Public Release: 

Researchers confirm IASLC characterization of uncertain R status with prognosis between R0 and R1

International Association for the Study of Lung Cancer

Yokohama, Japan - Oct. 17, 2017 - The findings of a recent study confirm the International Association for the Study of Lung Cancer (IASLC)'s proposed criteria for uncertain resection margin status, R(un), in residual tumor (R) classification. Dr. John Edwards of the University of Sheffield in the United Kingdom presented his team's findings today at the IASLC 18th World Conference on Lung Cancer (WCLC) in Yokohama, Japan.

R classification describes the tumor status following treatment, therefore reflecting the treatment's effectiveness, which impacts prognosis and potentially further treatment. Considering the important implications of R classification, the researchers undertook this study to analyze R status criteria using data collected from the IASLC Lung Cancer Staging Project.

The data analyzed included information on full R status and survival data of 14,712 patients undergoing NCSLC surgery. The researchers evaluated R status criteria and other relevant data including the number of N2 stations explored, lobe-specific systematic lymph node dissection (SLND), extra-capsular extension (ECE), status of the highest station, bronchial carcinoma in situ (cis) at bronchial resection margin (BRM) and pleural lavage cytology (PLC). Additionally, the researchers designated and tested revised categories of R0, R(un), R1 and R2 for survival impact.

Based on their results, the researchers confirmed the proposed criteria for R(un), upholding its prognosis between R0 and R1. Further prospective data collection will be necessary to fully understand the impact of these criteria on prognoses.

"In designing and analyzing clinical trials of adjuvant therapies, undertaking a thorough evaluation and characterization of R status is critical," said Dr. Edwards. "While more data collection will be necessary to see the full impact in a clinical setting, our confirmation of the International Association for the Study of Lung Cancer's proposed criteria is an important step."


About the WCLC

The World Conference on Lung Cancer (WCLC) is the world's largest meeting dedicated to lung cancer and other thoracic malignancies, attracting over 6,000 researchers, physicians and specialists from more than 100 countries. The goal is to disseminate the latest scientific achievements; increase awareness, collaboration and understanding of lung cancer; and to help participants implement the latest developments across the globe. Organized under the theme of "Synergy to Conquer Lung Cancer," the conference will cover a wide range of disciplines and unveil several research studies and clinical trial results. For more information, visit

About the IASLC

The International Association for the Study of Lung Cancer (IASLC) is the only global organization dedicated to the study of lung cancer and other thoracic malignancies. Founded in 1974, the association's membership includes more than 6,500 lung cancer specialists across all disciplines in over 100 countries, forming a global network working together to conquer lung and thoracic cancers worldwide. The association also publishes the Journal of Thoracic Oncology, the primary educational and informational publication for topics relevant to the prevention, detection, diagnosis and treatment of all thoracic malignancies. Visit for more information.

Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.