Abstract P3-13-20: Use of a 3-D bioabsorbable tissue marker in 61 patients over two years

Background: Breast conservation surgery (BCS) may preserve the breast but many women have less than optimal cosmetic outcomes. Increasingly, this has been addressed by the use of oncoplastic reconstruction.Now, targeting radiation treatment for boost or partial breast irradiation (PBI) using the seroma has become more difficult due to the adjacent tissue rearrangement and resultant “benign” seromas. Since the radiation dose generated increases by the third power of the radius (r3), there is a need to accurately focus radiation therapy to avoid chronic radiation side effects.We have used a 3-dimensional bioabsorbable tissue marker to accurately target the tumor bed while excluding inadvertent seromas caused by oncoplastic procedures. We report on tissue marker implantation on 61 consecutive breast conservation patients in regards to targeting, impact on cosmesis, imaging followup, ease of re-excision, as well as side effects and patient satisfaction.

METHODS: Consecutive lumpectomy patients who were candidates for targeted radiation therapy were considered for implantation with the 3-D bioabsorbable marker from May 2014 to June 2016. The tissue marker has a fixed array of 6 titanium clips and was sutured to the site of the excised breast cancer during lumpectomy.The framework of the implant resorbs slowly over time, while the clips remain permanently. All patients had oncoplastic reconstruction with total implant coverage. The marker was utilized for boost or partial breast irradiation (PBI) planning or treatment targeting. Data includes patient demographics, breast size, tumor characteristics, surgical and radiotherapy techniques, follow-up imaging, cosmesis and patient satisfaction.

Results:Data on 61 patients with median follow-up 12.7 months was analyzed (range 1.5–25.5). Median age was 62.4 years (range 33-74), 5 of women were postmenopausal and 15% had comorbidities. Cancer histology was in-situ (13%), invasive ductal (84%), invasive lobular (3%) of sizes T0 (13%), T1 (59%), T2 (25%), T3-4 (3%). Laterality and tumor location within the breast were typical. Re-excisions occurred in 11% of patients. No infections occurred in the postoperative period. One infection occurred with chemotherapy and another with repeated aspirations of oncoplastic area.No device was removed for infection, misplacement or patient-generated concerns. No cancer recurrences have been reported. Size of device used reflected size of the tumor; 2X2cm (44%), 2X3cm (34%) and 3X3cm (20%). The device was utilized by radiation oncologists for boost or PBI planning and treatment. Data on ease of setup and boost planning is being collected. Mammography at one year demonstrated marker clips coalescing as the bioabsorbable device dissolves. Evaluation of cosmetic appearance has shown good to excellent cosmesis as judged separately by both physicians and patients (92% and 94%).

Conclusions: Initial experience with 61 patients implanted with a novel 3-D absorbable device prospectively followed for an average of 12 months can be used in an array of breast cancer patients without device specific morbidity. Good to excellent cosmesis may be related to the addition of volume to the lumpectomy bed not seen with rearrangement of existing tissues.

Citation Format: Kaufman CS, Hall W, Behrndt V, Wolgamot G, Hill L, Zacharias K, Rogers A, Nix S, Schnell N. Use of a 3-D bioabsorbable tissue marker in 61 patients over two years [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P3-13-20.

Severe drug hypersensitivity reaction in a young woman treated with doxycycline

Doxycycline is a commonly prescribed medication for the management of acne vulgaris. Severe adverse reactions to this medication are uncommon. We describe an unusual case of a 20-year-old female who experienced a life-threatening hypersensitivity reaction, including fever, lymphadenopathy, hepatitis, nephritis and severe pneumonitis with respiratory failure following oral administration of doxycycline for facial acne.

Primary cutaneous neuroendocrine cell carcinoma (Merkel cell carcinoma) with prominent microcystic features, mimicking eccrine carcinoma

Although primary cutaneous neuroendocrine cell carcinoma [Merkel cell carcinoma (MCC)] may show divergent features, including microcystic ('tubuloglandular'), squamous, eccrine and rhabdomyoblastic, a diffuse microcystic pattern is exceedingly rare. In this study, we present two cases of MCC with prominent microcystic features, which precluded a definitive diagnosis in the initial punch biopsy. Both patients were middle-aged men with a history of rapidly growing plaques of the back or posterior neck. Punch biopsies from both patients revealed an infiltrating neoplasm with prominent microcystic features that mimick tubuloglandular structures, lined by hyperchromatic basaloid cells, which were strongly positive for chromogranin and BerEP4, variably positive for CK7 and CK5/6 and negative for CK20, synaptophysin, S-100, epithelial membrane antigen (EMA), gross cystic disease fluid protein-15 (GCDFP-15), estrogen/progesterone receptors (ER/PR), thyroid transcription factor 1 (TTF1) and carcinoembryonic antigen (CEA). The re-excision specimens showed a multifocal intra-epidermal component in one case and typical finely stippled nuclear chromatin in both cases. Although the lack of CK20 staining is unusual, the histologic characteristics along with the remaining immunohistochemical studies favor the diagnosis of a primary cutaneous neuroendocrine cell carcinoma over the variants of eccrine carcinoma or basal cell carcinoma with neuroendocrine differentiation. Our cases illustrate that prominent microcystic features, mimicking glandular differentiation, may occur in MCC and pose a diagnostic challenge in small biopsy specimens.

Unique Histopathologic Findings in a Patient With Adult-Onset Still Disease

Adult-onset Still disease (AOSD) is an uncommon disorder characterized by fever, polyarthralgia, elevated white blood cell count, and a maculopapular rash, the histologic features of which have not been well-known. A 55-year-old Asian woman presented initially with a "burning" and severely pruritic eruption on her face, hands, and arms, thought clinically to be urticaria. Within 1 month, she began spiking high fevers, developed diffuse joint pain, and had marked elevations of ferritin, C-reactive protein, and erythrocyte sedimentation rate, characteristic of AOSD. The cutaneous eruption became more widespread, involving the trunk, scalp, and remainder of the extremities, with diffuse thickening of the skin with papular and linear hyperpigmentation and accentuation. Biopsies from several locations showed focal hyperkeratosis associated with dyskeratotic keratinocytes with a peculiar, distinctive distribution in the upper epidermis and cornified layers. In addition, increased dermal mucin was present, with minimal fibroblast proliferation and inflammation. This unusual combination of diffuse dermal mucinosis and a unique pattern of dyskeratosis can present a challenge in generating an accurate differential diagnosis, and may represent an unusual response to chronic scratching or be a distinctive histologic manifestation of AOSD.

Replication of Mus dunni endogenous retrovirus depends on promoter activation followed by enhancer multimerization

Mus dunni endogenous virus (MDEV) is an apparently intact retrovirus that normally lies transcriptionally silent in cultured M. dunni cells, but the provirus can be activated by treatment of the cells with hydrocortisone or 5-iodo-2'-deoxyuridine. Sequence analysis of a molecular clone of the replicating virus revealed a simple retrovirus with a chimeric VL30/GALV-like structure. Interestingly, in the region of the long terminal repeat (LTR) that typically contains the retroviral transcription enhancers, we found over six 80-bp repeats with only a single mismatch, indicating that acquisition of the repeats was a recent event. Here we provide evidence for the following model of MDEV activation and replication. The MDEV provirus in M. dunni cells has a chimeric structure similar to that of the molecular clone but has only 1.15 copies of the 80-bp repeat sequence found in the molecular clone. Activating chemicals directly stimulate transcription from the LTR, allowing a low level of virus replication. Copying errors made during reverse transcription allow multimerization of the 80-bp enhancer region, resulting in viruses with higher transcriptional rates and improved fitness, but increased enhancer copy number is likely balanced by the natural instability of retroviral repeats and constraints imposed by virion packaging limits. The resultant population of replicating MDEV is widely heterogeneous, having from 2.15 to 13.15 enhancer repeats in the LTR. These results reveal a novel mechanism for regulation of transcription and replication of an endogenous retrovirus, in terms of both activation of the virus by the steroid hydrocortisone and the large number and variation in enhancer repeats observed.

Retrovirus packaging cells expressing the Mus dunni endogenous virus envelope facilitate transduction of CHO and primary hematopoietic cells

Mus dunni endogenous virus (MDEV) infects a wide variety of cell types from many different species. To take advantage of this broad host range, we have constructed packaging cells (PD223) that produce virions bearing the MDEV envelope. PD223 cells are able to package Moloney murine leukemia virus-based vectors at a titer of 4 x 10(5) infectious units per ml in the absence of contaminating replication-competent retrovirus. Vectors packaged by PD223 cells are able to transduce CHO cells, which are resistant to transduction by many retroviruses, at >/=25-fold higher efficiency than vectors having other pseudotypes. A vector packaged by PD223 was found to be among the most efficient for transducing primary baboon and human CD34(+) cells.

Sequence analysis of Mus dunni endogenous virus reveals a hybrid VL30/gibbon ape leukemia virus-like structure and a distinct envelope

Mus dunni endogenous virus (MDEV) can be activated from M. dunni cells by exposing the cells to hydrocortisone or 5-iodo-2'-deoxyuridine. Interference analysis has revealed that MDEV uses a receptor for cell entry that is different from those used by other murine retroviruses. The entire genome has now been sequenced, revealing a long terminal repeat (LTR)-gag-pol-env-LTR structure typical of simple retroviruses of the murine leukemia virus genus, with no additional open reading frames between env and the 3' LTR. The LTRs and other noncoding regions of MDEV are most closely related to those of VL30 elements, while the majority of the coding sequences are most closely related to those of gibbon ape leukemia virus. MDEV represents the first example of a naturally occurring, replication-competent virus with sequences closely related to VL30 elements. The U3 region of MDEV contains six nearly perfect 80-bp repeats and the beginning of a seventh, and the region expected to contain the packaging sequence contains approximately four imperfect 33-bp repeats. The receptor specificity domains of the envelope are unique among retroviruses and show no apparent similarity to regions of known proteins.

Molecular cloning of Mus dunni endogenous virus: an unusual retrovirus in a new murine viral interference group with a wide host range

Mus dunni endogenous virus (MDEV) is activated from cells of the Asian wild mouse M. dunni (also known as Mus terricolor) in response to treatment with either 5-iodo-2'-deoxyuridine or hydrocortisone. MDEV represents a new murine retrovirus interference group and thus appears to use a different receptor for entry into cells than do other murine retroviruses. Here we show that MDEV is also not in the gibbon ape leukemia virus or RD114 virus interference groups. A retroviral vector with an MDEV pseudotype was capable of efficiently infecting a wide variety of cells from different species, indicating that the MDEV receptor is widely expressed. We isolated a molecular clone of this virus which exhibited no hybridization to any cloned retrovirus examined, suggesting that MDEV has an unusual genome. One copy of a possible retrovirus element that weakly hybridized with MDEV was present in the genomes of laboratory strains of mice, while no such elements were present in other species examined. A virus activated by 5-iodo-2'-deoxyuridine from cells of a BALB/c mouse, however, was not related to MDEV by either hybridization or interference analyses.

Murine retroviruses use at least six different receptors for entry into Mus dunni cells

Murine retroviruses have been divided into six interference groups that use different receptors for cell entry: the ecotropic, xenotropic, polytropic, amphotropic, 10A1, and Mus dunni endogenous virus groups. Some interference is observed between xenotropic and polytropic viruses and between amphotropic and 10A1 viruses, indicating some overlap in receptor specificity between these groups, but otherwise these interference groups appear completely independent. In contrast, one study found interference among many of these groups when Mus dunni wild mouse cells were examined with an immunofluorescence assay to detect infection by the challenge virus. Here we have used a more direct assay for cell entry by using pseudotyped retroviral vectors to measure interference in M. dunni cells, and we find no evidence for extensive interference between members of different murine retrovirus groups. Indeed, our results in M. dunni cells are consistent with interference results observed in other cell types and indicate that the anomalous interference results previously observed in M. dunni cells with the immunofluorescence assay were most likely due to factors other than those that affect receptor-mediated virus entry. In summary, our results show that murine retroviruses use at least six different receptors for entry into M. dunni cells.

A novel murine retrovirus identified during testing for helper virus in human gene transfer trials

An important requirement for the use of retroviral vectors in human gene transfer experiments is the avoidance of human exposure to replication-competent (helper) retroviruses. To meet this requirement, we used a sensitive marker rescue assay for helper virus to screen vector-transduced cells prior to reinfusion into patients. This assay utilized Mus dunni cells harboring a retroviral vector that can be rescued by helper retroviruses. The assay indicated the presence of helper virus in medium exposed to hematopoietic cells from all patients tested, including six patients with various cancers and one patient with Gaucher's disease, whether or not the patient cells had been exposed to retroviral vectors. All of the helper viruses were in a single interference group. We have now shown that treatment of the M. dunni marker rescue assay cells with 5-iodo-2'-deoxyuridine or hydrocortisone can activate production of an apparently identical helper virus, which we have named M. dunni endogenous virus (MDEV). Thus, production of virus in the assays of patient materials was likely due to exposure of the marker rescue assay cells to the hydrocortisone present in the hematopoietic cell growth medium. MDEV does not belong to any of the known murine leukemia virus groups by interference analysis, and we have called the new group multitropic because of the wide range of cells from different species that MDEV can infect.