, bcl-2 and GST pi expression did not provide prognostic information. Multivariate analysis showed that cell proliferation, gender and nodal status retained their clinical relevance. In the subset of node-negative patients, TLI and p53 expression were indicators of survival. Moreover, the combined analysis of TLI and p53 expression identified a subgroup of node-negative patients with slowly proliferating and highly p53-expressing tumours who died within 1 year of radical surgery. These results indicate that in patients with operable oral cavity and oropharyngeal cancer, biomarkers can provide important information on clinical outcome.

Biological predictors of response to radiotherapy in cervical carcinomas.

On 21 patients with T1b-T3b tumours subjected to external radiotherapy and brachytherapy, the expression of P53 and glutathione S-transferase pi [GST-pi], immunohistochemically detected, the S-phase cells fraction (H-3-thymidine labeling index, TLI) and DNA content evaluated by image analysis were determined on biopsies before and after the first 10 Gy. P53 accumulation was reduced in 60% of P53-overexpressing tumours and not induced in P53-negative tumours, GST-pi was induced in about 40% of pretreatment GST-pi-negative cases, TLI was reduced in 70% of the cases regardless of pretreatment values, and DNA profiles remained unchanged in two-thirds of the cases. P53 accumulation was a predictor of 3-year relapse-free survival after radiotherapy, followed by GST-pi expression, whereas TLI did not influence prognosis.

p53 and bcl-2 expression correlates with clinical outcome in a series of node-positive breast cancer patients.

BACKGROUND AND PURPOSE: The tumor-suppressor gene TP53 and the proto-oncogene bcl-2 encode, respectively, for a nuclear phosphoprotein and for a mitochondrial protein involved in multiple cellular functions. The proteins provide prognostic information in node-negative breast cancer and are supposed to influence treatment responsiveness. We analyzed the predictive role of p53 and bcl-2 expression, alone and in association with other variables, in postmenopausal women with node-positive, estrogen receptor-positive (ER+) breast cancers treated with radical or conservative surgery plus radiotherapy and adjuvant tamoxifen for at least 1 year. PATIENTS AND METHODS: On 240 resectable cancers, we determined the expression of p53 and bcl-2, using immunohistochemistry, cell proliferation (3H-thymidine labeling index [3H-dT LI]), and ER and progesterone receptors (PgR). RESULTS: p53 expression and 3H-dT LI were weakly related to one another and both were unrelated to bcl-2. Relapse-free and distant metastasis-free survival at 5 years were significantly lower for patients with tumors that highly expressed p53 (P = .0001) and for those that weakly expressed or did not express bcl-2 (P = .02). However, p53, but not bcl-2, provided prognostic information independent of tumor size, axillary node involvement, steroid receptors, and 3H-dT LI. Moreover, the simultaneous p53 overexpression and lack of PgR identified patients at maximum risk of relapse, whereas bcl-2 overexpression, associated with a low 3H-dT LI or the presence of PgR, improved the prognostic resolution for low-risk patients. CONCLUSION: p53 expression appears to be indicative of clinical outcome in postmenopausal patients treated with tamoxifen. Whether p53 overexpression and weak bcl-2 expression are indicators of biologic aggressiveness, regardless of treatment, or of hormone resistance remains to be defined.

Changes in biological markers after primary chemotherapy for breast cancers.

The profiles of functional (proliferative rate and cell distribution in the cell cycle) and phenotypic (nuclear DNA content and hormone receptor status) biological markers and the expression of P53 and Bcl-2 proteins were prospectively evaluated in breast cancers before and after different regimens of primary chemotherapy. Overall, changes induced on the 2 proliferation indices (3H-thymidine labelling index, 3H-dT LI, and flow-cytometric S-phase fraction, FCM-S) mainly consisted of a decrease for rapidly proliferating tumours and an increase or no change for slowly proliferating tumours. However, when considered as a function of treatment type, changes of 3H-dT LI and FCM-S were superimposable in rapidly proliferating tumours, regardless of the type of treatment, and in slowly proliferating tumours only after anthracycline-including regimens. Conversely, following CMF, FCM-S was increased in 90% of the cases and 3H-dT LI in only 50%. Our data imply that the 2 proliferation indices could reflect different phenomena: an actual variation of proliferative activity by 3H-dT LI and an accumulation of cells in the S-phase by FCM-S. In addition, a higher accumulation of cells in G2-M phases could be detected by FCM after anthracycline-including regimens than after CMF. The fraction of P53-positive cells was reduced by primary chemotherapy in about 50% of P53-positive tumours, whereas Bcl-2 expression was only marginally affected. DNA ploidy and hormone receptor status did not change in about 75% of cases, regardless of the chemotherapeutic regimen.

Potentiation of cisplatin cytotoxicity by lonidamine in primary cultures of human ovarian cancer.

The ability of lonidamine, an energolytic derivative of indazole-carboxylic acid, to modulate the cytotoxic activity of cisplatin was investigated on primary cultures obtained from 11 human ovarian carcinomas. A 72-h postincubation with lonidamine potentiated the activity of a 1-h cisplatin treatment. Statistical analysis of the dose-effect plots indicated that the interaction between the two drugs was synergistic in 4 tumors and additive in the remaining 7 tumors. The occurrence of the synergistic effect was independent of some biological characteristics of the tumor cell population, such as cell kinetics (as assessed by 3H-thymidine labeling index), DNA content and the expression of the putative factor of cisplatin resistance, glutathione-S-transferase pi.