Impact of primary tumour resection on survival of patients with colorectal cancer and synchronous metastases treated by chemotherapy: results from the multicenter, randomised trial Fédération Francophone de Cancérologie Digestive 9601

OBJECTIVE

To assess the impact of primary tumour resection on overall survival (OS) of patients diagnosed with stage IV colorectal cancer (CRC).

DESIGN

Among the 294 patients with non-resectable colorectal metastases enrolled in the Fédération Francophone de Cancérologie Digestive (FFCD) 9601 phase III trial, which compared different first-line single-agent chemotherapy regimens, 216 patients (73%) presented with synchronous metastases at study entry and constituted the present study population. Potential baseline prognostic variables including prior primary tumour resection were assessed by univariate and multivariate Cox analyses. Progression-free survival (PFS) and OS curves were compared with the logrank test.

RESULTS

Among the 216 patients with stage IV CRC (median follow-up, 33 months), 156 patients (72%) had undergone resection of their primary tumour prior to study entry. The resection and non-resection groups did not differ for baseline characteristics except for primary tumour location (rectum, 14% versus 35%; p=0.0006). In multivariate analysis, resection of the primary was the strongest independent prognostic factor for PFS (hazard ratio (HR), 0.5; 95% confidence interval [CI], 0.4-0.8; p=0.0002) and OS (HR, 0.4; CI, 0.3-0.6; p<0.0001). Both median PFS (5.1 [4.6-5.6] versus 2.9 [2.2-4.1] months; p=0.001) and OS (16.3 [13.7-19.2] versus 9.6 [7.4-12.5]; p<0.0001) were significantly higher in the resection group. These differences in patient survival were maintained after exclusion of patients with rectal primary (n=43).

CONCLUSION

Resection of the primary tumour may be associated with longer PFS and OS in patients with stage IV CRC starting first-line, single-agent chemotherapy.

Factors for hematopoietic toxicity of carboplatin: refining the targeting of carboplatin systemic exposure

PURPOSE

Area under the curve (AUC) dosing is routinely carried out for carboplatin, but the chosen target AUC values remain largely empirical. This multicenter pharmacokinetic-pharmacodynamic (PK-PD) study was performed to determine the covariates involved in the interindividual variability of carboplatin hematotoxicity that should be considered when choosing individual target AUCs.

PATIENTS AND METHODS

Three hundred eighty-three patients received carboplatin as part of established regimens. A semi-physiologic population PK-PD model was applied to describe separately the time course of absolute neutrophil and platelet counts using NONMEM software. The plasma ultrafiltrable carboplatin concentration (C(Carbo)) was assumed to inhibit the proliferation of blood cell precursors through a linear model: drug effect = slope × C(Carbo). The slope corresponds to the patients' sensitivity to carboplatin hematotoxicity. The relationships between the patients' sensitivity to the neutropenic or thrombopenic effects of carboplatin and various covariates, including associated chemotherapies, demographic, biologic, and pharmacogenetic data, were studied.

RESULTS

The sensitivity of carboplatin-induced thrombocytopenia decreased in the case of concomitant paclitaxel chemotherapy (slope decreased by 24%), whereas it increased with coadministration of etoposide and gemcitabine (slope increased by 45% and 133%, respectively). For neutropenia, the sensitivity increased when carboplatin was combined with other cytotoxics (slope increased by 76%).

CONCLUSION

This study provides useful information to clinicians to better estimate the hematopoietic toxicity of carboplatin and thus choose more rationally carboplatin target AUCs as a function of pretreatment or concomitantly administered chemotherapies. For example, an AUC of 5 mg/mL · min is associated with a risk of grade 3 or 4 thrombocytopenia of 2% in combination with paclitaxel versus 38% with gemcitabine in a non-pretreated patient.

Characterizing consumer health terminology in the breast cancer field

Despite the large availability of medical information on the Internet, health consumers still encounter problems to find, interpret and understand this information. These problems are mainly due to their lack in medical knowledge and the difference between their language and the language of health professionals. In order to propose information retrieval services more adapted to health consumers language and knowledge, we have developed techniques to collect, identify and analyze the terms and the expressions used by lay persons to talk about breast cancer. The study of health consumers' language is a relatively recent research field. Many studies have been conducted to analyze and characterize the vocabulary used by health consumers to talk about medical subjects in English. We have conducted the same study for the French language in the breast cancer field. We have gathered a corpus of texts to identify terms and expressions used by health consumers who talk about breast cancer in French. The terms have been organized in a concept-based terminology. This terminology has been analyzed on several levels: concept level, term level, term-concept level and finally relation level.

Leukocyte 8-oxo-7,8-dihydro-2′-deoxyguanosine and comet assay in epirubicin-treated patients

Epirubicin fights cancer through topoisomerase II inhibition, hence producing DNA strand breaks that finally lead to cell apoptosis. But anthracyclines produce free radicals that may explain their adverse effects. Dexrazoxane--an iron chelator--was proven to decrease free radical production and anthracycline cardiotoxicity. In this article, we report the concentrations of cellular 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxo-dGuo) relative to 2'-deoxyguanosine (dGuo), and comet assay results from a study including 20 cancer patients treated with epirubicin. Plasma concentrations of vitamins A, E, C and carotenoids are also reported. All data were obtained before and immediately after epirubicin infusion. The ratios of 8-Oxo-dGuo to dGuo were measured in leukocyte DNA by HPLC-coulometry after NaI extraction of nucleic acids. Vitamins A and E and carotenoids were measured by HPLC-spectrophotometry. Vitamin C was measured by HPLC-spectrofluorimetry. Median 8-oxo-dGuo/dGuo ratios increased significantly from 0.34 to 0.48 lesions per 100,000 bases while per cent of tail DNA increased from 3.47 to 3.94 after chemotherapy 8-Oxo-dGuo/dGuo and per cent of tail DNA medians remained in the normal range. Only vitamin C decreased significantly from 55.4 to 50.3 microM Decreases in vitamins A, E, lutein and zeaxanthin were not significant, but concentrations were below the lower limit of the normal range both before and after chemotherapy. Only the correlation between comet assay results and vitamin C concentrations was significant (rho =-0.517, p = 0.023). This study shows that cellular DNA is damaged by epirubicin-generated free radicals which produce the mutagenic modified base 8-oxo-dGuo and are responsible for strand breaks. However, strand breaks are created not only by free radicals but also by topoisomerase II inhibition. In a previous study we did not find any significant change in urinary 8-oxo-dGuo excretion after adriamycin treatment. However, 8-oxo-dGuo may have increased at the end of urine collection as DNA repair and subsequent kidney elimination are relatively slow processes. In another study, authors used GC-MS to detect 8-oxo-dGuo in DNA and did not find any change after prolonged adriamycin infusion. Reasons for these apparent discrepancies are discussed.

Kinetics of HER2/neu ECD in 45 patients treated with trastuzumab (Herceptin) between January 2001 and June 2005 at the Grenoble University Hospital

The aim of this study was to evaluate the utility of HER2/neu ECD concentration as a marker of the efficacity of clinical response to Herceptin.

PATIENTS AND METHODS

Iterative measurements of HER2/neu ECD (ELISA c-erbB2/c-neu Rapid Format Elisa kit QIA10 Calbiochem) concentrations in 45 patients treated with Herceptin between January 2001 and June 2005 at the Grenoble University Hospital.

RESULTS

Changes in HER2/neu ECD concentrations were observed in 21 patients (47%). The baseline concentration was the concentration of circulating HER2/neu ECD before treatment with Herceptin. In 15 patients, the mean baseline concentration was 52 ng mL(-1) (extreme values 13-170), which normalized no later than at the time of the 3rd administration of Herceptin. Nine patients (60%) were still alive 5 years later (p<0.05). For 6 patients, the mean baseline concentration was 800 ng mL(-1) (extreme values 140-2000) which persisted and even increased during Herceptin therapy; fewer than 25% were alive 30 months later (p<0.05). In the case of the 24 patients whose HER2/neu ECD concentration remained <5 ng mL(-1), survival time was intermediate.

CONCLUSION

The study confirmed the utility of HER2/neu ECD in predicting therapeutic response. However, as in the case of other circulating tumor markers, it is only useful when there is a variation in concentration. This marker should now be evaluated in multi-center studies covering a large number of homogeneous subjects.

Evaluation of a manual ELISA kit for determination of HER2/neu in serum of breast cancer patients

BACKGROUND

Our aim was to conduct an analytical validation in a routine laboratory setting of the cerb-B2/c-neu ELISA assay kit from Calbiochem used to measure the extracellular domain (ECD) of HER2/neu in the serum of breast cancer patients.

MATERIALS AND METHODS

The evaluation was based on three different production lots used in a routine laboratory setting. The reference value was based on a population of 217 patients with breast cancer not overexpressing HER2.

RESULTS

The detection limit, below that given by the manufacturer, was 0.34 ng ml(-1) and the quantification limit was 0.90 ng ml(-1). Reproducibility and repeatability were at least 95%, precision coefficients of variation varied between 6 and 8.5% and trueness measured by dilution tests and the standard additions method varied between 97 and 107%. The threshold was estimated at 5 ng ml(-1).

CONCLUSION

This technique presents satisfactory levels of accuracy for routine laboratory use.

[Early detection of leptomeningeal metastasis in patients with metastatic breast carcinoma: validation of CA 15-3 measurement in cerebrospinal fluid]

Fifteen per cent of metastatic breast cancer will develop symptomatic leptomeningeal metastases. The introduction of trastuzumab (Herceptin) therapy has improved the response rates of survival of patients with metastatic breast cancer overexpressing HER2. Although previous studies are retrospective and of limited number, involving small study groups and different types of patient management, several authors have reported a 30% incidence of leptomeningeal metastases in patients with metastatic breast cancer overexpressing HER2 who were treated with trastuzumab, while 70 to 80% of cases of the disease were controlled systemically. In order to improve control of the disease at the level of the central nervous system (CNS), routine detection of leptomeningeal metastases in high-risk patients could be offered. CA 15-3 in cerebrospinal fluid (CSF) detection might be useful in helping to diagnose CNS metastases, particularly where cytology results are negative--which applies to 30% of cases--because tumor markers are more sensitive in detecting the tumor process. Our study validate CA 15-3 measurement in CSF and reference values were given.

HER2 overexpression and amplification in advanced ovarian cancer (AOC): Treatment with trastuzumab—A GINECO study

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Background: Variable rates of HER2 protein overexpression and gene amplification have been reported in AOC. Trastuzumab (Herceptin [H]) has been tested only as single agent and has shown a 7% response rate (RR) in heavily pre-treated AOC patients (pts) with 3+ and 2+ HER2 immunostaining (IHC) (Bookman MA et al, J Clin Oncol 2003). GINECO has explored the combination of H with paclitaxel (T) and carboplatin (C) in pts with resistant AOC (< 6 months) and HER2 gene amplification. Methods: 321 AOC pts were centrally screened for HER2 status (243 pts in first-line and 78 relapsing pts). All positive (3+) and doubtful (2+) cases were screened by fluorescence in-situ hybridisation (FISH). Pts with HER2 gene amplification, normal left ventricular ejection fraction (LVEF) and resistant relapse after first or second line of chemotherapy including TC were treated with T (175mg/m2, 3h), C (AUC 5) and H (9mg/kg first course, 6mg/kg subsequent courses) every 3 weeks. Results: Of the 321 cases tested, 22 (6,7%) were HER2+ by IHC and FISH. Only 7 pts (32%) with a median age of 56 (range: 48–70) met the eligibility criteria of the trial. Pts had measurable lesions (n=4) or elevated CA 125 level + non-measurable lesions (n=3). Three pts had complete response (6, 7+ and 24+ months) and 2 had stable disease (3 months). Toxicity was moderate: febrile neutropenia, Gr3 infection, Gr2 neurotoxicity and decrease of LVEF after 23 cycles of H were observed in one patient respectively. Conclusions: HER2 overexpression/amplification is low in advanced ovarian carcinoma (6,7 %). In this small prospective cohort of resistant patients, 3 of 7 have achieved complete remission when adding Trastuzumab to conventional chemotherapy.

No significant financial relationships to disclose.

Results of first-line weekly paclitaxel (P) + gemcitabine (G) in metastatic breast cancer (MBC): An AERO phase II trial

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Background: Three weekly paclitaxel and gemcitabine (PG) combination is recognised as an efficient treatment of metastatic breast cancer. Weekly paclitaxel has shown improved results comparatively with the three weekly administration. We conducted a study to evaluate a weekly schedule of PG combination in fist line treatment of metastatic breast cancer (MBC). Patients and methods: Patients with MBC were enrolled in this study to evaluate the feasibility and efficacy of P 80mg/m2 D1, 8, 15 and G 1,250 mg/m2 D1, 8 (at fixed dose rate of 10mg/m2 /min) and cycles were repeated every 21 days. This phase II trial had a 2 stages design. Overall response rate was the primary end point. Results: In the first step of the trial 19 pts were enrolled with a median age of 59.5 (range 40 - 74). Baseline ECOG < 2 in 89% of pts. Main metastatic sites were: bone (36 %), lung (36%), liver (36%) and lymph nodes (32%). 52 % of pts had only one metastatic site. Previous treatments included surgery (89%), radiotherapy (73%), anthracycline based chemotherapy (74%) and adjuvant hormontherapy (52%). 18 pts were evaluable for efficacy and toxicity. 6 achieved PR, 5 SD and 6 PD resulting in an ORR of 33%. All patients were evaluable for toxicity. Main grade 3–4 toxicities per patient were neutropenia (67%), febrile neutropenia (5%), anemia (17%), thrombocytopenia (33%), trasnsaminases leveations (11%) and dyspnia (5%). Chemotherapy was delayed frequently for toxicity reasons (delays or arrest for toxicity in 15 pts). Conclusion: This weekly PG regimen has some activity in MBC. Although life-threatening toxicities were uncommon, delays in haematological recovery are frequent, making the investigated schedule unsuitable for further studies.

[Table: see text]

Cost-effectiveness analysis of first-line chemotherapies in metastatic colorectal cancer. Results of the Fédération Francophone de Cancérologie Digestive (FFCD) 9601 randomized trial

BACKGROUND

The De Gramont regimen (or high-dose LV5FU2, HD-LV5FU2) is considered a standard treatment for metastatic colorectal cancer. The aim of the study was to evaluate the efficacy and the costs of three regimens as compared to HD-LV5FU2: raltitrexed (R), LV5FU2 with a lower dose of folinic acid (LD-LV5FU2), and weekly infusional 5FU (WI-FU).

METHODS

An economic analysis was performed prospectively as part of a randomized trial comparing first-line chemotherapy regimens in 294 patients with unresectable metastatic colorectal cancer. The primary endpoint was event-free survival (EFS). Direct medical costs were computed from the health system viewpoint using 2001 unit costs.

RESULTS

None of the three regimens improved EFS as compared to HD-LV5FU2. R was less effective and more toxic. The mean total cost per patient was euro 15,970 for HD-LV5FU2. The cost of R (10,687 euro) was lower than that of HD-LV5FU2 (p = 0.008). The cost of LD-LV5FU2 (14,888 euro) and of WI-FU (13,760 euro) was not significantly different from that of HD-LV5FU2.

CONCLUSION

The lower efficacy and increased toxicity of R made it a clinically inferior regimen despite its easy administration and lower cost. The HD-LV5FU2 protocol remains a better treatment. LD-LV5FU2 appeared a good alternative regimen because it reduced costs without jeopardizing its efficacy. The WI-FU regimen did not show a significant difference in terms of efficacy, but suggested toxicity to be slightly increased.

Could ovarian choriocarcinoma be detected by maternal serum screening for Down syndrome?

The incidence of ovarian malignancies during gestation ranges from 1 in 8000 to 1 in 20,000 deliveries. Ovarian malignancies that produce human chorionic gonadotropin (hCG) are limited to germ cell tumors, of which dysgerminoma is the most frequent (45%) malignant type encountered in pregnant patients, the others being ovarian choriocarcinoma and mixed germ cell tumors (Boulay and Podczaski, 1998). In women of childbearing age, it is hard to distinguish between metastatic choriocarcinoma on a complete mole and primary ovarian choriocarcinoma. Treatment is based on adnexectomy followed by chemotherapy. Given the extreme rarity of these tumors, the long-term prognosis is difficult to establish. Had the diagnosis for our patient been made during pregnancy, the therapeutic approach would have been discussed in terms of gestational age. In the last trimester, we could have suggested cesarean section followed by adnexectomy, and then chemotherapy. In the second-trimester, chemotherapy could have been discussed, although the fetal toxicity of cisplatin chemotherapy is not firmly defined (Ferrandina et al., 2005). This treatment is an alternative to termination of pregnancy. We retrospectively studied maternal serum biochemistry so as to assess the possibility of a diagnosis of ovarian choriocarcinoma at the time of maternal serum screening for Down syndrome.

A phase II study of an oxaliplatin/vinorelbine/5-fluorouracil combination in patients with anthracycline-pretreated and taxane-pretreated metastatic breast cancer

The aim of this phase II study was to evaluate safety and efficacy of an oxaliplatin/vinorelbine/5-fluorouracil (FON) combination in anthracycline and taxane-pretreated metastatic breast cancer patients. The following treatment was given: on day 1 of a 21-day cycle, oxaliplatin 130 mg/m (2-h intravenous infusion); on days 1 and 5, vinorelbine [dose level (DL) 1: 17.5 mg/m; DL2: 22 mg/m]; on days 1-5, continuous infusion 5-fluorouracil (DL1: 600 mg/m/day; DL2: 750 mg/m/day). Forty-seven patients were treated (DL1: 43; DL2: 4). Median age was 54 years; 68% had liver metastases, 53% were taxane refractory/resistant and 38% were anthracycline refractory/resistant. Patients received a median of six treatment cycles. Of 46 eligible patients, 16 had partial response; the overall response rate was 34.8% (95% confidence interval 21.3-50.3%), 11 had stable disease lasting more than 4 months. Median follow-up was 13.0 months, median time to progression 5.7 months and estimated overall survival 18.8 months. DL2 was too toxic with three patients having grade 3-4 toxicity, including one death. At DL1, 26 patients (60%) experienced grade 3-4 neutropenia (six febrile neutropenia) and eight had grade 3 oxaliplatin-specific peripheral neuropathy after a median of 646.4 mg/m oxaliplatin (range 124-1619 mg/m). Oxaliplatin (130 mg/m, day 1)/vinorelbine (17.5 mg/m, days 1,5)/5-fluorouracil (600 mg/m/day, days 1-5) demonstrate encouraging activity and a manageable safety profile in anthracycline- and taxane-pretreated metastatic breast cancer patients.

Randomised Trial Comparing Three Different Schedules of Infusional 5FU and Raltitrexed Alone as First-Line Therapy in Metastatic Colorectal Cancer

LV5FU2 with high-dose leucovorin (LV), weekly infusional 5-fluorouracil (5FU) (AIO schedule) and raltitrexed have been demonstrated to be active agents in first-line treatment of colorectal cancer. We performed a 4-arm randomised trial to compare (1) a low-dose intravenous bolus of LV (20 mg/m2), followed by an intravenous bolus of 5FU (400 mg/m2), followed by a 22-hour continuous infusion of 5FU (600 mg/m2) on day 1 and day 2/2 weeks (ldLV5FU2 arm), (2) a weekly continuous infusion of high-dose 5FU (2.6 g/m2/week) for 6 weeks followed by a rest week (HD-FU arm) and (3) raltitrexed (Tomudex arm; 3 mg/m2/3 weeks) to standard LV5FU2. From 1997 to 2001, 294 patients were included. The 4 arms were well balanced for sex ratio, age, WHO performance status, the primary tumour site and prior adjuvant chemotherapy. Treatment was stopped due to low accrual. Two toxicity-related deaths were observed in the Tomudex arm. The treatments gave rise to different rates of grade 3-4 neutropenia (3, 4, 11 and 14% of the patients in the LV5FU2, ldLV5FU2, HD-FU and Tomudex arms, respectively, p = 0.028), leucopenia and vomiting. At least one episode of grade 3-4 toxicity was observed in 27, 25, 38 and 47% of the patients in the LV5FU2, ldLV5FU2, HD-FU and Tomudex arms, respectively (p = 0.016). An objective response was observed in 28, 21, 22 and 10% of the patients in the LV5FU2, ldLV5FU2, HD-FU and Tomudex arms, respectively (p = 0.04). Progression-free survival (PFS) of the patients in the Tomudex arm was statistically lower compared to that of patients treated with LV5FU2 or ldLV5FU2 (combined group; p = 0.013, log rank test). In conclusion, Tomudex is more toxic and yields shorter PFS than infusional 5FU. Despite the early closure of the study and the lack of power of the comparison, it seems that ldLV5FU2 could be considered as an active, easier and less expensive option for the treatment of metastatic colorectal cancer compared to classic LV5FU2 or weekly HD-FU.

A model for the measurement of patient activity in a hospital suite

At the time of hospitalization, it is essential to evaluate the general health status of a patient and to follow up the trends during therapy. Our work is focused on a set of tools for the measurement of patient activity. In this paper, we propose a few indicators of the patient activities of daily living, such as mobility, agitation, repartitions of stays, and displacements. As a result of this work, a diagnostic system was developed that could lead to a deeper knowledge of human activity rhythms in normal situations.

The effectiveness of trastuzumab (Herceptin) combined with chemotherapy for gastric carcinoma with overexpression of the c-erbB-2 protein

The c-erbB-2 protein is overexpressed in 7% of gastric cancer cases, suggesting that anti-c-erbB-2 antibody therapy (trastuzumab; Herceptin) could be used. We report here a 28-year-old woman with metastatic gastric cancer overexpressing c-erbB-2 (3 + strong membrane staining on immunohistochemistry) who was treated with trastuzumab in combination with chemotherapy. A complete response was obtained with a combination of trastuzumab and oxaliplatin and was maintained with trastuzumab alone for 18 months. The patient relapsed and chemotherapy (capecitabine, docetaxel) was combined with the anti-c-erbB-2 antibody. The patient survived for 4 years with metastatic disease controlled for 2 years by immunochemotherapy. We conclude that the combination of trastuzumab and chemotherapy is efficient in the treatment of metastatic gastric carcinoma with overexpression of the c-erbB-2 protein.

[Adjuvant treatment of colon cancer MOSAIC study's main results]

Oxaliplatin in combination with 5-fluorouracil/leucovorin (LV5FU) improves the response rate and survival of patients with metastatic colorectal cancer. The objective of the Mosaic study was to evaluate the efficacy of this association in the adjuvant treatment of stage II and III colon cancer. This international study, including 2,246 patients, compared the efficacy of standard treatment with LV5FU2 alone to that of oxaliplatin-LV5FU (Folfox4 regimen) following R0 resection of the primary tumour. Both treatments were administered every two weeks for six months. At 3-year follow-up, the risk of relapse was decreased by 23% in the Folfox4 group (p = 0.002). The protocol was well tolerated, with an identical overall mortality during treatment (0.5%) in both groups. The main specific complication, peripheral sensory neuropathy was reversible in the great majority of cases. A new analysis at 4-year follow-up (median 48.6 months) confirmed the superior efficacy of the Folfox4 regimen compared to the standard treatment, the reduction in relapse risk being 24% (p = 0.0008). On the strength of these results, oxaliplatin was granted a marketing authorization for the indication adjuvant treatment of stage III colon cancer. Based on the data currently available, physicians should consider adjuvant treatment for stage II patients, making each individual decision for treatment on a case-by-case basis.

Prospect for anti-HER2 receptor therapy in breast cancer

The carcinogenesis process is characterized, in part, by the dysfunction of cellular communication pathways, such as the one involving HER2. HER2 is a member of the EGF receptor family, which participates in cell growth and proliferation. HER2 may be overexpressed in 15 to 30% of breast cancer cases and is associated with poor prognosis, shortened overall survival and shorter time to disease progression. Furthermore, an increasing number of studies have demonstrated the relevance of HER2 serum concentrations (sHER2, extracellular domain released into blood by proteolysis) as a predictive marker of resistance to chemotherapy in HER2-overexpressing metastatic breast cancer. The determination of HER2 overexpression/ amplification in the diagnosis of relapse of breast cancer is currently a routine procedure. Immunohistochemistry (IHC) and fluorescent in situ hybridization (FISH) techniques, which are used to detect HER2 expression in the tumor, are improving constantly, and other parallel techniques such as chromogenic in situ hybridization (CISH) are starting to emerge. sHER2 concentrations can be measured using ELISA techniques, which can be automated. All of these procedures still need to be standardized. The discovery of a monoclonal antibody (4D5) that can inhibit the growth and proliferation of cells overexpressing HER2 led to the development of trastuzumab. Like 4D5, trastuzumab recognizes an epitope on the extracellular domain of HER2. Moreover, trastuzumab is also able to stimulate antibody-dependent cellular toxicity (ADCC). It is administered alone or in combination (with navelbine, taxol, carboplatin...) in patients with metastatic breast cancer overexpressing HER2. Other active antibodies have since been discovered, as well as other specific molecules, such as tyrosine kinase inhibitors which will undoubtedly find a place in the therapeutic arsenal used in breast cancer, especially to avoid the emergence of resistance to treatment.

Prospect for anti-her2 receptor therapy in breast cancer

The carcinogenic process is characterized, in part, by the dysfunction of cellular communication pathways, such as the one involving HER2. HER2 is a member of the EGF receptor family, which participates in cell growth and proliferation. HER2 may be overexpressed in 15 to 30% of breast cancer cases and is associated with poor prognosis, shortened overall survival and shorter time to disease progression. Furthermore, an increasing number of studies have demonstrated the relevance of HER2 serum concentrations (sHER2, extracellular domain released into the blood by proteolysis) as a predictive marker of resistance to chemotherapy in HER2-overexpressing metastatic breast cancer. The determination of HER2 overexpression/ amplification in the diagnosis of relapse of breast cancer is currently a routine procedure. Immunohistochemistry (IHC) and fluorescent in situ hybridization (FISH) techniques, used to detect HER2 expression in the tumor, are improving constantly and other parallel techniques such as chromogenic in situ hybridization (CISH) are emerging. sHER2 concentrations can be measured using ELISA techniques, which can be automated. All of these procedures still need to be standardized. The discovery of a monoclonal antibody (4D5) that can inhibit the growth and proliferation of cells overexpressing HER2 led to the development of trastuzumab. Like 4D5, trastuzumab recognizes an epitope on the extracellular domain of HER2. Moreover, trastuzumab is also able to stimulate antibody-dependent cellular toxicity (ADCC). It is administered alone or in combination (with navelbine, taxol, carboplatin, etc.) in patients with metastatic breast cancer overexpressing HER2. Other active antibodies have since been discovered, as well as other specific molecules, such as tyrosine kinase inhibitors which will undoubtedly find a place in the therapeutic arsenal used in breast cancer, especially to avoid resistance to treatment.

Effects of permeability transition inhibition and decrease in cytochrome c content on doxorubicin toxicity in K562 cells

As mitochondria play a key role in the commitment to cell death, we have investigated the mitochondrial consequences of resistance to doxorubicin (DOX) in K562 cells. We found that the permeability transition pore (PTP) inhibitor cyclosporine A (CsA) failed to inhibit PTP opening in the resistant clone. Moreover, the Ca2+ loading capacity in the resistant clone was identical to that observed in the parent cells in the presence of CsA, suggesting that the PTP was already inhibited in a CsA-like manner in the resistant cells. In agreement with this proposal, the mitochondrial target of CsA cyclophilin D (CyD) decreased by half in the resistant cells. The levels of adenine nucleotide translocator, voltage anion-dependent channel, Bax, Bcl-2, Bcl-xL, AIF and Smac/Diablo, were similar in both cell lines, whereas cytochrome c content was divided by three in the resistant cells. Since P-glycoprotein inhibition did not restore DOX toxicity in the resistant cells, while DOX-induced cell death in the parent cells was prevented by either PTP inhibition or siRNA-induced decrease in cytochrome c content, we conclude that the inhibition of PTP opening and the decrease in cytochrome c content participate in the mechanism that makes K562 cells resistant to DOX.

Non-toxic and short treatment with gemcitabine inhibits in vitro migration of HT-1080 cells

Gemcitabine has demonstrated clinical activity in solid tumors. Several in vitro studies were carried out regarding its metabolism, toxicity and cell cycle effects, but none was done on the anti-metastasis potential of the drug. We sought to determine the effect of gemcitabine concentrations on migration velocity of HT-1080 cells at concentrations which do not alter cell cycle progression and proliferation. Cells were treated for 1 or 5 h at IC10-70 of gemcitabine in order to estimate its effects on viability, proliferation and migration capacity using flow cytometry and microscopy imaging, respectively. The gemcitabine treatment for 1 h had no effect on cell proliferation, viability, cycle or migration on HT-1080 cells. Even though the 5 h of exposure at IC10, IC20 and IC50 concentrations did not affect cell viability, proliferation and cell cycle repartition, the mean velocity of HT-1080 dramatically decreased by 50 and 30%, respectively. Gemcitabine at IC70 concentrations for 5 h of exposure first induced a time course inhibition of proliferation, together with a decrease in viability and altered cell morphology, and then inhibited cell migration by 50%. These data suggest the possibility to couple the anti-migratory property of gemcitabine with the known anti-tumoral effect in the treatment of tumors with high metastatic potential.