Varying recurrence rates and risk factors associated with different definitions of local recurrence in patients with surgically resected, stage I nonsmall cell lung cancer.
BACKGROUND
The objective of this study was to examine the effects of different definitions of local recurrence on the reported patterns of failure and associated risk factors in patients who undergo potentially curative resection for stage I nonsmall cell lung cancer (NSCLC).


METHODS
The study included 306 consecutive patients who were treated from 2000 to 2005 without radiotherapy. Local recurrence was defined either as 'radiation' (r-LR) (according to previously defined postoperative radiotherapy fields), including the bronchial stump, staple line, ipsilateral hilum, and ipsilateral mediastinum; or as 'comprehensive' (c-LR), including the same sites plus the ipsilateral lung and contralateral mediastinal and hilar lymph nodes. All recurrences that were not classified as "local" were considered to be distal.


RESULTS
The median follow-up was 33 months. The proportions of c-LR and r-LR at 2 years, 3 years, and 5 years were 14%, 21%, and 29%, respectively, and 7%, 12%, and 16%, respectively. Significant risk factors for c-LR on multivariate analysis were diabetes, lymphatic vascular invasion, and tumor size; and significant factors for r-LR were resection of less than a lobe and lymphatic vascular invasion. The proportions of distant (non-local) recurrence using these definitions at 2 years, 3 years, and 5 years were 10%, 12%, and 18%, respectively, and 14%, 19%, and 29%, respectively. Significant risk factors for distant failure were histology when using the c-LR definition and tumor size when using the r-LR definition.


CONCLUSIONS
Local recurrence increased nearly 2-fold when a broad definition was used instead of a narrow definition. The definition also affected which factors were associated significantly with both local and distant failure on multivariate analysis. Comparable definitions must be used when analyzing different series.
Division of Radiation Oncology, Penn State Hershey Cancer Institute, Hershey, Pennsylvania 17033, USA. jvarlotto@hmc.psu.edu
John M
JM
Varlotto
Abram
A
Recht
John C
JC
Flickinger
Laura N
LN
Medford-Davis
Anne-Marie
AM
Dyer
Malcolm M
MM
DeCamp
D000368:Aged; D002289:Carcinoma, Non-Small-Cell Lung / Q000473:pathology* / Q000601:surgery; D006801:Humans; D008175:Lung Neoplasms / Q000473:pathology* / Q000601:surgery; D009364:Neoplasm Recurrence, Local; D012008:Recurrence; D012307:Risk Factors