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1.
NPJ Breast Cancer ; 10(1): 29, 2024 Apr 18.
Article in English | MEDLINE | ID: mdl-38637568

ABSTRACT

Tumor-infiltrating lymphocytes (TILs) have been associated with outcomes in HER2-positive breast cancer patients treated with neoadjuvant chemotherapy and trastuzumab. However, it remains unclear if TILs could be a prognostic and/or predictive biomarker in the context of dual HER2-targeting treatment. In this study, we evaluated the association between TILs and pathological response (pCR) and invasive-disease free survival (IDFS) in 389 patients with stage II-III HER2 positive breast cancer who received neoadjuvant anthracycline-containing or anthracycline-free chemotherapy combined with trastuzumab and pertuzumab in the TRAIN-2 trial. Although no significant association was seen between TILs and pCR, patients with TIL scores ≥60% demonstrated an excellent 3-year IDFS of 100% (95% CI 100-100), regardless of hormone receptor status, nodal stage and attainment of pCR. Additionally, in patients with hormone receptor positive disease, TILs as a continuous variable showed a trend to a positive association with pCR (adjusted Odds Ratio per 10% increase in TILs 1.15, 95% CI 0.99-1.34, p = 0.070) and IDFS (adjusted Hazard Ratio per 10% increase in TILs 0.71, 95% CI 0.50-1.01, p = 0.058). We found no interactions between TILs and anthracycline treatment. Our results suggest that high TIL scores might be able to identify stage II-III HER2-positive breast cancer patients with a favorable prognosis.

2.
BMC Cancer ; 23(1): 1112, 2023 Nov 14.
Article in English | MEDLINE | ID: mdl-37964214

ABSTRACT

BACKGROUND: Follow-up of curatively treated primary breast cancer patients consists of surveillance and aftercare and is currently mostly the same for all patients. A more personalized approach, based on patients' individual risk of recurrence and personal needs and preferences, may reduce patient burden and reduce (healthcare) costs. The NABOR study will examine the (cost-)effectiveness of personalized surveillance (PSP) and personalized aftercare plans (PAP) on patient-reported cancer worry, self-rated and overall quality of life and (cost-)effectiveness. METHODS: A prospective multicenter multiple interrupted time series (MITs) design is being used. In this design, 10 participating hospitals will be observed for a period of eighteen months, while they -stepwise- will transit from care as usual to PSPs and PAPs. The PSP contains decisions on the surveillance trajectory based on individual risks and needs, assessed with the 'Breast Cancer Surveillance Decision Aid' including the INFLUENCE prediction tool. The PAP contains decisions on the aftercare trajectory based on individual needs and preferences and available care resources, which decision-making is supported by a patient decision aid. Patients are non-metastasized female primary breast cancer patients (N = 1040) who are curatively treated and start follow-up care. Patient reported outcomes will be measured at five points in time during two years of follow-up care (starting about one year after treatment and every six months thereafter). In addition, data on diagnostics and hospital visits from patients' Electronical Health Records (EHR) will be gathered. Primary outcomes are patient-reported cancer worry (Cancer Worry Scale) and overall quality of life (as assessed with EQ-VAS score). Secondary outcomes include health care costs and resource use, health-related quality of life (as measured with EQ5D-5L/SF-12/EORTC-QLQ-C30), risk perception, shared decision-making, patient satisfaction, societal participation, and cost-effectiveness. Next, the uptake and appreciation of personalized plans and patients' experiences of their decision-making process will be evaluated. DISCUSSION: This study will contribute to insight in the (cost-)effectiveness of personalized follow-up care and contributes to development of uniform evidence-based guidelines, stimulating sustainable implementation of personalized surveillance and aftercare plans. TRIAL REGISTRATION: Study sponsor: ZonMw. Retrospectively registered at ClinicalTrials.gov (2023), ID: NCT05975437.


Subject(s)
Breast Neoplasms , Humans , Female , Breast Neoplasms/therapy , Aftercare , Quality of Life , Prospective Studies , Interrupted Time Series Analysis , Multicenter Studies as Topic
3.
Eur J Cancer ; 102: 40-48, 2018 Oct.
Article in English | MEDLINE | ID: mdl-30125761

ABSTRACT

BACKGROUND: Dose-dense administration of chemotherapy and the addition of taxanes to anthracycline-based adjuvant chemotherapy have improved breast cancer survival substantially. However, clinical trials directly comparing the additive value of taxanes with dose-dense anthracycline-based chemotherapy are lacking. PATIENTS AND METHODS: In the multicentre, randomised, biomarker discovery Microarray Analysis in breast cancer to Tailor Adjuvant Drugs Or Regimens (MATADOR) trial, patients with pT1-3, pN0-3 breast cancer were randomised (1:1) between six adjuvant cycles of doxorubicin 60 mg/m2 and cyclophosphamide 600 mg/m2 every 2 weeks (ddAC) and six cycles of docetaxel 75 mg/m2, doxorubicin 50 mg/m2 and cyclophosphamide 500 mg/m2 every 3 weeks (TAC). The primary objective was to discover a predictive gene expression profile for ddAC and TAC benefit. Here we report the preplanned secondary end-point recurrence-free survival (RFS) and overall survival (OS). RESULTS: Between 2004 and 2012, 664 patients were randomised. At 5 years, RFS was 87% (95% confidence interval [CI] 83%-91%) in the ddAC-treated patients and 88% (84-92%) in the TAC-treated subgroup (hazard ratio [HR] 0.89, 95% CI 0.62-1.28, P = 0.53). OS at 5 years was 93% (90%-96%) in the ddAC-treated and 94% (91%-97%) in the TAC-treated patients (HR 0.89, 95% CI 0.57-1.39, P = 0.61). Anaemia was more frequent in ddAC-treated patients (62/327 patients [18.9%] versus 15/319 patients [4.7%], P < 0.001) and diarrhoea (21 [6.4%] versus 53 [16.6%], P<0.001) and peripheral neuropathy (15 [4.6%] versus 46 [14.4%], P < 0.001) were observed more often in TAC-treated patients. CONCLUSIONS: With a median follow-up of 7 years, no significant differences in RFS and OS were observed between six adjuvant cycles of ddAC and TAC in high-risk breast cancer patients. TRIAL REGISTRATION NUMBERS: ISRCTN61893718 and BOOG 2004-04.


Subject(s)
Adenocarcinoma/drug therapy , Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Breast Neoplasms/drug therapy , Cyclophosphamide/administration & dosage , Doxorubicin/administration & dosage , Adenocarcinoma/mortality , Adenocarcinoma/secondary , Antineoplastic Combined Chemotherapy Protocols/adverse effects , Breast Neoplasms/mortality , Breast Neoplasms/pathology , Chemotherapy, Adjuvant , Cyclophosphamide/adverse effects , Disease Progression , Doxorubicin/adverse effects , Female , Humans , Middle Aged , Neoplasm Recurrence, Local , Neoplasm Staging , Netherlands , Progression-Free Survival , Risk Assessment , Risk Factors , Time Factors
4.
Breast ; 25: 69-74, 2016 Feb.
Article in English | MEDLINE | ID: mdl-26614548

ABSTRACT

BACKGROUND: Serum levels of 25-OH vitamin D3 (vitamin D) have been shown to be prognostic for disease-free survival in patients with breast cancer. We investigated the predictive value of these levels for pathological response after neoadjuvant chemotherapy in patients with breast cancer taking part in the NEOZOTAC phase-III trial. Additionally, the effect of chemotherapy on vitamin D levels was studied. MATERIALS AND METHODS: Serum vitamin D was measured at baseline and before the last cycle of chemotherapy. The relationship between these measurements and clinical outcome, as defined by pathological complete response in breast and lymph nodes (pCR) was examined. RESULTS: Baseline and end of treatment vitamin D data were available in 169 and 91 patients, respectively. Median baseline vitamin D values were 58.0 nmol/L. In patients treated with chemotherapy only, serum vitamin D levels decreased during neoadjuvant chemotherapy (median decrease of 16 nmol/L, P = 0.003). The prevalence of vitamin D levels < 50 nmol/L increased from 38.3% at baseline to 55.9% after chemotherapy. In the total population, baseline and end of therapy vitamin D levels were not related to pathological response. No associations were found between pCR and vitamin D level changes. CONCLUSION: The significant decrease in vitamin D post-neoadjuvant chemotherapy suggests that vitamin D levels should be monitored and in case of decrease of vitamin D levels, correction may be beneficial for skeletal health and possibly breast cancer outcome.


Subject(s)
Breast Neoplasms/blood , Breast Neoplasms/pathology , Calcifediol/blood , Lymph Nodes/pathology , Neoadjuvant Therapy/adverse effects , Adult , Aged , Biomarkers, Pharmacological/blood , Breast Neoplasms/drug therapy , Chemotherapy, Adjuvant/adverse effects , Disease-Free Survival , Female , Humans , Middle Aged , Neoplasm Staging , Predictive Value of Tests , Prognosis , Treatment Outcome
5.
Breast Cancer Res Treat ; 149(2): 461-6, 2015 Jan.
Article in English | MEDLINE | ID: mdl-25556355

ABSTRACT

This side study investigated the effect of chemotherapy on thyroid function and the extent to which it can predict pathological complete response (pCR) in patients with early breast cancer taking part in NEOZOTAC phase III trial, randomizing between neoadjuvant chemotherapy with or without additional zoledronic acid. Moreover, we examined the impact of thyroid function on toxicity. Serum samples of 38 patients were available for analyses. Free thyroxin (fT4) and thyroid stimulating hormone (TSH) levels were compared between baseline and before the 6th cycle and between subjects with and without pCR. The relation between toxicity and the variation in fT4 and TSH levels during chemotherapy was tested. Samples at baseline and before the 6th cycle were available for 31 and 21 patients, respectively. The mean baseline fT4 level was 16.0 pmol/L and TSH level 1.11 mU/L, and these did not differ between both arms at each time point. During six cycles of chemotherapy, fT4 levels decreased (p = 0.0001), and TSH levels increased significantly (p = 0.019). Interestingly, the decrease of fT4 was significantly greater in patients without nausea, vomiting, or neuropathy, than in patients with those side effects (p = 0.037, p = 0.043, and p = 0.050, respectively). Baseline TSH levels tended to be higher in patients with pCR (p = 0.035 univariate analysis and p = 0.074 multivariate analysis). Chemotherapy blunts thyroid function, which was associated with less side effects. These data urge further evaluation of the effects of thyroid function on toxicity and outcome of breast cancer therapy.


Subject(s)
Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Breast Neoplasms/blood , Breast Neoplasms/drug therapy , Thyrotropin/blood , Thyroxine/blood , Adult , Aged , Antineoplastic Combined Chemotherapy Protocols/adverse effects , Biomarkers, Tumor/metabolism , Breast Neoplasms/pathology , Female , Humans , Middle Aged , Neoadjuvant Therapy , Neoplasm Staging , Thyroid Function Tests , Thyroid Gland/drug effects , Thyroid Gland/metabolism , Treatment Outcome
6.
Eur J Surg Oncol ; 40(10): 1216-21, 2014 Oct.
Article in English | MEDLINE | ID: mdl-25150151

ABSTRACT

BACKGROUND: Studies suggest that MRI is an accurate means for assessing tumor size after neoadjuvant chemotherapy (NAC). However, accuracy might be dependent on the receptor status of tumors. MRI accuracy for response assessment after homogenous NAC in a relative large group of patients with stage II/III HER2-negative breast cancer has not been reported before. METHODS: 250 patients from 26 hospitals received NAC (docetaxel, adriamycin and cyclophosphamide) in the context of the NEOZOTAC trial. MRI was done after 3 cycles and post-NAC. Imaging (RECIST 1.1) and pathological (Miller and Payne) responses were recorded. Accuracy measures were calculated and MRI and pathologically assessed tumor sizes were correlated. Tumor size over- and underestimation were quantified. RESULTS: Accuracy of MRI for determining pathological complete response (pCR) was 76%. The ROC-curve of MRI response and pCR had an area under the curve value of 0.63 (95% C.I. 0.52-0.74). The correlation coefficient of MRI and histopathological tumor measurements was 0.46 (p < 0.001). Correlations were different for ER-positive (r = 0.40, p < 0.001) and ER-negative (r = 0.76, p < 0.001) breast tumors. MRI under- and overestimated the tumor size in 47% and 40% of all patients. In cases of substantial tumor size underestimation (>2 cm), surgical margins were more often tumor positive compared to the rest of the patients (33% vs.12%, p = 0.005). CONCLUSION: MRI measurements correlated moderately with tumor size on the surgical specimen. Only in ER-negative breast tumors, MRI tumor sizes correlated sufficiently with residual tumor size on the pathological specimen. Therefore, post-NAC MRI should be interpreted with caution.


Subject(s)
Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Breast Neoplasms/pathology , Breast/pathology , Carcinoma/pathology , Magnetic Resonance Imaging , Adult , Aged , Area Under Curve , Breast Neoplasms/drug therapy , Breast Neoplasms/metabolism , Carcinoma/drug therapy , Carcinoma/metabolism , Chemotherapy, Adjuvant , Cyclophosphamide/administration & dosage , Diphosphonates/therapeutic use , Docetaxel , Doxorubicin/administration & dosage , Female , Humans , Imidazoles/therapeutic use , Middle Aged , Neoadjuvant Therapy , ROC Curve , Receptor, ErbB-2/metabolism , Receptors, Estrogen/metabolism , Taxoids/administration & dosage , Treatment Outcome , Tumor Burden , Zoledronic Acid
7.
Ann Oncol ; 25(5): 998-1004, 2014 May.
Article in English | MEDLINE | ID: mdl-24585721

ABSTRACT

BACKGROUND: The role of zoledronic acid (ZA) when added to the neoadjuvant treatment of breast cancer (BC) in enhancing the clinical and pathological response of tumors is unclear. The effect of ZA on the antitumor effect of neoadjuvant chemotherapy has not prospectively been studied before. PATIENTS AND METHODS: NEOZOTAC is a national, multicenter, randomized study comparing the efficacy of TAC (docetaxel, adriamycin and cyclophosphamide i.v.) followed by granulocyte colony-stimulating factor on day 2 with or without ZA 4 mg i.v. q 3 weeks inpatients withstage II/III, HER2-negative BC. We present data on the pathological complete response (pCR in breast and axilla), on clinical response using MRI, and toxicity. Post hoc subgroup analyses were undertaken to address the predictive value of menopausal status. RESULTS: Addition of ZA to chemotherapy did not improve pCR rates (13.2% for TAC+ZA versus 13.3% for TAC). Postmenopausal women (N = 96) had a numerical benefit from ZA treatment (pCR 14.0% for TAC+ZA versus 8.7% for TAC, P = 0.42). Clinical objective response did not differ between treatment arms (72.9% versus 73.7%). There was no difference in grade III/IV toxicity between treatment arms. CONCLUSIONS: Addition of ZA to neoadjuvant chemotherapy did not improve pathological or clinical response to chemotherapy. Further investigations are warranted in postmenopausal women with BC, since this subgroup might benefit from ZA treatment.


Subject(s)
Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Breast Neoplasms/drug therapy , Receptor, ErbB-2/metabolism , Adult , Aged , Breast Neoplasms/metabolism , Breast Neoplasms/pathology , Chemotherapy, Adjuvant , Cyclophosphamide/administration & dosage , Diphosphonates/administration & dosage , Docetaxel , Doxorubicin/administration & dosage , Female , Humans , Imidazoles/administration & dosage , Middle Aged , Neoadjuvant Therapy , Neoplasm Staging , Prospective Studies , Taxoids/administration & dosage , Treatment Outcome , Zoledronic Acid
8.
Ann Oncol ; 25(3): 599-605, 2014 Mar.
Article in English | MEDLINE | ID: mdl-24504445

ABSTRACT

BACKGROUND: Prospective data on chemotherapy for elderly patients with metastatic breast cancer (MBC) remain scarce. We compared the efficacy and safety of first-line chemotherapy with pegylated liposomal doxorubicin (PLD) versus capecitabine in MBC patients aged ≥65 years in a multicentre, phase III trial. PATIENTS AND METHODS: Patients were randomized to six cycles of PLD (45 mg/m(2) every 4 weeks) or eight cycles of capecitabine (1000 mg/m(2) twice daily, day 1-14 every 3 weeks). RESULTS: The study enrolled 78 of the planned 154 patients and was closed prematurely due to slow accrual and supply problems of PLD. Many included patients were aged ≥75 years (54%) and vulnerable (≥1 geriatric condition: 71%). The median dose intensity was 85% for PLD and 84% for capecitabine, respectively. In both arms, the majority of patients completed at least 12 weeks of treatment (PLD 73%; capecitabine 74%). After a median follow-up of 39 months, 77 patients had progressed and 62 patients had died of MBC. Median progression-free survival was 5.6 versus 7.7 months (P = 0.11) for PLD and capecitabine, respectively. Median overall survival was 13.8 months for PLD and 16.8 months for capecitabine (P = 0.59). Both treatments were feasible, grade 3 toxicities consisting of fatigue (both arms: 13%), hand-foot syndrome (PLD: 10%; capecitabine: 16%), stomatitis (PLD: 10%; capecitabine: 3%), exanthema (PLD: 5%) and diarrhoea (PLD: 3%; capecitabine: 5%). Only 1 of 10 patients aged ≥80 years completed chemotherapy, while 3 and 6 patients discontinued treatment due to toxicity or progressive disease, respectively. CONCLUSION: Both PLD and capecitabine demonstrated comparable efficacy and acceptable tolerance as first-line single-agent chemotherapy in elderly patients with MBC, even in vulnerable patients or patients aged ≥75 years. However, patients aged ≥80 years were unlikely to complete chemotherapy successfully. CLINICAL TRIAL NUMBERS: EudraCT 2006-002046-10; ISRCTN 11114726; CKTO 2006-09; BOOG 2006-02.


Subject(s)
Breast Neoplasms/drug therapy , Deoxycytidine/analogs & derivatives , Doxorubicin/analogs & derivatives , Fluorouracil/analogs & derivatives , Aged , Aged, 80 and over , Antibiotics, Antineoplastic/adverse effects , Antibiotics, Antineoplastic/pharmacology , Antimetabolites, Antineoplastic/adverse effects , Antimetabolites, Antineoplastic/therapeutic use , Antineoplastic Combined Chemotherapy Protocols/adverse effects , Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Breast Neoplasms/mortality , Capecitabine , Deoxycytidine/adverse effects , Deoxycytidine/therapeutic use , Disease-Free Survival , Doxorubicin/adverse effects , Doxorubicin/therapeutic use , Female , Fluorouracil/adverse effects , Fluorouracil/therapeutic use , Humans , Neoplasm Metastasis/drug therapy , Netherlands , Polyethylene Glycols/adverse effects , Polyethylene Glycols/therapeutic use , Prospective Studies , Treatment Outcome
9.
Breast ; 23(1): 81-7, 2014 Feb.
Article in English | MEDLINE | ID: mdl-24314824

ABSTRACT

AIM: To evaluate the association between baseline comprehensive geriatric assessment (CGA) or the Groningen Frailty Indicator (GFI) and toxicity in elderly metastatic breast cancer (MBC) patients treated with first-line palliative chemotherapy. PATIENTS AND METHODS: MBC patients (≥65 years) were randomized between pegylated liposomal doxorubicine or capecitabine. CGA included instrumental activities of daily living (IADL), cognition using the mini-mental state examination (MMSE), mood using the geriatric depression scale (GDS), comorbidity using the Charlson index, polypharmacy and nutritional status using the body mass index. Frailty on CGA was defined as one or more of the following: IADL ≤ 13, MMSE ≤ 23, GDS ≥ 5, BMI ≤ 20, ≥5 medications or Charlson ≥2. The cut-off for frailty on the GFI was ≥4. RESULTS: Of the randomized 78 patients (median age 75.5 years, range 65.8-86.8 years), 73 were evaluable for CGA; 52 (71%) had one or more geriatric conditions. Grade 3-4 chemotherapy-related toxicity was experienced by 19% of patients without geriatric conditions compared to 56% of patients with two geriatric conditions and 80% of those with three or more (p = 0.002). Polypharmacy was the only individual factor significantly associated with toxicity (p = 0.001). GFI had a sensitivity of 69% and a specificity of 76% for frailty on CGA, and was not significantly associated with survival or toxicity. CONCLUSION: In this study of elderly patients with MBC, the number of geriatric conditions correlated with grade 3-4 chemotherapy-related toxicity. Therefore, in elderly patients for whom chemotherapy is being considered, a CGA could be a useful addition to the decision-making process.


Subject(s)
Antineoplastic Agents/adverse effects , Breast Neoplasms/drug therapy , Deoxycytidine/analogs & derivatives , Doxorubicin/analogs & derivatives , Fluorouracil/analogs & derivatives , Geriatric Assessment , Activities of Daily Living , Aged , Aged, 80 and over , Antineoplastic Agents/therapeutic use , Body Mass Index , Breast Neoplasms/epidemiology , Breast Neoplasms/pathology , Capecitabine , Cognition Disorders/epidemiology , Comorbidity , Deoxycytidine/adverse effects , Deoxycytidine/therapeutic use , Depression/epidemiology , Doxorubicin/adverse effects , Doxorubicin/therapeutic use , Fatigue/chemically induced , Female , Fluorouracil/adverse effects , Fluorouracil/therapeutic use , Frail Elderly , Hand-Foot Syndrome/etiology , Humans , Mental Status Schedule , Palliative Care , Polyethylene Glycols/adverse effects , Polyethylene Glycols/therapeutic use , Polypharmacy , Risk Factors , Stomatitis/chemically induced , Treatment Outcome
10.
Breast ; 22(4): 556-9, 2013 Aug.
Article in English | MEDLINE | ID: mdl-23305962

ABSTRACT

BACKGROUND: In a Dutch multicentre study, elderly (65 + year) metastatic breast cancer patients, eligible for first-line chemotherapy, were randomised between two types of single-agent chemotherapy. As accrual was slow, with 78 randomised patients between April 2007 and September 2011, we explored potential barriers in the accrual process and their consequences for characteristics of included patients. METHODS: We sent surveys on the reasons for non-inclusion to all coordinating investigators. We also examined inclusion in a concurrent, non-elderly breast cancer study of the trialists' group and analysed baseline geriatric characteristics of included patients. RESULTS: Investigators from fifteen participating centres returned the survey. Most commonly reported barriers to inclusion were: patient's refusal of chemotherapy (n = 8) or of randomisation (n = 9), impaired cognition (n = 3) and insufficient cardiac function (n = 2). Oncologists' preference for combination regimens over single-agent chemotherapy was reported twice. Twenty-eight potentially eligible patients, aged 65-71 years, were included in a concurrent, study investigating combination chemotherapy in fit non-elderly patients with metastatic breast cancer. However, baseline characteristics of the included patients showed that the OMEGA study succeeded in including frail and older patients, with a performance status of 2 in 22% of patients and 54% of patients aged 75 years or older. CONCLUSION: Accrual in this study was mainly hampered by patient's refusal or preference for a particular type of treatment, and an overall condition considered as too fit or too frail for inclusion. Future trials in elderly metastatic breast cancer patients should focus on non-restrictive inclusion criteria as well as on education of physicians and elderly patients on the advantages of trial participation.


Subject(s)
Antineoplastic Agents/therapeutic use , Breast Neoplasms/drug therapy , Patient Selection , Randomized Controlled Trials as Topic/methods , Aged , Aged, 80 and over , Breast Neoplasms/pathology , Female , Humans , Netherlands , Treatment Refusal
11.
Br J Cancer ; 74(4): 619-24, 1996 Aug.
Article in English | MEDLINE | ID: mdl-8761380

ABSTRACT

Gallium-67 is a radionuclide that accumulates in haematological malignancies and is used for diagnostic purposes. Uptake of 67Ga into the cell occurs via the transferrin receptor, which is differentially expressed during the various cell cycle phases. With the aim of selectively increasing 67Ga uptake, we studied whether the transferrin receptor (TfR) expression could be modulated in the U937 and U715 lymphoma cell lines by cytostatic drugs inducing cell cycle phase accumulation. We tested clinically relevant drugs such as 1-beta-D-arabinofuranosylcytosine (Ara-C), hydroxyurea and methotrexate. Cytotoxicity was determined by testing the clonogenic capacity of the lymphoma cell lines. All three drugs induced an increase in S-phase content, TfR expression and 67Ga uptake in U937 and U715 single cells. The combinations of drugs and 67Ga resulted in an additive effect on the clonogenic capacity. In U937 spheroids, cultured by the fibrin clot technique, we found an accumulation in the S-phase too as well as an increase of the transferrin receptor expression after Ara-C preincubation. As in single cells 67Ga uptake was increased without synergistic effects on the clonogenic capacity. In conclusion, priming with drugs induces increased transferrin receptor expression and 67Ga uptake. Inhibition of clonogenic capacity was additive rather than synergistic.


Subject(s)
Antineoplastic Agents/toxicity , Cell Survival/radiation effects , Gallium Radioisotopes/pharmacokinetics , Receptors, Transferrin/biosynthesis , Biological Transport , Cell Cycle/drug effects , Cell Division/drug effects , Cell Line , Cell Survival/drug effects , Cytarabine/toxicity , Flow Cytometry , Gallium Radioisotopes/toxicity , Gene Expression/drug effects , Humans , Hydroxyurea/toxicity , Lymphoma , Methotrexate/toxicity , Tumor Cells, Cultured , Tumor Stem Cell Assay
12.
Int J Radiat Oncol Biol Phys ; 35(3): 507-17, 1996 Jun 01.
Article in English | MEDLINE | ID: mdl-8655374

ABSTRACT

PURPOSE: The purpose of the present study was to investigate if there were differences between U715 spheroids and single cells in the radiotoxic effect of 67Ga on cell growth and clonogenic capacity in vitro and to generate dosimetric approaches for the multicellular tumor model. METHODS AND MATERIALS: Human lymphoma U715 cells were cultured in vitro as single cells and multicellular spheroids, grown with the use of a combination of fibrin clot technique, spinner flasks, and liquid-overlay culture. Cells were incubated with 2.96-8.88 MBq/ml 67Gallium for 4 days. Spheroids were dispersed to single cells by treatment with plasmin. Residual proliferative and clonogenic capacity after 67Ga incubation were assayed using the MTT-test and clonogenic test, respectively. Autoradiography was performed with 1 microm sections and Ilford L4 liquid photographic emulsion. Dosimetric approaches were made, based on the MIRD-approach. RESULTS: During 67Ga incubation proliferation was inhibited. The residual proliferative or clonogenic capacity was inhibited by 8.88 MBq/ml for 39 and 88%, respectively. For single cells with 6.66 MBq/ml these inhibitions were 64 and 96%, respectively. Autoradiography showed an homogeneous distribution of 67Ga in spheroids and single cells. In single cells a 2.1-3.5 times higher 67Ga uptake/cell than in spheroids produced an equitoxic effect. The uptake parameters were implemented in new dosimetric approaches and showed that the efficacy of intracellular 67Ga was two times higher in spheroid clusters than in single cells due to energy deposition of internal conversion electrons within the cell clusters with a mean diameter size of nine cells. Both for proliferative and clonogenic capacity the exponential survival curves were superimposed. CONCLUSIONS: With the new approaches made in our dosimetric model the discrepancy found between 67Ga accumulation and radiotoxic effect in spheroids as compared to single cells can be explained by additional effects of the crossfire of internal conversion electrons within clusters of about nine cells in diameter in spheroids. Only twice as much 67Ga was needed to reach equitoxic absorbed doses in spheroids than was needed in single cells. Such might be important for the use of 67Ga treatment of small metastasis of malignant lymphoma.


Subject(s)
Gallium Radioisotopes/pharmacology , Gallium Radioisotopes/pharmacokinetics , Spheroids, Cellular/metabolism , Spheroids, Cellular/radiation effects , Autoradiography , Cell Count/radiation effects , Cell Division/radiation effects , Cell Survival/radiation effects , Humans , Lymphoma/metabolism , Lymphoma/pathology , Radiation Dosage , Spheroids, Cellular/pathology , Tumor Cells, Cultured
13.
Int J Radiat Biol ; 64(6): 749-59, 1993 Dec.
Article in English | MEDLINE | ID: mdl-7903343

ABSTRACT

The selective uptake of the Auger- and internal conversion electrons emitting radionuclide 67Ga in malignant tumours may have therapeutic potential. We studied several factors which might affect the uptake and radiotoxicity of 67Ga in the human lymphoma cell line U-715. The 67Ga uptake was dependent on transferrin in a dose-dependent manner. The highest 67Ga uptake was found in the presence of 50 micrograms/ml purified human transferrin. Serum components other than transferrin negatively influenced the 67Ga uptake. Cells were adapted to a serum-free medium in which cells could be maintained for months and without factors disturbing 67Ga uptake. We demonstrated that there was a positive correlation between cell viability and 67Ga uptake (r = 0.97). Preculturing of cells in iron- and transferrin-deficient medium prior to 67Ga uptake led to upregulation of the transferrin receptor and a three-fold increase of 67Ga uptake. Uptake in these cells could be blocked by 72% by anti-transferrin-receptor monoclonal antibodies. Autoradiography of U-715 cells after 67Ga incubation showed intracellular 67Ga both in the cytoplasm and nucleus. Cell fractionation of 67Ga-loaded cells showed 27% of 67Ga present in the nuclei. Culturing of cells for 4 days in the presence of 3 MBq/ml 67Ga resulted in a 45% decrease of cell proliferation. The clonogenic capacity was diminished by 91%. In conclusion, we have demonstrated that 67Ga uptake is a transferrin-receptor-dependent mechanism of vital cells, and that after uptake 67Ga enters the cytosol and nucleus and has a strong cytotoxic effect on clonogenic capacity.


Subject(s)
Gallium Radioisotopes/pharmacokinetics , Lymphoma/metabolism , Cell Line , Cell Nucleus/metabolism , Cell Nucleus/radiation effects , Cytoplasm/metabolism , Cytoplasm/radiation effects , Gallium Radioisotopes/therapeutic use , Humans , Lymphoma/radiotherapy , Transferrin/physiology , Tumor Cells, Cultured
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