Response evaluation and long-term follow-up

Lymphopenia during routine follow-up may predict relapse in patients with extranodal NK/T cell lymphoma

Recently, absolute lymphocyte count (ALC) at diagnosis, as a surrogate marker of host immunity, has been reported to be a prognostic factor for clinical outcomes in extranodal NK/T cell lymphoma (ENKTL). In this retrospective study, we set out to investigate whether ALC at the time of confirmed relapse or at last follow-up is a marker for relapse after chemoradiotherapy in 84 patients with stage I/II ENKTL. Receiver operating characteristics (ROC) curve and area under the curve (AUC) analysis showed that ALC at follow-up was a significant marker for relapse (AUC = 0.883, P < 0.001). Using 1.215 × 10(9)/L as the optimal cutoff value of ALC, 44 patients (52.4%) were in lower ALC group and 40 patients (47.6%) were in higher ALC group. The sensitivity and specificity for ALC at the time of confirmed relapse or at last follow-up was 94.1 and 76.0%, respectively. The relative risk of relapse with an ALC < 1.215 × 10(9)/L was 14.5. The positive predictive value with an ALC < 1.215 × 10(9)/L was 72.7%, and the negative predictive value with an ALC ≥ 1.215 × 10(9)/L was 95.0%. The 4-year cumulative incidence rate for an ALC < 1.215 × 10(9)/L was 73.2% compared with 3.2% for an ALC ≥ 1.215 × 10(9)/L (P < 0.001). In a multivariate regression analysis, ALC at the time of confirmed relapse or last follow-up remained to be a significant factor for relapse (P < 0.001). In conclusion, lymphopenia observed during routine follow-up can predict relapse in patients with ENKTL, which needs further validation in prospective trials.

Lymphopenia assessed during routine follow-up after immunochemotherapy (R-CHOP) is a risk factor for predicting relapse in patients with diffuse large B-cell lymphoma

A specific predictor during routine follow-up to ascertain risk for relapse after standard chemotherapy in non-Hodgkin's lymphoma (NHL) has not been identified. Thus, we studied absolute lymphocyte count (ALC) as a marker of poststandard chemotherapy (rituximab, cyclophosphamide, adriamycin, vincristine and prednisone (R-CHOP)) NHL relapse in patients with diffuse large B-cell lymphoma (DLBCL). ALC was obtained at the time of confirmed relapse and at last follow-up. From 2000 until 2006, 149 consecutive DLBCL patients, originally diagnosed, treated with R-CHOP and followed up at Mayo Clinic, Rochester, were included in this study. Patients at last follow-up without relapse (N=112) had a higher ALC compared with those with relapsed lymphoma ((N=37) median ALC x 10(9)/l of 1.43 (range: 0.33-4.0) versus 0.67 (range: 0.18-1.98), P<0.0001, respectively). ALC at the time of confirmed relapse was a strong predictor for relapse with an area under the curve =0.91 (P<0.0001). An ALC <0.96 x 10(9)/l at the time of confirmed relapse had a positive predictive value of 72% and a positive likelihood ratio of 7.4 to predict relapse after R-CHOP in DLBCL. Patients with an ALC>or=0.96 x 10(9)/l (N=103) had a cumulative incidence of relapse of 6 versus 79% with an ALC <0.96 x 10(9)/l (N=46) (P<0.0001). This study suggests that lymphopenia measured by ALC can be used as a marker to assess risk of DLBCL relapse during routine follow-up after standard chemotherapy.

Drug insight: antiangiogenic therapies for gastrointestinal cancers--focus on monoclonal antibodies

Tumor angiogenesis is strongly induced by vascular endothelial growth factor (VEGF), which is overexpressed in most human gastrointestinal cancers. VEGF overexpression is known to be associated with poor prognosis and survival in patients with various solid tumors. The humanized monoclonal anti-VEGF antibody bevacizumab (Avastin, Genentech Inc., South San Francisco, CA) is a prototypic antiangiogenic compound, and has proven therapeutic benefit combined with conventional chemotherapy-namely, significantly improved progression-free survival in patients with metastatic colorectal cancer. Bevacizumab is the only anti-VEGF antibody that has been approved by the FDA and the European Medicines Agency for the treatment of metastatic colorectal cancer. Several ongoing clinical studies are evaluating the potential of bevacizumab therapy for other gastrointestinal cancers, in combination with chemotherapy, other targeted therapies and/or radiation. Soluble chimeric receptors, tyrosine kinase inhibitors, and monoclonal antibodies against VEGF and molecular targets in the integrin and Delta-like protein 4-Notch pathways are being developed. As tumors acquire resistance to anti-VEGF therapy, further development of antiangiogenic and vascular targets and therapy is warranted.