[Advances in sentinel node biopsy for breast cancer].

SN biopsy (SNB) has evolved rapidly during the past decade and has now become a standard of surgical care for patients with breast cancer. The primary purpose of SNB is to minimize patient morbidity from axillary staging, but SNB also presents research opportunities to further understand the role of the sentinel node in the natural history of breast cancer. We have attempted to highlight several issues regarding SN and its biopsy in this review, including:(1) Investigation of the optimal particle size for radiotracers. The success of SNB is, in large part, attributed to the particle size of radiolabeled tracers. Electron microscopy demonstrated significant accumulation of the tracer (tin colloid) in harvested SN, of which particle sizes were in the range of 100-150 nm. Therefore, this appeared to be a suitable particle size for SN identification. (2) Invention of a new gamma probe. A cord-and boxless handheld gamma probe was invented, which was more sensitive to radioactivity and involved a background subtraction function based on defined criteria. (3) Characterization of the immunologic response against tumor antigens. Fluorescence-activated cell sorting (FACS) analyses were performed to determine the phenotypic characteristics of B cells and T cells in SN. They revealed an increase in B cells expressing co-stimulated molecules as antigen-presenting cells in SN, compared with non-SN. With respect to T cells, a heterogeneous pattern of naive and memory T cells (TCM) was demonstrated in SN, in contrast to homogeneous pattern with TCM in non-SN. These results may support the concept that B cells play a significant role in antigen presentation required for T cell activation. Studies are currently in progress to test these possibilities.

New cytotoxic agents and schedules for advanced breast cancer.

Cytotoxic chemotherapy is important for treatment of women with hormone-insensitive or hormone-refractory advanced breast cancer. A variety of agents are effective, alone or in combination. The clinical activity and side effects of many agents, as well as principles for use of chemotherapy, are reviewed. Recent advances in chemotherapy for breast cancer include important studies on the role of dose-intensity, modifications of available agents to reduce side effects, and the availability of oral chemotherapeutics. Finally, the combination of chemotherapy with novel biological agents may improve outcomes for women with certain types of breast cancer. The growing availability of such biological therapies given in combination with chemotherapy may mean better survival in the future for women with advanced breast cancer.

Clinical activity of trastuzumab and vinorelbine in women with HER2-overexpressing metastatic breast cancer.

PURPOSE: To determine the response rate and toxicity profile of trastuzumab administered concurrently with weekly vinorelbine in women with HER2-overexpressing advanced breast cancer. PATIENTS AND METHODS: Forty women with HER2-positive (+3 by immunohistochemistry, n = 30; +2 or positive, n = 10) breast cancer were enrolled onto a study of trastuzumab (4 mg/kg x 1, 2 mg/kg weekly thereafter) and vinorelbine (25 mg/m2 weekly, with dose adjusted each week for neutrophil count). Eighty-two percent of women had received prior chemotherapy as part of adjuvant (30%), metastatic (25%), or both (28%) treatment, including substantial portions of patients who had previously received either anthracyclines (20%), taxanes (15%), or both types (38%) of chemotherapy. RESULTS: Responses were observed in 30 of 40 patients (overall response rate, 75%, conditional corrected 95% confidence interval, 57% to 89%). The response rate was 84% in patients treated with trastuzumab and vinorelbine as first-line therapy for metastatic disease, and 80% among HER2 +3 positive patients. High response rates were also seen in women treated with second- or third-line therapy, and among patients previously treated with anthracyclines and/or taxanes. Combination therapy was feasible; patients received concurrent trastuzumab and vinorelbine in 93% of treatment weeks. Neutropenia was the only grade 4 toxicity. No patients had symptomatic heart failure. Grade 2 cardiac toxicity was observed in three patients. Prior cumulative doxorubicin dose in excess of 240 mg/m2 and borderline pre-existing cardiac function were associated with grade 2 cardiac toxicity. CONCLUSION: Trastuzumab in combination with vinorelbine is highly active in women with HER2-overexpressing advanced breast cancer and is well tolerated.

Phase I clinical trial of 7-cyanoquinocarcinol (DX-52-1) in adult patients with refractory solid malignancies.

PURPOSE: A phase I study of the antitumor antibiotic 7-cyanoquinocarcinol, DX-52-1, was conducted in patients with refractory solid malignancies. This study sought to determine the maximum tolerated dose and principal toxicities of this agent and to characterize its pharmacokinetic behavior. METHODS: Patients were required to have adequate bone marrow, renal and hepatic function. DX-52-1 was administered by i.v. continuous infusion over a 6-h period each week for four consecutive weeks followed by a 2-week rest period, which constituted one cycle of treatment. RESULTS: Initial dose levels were 3, 6, and 10 mg/m2. An intermediate dose level of 8 mg/m2 was added after acceptable toxicity was observed at the 6 mg/m2 dose level, but dose-limiting toxicities, including life-threatening ones, were seen at the 10 mg/m2 dose level in all three patients. The maximum tolerated dose (MTD) was subsequently determined to be 6 mg/m2. Because a clear pattern of toxicities was not initially evident, a larger than usual number of additional patients (16) were enrolled at the MTD to better distinguish toxicities due to the study drug from those secondary to the patients' underlying malignancies. Even at the MTD, the drug was poorly tolerated, with gastrointestinal toxicities (abdominal pain, nausea, vomiting and increased liver function tests) predominating and dose-limiting. Pharmacokinetic studies revealed that the mean maximum plasma concentration of DX-52-1 in patients evaluated at the MTD (138.8 +/- 59.3 ng/ml, n = 19) was considerably lower than the concentrations required for cytostatic or cytotoxic activity against sensitive human tumor cell lines in vitro. Further, the weekly dose intensity of the most efficacious treatment schedule identified during in vivo antitumor efficacy studies was 60 times greater than the 6 mg/m2 weekly dose tolerated by cancer patients. None of the 33 patients participating in this study, including the 22 patients evaluated at the MTD, had any response to treatment. CONCLUSION: Given the poor tolerability, the inability to achieve drug levels necessary to inhibit in vitro or in vivo tumor growth, and the lack of any responses in our study, DX-52-1, as given by this schedule, does not appear to warrant further investigation in phase II studies.

Quality of life issues among women undergoing high-dose chemotherapy for breast cancer.

High-dose chemotherapy with autologous stem cell support for the treatment of breast cancer can have a profound effect on patients' quality of life (QOL). This article reviews findings from studies assessing QOL before, during, and after high-dose chemotherapy. The impact of high-dose therapy on overall QOL and specific aspects of QOL including physical functioning, symptoms, psychosocial/emotional and cognitive functioning, sexual functioning, and role functioning is considered. High-dose chemotherapy with stem cell transplant results in largely transient impairment of overall QOL and physical functioning, with subsequent improvement to baseline or better over time. Despite these encouraging global QOL findings, many patients continue to suffer considerable symptoms and concerns attributable to their transplant long after completion of the therapy. Additional research in this area is needed to optimize QOL for patients receiving high-dose chemotherapy.

Docetaxel administered on a weekly basis for metastatic breast cancer.

PURPOSE: To evaluate the safety and efficacy of weekly docetaxel in women with metastatic breast cancer. PATIENTS AND METHODS: Twenty-nine women were enrolled onto a study of weekly docetaxel given at 40 mg/m(2)/wk. Each cycle consisted of 6 weeks of therapy followed by a 2-week treatment break, repeated until disease progression or removal from study for toxicity or patient preference. Fifty-two percent of patients had been previously treated with adjuvant chemotherapy; 21% had received prior chemotherapy for metastatic breast cancer, and 31% had previously received anthracyclines. All patients were assessable for toxicity; two patients were not assessable for response but are included in an intent-to-treat analysis. RESULTS: Patients received a median of 18 infusions, with a median cumulative docetaxel dose of 720 mg/m(2). There were no complete responses. Twelve patients had partial responses (overall response rate, 41%; 95% confidence interval, 24% to 61%), all occurring within the first two cycles. Similar response rates were observed among subgroups of patients previously treated either with any prior chemotherapy or with anthracyclines. An additional 17% of patients had stable disease for at least 6 months. The regimen was generally well tolerated. There was no grade 4 toxicity. Only 28% of patients had any grade 3 toxicity, most commonly neutropenia and fatigue. Acute toxicity, including myelosuppression, was mild. Fatigue, fluid retention, and eye tearing/conjunctivitis became more common with repetitive dosing, although these side effects rarely exceeded grade 2. Dose reductions were made for eight of 29 patients, most often because of fatigue (n = 5). CONCLUSION: Weekly docetaxel is active in treating patients with metastatic breast cancer, with a side effect profile that differs from every-3-weeks therapy.

Oral 5-FU analogues in the treatment of breast cancer.

Three oral 5-fluorouracil (5-FU) therapies have been approved by the US Food and Drug Administration or are in development for the treatment of patients with breast cancer: capecitabine, UFT, and 5-FU/eniluracil. Capecitabine has been approved for breast cancer patients whose disease is paclitaxel-resistant, and either anthracycline-resistant or for whom further anthracycline use is not indicated. A response rate of 20% was observed in an open-label phase II trial of capecitabine in heavily pretreated patients with metastatic breast cancer. Diarrhea and hand-foot syndrome were the most frequently reported toxicities. In a randomized phase II study of capecitabine vs paclitaxel in breast cancer patients who had failed anthracyclines, response rates were 36% for capecitabine vs 21% for paclitaxel. Several phase II trials of 5-FU/eniluracil in breast cancer are ongoing. Preliminary response data from one of these trials on 31 patients with anthracycline- and taxane-resistant advanced breast cancer showed a 16% partial response rate. Grade 3-4 treatment-related toxicities included diarrhea (8%), nausea (3%), and granulocytopenia (3%). In Japan, UFT is widely used for the treatment of breast cancer in both the adjuvant and metastatic settings, though studies in the United States are just getting under way. A phase II trial conducted in Madrid, Spain evaluated the combination of UFT, methotrexate, and leucovorin as salvage therapy for breast cancer patients. The overall response rate was 38% among 21 patients, and diarrhea was the most common toxicity. Many questions remain unanswered about the optimal use of oral 5-FU agents in breast cancer. There seems little question that these agents have substantial activity and will find a place in the therapeutic armamentarium.

A Phase I trial of ifosfamide and paclitaxel with granulocyte-colony stimulating factor in the treatment of patients with refractory solid tumors.

BACKGROUND: Ifosfamide and paclitaxel are antineoplastic agents with broad activity and with different mechanisms of action. A Phase I trial was conducted to determine the maximum tolerated dose and associated toxicities of these agents when used in combination. METHODS: Patients with refractory, incurable solid tumors were entered on a 5-step Phase I trial of ifosfamide, given in doses of 2-3 g/m2 intravenous (i.v.) bolus for 3 days with mesna support, and paclitaxel, given in doses of 135-190 g/m2 i.v. by continuous infusion over 24 hours. Paclitaxel was given after the first dose of ifosfamide on Day 1. RESULTS: Twenty-three patients were treated, and the maximum tolerated dose was the highest planned dose level of the trial: ifosfamide, 3 g/m2/day i.v. for 3 days, and paclitaxel, 190 mg/m2 i.v. over 24 hours. Hematologic toxicity was not dose-limiting, and although neutropenia occurred, it was brief (median, 2-4 days) and resulted in hospitalization for neutropenia and fever in only 7 of 111 courses of therapy. For patients treated at the highest dose level, only 1 of 50 courses of therapy resulted in hospitalization for neutropenia and fever. Nonhematologic toxicity also was not severe and no significant neuropathy occurred. Although patients entered into the study were heavily pretreated, responses were observed, particularly in patients with breast or ovarian carcinoma. CONCLUSIONS: Ifosfamide and paclitaxel can be administered safely in the doses used in this study and there are indications of significant antitumor effect. Further studies are necessary to explore the antineoplastic activity of this regimen, particularly for patients with breast and ovarian carcinoma.

The presence of membrane-bound stem cell factor on highly immature nonmetachromatic mast cells in the peripheral blood of a patient with aggressive systemic mastocytosis.

BACKGROUND: Systemic mastocytosis is characterized by mast cell infiltration of bone marrow and tissues in the absence of identified circulating bone marrow-derived progenitors. A 58-year-old man was first seen with aggressive systemic mastocytosis manifested by urticaria pigmentosa, hepatosplenomegaly, generalized bone lesions, anemia, thrombocytopenia, monoclonal gammopathy, and increased urine histamine levels. OBJECTIVES AND METHODS: A rapidly progressive anemia and thrombocytopenia dictated a splenectomy. We sought to identify the mast cell progenitors in the peripheral blood and to provide evidence of their maturation in tissues with immunohistochemical and ultrastructural analyses. RESULTS: The peripheral blood contained 1% to 3% nonmetachromatic mononuclear cells with eccentric nuclei that expressed the mast cell proteases, tryptase and carboxypeptidase A, along with c-kit, stem cell factor (SCF), and high-affinity IgE receptor (Fc epsilon RI), but not chymase. Similar mononuclear cells colocalized in the spleen and lymph nodes with mature, metachromatic mast cells that expressed tryptase, chymase, carboxypeptidase A, c-kit, SCF, and Fc epsilon RI. Electron microscopy disclosed, at each site, a mature mast cell population with electron-dense, scroll-poor granules. CONCLUSIONS: The peripheral blood of a patient with aggressive systemic mastocytosis contained immature mononuclear cells of the mast cell lineage that express c-kit, SCF, tryptase, carboxypeptidase A, and Fc epsilon RI. These cells were also found in the skin, spleen, and lymph nodes where they presumably expand, differentiate, and mature, assuming the mast cell phenotype for those tissues characterized by metachromasia, expression of a full range of mast cell-related secretory granule proteases, and ultrastructural appearance. The presence of SCF on the surface membrane of the circulating, highly immature mast cells suggests an autocrine regulation of the c-kit-SCF interaction.