Tipifarnib Plus Trastuzumab in Treating Patients With Metastatic Breast Cancer

DISEASE CHARACTERISTICS: * Histologically or cytologically confirmed metastatic adenocarcinoma of the breast * HER2/neu 3+ by immunohistochemical staining * 2+ eligible provided HER2/neu positive by fluorescent in-situ hybridization (FISH) * HER2/neu positive by FISH alone allowed * Unidimensionally measurable disease * At least 20 mm by conventional techniques OR at least 10 mm by spiral CT scan * Must have received prior trastuzumab (Herceptin) * Patients with known brain metastases meeting any of the following criteria are not eligible: * Require high-dose steroid therapy or enzyme-inducing anticonvulsant drugs * No prior cranial radiotherapy * Have progressive neurologic dysfunction that would preclude study evaluation * Have evidence of progressive CNS disease by CT scan or MRI * Hormone receptor status: * Not specified PATIENT CHARACTERISTICS: Age * Over 18 Sex * Male or female Menopausal status * Not specified Performance status * ECOG 0-2 OR * Karnofsky 70-100% Life expectancy * At least 12 weeks Hematopoietic * Absolute neutrophil count at least 1,500/mm\^3 * Platelet count at least 100,000/mm\^3 * Hemoglobin at least 9.0 g/dL Hepatic * Bilirubin no greater than 1.5 times upper limit of normal (ULN) * AST and ALT no greater than 2.5 times ULN (5 times ULN if liver metastases present) Renal * Creatinine no greater than 1.5 times ULN OR * Creatinine clearance greater than 60 mL/min Cardiovascular * No symptomatic congestive heart failure * No unstable angina pectoris * No cardiac arrhythmia * Ejection fraction greater than 50% by MUGA or echocardiogram Gastrointestinal * No gastrointestinal tract disease resulting in an inability to tolerate oral medication * No requirement for IV alimentation * No active peptic ulcer disease Other * Not pregnant or nursing * Negative pregnancy test * Fertile patients must use effective contraception * No significant traumatic injury within the past 21 days * No other malignancy within the past 3 years except nonmelanoma skin cancer or carcinoma in situ of the cervix * No ongoing or active infection * No prior allergic reaction attributed to compounds of similar chemical or biological composition to tipifarnib (e.g., quinolones) or trastuzumab * No psychiatric illness or social situation that would preclude study compliance * No other concurrent medical illness that would preclude study compliance PRIOR CONCURRENT THERAPY: Biologic therapy * See Disease Characteristics * No prior bone marrow transplantation with high-dose chemotherapy * No concurrent immunotherapy Chemotherapy * See Biologic therapy * No more than 2 prior chemotherapy regimens for metastatic disease * More than 4 weeks since prior chemotherapy (6 weeks for nitrosoureas or mitomycin) and recovered * Prior combination chemotherapy allowed * No concurrent chemotherapy Endocrine therapy * See Disease Characteristics * Prior hormonal therapy allowed * No concurrent hormonal therapy for cancer Radiotherapy * See Disease Characteristics * More than 4 weeks since prior wide-field radiotherapy and recovered * No concurrent radiotherapy Surgery * Prior modified radical mastectomy or lumpectomy with axillary node dissection allowed * Prior resection of metastatic lesions allowed * More than 21 days since prior major surgery * No prior surgery affecting absorption Other * No prior tipifarnib * More than 6 weeks since initiation of bisphosphonate therapy (if bone lesions are the only site of measurable disease) * Bisphosphonate therapy may not be initiated during study * No other concurrent investigational agents * No other concurrent anticancer therapy * No concurrent antacids within 2 hours of study drug