Ex-vivo assessment of drug response on breast cancer primary tissue with preserved microenvironments.

Interaction between cancerous, non-transformed cells, and non-cellular components within the tumor microenvironment plays a key role in response to treatment. However, short-term culture or xenotransplantation of cancer specimens in immunodeficient animals results in dramatic modifications of the tumor microenvironment, thus preventing reliable assessment of compounds or biologicals of potential therapeutic relevance. We used a perfusion-based bioreactor developed for tissue engineering purposes to successfully maintain the tumor microenvironment of freshly excised breast cancer tissue obtained from 27 breast cancer patients and used this platform to test the therapeutic effect of antiestrogens as well as checkpoint-inhibitors on the cancer cells. Viability and functions of tumor and immune cells could be maintained for over 2 weeks in perfused bioreactors. Next generation sequencing authenticated cultured tissue specimens as closely matching the original clinical samples. Anti-estrogen treatment of cultured estrogen receptor positive breast cancer tissue as well as administration of pertuzumab to a Her2 positive breast cancer both had an anti-proliferative effect. Treatment with anti-programmed-death-Ligand (PD-L)-1 and anti-cytotoxic T lymphocyte-associated protein (CTLA)-4 antibodies lead to immune activation, evidenced by increased lymphocyte proliferation, increased expression of IFNγ, and decreased expression of IL10, accompanied by a massive cancer cell death in ex vivo triple negative breast cancer specimens. In the era of personalized medicine, the ex vivo culture of breast cancer tissue represents a promising approach for the pre-clinical evaluation of conventional and immune-mediated treatments and provides a platform for testing of innovative treatments.

Assessment of CD37 B-cell antigen and cell of origin significantly improves risk prediction in diffuse large B-cell lymphoma.

CD37 (tetraspanin TSPAN26) is a B-cell surface antigen widely expressed on mature B cells. CD37 is involved in immune regulation and tumor suppression but its function has not been fully elucidated. We assessed CD37 expression in de novo diffuse large B-cell lymphoma (DLBCL), and investigated its clinical and biologic significance in 773 patients treated with rituximab plus cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP) and 231 patients treated with CHOP. We found that CD37 loss (CD37-) in ∼60% of DLBCL patients showed significantly decreased survival after R-CHOP treatment, independent of the International Prognostic Index (IPI), germinal center B-cell-like (GCB)/activated B-cell-like (ABC) cell of origin, nodal/extranodal primary origin, and the prognostic factors associated with CD37-, including TP53 mutation, NF-κBhigh, Mychigh, phosphorylated STAT3high, survivinhigh, p63-, and BCL6 translocation. CD37 positivity predicted superior survival, abolishing the prognostic impact of high IPI and above biomarkers in GCB-DLBCL but not in ABC-DLBCL. Combining risk scores for CD37- status and ABC cell of origin with the IPI, defined as molecularly adjusted IPI for R-CHOP (M-IPI-R), or IPI plus immunohistochemistry (IHC; IPI+IHC) for CD37, Myc, and Bcl-2, significantly improved risk prediction over IPI alone. Gene expression profiling suggested that decreased CD20 and increased PD-1 levels in CD37- DLBCL, ICOSLG upregulation in CD37+ GCB-DLBCL, and CD37 functions during R-CHOP treatment underlie the pivotal role of CD37 status in clinical outcomes. In conclusion, CD37 is a critical determinant of R-CHOP outcome in DLBCL especially in GCB-DLBCL, representing its importance for optimal rituximab action and sustained immune responses. The combined molecular and clinical prognostic indices, M-IPI-R and IPI+IHC, have remarkable predictive values in R-CHOP-treated DLBCL.

Detailed assessment of microvasculature markers in non-small cell lung cancer reveals potentially clinically relevant characteristics.

Tumor angiogenesis is important for the progression of cancer and is orchestrated by various factors associated with tumor vessels, tumor cells, and stromal cells. Angiogenic signaling in non-small cell lung cancer (NSCLC) needs to be further clarified, especially regarding existing and upcoming therapeutic approaches. Expression of CD34, CD105, Mel-CAM, VE-cadherin, D2-40, VEGF, VEGFR1, and VEGFR2 was assessed immunohistochemically on a cohort of 371 well documented, surgically resected NSCLC using a standardized tissue microarray platform. Extensive clinical data and a postoperative follow-up period of up to 18 years allowed us to assess clinicopathological correlations in detail. Microvasculature in NSCLC was significantly denser at the tumor periphery as compared to the tumor center. Squamous cell carcinomas (SCC) were associated with a notably lower microvessel density (MVD) than adenocarcinomas (ACA). CD105 was present at significantly higher levels on stromal cells of ACA as compared to SCC. Expression of VE-cadherin by tumor cells (6% of cases, mainly ACA) as well as decreased MVD in the tumor centers was independently associated with poor prognosis in the entire cohort. Low MVD in SCC might be related to lower efficacy of and fatal bleeding during therapy with bevacizumab. In other NSCLC entities for which treatment with VEGF inhibitors is studied in clinical trials, the predictive value of MVD for therapy response merits to be prospectively examined. Our data suggest that patients with ACA may be candidates for therapies targeting CD105. VE-cadherin is another promising target for therapy, but its expression also provides independent prognostic information.