Sorafenib, but not sunitinib, induces regulatory T cells in the peripheral blood of patients with metastatic renal cell carcinoma.

Induction of regulatory T cells (Treg) is an important mechanism leading to tolerance against tumors. Increased levels of Treg have been described in renal cell carcinoma (RCC) patients and seem to correlate with an adverse outcome. Our study aimed to analyze the influence of sorafenib and sunitinib on the frequency of Treg in patients with metastatic RCC (mRCC). Treg were analyzed by flow cytometry in the peripheral blood (PB) of patients (n=19) with histologically confirmed mRCC under treatment with either sunitinib (50 mg/d, n=11) or sorafenib (800 mg/d, n=8). Blood samples were taken before treatment and during the first, second, and third months of therapy. Flow cytometric analysis of PB mononuclear cells was performed using fluorochrome-labeled antibodies against CD3, CD4, CD25, and FOXp3. During the first month of therapy, patients treated with sorafenib showed a significant increase in FOXp3CD3CD4CD25 Treg (13.5 vs. 36.3% of gated cells, P=0.02, or 0.35 vs. 0.49% of total cells) and the ratio FOXp3 T cells/FOXp3 T cells (0.16 vs. 0.56 of gated cells, P=0.02). These elevated levels persisted throughout the treatment period. There was no influence of sunitinib on the frequency of Treg in our cohort of patients. Sorafenib, but not sunitinib, leads to an early and sustained increase in Treg in PB of mRCC patients. In immunoresponsive tumors such as RCC, immunological effects of kinase inhibitors are particularly relevant for the design of combination trials with immunotherapeutic agents. Our study suggests that sorafenib should be avoided in such a therapeutic setting.

Nilotinib for the treatment of chronic myeloid leukemia.

The introduction of targeted therapy has revolutionized the treatment of chronic myeloid leukemia (CML). The pivotal role of the Philadelphia chromosome, resulting from the breakpoint cluster region-Abelson (BCR-ABL) translocation, led to the development of imatinib mesylate, a tyrosine kinase inhibitor with significant activity against the BCR-ABL oncoprotein. Unprecedented clinical activity in CML led to rapid approval and established first-line therapy with imatinib mesylate as the standard of care in most patients. However, the occurrence of imatinib resistance or intolerance has sparked the development of newer drugs with increased activity or specificity. Nilotinib is a second-generation tyrosine kinase inhibitor that has been rationally designed on the basis of imatinib. An overview is given on clinical results in imatinib-resistant or -intolerant patients that led to its current approval as second-line therapy for the chronic and accelerated phases of CML. Future studies will address the role of nilotinib as first-line therapy, in combination strategies and in the context of specific BCR-ABL mutations.

Genetic dissection of apoptosis and cell cycle control in response of colorectal cancer treated with preoperative radiochemotherapy.

BACKGROUND: In previous analyses we identified therapy-induced upregulation of the CDK inhibitor p21CIP/WAF-1 and consequently decreased tumor cell proliferation or loss of Bax as adverse factors for survival in rectal cancer treated with radiochemotherapy. Here, we address the individual role of p53 and its transcriptional targets, p21CIP/WAF-1 and Bax, on apoptosis induced by individual components of multimodal anticancer therapy, i.e. 5-fluorouracil (5-FU), ionising gamma-radiation (IR) and heat shock/hyperthermia. METHODS: We analysed tumor samples 66 patients with rectal carcinoma treated by a neoadjuvant approach with radiochemotherapy +/- heat shock/hyperthermia for the expression and mutation of p53 and the expression of p21CIP/WAF-1 and Bax. These data were correlated with the tumor response. The functional relevance of p53, p21CIP/WAF-1 and Bax was investigated in isogeneic HCT116 cell mutants treated with 5-FU, IR and heat shock. RESULTS: Rectal carcinoma patients who received an optimal heat shock treatment showed a response that correlated well with Bax expression (p = 0.018). Local tumor response in the whole cohort was linked to expression of p21CIP/WAF-1 (p < 0.05), but not p53 expression or mutation. This dichotomy of p53 pathway components regulating response to therapy was confirmed in vitro. In isogeneic HCT116 cell mutants, loss of Bax but not p53 or p21CIP/WAF-1 resulted in resistance against heat shock. In contrast, loss of p21CIP/WAF-1 or, to a lesser extent, p53 sensitized predominantly for 5-FU and IR. CONCLUSION: These data establish a different impact of p53 pathway components on treatment responses. While chemotherapy and IR depend primarily on cell cycle control and p21, heat shock depends primarily on Bax. In contrast, p53 status poorly correlates with response. These analyses therefore provide a rational approach for dissecting the mode of action of single treatment modalities that may be employed to circumvent clinically relevant resistance mechanisms in rectal cancer.

Adjuvant chemotherapy with folinic acid and 5-fluorouracil in patients with locally advanced rectal cancer previously treated by preoperative radiochemotherapy and curative tumor resection.

BACKGROUND AND AIMS: The role of postoperative adjuvant chemotherapy in patients with rectal cancer pretreated by preoperative radiochemotherapy (RCT) and curative surgery is still poorly investigated. PATIENTS AND METHODS: We pooled data from both arms of a phase III trial in which patients with locally advanced (T3/4) rectal cancer were randomized to preoperative RCT alone or combined with pelvic radio-frequency hyperthermia. After surgery, R0-resected patients were scheduled to adjuvant chemotherapy with four monthly courses of 50 mg folinic acid (FA) and gradually escalated 5-fluorouracil (5-FU, 350-500 mg/m2, days 1-5). Reasons preventing initiation of chemotherapy and treatment-related toxicities were evaluated. Patients' characteristics and survival parameters were compared between the treated and untreated patient groups. RESULTS: Out of 93 patients, 73 (79%) started adjuvant chemotherapy, whereas 19 (21%) did not, mostly due to perioperative complications and refusal. Chemotherapy-related toxicities were mild to moderate in most cases, but--together with protracted postoperative complications--prevented the intended dose escalation of 5-FU in 71% of patients. Distant-failure-free (p=0.03) and overall survival (p=0.03) were improved in the chemotherapy group, although there was a negative selection of patients with unfavourable characteristics into the untreated patient group. INTERPRETATION/CONCLUSION: Adjuvant chemotherapy using FA and 5-FU can be safely applied to the majority of patients with rectal cancer pretreated by RCT and surgery. Survival data are not suitable to allow far-reaching conclusions, but are in line with suggestions of a favourable effect of adjuvant chemotherapy in these patients.