ANGIOGENESIS INHIBITORS AND EVALUATION OF RESPONSE

Angiogenesis Inhibitor Therapy May Affect Assessment of Tumor Response

NEW YORK (Reuters Health) Jan 09 - The appearance of tumor cavitation after angiogenesis inhibitor treatment of non-small-cell lung cancer (NSCLC) may alter response assessments, according to a report in the December 1st online edition of the Journal of Clinical Oncology.

In recently completed trials of combination chemotherapy including an inhibitor of angiogenesis (a VEGF receptor inhibitor), the authors observed cavitation in pulmonary lesions that was associated with treatment response.

Dr. Simon J. Crabb from University of Southampton in the UK and colleagues hypothesized that incorporating an assessment of cavitation could influence the overall response assessment. To this end, they evaluated the tumor response in NSCLC patients after treatment with an angiogenesis inhibitor.

More patients who received the VEGF receptor inhibitor in the trials were found to have cavitation in lesions after treatment, compared with patients who did not receive the VEGF receptor inhibitor, the authors report.

Three of eight patients with marked pulmonary cavitation had partial responses, four had stable disease, and one had progressive disease, the researchers note.

In some patients, analysis using RECIST (Response Evaluation Criteria in Solid Tumors) guidelines did not seem to describe adequately the change in tumor tissue volume if cavitation was present, the report indicates, whereas the alternate method that took cavitation into account was able to describe decreases in tumor volume of target lesions that responded by undergoing cavitation.

"Cavitation may be an angiogenesis inhibitor class effect, and evaluation of response and subsequent progression in the presence of cavitation may be problematic," the authors conclude.

"Further investigation is indicated, particularly regarding the effect of cavitation on response designation and duration and survival outcomes, in large phase III trials of chemotherapy with or without angiogenesis inhibition," the investigators say.

"We plan to undertake such an analysis in a current NCIC CTG phase II/III randomized comparison of platinum-based chemotherapy with either cediranib or placebo in advanced NSCLC."