Vaccination during myeloid cell depletion by cancer chemotherapy fosters robust T cell responses.

Therapeutic vaccination with human papillomavirus type 16 synthetic long peptides (HPV16-SLPs) results in T cell-mediated regression of HPV16-induced premalignant lesions but fails to install clinically effective immunity in patients with HPV16-positive cervical cancer. We explored whether HPV16-SLP vaccination can be combined with standard carboplatin and paclitaxel chemotherapy to improve immunity and which time point would be optimal for vaccination. This was studied in the HPV16 E6/E7-positive TC-1 mouse tumor model and in patients with advanced cervical cancer. In mice and patients, the presence of a progressing tumor was associated with abnormal frequencies of circulating myeloid cells. Treatment of TC-1-bearing mice with chemotherapy and therapeutic vaccination resulted in superior survival and was directly related to a chemotherapy-mediated altered composition of the myeloid cell population in the blood and tumor. Chemotherapy had no effect on tumor-specific T cell responses. In advanced cervical cancer patients, carboplatin-paclitaxel also normalized the abnormal numbers of circulating myeloid cells, and this was associated with increased T cell reactivity to recall antigens. The effect was most pronounced starting 2 weeks after the second cycle of chemotherapy, providing an optimal immunological window for vaccination. This was validated with a single dose of HPV16-SLP vaccine given in this time window. The resulting proliferative HPV16-specific T cell responses were unusually strong and were retained after all cycles of chemotherapy. In conclusion, carboplatin-paclitaxel therapy fosters vigorous vaccine-induced T cell responses when vaccination is given after chemotherapy and has reset the tumor-induced abnormal myeloid cell composition to normal values.

The need for improvement of the treatment of advanced and metastatic cervical cancer, the rationale for combined chemo-immunotherapy.

The prognosis of patients with metastatic cervical cancer is poor with a median survival of 8-13 months. Despite the potency of chemotherapeutic drugs, this treatment is rarely curative and should be considered palliative only. The last decades, targeted therapies such as immunotherapy have emerged as an attractive option for the treatment of these patients. Immunotherapy can consist of different modalities such as monoclonal antibodies, adoptive lymphocyte transfer and vaccines, which all are intended to augment the antitumor immune responses in cancer patients. The available evidence indicates that both active and adoptive immunotherapeutical strategies are quite effective against small tumor burdens, but are usually insufficient to eradicate the disease in patients with advanced stages of different kinds of cancer, despite strong induction of tumor-specific immune responses. Although chemotherapy and immunotherapy have not shown to be curative as single modalities, accumulating evidence suggests that combinations of these treatments hold potential for improved clinical outcomes in advanced stages of cancer. Therefore, the combination of chemotherapy and immunotherapy is no longer considered incompatible, because of the emerging insight that certain chemotherapy-based cancer treatments may activate the immune system against the tumor through several molecular and cellular mechanisms. Chemotherapeutic agents and immunotherapy may thus be synergistic and enhance the clinical response. In this review, we show the rationale for combined chemo-immunotherapeutic strategies, and summarize recent data from clinical trials performed in patients with different types of cancer. Challenges such as the selection of the optimal dose and treatment schedule, will be discussed as well as the identification of immune-specific biomarkers. Furthermore, we evaluated the long-term clinical outcomes of patients with advanced cervical cancer treated with HPV16 E6/E7 SLP vaccination with or without chemotherapy. Finally, the future of vaccination therapy in combination with chemotherapy for the treatment of cervical cancer is discussed.

Right ventricular outflow tract reconstruction with the bovine jugular vein graft: 5 years' experience with 133 patients.

BACKGROUND: We analyzed the results in two centers of using bovine jugular vein graft for right ventricular outflow tract reconstruction. METHODS: From April 1999 to July 2005, 133 children with a median age of 30.9 months (range, 4 days to 19 years) underwent graft implantation. Echocardiography was performed during follow-up and retrospectively reviewed. RESULTS: Nongraft-related early mortality occurred in 8 patients. Late mortality occurred in 11 patients, 2 late deaths were graft related (endocarditis). Median follow-up was 31.6 months (range, 1 to 73). Twelve patients received a new graft, because of endocarditis (3), distal pulmonary artery branch stenosis (4), graft obstruction caused by fibrosis (4), or thrombosis (1). Echocardiography Doppler studies showed good conduit function, with 92% of the patients having absent, trivial, or only mild valve regurgitation at last follow-up. A moderate degree of conduit stenosis due to external compression was observed in 2 patients. Twenty-five patients with otherwise intact conduits had hemodynamically significant distal stenosis. In most cases, the pulmonary branch stenosis was related to preoperative small pulmonary arteries and young age at operation. At 31.6 months, significant graft dilatation was observed in 4 grafts and was related to pulmonary artery branch obstruction or pulmonary hypertension. Calcification did not occur in 5 years time. Survival was 85.7%, freedom from conduit explantation was 91%, and freedom from intervention for pulmonary artery branch stenosis was 80% after 5 years. CONCLUSIONS: The bovine jugular vein graft is a valuable right ventricular outflow tract conduit, but younger age and small pulmonary arteries increase the risk of distal conduit stenosis.