Metastasis dynamics for non-small-cell lung cancer: effect of patient and tumor-related factors.

BACKGROUND: We studied event dynamics (probability of an event occurring over a specific time interval) in patients undergoing surgery for early-stage non-small-cell lung cancer (NSCLC) according to patient and tumor characteristics. METHODS: By using a database of 1506 patients who underwent initial surgery for NSCLC, event dynamics, based on a time-specific hazard rate, were evaluated. The event of interest was the development of distant metastases, with or without a local recurrence. The effect of sex, tumor size, nodal involvement, histology, lymphovascular space invasion, pleural invasion, age, and race were studied. RESULTS: The hazard rate for developing distant metastases was not constant over time but was characterized by specific peaks, the first being approximately 9 months after surgery and the second at 18 to 20 months for men and 24 to 26 months for women. For women, the hazard rate peaked considerably in the first year. For men, the hazard rate peaks were smaller but lasted for a longer duration. Pathologic factors associated with a higher risk of recurrence (eg, size, lymph node involvement, pleural invasion) all increased the sex-specific hazard rates. CONCLUSIONS: The probability of developing distant metastases after surgery for NSCLC peaks at specific and consistent time intervals after surgery, with specific differences between men and women. A factor-specific modulation of peak heights that ranged from no impact (eg, race) to relevant effects for primary tumor size, nodal involvement, and pleural invasion, possibly related to sex, was also observed. The bimodal distant metastases dynamics may be an intrinsic feature of metastatic progression in NSCLC.

Recurrence dynamics for non-small-cell lung cancer: effect of surgery on the development of metastases.

INTRODUCTION: We study event rates over time (event dynamics) in patients undergoing surgery for early-stage non-small-cell lung cancer (NSCLC). METHODS: Using a database of patients undergoing initial surgery for NSCLC, the event dynamics, based on the hazard rate, were evaluated. Events evaluated included time to any treatment failure, local recurrence, distant metastasis (DM), and development of a second primary lung cancer. RESULTS: Among 1506 patients, time to any treatment failure dynamics demonstrated an initial surge in the hazard rate 9 months after surgery, followed by two smaller peaks at the end of the second and fourth years, respectively. This pattern was dominated by DM events. Two distinguishable peaks were noted for local recurrence in the first and second years. In contrast, the hazard rate for second primary lung cancer exhibited a more uniform pattern over time. The DM dynamics was analyzed by sex and three peaks emerged for both sexes. The timing of the first peak was similar for both sexes, at 7 to 9 months after surgery. The second peak occurred earlier in men (18-20 months) than women (24-26 months). For both sexes the third peak appeared during the fourth year. CONCLUSIONS: Recurrence dynamics of resected early-stage NSCLC displays a multipeak pattern, which supports the hypothesis of a metastasis growth model previously described for early-stage breast cancer. The model assumes both cellular and micrometastatic tumor dormancy and a transient phase of acceleration of metastatic growth following surgical excision of the primary tumor.

Factors associated with the development of brain metastases: analysis of 975 patients with early stage nonsmall cell lung cancer.

BACKGROUND: The risk of developing brain metastases after definitive treatment of locally advanced nonsmall cell lung cancer (NSCLC) is approximately 30%-50%. The risk for patients with early stage disease is less defined. The authors sought to investigate this further and to study potential risk factors. METHODS: The records of all patients who underwent surgery for T1-T2 N0-N1 NSCLC at Duke University between the years 1995 and 2005 were reviewed. The cumulative incidence of brain metastases and distant metastases was estimated by using the Kaplan-Meier method. A multivariate analysis assessed factors associated with the development of brain metastases. RESULTS: Of 975 consecutive patients, 85% were stage I, and 15% were stage II. Adjuvant chemotherapy was given to 7%. The 5-year actuarial risk of developing brain metastases and distant metastases was 10%(95% confidence interval [CI], 8-13) and 34%(95% CI, 30-39), respectively. Of patients developing brain metastases, the brain was the sole site of failure in 43%. On multivariate analysis, younger age (hazard ratio [HR], 1.03 per year), larger tumor size (HR, 1.26 per cm), lymphovascular space invasion (HR, 1.87), and hilar lymph node involvement (HR, 1.18) were associated with an increased risk of developing brain metastases. CONCLUSIONS: In this large series of patients treated surgically for early stage NSCLC, the 5-year actuarial risk of developing brain metastases was 10%. A better understanding of predictive factors and biological susceptibility is needed to identify the subset of patients with early stage NSCLC who are at particularly high risk.

Timing of local and distant failure in resected lung cancer: implications for reported rates of local failure.

INTRODUCTION: Most adjuvant lung cancer trials only report first sites of failure. The relative timing of local (i.e., local/regional) versus distant recurrence after surgery could potentially affect reported rates of local failure. We assessed this phenomenon in a large group of patients undergoing surgery for early-stage lung cancer. METHODS: This institutional review board-approved retrospective study identified all patients who underwent surgery at Duke University Medical Center for pathologic stages I to II non-small cell lung cancer between 1995 and 2005. Medical records and pertinent radiographs were reviewed to assess for local and distant sites of recurrence. Both first and subsequent failures were examined. The time interval between surgery and date of local and/or distant failure was compared using the Mann-Whitney U test. RESULTS: Of 975 patients undergoing surgery, 250 patients developed recurrent disease (43 local only, 110 distant only, and 97 both). The median time from surgery to local failure was 13.9 months (range, 1-79). The median time to distant failure was 12.5 months (range, 1-79 months). These were not significantly different (p = 0.34). Among 97 patients who experienced both local and distant failure, 72 (74%) failed at both sites simultaneously, 19 (20%) failed at local sites first, and 6 (6%) failed at distant sites first. CONCLUSIONS: The time interval from surgery to either local or distant failure is not significantly different. Patterns of failure analyses in which only first sites of failure are scored will underestimate the frequency of local recurrence. Nevertheless, the magnitude of this error is expected to be small.

Local recurrence after surgery for early stage lung cancer: an 11-year experience with 975 patients.

BACKGROUND: The objective of the current study was to evaluate the actuarial risk of local failure (LF) after surgery for stage I to II nonsmall cell lung cancer (NSCLC) and assess surgical and pathologic factors affecting this risk. METHODS: The records, including pertinent radiologic studies, of all patients who underwent surgery for T1 to T2, N0 to N1 NSCLC at Duke University between 1995 and 2005 were reviewed. Risks of disease recurrence were estimated using the Kaplan-Meier method. A multivariate Cox regression analysis assessed factors associated with LF in the entire cohort and a subgroup undergoing optimal surgery for stage IB to II disease. RESULTS: For all 975 consecutive patients, the 5-year actuarial risk of local and/or distant disease recurrence was 36%. First sites of failure were local only (25%), local and distant (29%), and distant only (46%). The 5-year actuarial risk of LF was 23%. On multivariate analysis, squamous/large cell histology (hazards ratio [HR], 1.98), stage > IA (HR, 2.02), and sublobar resections (HR, 1.99) were found to be independently associated with a higher risk of LF. For the subset of patients (n = 445) undergoing at least a lobectomy with negative surgical margins and currently considered for adjuvant chemotherapy (stage IB-II disease), the 5-year actuarial risk of LF was 27%. Within this subgroup, squamous/large cell histology (HR, 2.5) and lymphovascular space invasion (HR, 1.74) were associated with a higher risk of LF. The 5-year rate of LF was 13%, 32%, and 47%, respectively, with 0, 1, or 2 risk factors. CONCLUSIONS: Greater than half of disease recurrences after surgery for early stage NSCLC involved local sites. Pathologic factors may help to distinguish those patients at highest risk.