Adjuvant abemaciclib combined with endocrine therapy for high-risk early breast cancer: updated efficacy and Ki-67 analysis from the monarchE study.

BACKGROUND: Adjuvant abemaciclib combined with endocrine therapy (ET) previously demonstrated clinically meaningful improvement in invasive disease-free survival (IDFS) and distant relapse-free survival (DRFS) in hormone receptor-positive, human epidermal growth factor receptor 2-negative, node-positive, high-risk early breast cancer at the second interim analysis, however follow-up was limited. Here, we present results of the prespecified primary outcome analysis and an additional follow-up analysis. PATIENTS AND METHODS: This global, phase III, open-label trial randomized (1 : 1) 5637 patients to adjuvant ET for ≥5 years ± abemaciclib for 2 years. Cohort 1 enrolled patients with ≥4 positive axillary lymph nodes (ALNs), or 1-3 positive ALNs and either grade 3 disease or tumor ≥5 cm. Cohort 2 enrolled patients with 1-3 positive ALNs and centrally determined high Ki-67 index (≥20%). The primary endpoint was IDFS in the intent-to-treat population (cohorts 1 and 2). Secondary endpoints were IDFS in patients with high Ki-67, DRFS, overall survival, and safety. RESULTS: At the primary outcome analysis, with 19 months median follow-up time, abemaciclib + ET resulted in a 29% reduction in the risk of developing an IDFS event [hazard ratio (HR) = 0.71, 95% confidence interval (CI) 0.58-0.87; nominal P = 0.0009]. At the additional follow-up analysis, with 27 months median follow-up and 90% of patients off treatment, IDFS (HR = 0.70, 95% CI 0.59-0.82; nominal P < 0.0001) and DRFS (HR = 0.69, 95% CI 0.57-0.83; nominal P < 0.0001) benefit was maintained. The absolute improvements in 3-year IDFS and DRFS rates were 5.4% and 4.2%, respectively. Whereas Ki-67 index was prognostic, abemaciclib benefit was consistent regardless of Ki-67 index. Safety data were consistent with the known abemaciclib risk profile. CONCLUSION: Abemaciclib + ET significantly improved IDFS in patients with hormone receptor-positive, human epidermal growth factor receptor 2-negative, node-positive, high-risk early breast cancer, with an acceptable safety profile. Ki-67 index was prognostic, but abemaciclib benefit was observed regardless of Ki-67 index. Overall, the robust treatment benefit of abemaciclib extended beyond the 2-year treatment period.

Dose tailoring of adjuvant chemotherapy for breast cancer based on hematologic toxicities: further results from the prospective PANTHER study with focus on obese patients.

Background: Adjuvant chemotherapy (ACT) for breast cancer improves relapse-free survival (BCRFS) and overall survival. Differences in terms of efficacy and toxicity could partly be explained by the significant interpatient variability in pharmacokinetics which cannot be captured by dosing according to body surface area. Consequently, tailored dosing was prospectively evaluated in the PANTHER trial. Patients and methods: PANTHER is a multicenter, open-label, randomized phase III trial which compared tailored, dose-dense (DD) epirubicin/cyclophosphamide (E/C) and tailored docetaxel (D) (tDD) with standard interval 5-fluorouracil/E/C and D. The primary end point was BCRFS and the primary efficacy analysis has been previously published. In this secondary analysis, we aimed to retrospectively explore the concept of dose tailoring. Our two hypotheses were that BCRFS would not vary depending on the cumulative administered epirubicin dose; and that dose tailoring would lead to appropriate dosing and improved outcomes for obese patients, who are known to have worse prognosis and increased toxicity after DD ACT. Results: Patients treated with tDD had similar BCRFS regardless of the cumulative epirubicin dose (P = 0.495), while obese patients in this group [body mass index (BMI) ≥30] had improved BCRFS compared with nonobese ones (BMI <30) [hazard ratio (HR) = 0.51, 95% confidence interval (CI) 0.30-0.89, P = 0.02]. Moreover, tDD was associated with improved BCRFS compared with standard treatment only in obese patients (HR = 0.49, 95% CI 0.26-0.90, P = 0.022) but not in nonobese ones (HR = 0.79, 95% CI 0.60-1.04, P = 0.089). The differences were not formally statistically significant (P for interaction 0.175). There were no differences in terms of toxicity across the epirubicin dose levels or the BMI groups. Conclusions: Dose tailoring is a feasible strategy that can potentially improve outcomes in obese patients without increasing toxicity and should be pursued in further clinical studies. ClinicalTrials.gov identifier: NCT00798070.

Final efficacy and updated safety results of the randomized phase III BEATRICE trial evaluating adjuvant bevacizumab-containing therapy in triple-negative early breast cancer.

BACKGROUND: The purpose of this analysis was to assess the long-term impact of adding bevacizumab to adjuvant chemotherapy for early triple-negative breast cancer (TNBC). METHODS: Patients eligible for the open-label randomized phase III BEATRICE trial had centrally confirmed triple-negative operable primary invasive breast cancer (pT1a-pT3). Investigators selected anthracycline- and/or taxane-based chemotherapy for each patient. After definitive surgery, patients were randomized 1:1 to receive ≥4 cycles of chemotherapy alone or with 1 year of bevacizumab (5 mg/kg/week equivalent). Stratification factors were nodal status, selected chemotherapy, hormone receptor status, and type of surgery. The primary end point was invasive disease-free survival (IDFS; previously reported). Secondary outcome measures included overall survival (OS) and safety. RESULTS: After 56 months' median follow-up, 293 of 2591 randomized patients had died. There was no statistically significant difference in OS between treatment arms in either the total population (hazard ratio 0.93, 95% confidence interval [CI] 0.74-1.17; P = 0.52) or pre-specified subgroups. The 5-year OS rate was 88% (95% CI 86-90%) in both treatment arms. Updated IDFS results were consistent with the primary IDFS analysis. Five-year IDFS rates were 77% (95% CI 75-79%) with chemotherapy alone versus 80% (95% CI 77-82%) with bevacizumab. From 18 months after first study dose to study end, new grade ≥3 adverse events occurred in 4.6% and 4.5% of patients in the two arms, respectively. CONCLUSION: Final OS results showed no significant benefit from bevacizumab therapy for early TNBC. Late-onset toxicities were rare in both groups. Five-year OS and IDFS rates suggest that the prognosis for patients with TNBC is better than previously thought. CLINICALTRIALS.GOV: NCT00528567.

Prognostic impact of breast cancer subtypes in elderly patients.

We aimed to analyse the impact of breast cancer (BC) subtypes on the clinical course of disease with special emphasis on the occurrence of brain metastases (BM) and outcome in an elderly BC population. A total number of 706 patients ≥65 years receiving treatment for BC from 2007 to 2011 were identified from a BC database. 62 patients diagnosed with DCIS and 73 patients with incomplete datasets were excluded, leaving 571 patients for this analysis. Patient characteristics, biological tumour subtypes, and clinical outcome including overall survival (OS) were obtained by retrospective chart review. 380/571 (66, 5 %) patients aged 65-74 years were grouped among the young-old, 182/571 (31.9 %) patients aged 75-84 years among the old-old, and 29/571 (5.1 %) patients aged ≥85 years among the oldest-old. 392/571 (68.8 %) patients presented with luminal BC, 119/571 (20.8 %) with HER2-positive, and 59/571 (10.3 %) with triple-negative BC (TNBC). At 38 months median follow-up, 115/571 (20.1 %) patients presented with distant recurrence. A higher recurrence rate was observed in the HER2-positive subtype (43/119 (36.1 %)), as compared to TNBC (15/59 (25.4 %)) and luminal BC (57/392 (14.5 %); p < 0.001). BM were detected at a significantly higher rate in HER2-positive BC patients (9/119 (7.6 %)), as compared to TNBC (2/59 (3.4 %)) and luminal BC patients (6/392 (1.5 %); p = 0.003). Diagnosis of metastatic disease (HR 7.7; 95 % CI 5.2-11.4; p < 0.001) as well as development of BM (HR 3.5; 95 % CI 1.9-6.4; p < 0.001) had a significantly negative impact on OS in a time-dependent covariate cox regression model. In contrast to younger BC patients, outcome in this large cohort of elderly patients suggests that HER2-positive disease-not TNBC-featured the most aggressive clinical course with the highest rates of metastatic spread and BM. In-depth analysis regarding a potentially distinct biology of TNBC in elderly is therefore warranted.

Epirubicin and docetaxel with or without capecitabine as neoadjuvant treatment for early breast cancer: final results of a randomized phase III study (ABCSG-24).

BACKGROUND: This randomized phase III trial compared pathologic complete response (pCR) rates of early breast cancer (EBC) following neoadjuvant epirubicin-docetaxel (ED)±capecitabine (C), and evaluated the addition of trastuzumab in HER2-positive tumors. PATIENTS AND METHODS: Patients with invasive breast cancer (except T4d) were randomly assigned to receive six 3-weekly cycles of ED (both 75 mg/m2)±C (1000 mg/m2, twice daily, days 1-14). Patients with HER2-positive disease were further randomized to receive trastuzumab (8 mg/kg, then 6 mg/kg every 3 weeks) or not. Primary end point: pCR rate at the time of surgery. RESULTS: Five hundred thirty-six patients were randomized to ED (n=266) or EDC (n=270); 93 patients were further randomized to trastuzumab (n=44) or not (n=49). pCR rate was significantly increased with EDC (23.0% versus 15.4% ED, P=0.027), and nonsignificantly further increased with trastuzumab (38.6% EDC versus 26.5% ED, P=0.212). Rates of axillary node involvement at surgery and breast conservation were improved with EDC versus ED, but not significantly; the addition of trastuzumab had no further impact. Hormone receptor status, tumor size, grade, and C (all P≤0.035) were independent prognostic factors for pCR. Trastuzumab added to ED±C significantly increased the number of serious adverse events (35 versus 18; P=0.020), mainly due to infusion-related reactions. CONCLUSION: These findings show that the integration of C into a neoadjuvant taxane-/anthracycline-based regimen is a feasible, safe, and effective treatment option, with incorporation of trastuzumab in HER2-positive disease. CLINICAL TRIAL NUMBER: NCT00309556, www.clinicaltrials.gov.

Aromatase inhibitors with or without gonadotropin-releasing hormone analogue in metastatic male breast cancer: a case series.

BACKGROUND: Data regarding the safety and effectiveness of aromatase inhibitors (AIs) as monotherapy or combined with gonadotropin-releasing hormone (GnRH) analogue in male breast cancer are scarce. METHODS: In this retrospective chart review, cases of male breast cancer patients treated with AIs with or without a GnRH analogue were evaluated. RESULTS: Twenty-three men were included into this case series. Aromatase inhibitors in combination with or without a GnRH analogue were given as first-line therapy in 60.9% and as second-line therapy in 39.1% of patients, respectively. All patients had visceral metastases, whereas in five of them bone lesions coexisted. In all cases AIs were tolerated well, and no case of grade 3 and 4 adverse events was reported. A partial response was observed in 26.1% of patients and stable disease in 56.5%. Median overall survival (OS) was 39 months and median progression-free survival (PFS) was 13 months. Regarding OS and PFS, no significant effects of GnRH analogue co-administration or type of AI were noted. CONCLUSION: Our study shows that AIs with or without GnRH analogues may represent an effective and safe treatment option for hormone-receptor positive, pretreated, metastatic, male breast cancer patients.

Efficacy of tamoxifen ± aminoglutethimide in normal weight and overweight postmenopausal patients with hormone receptor-positive breast cancer: an analysis of 1509 patients of the ABCSG-06 trial.

BACKGROUND: There exists evidence that body mass index (BMI) impacts on the efficacy of aromatase inhibitors in patients with breast cancer. The relationship between BMI and the efficacy of tamoxifen is conflicting. We investigated the impact of BMI on the efficacy of single tamoxifen and tamoxifen plus an aromatase inhibitor in the well-defined prospective study population of the ABCSG-06 trial. METHODS: ABCSG-06 investigated the efficacy of tamoxifen vs tamoxifen plus aminoglutethimide in postmenopausal women with hormone receptor-positive breast cancer. Taking BMI at baseline, patients were classified as normal weight (BMI=18.5-24.9 kg m(-)(2)), overweight (BMI=25-29.9 kg m(-)(2)), and obese (30 kg m(-)(2)) according to WHO criteria. RESULTS: Overweight+obese patients had an increased risk for distant recurrences (hazard ratio (HR): 1.51; Cox P=0·018) and a worse overall survival (OS; HR: 1·49; Cox P=0·052) compared with normal weight patients. Analysing patients treated with single tamoxifen only, no difference between overweight+obese patients and normal weight patients regarding distant recurrence-free survival (HR: 1.35; Cox P=0·24) and OS (HR: 0.99; Cox P=0·97) could be observed. In contrast, in the group of patients treated with the combination of tamoxifen plus aminoglutethimide, overweight+obese patients had an increased risk for distant recurrences (1.67; Cox P=0·03) and a worse OS (1.47; Cox P=0·11) compared with normal weight patients. CONCLUSION: BMI impacts on the efficacy of aromatase inhibitor-based treatment but not single tamoxifen.

Brain-only metastatic breast cancer is a distinct clinical entity characterised by favourable median overall survival time and a high rate of long-term survivors.

BACKGROUND: The clinical course of breast cancer patients with brain metastases (BM) as only metastatic site (brain-only metastatic breast cancer (BO-MBC)) has been insufficiently explored. METHODS: All breast cancer patients with BM treated at our institution between 1990 and 2011 were identified. For each patient, full information on follow-up and administered therapies was mandatory for inclusion. Oestrogen receptor, progesterone receptor and Her2 status were determined according to standard protocols. Statistical analyses including computation of survival probabilities was performed. RESULTS: In total, 222 female patients (26% luminal; 47% Her2; 27% triple negative) with BM of MBC were included in this study. In all, 38/222 (17%) BM patients did not develop extracranial metastases (ECM) during their disease course and were classified as BO-MBC. Brain-only-MBC was not associated with breast cancer subtype or number of BM. The median overall survival of BO-MBC patients was 11 months (range 0-69) and was significantly longer than in patients with BM and ECM (6 months, range 0-104; P=0.007). In all, 7/38 (18%) BO-MBC patients had long-term survival of >3 years after diagnosis of BM and long-term survival was significantly more common in BO-MBC patients as compared with BM patients with ECM (P<0.001). CONCLUSIONS: Brain-only metastatic behaviour occurs in around 17% of breast cancer with BM and is not associated with breast cancer subtype. Exploitation of all multimodal treatment options is warranted in BO-MBC patients, as these patients have favourable prognosis and long-term survival is not uncommon.

Safety results from a phase III study (TURANDOT trial by CECOG) of first-line bevacizumab in combination with capecitabine or paclitaxel for HER-2-negative locally recurrent or metastatic breast cancer.

BACKGROUND: We report safety data from a randomised, phase III study (CECOG/BC.1.3.005) evaluating first-line bevacizumab plus paclitaxel or capecitabine for locally recurrent or metastatic breast cancer. PATIENTS AND METHODS: Patients aged ≥18 years with human epidermal growth factor receptor-2-negative breast adenocarcinoma were randomised to Arm A: bevacizumab 10 mg/kg days 1 and 15; paclitaxel 90 mg/m(2) days 1, 8, and 15, every 4 weeks; or Arm B: bevacizumab 15 mg/kg day 1; capecitabine 1000 mg/m(2) b.i.d., days 1-14, every 3 weeks, until disease progression, unacceptable toxicity or consent withdrawal. RESULTS: A post hoc interim safety analysis included 561 patients (Arm A: 284, Arm B: 277). The regimens demonstrated similar frequencies of all-grade and serious adverse events (SAEs), but different safety profiles. Treatment-related events occurred in 85.2% (Arm A) and 78.0% (Arm B) of patients. Fatigue was most common in Arm A (30.6% versus 23.5% Arm B), and hand-foot syndrome (HFS) most common in Arm B (49.5% versus 2.5% Arm A). Diarrhoea (Arm A: 0.4%, Arm B: 1.4%) and pulmonary embolism (Arm A: 0.7%, Arm B: 1.1%) were the most frequently reported SAEs. CONCLUSION: These findings are in-line with safety data for bevacizumab plus paclitaxel or capecitabine, reported in previous phase III trials.

Phase IB study of the EpCAM antibody adecatumumab combined with docetaxel in patients with EpCAM-positive relapsed or refractory advanced-stage breast cancer.

BACKGROUND: Targeted therapy options in HER2-negative breast cancer are limited. This open-label, multicenter phase IB dose-escalation trial was conducted to determine safety, tolerability, and antitumor activity of a combination of docetaxel (Taxotere) and increasing doses of adecatumumab, a human IgG1 antibody targeting epithelial cell adhesion molecule (EpCAM), in EpCAM-positive relapsed or primary refractory advanced-stage breast cancer. PATIENTS AND METHODS: Patients pretreated with up to four prior chemotherapy regimens received increasing adecatumumab doses either every 3 weeks (q3w) or weekly (qw) combined with docetaxel (100 mg/m(2) q3w). Primary end points were safety and tolerability. Antitumor activity was evaluated according to RECIST. Clinical benefit was defined as complete or partial response or stable disease for ≥24 weeks. RESULTS: Thirty-one evaluable patients were treated. Most adverse events were mild to moderate in severity. Neutropenia, leukocytopenia, lymphopenia, and diarrhea (dose-limiting) were the most frequent toxic effects. Maximum tolerated doses of adecatumumab given in combination with docetaxel were 550 mg/m(2) q3w and 360 mg/m(2) qw. Clinical benefit was observed in 44% of patients treated with q3w adecatumumab and docetaxel, increasing to 63% in patients with high EpCAM-expressing tumors. CONCLUSION: Combination therapy of adecatumumab and docetaxel is safe, feasible, and potentially active in heavily pretreated advanced-stage breast cancer.

Brain metastases free survival differs between breast cancer subtypes.

BACKGROUND: Brain metastases (BM) are frequently diagnosed in patients with HER-2-positive metastatic breast cancer; in addition, an increasing incidence was reported for triple-negative tumours. We aimed to compare brain metastases free survival (BMFS) of breast cancer subtypes in patients treated between 1996 until 2010. METHODS: Brain metastases free survival was measured as the interval from diagnosis of extracranial breast cancer metastases until diagnosis of BM. HER-2 status was analysed by immunohistochemistry and reanalysed by fluorescent in situ hybridisation if a score of 2+ was gained. Oestrogen-receptor (ER) and progesterone-receptor (PgR) status was analysed by immunohistochemistry. Brain metastases free survival curves were estimated with the Kaplan-Meier method and compared with the log-rank test. RESULTS: Data of 213 patients (46 luminal/124 HER-2/43 triple-negative subtype) with BM from breast cancer were available for the analysis. Brain metastases free survival differed significantly between breast cancer subtypes. Median BMFS in triple-negative tumours was 14 months (95% CI: 11.34-16.66) compared with 18 months (95% CI: 14.46-21.54) in HER-2-positive tumours (P=0.001) and 34 months (95% CI: 23.71-44.29) in luminal tumours (P=0.001), respectively. In HER-2-positive patients, co-positivity for ER and HER-2 prolonged BMFS (26 vs 15 m; P=0.033); in luminal tumours, co-expression of ER and PgR was not significantly associated with BMFS. Brain metastases free survival in patients with lung metastases was significantly shorter (17 vs 21 months; P=0.014). CONCLUSION: Brain metastases free survival in triple-negative breast cancer, as well as in HER-2-positive/ER-negative, is significantly shorter compared with HER-2/ER co-positive or luminal tumours, mirroring the aggressiveness of these breast cancer subtypes.

Impact of anti-HER2 therapy on overall survival in HER2-overexpressing breast cancer patients with brain metastases.

BACKGROUND: Trastuzumab-based therapy after diagnosis of brain metastases (BM) may improve survival due to prolonged systemic disease control. We investigated whether lapatinib may yield additional survival benefit. METHODS: Eighty patients with BM from HER2-positive breast cancer were identified. Karnofsky Performance Score (KPS) of at least 70 was required. We included a control group of 37 patients treated before 2003, when continuation of trastuzumab after diagnosis of BM was not yet recommended. Remainders received either trastuzumab or lapatinib and trastuzumab (either concomitantly or sequentially) with or without chemotherapy. RESULTS: Median overall survival (OS) in patients receiving trastuzumab after diagnosis of BM was 13 months; corresponding numbers were 9 months in patients treated with chemotherapy, and 3 months with radiotherapy alone. Median OS was not reached in the lapatinib group. Addition of lapatinib prolonged OS over trastuzumab alone (P=0.002). After correction for potential confounders, lapatinib therapy remained an independent positive predictor for survival (HR 0.279; P=0.012). INTERPRETATION: This retrospective single-centre study suggests that the introduction of lapatinib improved survival in patients with BM from HER2-positive breast cancer. Patients with KPS ≥70 may benefit when treated with lapatinib in addition to trastuzumab after completion of local therapy.

Long-term persistence of acquired resistance to 5-fluorouracil in the colon cancer cell line SW620.

Treatment resistance to antineoplastic drugs represents a major clinical problem. Here, we investigated the long-term stability of acquired resistance to 5-fluorouracil (FU) in an in vitro colon cancer model, using four sub-clones characterised by increasing FU-resistance derived from the cell line SW620. The resistance phenotype was preserved after FU withdrawal for 15weeks (~100 cell divisions) independent of the established level of drug resistance and of epigenetic silencing. Remarkably, resistant clones tolerated serum deprivation, adopted a CD133(+) CD44(-) phenotype, and further exhibited loss of membrane-bound E-cadherin together with predominant nuclear ß-catenin localisation. Thus, we provide evidence for a long-term memory of acquired drug resistance, driven by multiple cellular strategies (epithelial-mesenchymal transition and selective propagation of CD133(+) cells). These resistance phenomena, in turn, accentuate the malignant phenotype.

Activity of fulvestrant in HER2-overexpressing advanced breast cancer.

BACKGROUND: Human epidermal growth factor receptor 2 (HER2) overexpression increases the aggressiveness of breast cancer cells resulting in poorer prognosis. Patients with HER2-positive disease are less responsive to endocrine therapies. Trastuzumab monotherapy results in objective responses in only approximately 15% of patients. Fulvestrant retains activity in cells overexpressing HER2 that are resistant to other endocrine treatments. This retrospective study evaluated response to fulvestrant treatment among HER2-positive patients with advanced breast cancer (ABC). PATIENTS AND METHODS: Clinical experience data from 10 treatment centres were pooled. Postmenopausal patients with predominantly hormone receptor-positive and HER2-positive disease were included. Clinical benefit (CB) was defined as the proportion of patients achieving a response to treatment (partial or complete) or stable disease lasting >/=6 months. RESULTS: Data for 102 patients were analysed. Fulvestrant resulted in an overall CB rate of 42% (43/101) in HER2-positive patients and 40% (25/63) in patients with visceral disease. Median duration of treatment was 14.5 months (range 6-44 months). Fulvestrant showed activity up to the fourth line of endocrine therapy and up to the seventh line of overall therapy. CONCLUSIONS: Results indicate that fulvestrant may be a suitable treatment option in extensively pre-treated patients with HER2-positive, hormone receptor-positive ABC. Further exploration of its use in this patient population is warranted.

A prospective randomised phase III trial of adjuvant chemotherapy with 5-fluorouracil and leucovorin in patients with stage II colon cancer.

The purpose of this trial was to investigate the efficacy of adjuvant chemotherapy with 5-fluorouracil (5-FU) and leucovorin (LV) in stage II colon cancer. Patients with stage II colon cancer were randomised to either adjuvant chemotherapy with 5-FU/LV (100 mg m(-2) LV+450 mg m(-2) 5-FU weekly, weeks 1-6, in 8 weeks cycles x 7) or surveillance only. Five hundred patients were evaluable for analyses. After a median follow-up of 95.6 months, 55 of 252 patients (21.8%) have died in the 5-FU/LV arm and 58 of 248 patients (23.4%) in the surveillance arm. There was no statistically significant difference in overall survival (OS) between the two treatment arms (hazard ratios, HR 0.88, 95% CI 0.61-1.27, P=0.49). The relative risk for tumour relapse was higher for patients on the surveillance arm than for those on the 5-FU/LV arm; however, this difference was not statistically significant (HR 0.69, 95% CI 0.45-1.06, P=0.09). Consequently, disease-free survival (DFS) was not significantly different between the two trial arms. In conclusion, results of this trial demonstrate a trend to a lower risk for relapse in patients treated with adjuvant 5-FU/LV for stage II colon cancer. However, in this study with limited power to detect small differences between the study arms, adjuvant chemotherapy failed to significantly improve DFS and OS.

Dalteparin for prevention of catheter-related complications in cancer patients with central venous catheters: final results of a double-blind, placebo-controlled phase III trial.

BACKGROUND: Cancer patients receiving chemotherapy experience thromboembolic complications associated with the use of long-term indwelling central venous catheters (CVCs). This prospective, double-blind, placebo-controlled, multicenter study evaluated whether prophylactic treatment with a low molecular weight heparin could prevent clinically relevant catheter-related thrombosis. PATIENTS AND METHODS: Patients with cancer undergoing chemotherapy for at least 12 weeks (n=439) were randomly assigned, in a 2:1 ratio, to receive either dalteparin (5000 IU) or placebo, by subcutaneous injection, once daily for 16 weeks. Patients underwent upper extremity evaluation with either venography or ultrasound at the time of a suspected catheter-related complication (CRC) or upon completion of study medication. The primary end point, as determined by a blinded adjudication committee, was the occurrence of a CRC, defined as the first occurrence of any one of the following: clinically relevant catheter-related thrombosis that was symptomatic or that required anticoagulant or fibrinolytic therapy; catheter-related clinically relevant pulmonary embolism; or catheter obstruction requiring catheter removal. RESULTS: There was no significant difference in the frequency of CRCs between the dalteparin arm (3.7%) and the placebo arm (3.4%; P=0.88), corresponding to a relative risk of 1.0883 (95% confidence interval 0.37-3.19). No difference in the time to CRC was observed between the two arms (P=0.83). There was no significant difference between the dalteparin and placebo groups in terms of major bleeding (1 versus 0) or overall safety. CONCLUSIONS: Dalteparin prophylaxis did not reduce the frequency of thromboembolic complications after CVC implantation in cancer patients. Dalteparin was demonstrated to be safe over 16 weeks of treatment in these patients.