Examination of Immune Competence in Breast Cancer Patients at Six Months Post Surgery and Adjuvant Therapy through Assessment of T Cell and Dendritic Cell Functionality

It has long been known that immune suppression is induced by the presence of a tumor, resulting in compromised T cell and dendritic cell (DC) functionality. What is not well understood is how soon the immune system recovers normal functionality following surgical removal of tumors and adjuvant therapy. This timing is of critical importance, as the effectiveness of therapeutic immune strategies relies on optimal presentation of antigens and activation of T cells. Blood from breast cancer patients was collected prior to surgery and at 3 and 6 months post adjuvant therapy. Patients were treated with surgery (breast conservation or mastectomy) and chemotherapy (CT) (n=22) or surgery without chemotherapy (n=38). Most patients had radiation therapy (RT). Blood from 22 healthy woman of similar age served as controls. T cell functionality (TCF) was determined following stimulation with plate-bound anti-CD3 (1 µg/ml) and anti-CD28 (0.5 µg/ml) and proliferation was measured by 3H-thymidine uptake. DC functionality (DCF) was determined by ability to present allo-antigens in a mixed lymphocyte reaction. Values for the normal samples determined the normal ranges (NR). Responses were grouped into 4 categories based on their status at 6 months: Group 1 - remained in NR; Group 2 - climbed into NR; Group 3 - remained below NR; Group 4 - fell below NR. Analysis of immunosuppression will be based on lymphocyte subsets, cytokine, COX-2, and PGE2 metabolite levels.T Cell Proliferation AllWith CTNo CT N=60N=22N=38Group 120%14%24%Group 223%23%24%Group 338%41%37%Group 418%23%16% DC Function AllWith CTNo CT N=58N=20N=38Group 143%35%47%Group 219%25%16%Group 317%15%18%Group 421%25%18% Forty-three percent of patients had normal levels (Groups 1 and 2) for TCF and 62% for DCF by 6 months post adjuvant therapy, suggesting that breast cancer patients are potentially amenable to vaccine therapy. 28% of patients had both TCF and DCF in NR; 50% had either TCF or DCF in NR; and 22% had neither in NR. The percentage of patients who had TCF in NR by adjuvant therapy was: 35% CT+RT (6/17); 33% CT (1/3); 52% (17/33) RT; and 20% (1/5) neither. The percentage of patients who had DCF in NR by adjuvant therapy was: 67% (10/15) CT+RT; 33% (1/3) CT; 67% (22/33) RT; and 40% (2/5) neither. Proper understanding of the effects of tumor, chemotherapy and radiation therapy on immune function, especially the effects on T cells and DCs, may enable us to identify the appropriate patients in whom to study immunotherapy approaches in women with early breast cancer and to examine strategies to counteract cancer-related defects in immune function. (supported by P50CA116201)

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 4131.

Identification of targetable cellular subsets within melanoma tumors

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Background: Human tumors, including melanoma, are complex mixtures of individual, molecularly distinct subpopulations, or clones of cancer cells. Effective cancer therapy will likely require targeting of all tumor subsets within a given cancer. Understanding the tumor complexity and the ability to identify points of therapeutic vulnerability within the individual tumor subsets will be essential for development of effective personalized cancer therapies. Methods: We have developed an approach that combines identification of individual tumor subsets using a multiparameter nuclear flow cytometry coupled with a high-resolution genomic analysis using the array-based comparative genomic hybridization (aCGH). Melanoma nuclei were isolated from tumor tissues and subjected to flow cytomery using melanocyte-specific antibodies (to separate melanoma cells from stroma) and DNA content, to separate individual tumor subpopulations. DNA extracted from isolated nuclear subpopulations was extracted and analyzed by aCGH. This approach was adopted for both fresh-frozen and paraffin-embedded clinical specimens. Results: We initially demonstrate the feasibility of the outlined approach by successful separation of melanoma from stromal nuclei and separation of individual melanoma nuclear subpopulations by DNA content. aCGH analysis of the DNA derived from isolated tumor subpopulations allowed successful identification of potentially targetable molecular aberrations in individual subsets of tumor cells. Notably, such aberrations were often not detected in unsorted, bulk tumors analyzed by the same high-resolution aCGH approach. Conclusions: We demonstrate a feasible approach to in-depth molecular analysis of tumor subpopulations within a clinical cancer tissue. This approach allows identification of potentially targetable molecular aberrations within individual tumor subsets, thus opening a possibility for a broad tumor targeting through design of individually-tailored therapeutic approaches.

No significant financial relationships to disclose.

Granulocyte macrophage colony stimulating factor as adjuvant therapy for resected stage III/IV melanoma: Retrospective review of a single institutional experience

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Background: Preliminary data suggesting positive clinical outcome in patients treated with adjuvant granulocyte macrophage colony stimulating factor (GM-CSF) following surgical resection of stage III/IV melanoma already exist (Spitler et al). A compassionate use protocol for the treatment of such patients with the “Spitler” regimen (GM-CSF administered at 250 mcg/day s.c. for 14 days of a 28 day cycle) has been ongoing at Mayo Clinic. Herein we present a retrospective review. Methods: Between 1998 and 2006, data was collected from 30 patients rendered disease free by surgery who received adjuvant GM-CSF. GM-CSF was administered per the “Spitler” regimen, although one patient received a reduced dose of 125mcg/day. The Kaplan-Meier approach was used to estimate relapse free survival. Results: Thirty patients (14 Female) with a median age of 53 and excellent performance status were evaluated. Most patients had resected stage III melanoma (Stage II/III/IV: 1/20/9). Median followup was 33 months (3–96). Twenty one patients were treated with GM-CSF for at least 12 months. Overall, relapse-free survival at 1 year was estimated to be 69% (95% confidence interval (CI) of 54% to 88%), reducing to 44% (95% CI of 29% to 67%) at 3 years. According to stage, relapse free survival at 1 year was 70% (III) and 63% (IV), and at 3 years was 54% (III), and 13% (IV). Among the 21 patients completing at least 1 year of therapy, relapse free survival at 3 years was 52%. Seventeen patients relapsed (III/IV: 10/7). Six of these patients were retreated and only two relapsed. Toxicities were grade 1 with most common being injection site rash (23%), asthenia (17%), myalgia (17%), and fever (7%). One patient required dose modification for elevated liver function tests. Conclusions: Although limited in scope, our data further support a potential beneficial effect of adjuvant GM-CSF in resected stage III/IV melanoma. Recurrences in the treated population were often localized and amenable to further surgical treatment. The clinical relevance of this strategy is currently being prospectively tested (E4697, now closed to accrual).

No significant financial relationships to disclose.