A combinatorial biomarker predicts pathologic complete response to neoadjuvant lapatinib and trastuzumab without chemotherapy in patients with HER2+ breast cancer.

BACKGROUND: HER2-positive (+) breast cancers, defined by HER2 overexpression and/or amplification, are often addicted to HER2 to maintain their malignant phenotype. Yet, some HER2+ tumors do not benefit from anti-HER2 therapy. We hypothesize that HER2 amplification levels and PI3K pathway activation are key determinants of response to HER2-targeted treatments without chemotherapy. PATIENTS AND METHODS: Baseline HER2+ tumors from patients treated with neoadjuvant lapatinib plus trastuzumab [with endocrine therapy for estrogen receptor (ER)+ tumors] in TBCRC006 (NCT00548184) were evaluated in a central laboratory for HER2 amplification by fluorescence in situ hybridization (FISH) (n = 56). HER2 copy number (CN) and FISH ratios, and PI3K pathway status, defined by PIK3CA mutations or PTEN levels by immunohistochemistry were available for 41 tumors. Results were correlated with pathologic complete response (pCR; no residual invasive tumor in breast). RESULTS: Thirteen of the 56 patients (23%) achieved pCR. None of the 11 patients with HER2 ratio <4 and/or CN <10 achieved pCR, whereas 13/45 patients (29%) with HER2 ratio ≥4 and/or CN ≥10 attained pCR (P = 0.0513). Of the 18 patients with tumors expressing high PTEN or wild-type (WT) PIK3CA (intact PI3K pathway), 7 (39%) achieved pCR, compared with 1/23 (4%) with PI3K pathway alterations (P = 0.0133). Seven of the 16 patients (44%) with HER2 ratio ≥4 and intact PI3K pathway achieved pCR, whereas only 1/25 (4%) patients not meeting these criteria achieved pCR (P = 0.0031). CONCLUSIONS: Our findings suggest that there is a clinical subtype in breast cancer with high HER2 amplification and intact PI3K pathway that is especially sensitive to HER2-targeted therapies without chemotherapy. A combination of HER2 FISH ratio and PI3K pathway status warrants validation to identify patients who may be treated with HER2-targeted therapy without chemotherapy.

Proteasome inhibition with bortezomib (PS-341): a phase I study with pharmacodynamic end points using a day 1 and day 4 schedule in a 14-day cycle.

PURPOSE: We performed a phase I study of a day (D) 1 and D4 bortezomib administration once every 2 weeks to determine the recommended phase II dose and toxicity profile, and the extent of 20S proteasome inhibition obtained. PATIENTS AND METHODS: Patients with solid tumors or lymphomas were treated with bortezomib at 0.25 to 1.9 mg/m2 on D1 and D4, every 2 weeks. 20S proteasome levels in blood were assayed at baseline and at 1, 4, and 24 hours postdose in cycle 1. RESULTS: On this D1 and D4 every 2 weeks' schedule, dose-limiting toxicity (DLT) was evident at the 1.75 and 1.9 mg/m2 dose levels, most commonly in patients receiving individual total doses > or = 3.0 mg. The main DLT was peripheral neuropathy evident at the higher doses and in patients previously exposed to neurotoxic agents. Other DLTs included diarrhea and fatigue; grade 3 thrombocytopenia was also noted. Reversible inhibition of 20S proteasome activity was dose dependent and best fit a total dose (mg) per fraction rather than mg/m2; 70% of baseline activity was inhibited by a dose of 3.0 to 3.5 mg given on D1 and on D4 every other week. Antitumor effects short of confirmed partial responses were observed in patients with melanoma, non-small-cell lung cancer, and renal cell carcinoma. CONCLUSION: Bortezomib (PS-341) is a novel antineoplastic agent that is well tolerated at doses not exceeding 3.0 mg (equivalent to 1.75 mg/m2), repeated on D1 and D4 every other week. This dose correlates with 70% inhibition of 20S proteasome activity. DLTs include neuropathy, fatigue, and diarrhea.

Endoscopic ultrasound in the evaluation of gastric small lymphocytic mucosa-associated lymphoid tumors.

PURPOSE: Low-grade, small lymphocytic lymphomas of the mucosa-associated lymphoid tissue (MALT) have recently been shown to be associated with Helicobacter pylori infections. Regression of these tumors has been reported with antibiotic therapy. Here we evaluate endoscopic ultrasound (EUS) as on objective method to evaluate pretreatment disease and posttherapy response. MATERIALS AND METHODS: We retrospectively reviewed 20 patients initially diagnosed elsewhere with MALT lymphoma. All patients had their initial endoscopic biopsies (EGDs) reviewed at Memorial Sloan-Kettering Cancer Center (MSKCC). All patients had EUS performed at the time of consultation and on completion of therapy if treated at our center. Antral biopsies were stained with a modified Steiner preparation to determine infection by H pylori. RESULTS: Gastric low-grade lymphoma was confirmed in 16 of 20 patients; 11 of 16 had previously received antibiotic therapy for biopsy-positive H pylori infection. All gastric lymphomas had an abnormal EUS: eight with discrete tumor masses and eight with gastric wall infiltration (submucosa, n = 4; muscularis propria, n = 3; serosa, n = 1). On completion of lymphoma treatment with chemotherapy, radiotherapy, or surgery, 11 of 16 patients underwent follow-up EUS. Five patients received care elsewhere and did not return for posttreatment EUS. The gastric wall was normal with no evidence of disease on EUS-guided biopsy in eight of 11 patients. The remaining three patients had abnormal gastric walls. One was biopsy-negative and two had residual lymphoma. Four patients were found to have benign lymphoid aggregates in association with H pylori on initial EGD and EUS biopsies. All four patients were previously untreated with antibiotics. EUS showed prominent mucosa, but no significant findings within the gastric wall. CONCLUSION: EUS appears useful to stage objectively and evaluate therapeutic outcome in the management of gastric, low-grade MALT lymphomas. It also helps to distinguish benign lymphoid aggregates from lymphoma associated with H pylori infection. EUS findings may have a significant impact on assessment and therapeutic recommendations.

Whole body PET/CT for initial staging of choroidal melanoma.

AIM: To investigate the value of whole body positron emission tomography/computed tomography (PET/CT) in screening for metastatic choroidal melanoma in patients initially diagnosed with choroidal melanoma. METHODS: 52 patients with choroidal melanoma underwent whole body PET/CT as part of their metastatic investigation. PET/CT scans were used as a screening tool at the time of their initial diagnosis. A physical examination, liver function tests, and a baseline chest x ray were also obtained. PET/CT images (utilising intravenous18-fluoro-2-deoxyglucose (FDG)) were studied for the presence of metastatic melanoma. The standards for reference were further imaging and/or subsequent biopsies. RESULTS: Two of 52 (3.8%) patients were found to have metastatic melanoma before treatment. The most common sites for metastases were the liver (100%), bone (50%), and lymph nodes (50%). Brain involvement was also present in one patient. One patient (50%) had involvement of multiple sites. Haematological liver enzyme assays were normal in both patients. PET/CT showed false positive results in three patients (5.7%) when further evaluated by histopathology and/or additional imaging. In seven patients (13.4%) PET/CT imaging detected benign lesions in the bone, lung, lymph nodes, colon, and rectum. CONCLUSION: PET/CT imaging can be used as a screening tool for the detection and localisation of metastatic choroidal melanoma. Liver enzyme assays did not identify liver metastases, while PET/CT revealed both hepatic and extrahepatic metastatic melanoma. PET/CT imaging may improve upon the conventional methods of screening for detection of metastatic disease in patients initially diagnosed with choroidal melanoma.

Immunoproliferative small intestinal disease: case report and literature review.

Immunoproliferative small intestinal disease (IPSID) is a subtype of lymphoma of mucosa-associated lymphoid tissue. Notable for a high production of alpha-heavy chains, it is designated alpha-heavy-chain disease. IPSID is a debilitating disease that has a predilection for impoverished populations of developing countries. It has been documented primarily in subjects of Middle Eastern countries and thus was previously referred to as Mediterranean lymphoma. We report the case of a 42-year-old man from Senegal who presented with chronic diarrhea, dehydration, and weight loss. The endoscopic, pathologic, and serologic findings before, during, and after treatment with fludarabine phosphate are presented. We review the literature concerning current concepts on the etiology, pathogenesis, and management of IPSID.