Cystic pancreatic neoplasms: an emerging problem.

Widespread usage of advanced abdominal imaging has resulted in an increased finding of cystic lesions in the pancreas in asymptomatic patients. Greater than 90% of cystic pancreatic lesions are of inflammatory origin, the well-known pancreatic pseudocysts. The critical issue confronting specialists is differentiating inflammatory lesions from neoplastic lesions.

Anti-CD3 x anti-epidermal growth factor receptor (EGFR) bispecific antibody redirects T-cell cytolytic activity to EGFR-positive cancers in vitro and in an animal model.

PURPOSE: Targeting epidermal growth factor receptor (EGFR) overexpressed by many epithelial-derived cancer cells with anti-EGFR monoclonal antibodies (mAb) inhibits their growth. A limited number of clinical responses in patients treated with the anti-EGFR mAb, (cetuximab), may reflect variability in EGFR type or signaling in neoplastic cells. This study combines EGFR-targeting with the non-MHC-restricted cytotoxicity of anti-CD3 activated T cells (ATC) to enhance receptor-directed cytotoxicity. EXPERIMENTAL DESIGN: ATC from normal and patient donors were expanded ex vivo. Specific cytolytic activity of ATC armed with anti-CD3 x anti-EGFR (EGFRBi) against EGFR-expressing cancer cells derived from lung, pancreas, colon, prostate, brain, skin, or EGFR-negative breast cancer cells was evaluated in (51)Cr release assays. In vivo studies comparing tumor growth delay induced by EGFRBi-armed ATCs or cetuximab were done in severe combined immunodeficient/Beige mice (SCID-Beige) bearing COLO 356/FG pancreatic and LS174T colorectal tumors. RESULTS: At effector/target ratios from 3.125 to 50, both EGFRBi-armed normal and patient ATC were significantly more cytotoxic, by 23% to 79%, against EGFR-positive cells over ATC, cetuximab, anti-CD3 alone, or ATC armed with irrelevant BiAb directed at CD20. EGFRBi-armed ATC also secreted significantly higher levels of some T(H1)/T(H2) cytokines compared with ATC alone. In mice, i.v. infusions of EGFRBi-armed ATC (0.001 mg equivalent/infusion) were equally effective as cetuximab (1 mg/infusion) alone for significantly delaying growth of established COLO 356/FG but not LS174T tumors compared with mice that received ATC alone or vehicle (P < 0.001). CONCLUSIONS: Combining EGFR antibody targeting with T cell-mediated cytotoxicity may overcome some limitations associated with EGFR-targeting when using cetuximab alone.

Real-time Imaging of the Resection Bed Using a Handheld Probe to Reduce Incidence of Microscopic Positive Margins in Cancer Surgery.

Wide local excision (WLE) is a common surgical intervention for solid tumors such as those in melanoma, breast, pancreatic, and gastrointestinal cancer. However, adequate margin assessment during WLE remains a significant challenge, resulting in surgical reinterventions to achieve adequate local control. Currently, no label-free imaging method is available for surgeons to examine the resection bed in vivo for microscopic residual cancer. Optical coherence tomography (OCT) enables real-time high-resolution imaging of tissue microstructure. Previous studies have demonstrated that OCT analysis of excised tissue specimens can distinguish between normal and cancerous tissues by identifying the heterogeneous and disorganized microscopic tissue structures indicative of malignancy. In this translational study involving 35 patients, a handheld surgical OCT imaging probe was developed for in vivo use to assess margins both in the resection bed and on excised specimens for the microscopic presence of cancer. The image results from OCT showed structural differences between normal and cancerous tissue within the resection bed following WLE of the human breast. The ex vivo images were compared with standard postoperative histopathology to yield sensitivity of 91.7% [95% confidence interval (CI), 62.5%-100%] and specificity of 92.1% (95% CI, 78.4%-98%). This study demonstrates in vivo OCT imaging of the resection bed during WLE with the potential for real-time microscopic image-guided surgery.

Surgical management of primary breast sarcoma.

Primary sarcoma constitutes less than one per cent of breast malignancies. A retrospective review of this disease at our institution was undertaken to assess the effect of different treatment modalities on outcome. Over a 24-year period 28 patients were identified. Follow-up ranged from one to 228 months. Partial mastectomy was done in seven patients, whereas ten underwent total mastectomy and nine had modified radical mastectomy. Two refused surgery. All margins of resection were negative. In total ten axillary lymph node dissections were done with no positive nodes identified. Pathologic analysis of tumors revealed a variety of sarcomas including high-grade malignant cystosarcoma phyllodes in 13. Recurrence of disease occurred in two women, both with malignant cystosarcoma phyllodes. One was a local recurrence in a patient who had undergone partial mastectomy. This was successfully treated with a total mastectomy. The second recurrence involved a distant metastasis in a patient treated with modified radical mastectomy that eventually led to her death. For the entire group the disease-free survival was 75 per cent at 10 years whereas overall survival was 87.5 per cent. In conclusion an adequate margin of resection is the single most important determinant of long-term survival. Axillary lymph node dissection is not necessary for the treatment of these tumors.