Developing effective cancer vaccines: design and monitoring are critical

Tumor-infiltrating lymphocytes, tumor characteristics, and recurrence in patients with early breast cancer

BACKGROUND

The balance in the immune system between immune surveillance against non-self-antigens and tolerance of self-antigens is known to be associated with the prognosis of breast cancer patients. However, immunologic signals in tumor microenvironment according to biological characteristics of cancer cells have not been clearly elucidated. CD4(+) T cells, CD8(+) T cells, and forkhead box P3-positive (Foxp3) regulatory T cells (Tregs) are the main keys for immune surveillance and tolerance, respectively. We evaluated the correlations between the immunologic balance and tumor characteristics and their impact on recurrence.

PATIENTS AND METHODS

CD8(+) T cells and Foxp3(+) Tregs were detected by immunohistochemistry using the paraffin-embedded tumor samples from the 72 patients with early stage (I to III) breast cancer. Clinicopathologic data including tumor size and grade, lymph node metastasis, stage, patient's age, expression status of estrogen receptor (ER), progesterone receptor, p53, Ki-67, and human epidermal growth factor receptor-2/neu, and recurrence were reviewed.

RESULTS

The decreased number of CD8(+) T cells was significantly associated with tumors with lymph node metastasis (P=0.027), higher stage (stage III, P=0.013), and immunopositivity of Ki-67 (P=0.026). In contrast, the increased number of Foxp3(+) Tregs was significantly correlated with tumors with lymph node metastasis (P=0.027), immunopositivity for p53 (P=0.026), and positive for Ki-67 (P<0.001). There were significant correlations between the increased Foxp3(+) Treg/CD4(+) T-cell ratio and lymph node metastasis (P=0.011), the expression of ER (P=0.023), and immunopositivity of p53 (P=0.031) and Ki-67 (P= 0.003). Of note, lower Foxp3(+) Treg/CD4(+) T-cell ratio was significantly associated with triple-negative breast cancer (P=0.004). Disease-free survival of analyzed patients was significantly associated with the number of Foxp3(+) Tregs (dichotomized by a cutoff point of 17, P= 0.014) only. Univariate analysis indicated that tumor grade (P=0.017), the expression of ER (P=0.032), and non-triple-negative breast cancer (P=0.022) were independent prognostic factors for disease-free survival.

CONCLUSIONS

Our data showed that lymph node metastases, immunopositivity of p53 and Ki67, and non-triple-negative tumors were associated with high regulatory T-cell infiltration. The role of immunologic balance as a prognostic marker for recurrence must be evaluated more clearly in the future study.

Current advances, problems and prospects for vaccine-based immunotherapy in follicular non-Hodgkin's lymphoma

Despite advances in chemotherapy, radiotherapy and combined modality treatment, a significant proportion of non-Hodgkin's lymphomas remain incurable. The disease usually responds well to chemotherapy or radiation, but relapses are observed within months to a few years, with frequent failure of subsequent therapies. High-dose chemotherapy with or without radiation and autologous or allogeneic hematopoietic stem cell transplantation provide higher cure rates and longer remissions in certain patients with aggressive lymphomas. However, the higher treatment-related morbidity and mortality of high-dose chemotherapy has driven a search for new and more tumor-specific treatment modalities, such as immunotherapy. Tumor antigens expressed by B-cell lymphomas, such as the "idiotype antigen", are seen as unique and specific target molecules for direct lymphoma immunotherapy. This review will delineate advances, problems and prospects for approaches to anti-B cell lymphoma immunotherapy where pre-clinical studies and proof of principle have been directly translated to patient care.

FOXP3+ Tregs and B7-H1+/PD-1+ T lymphocytes co-infiltrate the tumor tissues of high-risk breast cancer patients: Implication for immunotherapy

BACKGROUND

Recent studies have demonstrated a direct involvement of B7-H1, PD-1 and FOXP3 molecules in the immune escape of cancer. B7-H1 is an inhibitory molecule that binds to PD-1 on T lymphocytes, while FOXP3 is a marker for regulatory T cells (Tregs). We have previously demonstrated the association of B7-H1-expressing T infiltrating lymphocytes (TIL) with high-risk breast cancer patients while other studies reported the involvement of FOXP3+ Tregs as a bad prognostic factor in breast tumors. Although the co-existence between the two types of cells has been demonstrated in vitro and animal models, their relative infiltration and correlation with the clinicopathological parameters of cancer patients have not been well studied. Therefore, we investigated TIL-expressing the B7-H1, PD-1, and FOXP3 molecules, in the microenvironment of human breast tumors and their possible association with the progression of the disease.

METHODS

Using immunohistochemistry, tumor sections from 62 breast cancer patients were co-stained for B7-H1, PD-1 and FOXP3 molecules and their expression was statistically correlated with factors known to be involved in the progression of the disease.

RESULTS

A co-existence of B7-H1+ T lymphocytes and FOXP3+ Tregs was evidenced by the highly significant correlation of these molecules (P < .0001) and their expression by different T lymphocyte subsets was clearly demonstrated. Interestingly, concomitant presence of FOXP3+ Tregs, B7-H1+ and PD-1+ TIL synergistically correlated with high histological grade (III) (P < .001), estrogen receptor negative status (P = .017), and the presence of severe lymphocytic infiltration (P = .022).

CONCLUSION

Accumulation of TIL-expressing such inhibitory molecules may deteriorate the immunity of high-risk breast cancer patients and this should encourage vigorous combinatorial immunotherapeutic approaches targeting Tregs and B7-H1/PD-1 molecules.

The B7-H1 (PD-L1) T lymphocyte-inhibitory molecule is expressed in breast cancer patients with infiltrating ductal carcinoma: correlation with important high-risk prognostic factors

B7-H1 molecule increases the apoptosis of tumor-reactive T lymphocytes and reduces their immunogenicity. Breast cancer is the second most common cause of mortality after lung cancer. Direct evidence linking B7-H1 with cancer has been shown in several malignancies; however, its expression in breast cancer has not been investigated. We used immunohistochemistry to investigate the expression of the B7-H1 molecule in 44 breast cancer specimens and to study its correlation with patients' clinicopathological parameters. The expression of B7-H1 was shown in 22 of 44 patients and was not restricted to the tumor epithelium (15 of 44, 34% in tumor cells), but was also expressed by tumor-infiltrating lymphocytes (TIL; 18 of 44, 41%). Interestingly, intratumor expression of B7-H1 was significantly associated with histologic grade III-negative (P = .012), estrogen receptor-negative (P = .036), and progesterone receptor-negative (P = .040) patients. In addition, the expression of B7-H1 in TIL was associated with large tumor size (P = .042), histologic grade III (P = .015), positivity of Her2/neu status (P = .019), and severe tumor lymphocyte infiltration (P = .001). Taken together, these data suggest that B7-H1 may be an important risk factor in breast cancer patients and may represent a potential immunotherapeutic target using monoclonal antibody against the B7-H1 molecule.

Overview of the clinical efficacy of investigational anticancer drugs

The purpose of this overview was to make a broad inventory of investigational drugs for medicinal cancer treatment and, specifically, to indicate the evidence of clinical efficacy. Information was retrieved from electronic database searches in Medline and CANCERLIT and relevant published reviews. As the most recent findings are first reported as conference abstracts, an important basis for identification of new drugs and clinical results was a hand search of 13,392 abstracts from five major recent cancer conferences. A total of 209 investigational approaches or drugs were identified and classified into one of eight groups according to proposed mechanism of action. For 28 drugs/approaches survival data were available from randomized controlled trials. Statistically significant benefit was observed for only 12. In earlier phases no or modest anticancer activity was reported. It is speculated that the expanding knowledge in tumour biology might not easily translate into new substantially better anticancer drugs.