Use of Postoperative Radiotherapy (PORT) for Resectable Non-Small Cell Lung Cancer (NSCLC).
Reviewer: Christopher Dolinsky, MD
University of Pennsylvania School of Medicine
Last Modified: October 21, 2005
Presenter: J. E. Bekelman, MD
Presenter's Affiliation: Memorial Sloan Kettering Cancer Center, NY, NY
Type of Session: Scientific
- In 1998, the PORT meta-analysis of nine clinical trials (2128 patients) concluded that when compared to surgery alone, the use of post-operative radiation therapy (PORT) for NSCLC patients with N0 and N1 disease was detrimental and it was equivocal with N2 disease.
- The authors wanted to characterize the utilization of PORT with resected NSCLC before and after the 1998 analysis.
- The authors also wanted to find which predictors existed for the use of PORT.
- The SEER program contains 11 tumor registries and 14% of the population and has both demographic and tumor specific data available.
Materials and Methods
- The authors used the SEER program to identify patients with pathologically confirmed NSCLC between 1992 and 2002 who were stage I, II, or IIIA.
- Patients were excluded if they had incomplete data, a previous malignancy, multiple primaries, or received pre/intraop radiation or other radiation modalities.
- The final cohort contained 22,953 patients.
- Of the final cohort, 19,205 did not receive PORT, and 3,748 did receive post operative PORT.
- The use of PORT decreased for all patient subgroups after the meta-analysis of 1998.
- For patients with N1 disease, PORT use declined from 44% in 1995 to 23% in 2001.
- For patients with N2 disease, PORT use declined from 63% in 1995 to 42% in 2001.
- The use of PORT is highest among the youngest patients treated.
- The use of PORT is declining.
- The decline in PORT coincides with the PORT meta-analysis.
- There is a higher frequency of PORT among young patients.
- There is room for further evaluation of this practice.
- It is important to study dynamics of changing practice patterns.
- The clinical guidelines put forward by large governing bodies are not always in agreement when it comes to PORT.
This is an interesting piece of research from the group at Memorial Sloan Kettering Cancer Center . The PORT meta-analysis, while on its surface eliminating the rationale for PORT, was not a perfect paper. There are a number of criticisms to the PORT meta-analysis, and data from that paper can be used to support the use of PORT in selected patients (especially N2 patients). It is not a safe conclusion to state that all physicians should have stopped using PORT since the publication of the meta-analysis. It is unclear from this research whether or not PORT was used appropriately, and it is probably too difficult to use the SEER database to determine this question. The operative findings, margin status, and histologic features may all have influenced the decision to recommend PORT after surgery. This research does show what it set out to though; that the use of PORT has decreased following the publication of the meta-analysis. It is interesting to learn about how physicians change their practice patterns based on the published literature. Many different variables will likely influence how physicians use the literature including: where something is published, how dutifully and intelligently physicians read the literature, and the perceived value of the research published. In the case of the PORT meta-analysis, the perceived value of the research may not be as high as the authors of this abstract think it should be, and this may have influenced the patterns of care in the since its publication.