Effects of neratinib on health-related quality of life in women with HER2-positive early-stage breast cancer: longitudinal analyses from the randomized phase III ExteNET trial.

BACKGROUND: We report longitudinal health-related quality-of-life (HRQoL) data from the international, randomized, double-blind, placebo-controlled phase III ExteNET study, which demonstrated an invasive disease-free survival benefit of extended adjuvant therapy with neratinib over placebo in human epidermal growth factor receptor-2-positive early-stage breast cancer. PATIENTS AND METHODS: Women (N = 2840) with early-stage HER2-positive breast cancer who had completed trastuzumab-based adjuvant therapy were randomly assigned to neratinib 240 mg/day or placebo for 12 months. HRQoL was an exploratory end point. Patients completed the Functional Assessment of Cancer Therapy-Breast (FACT-B) and EuroQol 5-Dimensions (EQ-5D) questionnaires at baseline and months 1, 3, 6, 9, and 12. Changes from baseline were compared using analysis of covariance with no imputation for missing values. Sensitivity analyses used alternative methods. Changes in HRQoL scores were regarded as clinically meaningful if they exceeded previously reported important differences (IDs). RESULTS: Of the 2840 patients (intention-to-treat population), 2407 patients were evaluable for FACT-B (neratinib, N = 1171; placebo, N = 1236) and 2427 patients for EQ-5D (neratinib, N = 1186; placebo, N = 1241). Questionnaire completion rates exceeded 85%. Neratinib was associated with a decrease in global HRQoL scores at month 1 compared with placebo (adjusted mean differences: FACT-B total, -2.9 points; EQ-5D index, -0.02), after which between-group differences diminished at later time-points. Except for the FACT-B physical well-being (PWB) subscale at month 1; all between-group differences were less than reported IDs. The FACT-B breast cancer-specific subscale showed small improvements with neratinib at months 3-9, but all were less than IDs. Sensitivity analyses exploring missing data did not change the results. CONCLUSIONS: Extended adjuvant neratinib was associated with a transient, reversible decrease in HRQoL during the first month of treatment, possibly linked to treatment-related diarrhea. With the exception of the PWB subscale at month 1, all neratinib-related HRQoL changes did not reach clinically meaningful thresholds. ClinicalTrials.gov: NCT00878709.

Pretreatment leukaemia cell drug resistance is correlated to clinical outcome in acute myeloid leukaemia.

In 85 adult patients diagnosed with acute myeloid leukaemia (AML) and treated at the same institution during a 5-yr period, the clinical significance of in vitro cellular drug resistance to the anthracyclines aclarubicin (Acla) and daunorubicin (Dau) as well as the nucleoside analogue cytarabine (Ara-C) was investigated using a 4-d MTT (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide) assay. In 59 patients of whom 40 were treated by the combination of Acla and Ara-C we found that leukaemia cell drug resistance towards Acla was higher (by a factor 2.80) in patients who failed to enter complete remission (CR) after the first cycle of induction chemotherapy as compared to patients who entered complete remission. The relationship was significant in univariate as well as multivariate analysis (p=0.02 and 0.03, respectively). By contrast, no in vitro single drug resistance values were consistently correlated to other parameters of clinical outcome (overall CR rate, overall survival (OS), or continuous complete remission (CCR)), whereas the combined Acla and Ara-C drug resistance profile (Acla/Ara-C DRP) was of prognostic significance to overall survival of all 85 patients (p=0.004) as well as to the CCR of 39 complete responders (p=0.04). These findings remained statistically significant in multivariate analyses correcting for other variables influencing clinical outcome including patient age, leukocyte count, karyotype, FAB-subtype, and presence/absence of secondary AML. We conclude that the in vitro drug resistance of leukaemia cells at time of disease presentation appears to be independent of prognostic significance to short- and long-term clinical outcome in AML.

MDR1 gene expression and drug resistance of AML cells.

We investigated the cellular drug resistance to aclarubicin (Acla), cytosine arabinoside (Ara-C), daunorubicin (Dau), doxorubicin (Dox), etoposide (Etop) and mitoxantrone (Mitox) using the MTT assay at time of disease presentation in 93 cases of acute myeloid leukaemia (AML). In 31 cases we concomitantly investigated MDR1 (multiple drug resistance 1 gene) expression (semi-quantitative competitive RT-PCR) of the leukaemic cells. Drug resistance towards Dau, Dox and Etop was correlated to the MDR1 expression of the AML cells (P<0.05) with high MDR1 expression being associated with high drug resistance towards these drugs. Although the data did not allow firm conclusions to be drawn on the correlation between MDR1 expression and drug resistance towards Ara-C and Mitox, the drug resistance towards Acla clearly was not correlated to, or dependent on, the MDR1 expression level of the AML blast cells. In addition, when examining the cross-activities among the six drugs distinct patterns emerged. Thus, high to very high degrees of cross-activity were found to exist between Dau, Dox, Etop and Mitox, whereas Ara-C had moderate cross-activity with the other drugs except Acla, which showed absent to moderate cross-activity with the other drugs. We conclude that MDR1 gene expression is of significance for cellular drug resistance towards specific (MDR1-related) drugs in AML, whereas it is not of significance regarding drug resistance towards other drugs, which is the case with the anthracycline Acla. We suggest that in the place of other more or less complicated ways to circumvent MDR1-mediated drug resistance, Acla may be used to replace Dau, Dox and other MDR1-related drugs if proven as potent as the drug it is to substitute.

Relation of blast cell survival and proliferation to chemotherapy resistance in AML.

We have investigated the in vitro blast cell survival (viability) and drug resistance to cytosine arabinoside (Ara-C), daunorubicin (Dau), mitoxantrone (Mitox) and aclarubicin (Acla) of fresh leukaemic blast cells from 80 patients with newly diagnosed acute myeloid leukaemia (AML) employing the semiautomated colourimetric MTT(3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide)-assay. In 15 cases we concurrently investigated the relation between in vitro blast cell survival (MTT assay) and blast cell proliferation (3H-thymidine incorporation) in the presence and absence of myeloid growth factors (GFs) G-CSF, GM-CSF and IL-3 (individually and in combination). A highly significant correlation was found between blast cell survival and blast cell proliferation (r = 0.87, P < 1 x 10(-4). Furthermore, in 40 evaluable adult patients who completed intravenous induction chemotherapy and were evaluable for response to chemotherapy we found a positive correlation between in vitro blast survival (MTT assay) and response to chemotherapy with high blast survival being associated with poor response to chemotherapy (P = 0.05). Moreover, in a multivariate analysis, high blast cell survival was significantly associated with high CD13 expression and monocytic phenotype (P = 0.0003 and P = 0.02, respectively). Furthermore, we found an inverse relationship between the baseline proliferation of the blasts and the magnitude of response to the GFs (P < 0.02), indicating that cells with low baseline proliferation were more readily stimulated by growth factors. Finally, we found a significant correlation between leukaemic cell survival and cellular drug resistance towards Dau (P = 0.001) and Mitox (P = 0.03), but not towards Ara-C (P = 0.68) and Acla (P = 0.13). We conclude that high in vitro leukaemic cell survival is associated with drug resistance in vivo and in vitro, and furthermore is correlated with high blast cell proliferation and some adverse prognostic factors previously identified in AML.

Synergistic and antagonistic effects of myeloid growth factors on in vitro cellular killing by cytotoxic drugs.

The effect of stimulating acute myeloid leukemia blast cells with a combination of growth factors (G-CSF, GM-CSF, and IL-3) on cellular resistance to the antileukemia drugs Ara-C, daunorubicin, aclarubicin, and mitoxantrone was studied. For assessment of in vitro cellular drug resistance the MTT assay was employed. Stimulated cells showed enhanced sensitivity to Ara-C (p < 0.02), whereas a significant increase in cellular drug resistance to daunorubicin (p < 0.02) was observed. Variable and statistically non-significant changes in drug resistance to aclarubicin and mitoxantrone was induced by stimulation of the blast cells. We conclude on the basis of these observations that myeloid growth factors should be used with caution in combination with daunorubicin in AML treatment until further confirmatory evidence has been presented by other investigators.

A suction blister method that gives epidermal biopsies from mice of different ages, suitable for histologic studies of Langerhans cells.

A modified suction blister device has been developed. It allows in vivo retrieval of 3 x 3 mm2 mouse epidermis biopsies. Separation takes place exactly at the epidermal-dermal junction. Young skin and iso-grafted skin require suction with a lower bar value than skin from young and old non-grafted animals. Langerhans cells in biopsies were identified both with ATPase staining and with monoclonal antibody. Suction blisters produce Langerhans cell counts similar to those obtained on EDTA-separated epidermis.

Syngrafting skin among mice of similar and different ages increases the number of Langerhans cells and decreases responsiveness to 1,4-dinitrofluorobenzene.

Counting on suction blister skin biopsies, the number of Langerhans cells per mm2 in BALB/c mouse epidermis was found identical in 1-, 11-, and 22-month-old animals, but consistently elevated in syngrafted skin 10 months after transplantation. This effect of grafting was independent of whether young or old skin was transferred to young or old recipients. Skin swelling induced by dinitrofluorobenzene (DNFB) sensitization was reduced in 22-month-old non-grafted mice and in grafted skin irrespective of donor and recipient age.

Synthesis, tissue distribution and cytostatic properties of two new daunorubicin derivatives of 2-thiouracil containing a guanidine bridge.

In further attempts to utilize the affinity of 2-thiouracil for melanin-producing tissues in the design of drugs active against malignant melanomas, guanidine-bridged adducts of the anthraquinone drug daunorubicin (1a) with 2-thiouracil were prepared (Scheme 3). The expected adduct (4), and a by-product in its preparation (5) (Scheme 3), were inactive against murine melanoma, in vivo, and did not show affinity for melanin-producing tissues. They were efficient DNA intercalating agents, but were much less cytostatic than daunorubicin against Cloudman melanoma, and were inactive, in vitro, against human cervical carcinoma MS 751. The coupling chemistry employed may have application in current attempts to effect binding of drugs to high molecular weight targeting antigens.

Susceptibility to carcinogenic effect of irradiation. Relationship to age at time of exposure.

Age at time of exposure is an important host factor influencing the subsequent cancer risk. Before completion of organogenesis, the fetus may be rather resistant, but thereafter the growing tissues of children are more susceptible than those of young adults. At greater age of adults at the time of exposure there is an increase in the subsequent absolute number of 'excess' cancer cases, but the relative risk (excess in relation to expectation) is rather constant for a given kind of radiation exposure as judged from the presently rather small number of investigations.