Phase I study of continuous and intermittent schedules of lapatinib in combination with vinorelbine in solid tumors

BACKGROUND

Chemotherapy in combination with small-molecule epidermal growth factor receptor inhibitors has yielded inconsistent results. Based on preclinical models, we conducted a phase I trial of two schedules of lapatinib and vinorelbine.

PATIENT AND METHODS

Patients had advanced solid tumors and up to two prior chemotherapeutic regimens. Patients were enrolled on two dose-escalating schedules of lapatinib, continuous (arm A) or intermittent (arm B), with vinorelbine on days 1, 8, and 15 of a 28-day cycle. Tumors from a subset of patients were evaluated for gene mutations and expression of targets of interest.

RESULTS

Fifty-one patients were treated. The most common grade 3/4 toxic effects included leukopenia, neutropenia, and fatigue. Dose-limiting toxic effects were grade 3 infection, febrile neutropenia, and diarrhea (arm A) and bone pain and fatigue (arm B). The maximum tolerated dose was vinorelbine 20 mg/m(2) weekly and lapatinib 1500 mg daily (arm A) and vinorelbine 25 mg/m(2) weekly and lapatinib 1500 mg intermittently (arm B). One patient on each arm had a complete response; both had human epidermal growth factor receptor 2-positive breast cancer. In a subset of patients, lack of tumor PTEN expression correlated with a shorter time to progression.

CONCLUSION

In an unselected population, two schedules of lapatinib and vinorelbine were feasible and well tolerated.

The incidence of venous thromboembolism among patients with primary lung cancer

BACKGROUND

The incidence of venous thromboembolism (VTE) by lung cancer histology and stage is unknown.

OBJECTIVES

To determine the incidence of VTE and the risk factors associated with development of VTE in a large population-based study of patients with non-small cell and small cell lung cancer.

METHODS

The California Cancer Registry was merged with the Patient Discharge Data Set to determine the incidence of VTE among lung cancer cases diagnosed between 1993 and 1999.

RESULTS

Among 91 933 patients with newly diagnosed lung cancer, the 1-year and 2-year cumulative VTE incidences were 3.0% and 3.4%, respectively, with a person-time rate of 7.2 events/100 patient-years during the first 6 months. The 1-year incidence of VTE was significantly increased in comparison to the general population [standardized incidence ratio = 21.2, 95% confidence interval (CI) = 20.4-22.0]. In a multivariate model, significant predictors of developing VTE within 1 year of non-small cell lung cancer (NSCLC) diagnosis were: younger age, the number of chronic medical comorbidities [hazard ratio (HR) = 2.8 if 3 vs. 0, 95% CI = 2.5-3.1], advancing cancer stage (HR = 4.0 for metastatic vs. local disease, 95% CI = 3.4-4.6) and adenocarcinoma histology (HR = 1.9 vs. squamous cell, 95% CI = 1.7-2.1). In multivariate models, VTE was a significant predictor of death within 2 years for both NSCLC and small cell lung cancer (SCLC), HR = 2.3, 95% CI = 2.2-2.4, and HR = 1.5, 95% CI = 1.3-1.7, respectively.

CONCLUSIONS

Approximately 3% of lung cancer patients developed VTE within 2 years. The diagnosis of VTE was associated with a higher risk of death within 2 years for NSCLC and SCLC.

Serum glycan analysis in metastatic breast cancer

11504

Background: There is a need for a reliable breast cancer biomarker that can predict a patient’s response to therapy. Serum glycans, or oligosaccharides, are of particular interest as over half of all proteins are glycosylated and alterations in glycosylation influence growth, adhesion, metastasis and immune surveillance of tumor, among other important functions. Serum glycans can be analyzed by high resolution mass spectrometry. Methods: Sera from patients with known metastatic breast cancer and age-matched healthy controls without medical problems were prospectively analyzed by mass spectroscopy. Women over the age of 18, who were not pregnant or breastfeeding, and who were without other active cancers were eligible. Samples were de-identified for laboratory personnel who analyzed sera by matrix-assisted laser desoprtion/ionization (MALDI) and Fourier transform ion-cyclotron resonance mass sepctrometry (FT ICR MS). Glycans were also profiled by chromatographic separation using a microchip nanoLC (Agilent) with a time-of-flight (TOF) mass analyzers. Results: Sera from 25 patients with metastatic breast cancer and 25 controls were evaluated. The mass profiles were obtained corresponding to both N-linked oligosaccharides (N-glycans) and O-linked oligosaccharides (O-glycans). Distinct variations in glycosylation were observed among sera analyzed from patients with metastatic breast cancer compared to controls. Specific glycan masses were analyzed and found to correspond to N-glycans. The chromatographic glycan profile showed individual glycans that were distinct for the cancer patients. Conclusions: Analysis of serum gylcans by mass spectrometry represents a new paradigm of cancer biomarker studies, focusing on post-translational modifications of proteins, rather than protein expression. Further refinement of this technology may be clinically useful in monitoring response to therapy in metastatic breast cancer.

No significant financial relationships to disclose.

Prospective multicenter study of the impact of the 21-gene recurrence score (RS) assay on medical oncologist (MO) and patient (pt) adjuvant breast cancer (BC) treatment selection

577

Background: The 21-gene RS assay has been validated to quantify the risk of distant recurrence in tamoxifen treated pts in N-ER+BC and predict magnitude of chemotherapy benefit. Since there is little data regarding the impact of RS on MO and pt decision making, this multi-center study was designed to prospectively examine whether RS affects MO and pt adjuvant treatment selection. Methods: MOs stated their treatment recommendation and confidence in it while pts indicated treatment choice pre and post RS assay. RS were returned to MO and pt for routine clinical care. Frequency distributions and co-frequency tables are used to display categorical distributions of nominal variables; means and standard deviations are used to summarize continuous variables. Results: 15 MOs at 1 community and 3 academic practices consecutively enrolled 93 pts (89 evaluable) with N-ER+BC. The treatment plan changed in 31.5% of MOs and 27% of pts. The frequency of treatment changes are in the table below. The largest change induced by RS results was conversion from pre-test CHT to post-test HT (22.5% of MO, 10.1% of pts). MOs stated RS results increased confidence in 68 (76%). 90% of pts felt the RS assay influenced their treatment choice; 95% were glad they took the test. Conclusion: The results of this study indicate that the RS assay does impact MO adjuvant treatment recommendations, pt treatment choice, and confidence in the treatment plan. Investigator initiated trial supported by an unrestricted clinical trial grant from Genomic Health Inc.

[Table: see text]

No significant financial relationships to disclose.

SWOG 0338: A phase II trial of imatinib mesylate in combination with capecitabine in metastatic breast cancer

10529

Background: Imatinib mesylate targets c-kit and platelet derived growth factor receptor (PDGFR) tyrosine kinases, and both are variably expressed in breast cancer. Inhibition of PDGFR by imatinib mesylate may decrease tumor interstitial pressure and improve delivery of chemotherapy. Based on preclinical synergy, SWOG conducted a phase II trial in metastatic breast cancer. Methods: Patients were eligible if they had adenocarcinoma of the breast that had progressed on at least 1 but ≤ 2 prior chemotherapy regimens for metastatic disease. No prior 5-FU or capecitabine for metastatic disease was allowed. Patients had to be > 18 years with a Zubrod performance status ≤ 2 and have adequate organ function. Patients with brain metastases were ineligible. Patients received imatinib mesylate 400 mg orally daily and capecitabine 1000 mg/m2 orally twice daily on days 1–14 of a 21-day cycle. If tolerated, the imatinib mesylate was increased to 600 mg daily in subsequent cycles. This was a 2-stage design with 25 patients with measurable disease accrued in the first stage. A total of 70 patients was planned, including those with nonmeasurable disease, if accrual proceeded to the second stage. The primary endpoint was to determine the confirmed response rate (RR) to the combination therapy. Secondary endpoints were to estimate the 6-month progression free survival, to determine the toxicities, and to explore c-kit and PDGFR in this population. Results: 27 patients were accrued; 6 were ineligible. 19 patients received therapy and were evaluable for toxicity. The median age was 59 years (36–78). Four responses were seen: 1 complete, 1 confirmed partial, and 2 unconfirmed partial (RR 21%). The 6-month progression free survival was 16%. There were no grade 4 toxicities. The most common grade 3 toxicities, seen in 7 patients, were diarrhea, fatigue, and hand-foot syndrome. As 2 of the 4 responses were unconfirmed, accrual did not proceed to the second stage. Conclusions: The combination of imatinib mesylate and capecitabine was well tolerated in patients with metastatic breast cancer, but the RR was not better than was seen in a prior study of single agent capecitabine. Correlative studies to explore c-kit, PDGFR, and estrogen receptor expression and response are in progress.

No significant financial relationships to disclose.

Genetic evaluation of cancer: the importance of family history

Although the etiology of most cancers is thought to be sporadic and multifactorial, 5% to 10% of breast, ovarian, and colon cancers result from defects or mutations in specific genes inherited by a person through the germline. Distinctions may be made between hereditary and sporadic cancers. Because the risk of developing cancer is greater for persons from a hereditary cancer family than for the general public, these people should be considered for early detection and prevention options. Testing for selected cancer genes is available commercially, and physicians must determine which patients are appropriate candidates for these tests. Risk-reduction strategies and options for high-risk patients as well as legal and ethical issues pertaining to genetic counseling and testing will be considered.

Emerging roles of BRCA1 in transcriptional regulation and DNA repair

BRCA1 was the first breast cancer susceptibility gene to be identified and cloned. In individuals from high-risk families, mutations in BRCA1 increase the lifetime risk of developing breast cancer eight to tenfold, compared to the general population. How the BRCA1 protein product normally functions to suppress tumor formation and how defects in the gene can ultimately lead to breast cancer have been the focus of intense scrutiny by the scientific and medical communities. BRCA1 has intrinsic transactivation activity and is able to activate the p21 promoter. In addition, BRCA1 is linked to a number of genes involved in transcriptional regulation, including CtIP, c-Myc, the RNA holoenzyme complex, and the histone deacetylase complex. Moreover, BRCA1 is essential for cellular response to DNA damage repair. Inactivation of Brca1 in mouse embryonic stem and fibroblast cells results in increased cell sensitivity to DNA-damaging agents. In human cells, BRCA1 binds to both Rad50 and Rad51 and colocalizes with these proteins at repair foci. Part of BRCA1's response to DNA damage may in fact be corroborated through transcriptional regulation. The expression of GADD45, a DNA damage-responsive gene, is increased immediately after induction of BRCA1. Recently, BRCA1 was shown to repress estradiol (E2)-responsive ER-alpha-mediated transcriptional activity, potentially linking the multiple functions of BRCA1 to specific tissue targets. These recent developments in BRCA1 function are an encouraging step toward understanding the role of BRCA1 in breast cancer formation.