Better understanding of new T-size descriptors on adjuvant chemotherapy effect needed

Authors draw no specific recommendations due to size of study

The most recent research released in June's Journal of Thoracic Oncology indicates there might be a positive correlation between tumor size and adjuvant platinum based chemotherapy in surgically resected patients with node negative non-small cell lung cancer. The study, published in the June 2012 issue of the International Association for the Study of Lung Cancer's (IASLC) Journal of Thoracic Oncology, analyzed the effect of tumor size and KRAS mutations on survival benefit from adjuvant platinum based chemotherapy in patients with node negative non-small cell lung cancer.

The purpose of the retrospective study was to apply the most current, 7th edition, TNM staging system, to a retrospective cohort of surgically resected, node negative, non-small cell lung cancer patients who were treated with adjuvant platinum based chemotherapy. Previous clinical trials confirmed a survival benefit for adjuvant platinum based chemotherapy for patients with stage II-IIIa non-small cell lung cancer. In addition, the authors explored the interaction between tumor size and KRAS mutations in predicting a benefit from the chemotherapy.

After analyzing data from 461 patients that were part of two previous adjuvant trials, JBR.10 and CALBG 9633, the authors found a positive correlation between the size of the tumor and efficacy of chemotherapy with respect to disease free survival. There was no clear demarcation of what T size threshold correlated with benefit of chemotherapy. KRAS mutation was detected in 27 percent of the specimens, correlated with a worse prognosis but not with the size of the tumor.

"Thus, our study reinforces the pressing need for improved understanding of the impact of the new T-size descriptors on adjuvant chemotherapy effect," the authors say. "This is particularly valid when we consider that up to 77 percent of surveyed lung cancer physicians would alter patient management in response to a change in stage designation."