Unexpected observations on tumor size and survival in stage IA non-small cell lung cancer

Effect of tumor size on prognosis of node-negative lung cancer with sufficient lymph node examination and no disease extension

Background

The effect of tumor size on the prognosis of node-negative non-small-cell lung cancer (NSCLC) might be biased by missed lymph node metastasis and local disease extension.

Methods

We investigated 2,260 patients with N0M0 NSCLC in the Surveillance, Epidemiology and End Results (SEER) database diagnosed from 1998 to 2012. Eligible patients had $18 lymph nodes examined and no disease extension. Tumor size was classified as T1a (0–10 mm), T1b (11–20 mm), T1c (21–30 mm), T2a (31–40 mm), T2b (41–50 mm), T3 (51–70 mm), and T4 (>70 mm).

Results

The 5-year cancer-specific survival (CSS) rates for T1a, T1b, T1c, T2a, T2b, T3, and T4 patients were 85.6%, 84.4%, 79.9%, 77.9%, 70.0%, 63.0%, and 61.7%, respectively. The 5-year overall survival (OS) rates for T1a, T1b, T1c, T2a, T2b, T3, and T4 patients were 77.8%, 74.1%, 68.2%, 64.5%, 58.7%, 53.2%, and 57.3%, respectively. Using T1a as the reference, the hazard ratio generally increased with tumor size in the multivariate analysis of CSS and OS, with the exception of T4 patients.

Conclusion

After adjusting for lymph node examination and disease extension, tumor size still had a significant effect on CSS in NSCLC, although the effect seemed to be smaller than that in a more generalized population.

Relationship between tumor size and survival in non-small-cell lung cancer (NSCLC): an analysis of the surveillance, epidemiology, and end results (SEER) registry

INTRODUCTION

Tumor size is a known prognostic factor for early stage non-small-cell lung cancer (NSCLC), but its significance in node-positive and locally invasive NSCLC has not been extensively characterized. We queried the Surveillance, Epidemiology, and End Results database to evaluate the prognostic value of tumor size for early stage and node-positive and locally invasive NSCLC.

METHODS

Patients in Surveillance, Epidemiology, and End Results registry with NSCLC diagnosed between 1998 and 2003 were analyzed. Tumor size was analyzed as a continuous variable. Other demographic variables included age, gender, race, histology, primary tumor extension, node status, and primary treatment modality (surgery vs. radiation). The Kaplan-Meier method was used to estimate overall survival (OS). Cox proportional hazard model was used to evaluate whether tumor size was an independent prognostic factor.

RESULTS

In all, 52,287 eligible patients were subgrouped based on tumor extension and node status. Tumor size had a significant effect on OS in all subgroups defined by tumor extension or node status. In addition, tumor size also had statistically significant effect on OS in 15 of 16 subgroups defined by tumor extension and nodal status after adjustment for other clinical variables. Our model incorporating tumor size had significantly better predictive accuracy than our alternative model without tumor size.

CONCLUSIONS

Tumor size is an independent prognostic factor, for early stage and node-positive and locally invasive disease. Prediction tools, such as nomograms, incorporating more detailed information not captured in detail by the routine tumor, node, metastasis classification, may improve prediction accuracy of OS in NSCLC.

The assessment of the role of baseline low-dose CT scan in patients at high risk of lung cancer

BACKGROUND

Despite the progress in contemporary medicine comprising diagnostic and therapeutic methods, lung cancer is still one of the biggest health concerns in many countries of the world. The main purpose of the study was to evaluate the detection rate of pulmonary nodules and lung cancer in the initial, helical low-dose CT of the chest as well as the analysis of the relationship between the size and the histopathological character of the detected nodules.

MATERIAL/METHODS

We retrospectively evaluated 1999 initial, consecutive results of the CT examinations performed within the framework of early lung cancer detection program initiated in Szczecin. The project enrolled persons of both sexes, aged 55-65 years, with at least 20 pack-years of cigarette smoking or current smokers. The analysis included assessment of the number of positive results and the evaluation of the detected nodules in relationship to their size. All of the nodules were classified into I of VI groups and subsequently compared with histopathological type of the neoplastic and nonneoplastic pulmonary lesions.

RESULTS

Pulmonary nodules were detected in 921 (46%) subjects. What is more, malignant lesions as well as lung cancer were significantly, more frequently discovered in the group of asymptomatic nodules of the largest dimension exceeding 15 mm.

CONCLUSIONS

The initial, low-dose helical CT of the lungs performed in high risk individuals enables detection of appreciable number of indeterminate pulmonary nodules. In most of the asymptomatic patients with histopathologically proven pulmonary nodules greater than 15 mm, the mentioned lesions are malignant, what warrants further, intensified diagnostics.

Screening for lung cancer with low-dose computed tomography: a systematic review and meta-analysis of the baseline findings of randomized controlled trials

OBJECTIVES

Lung cancer is the leading cause of death among all cancers. An estimated 29% of the global population older than 15 years currently smokes tobacco. The presence of a high risk population, relatively asymptomatic nature of the disease in the early phase, and relatively good prognosis when discovered early makes screening for lung cancer an attractive proposition. We performed a systematic review and a meta-analysis of the baseline results of randomized controlled trials so far published, which included more than 14,000 patients. Analysis was used to determine whether data was for or against the screening of lung cancers using low-dose computed tomography (LDCT).

DESIGN

Random effect meta regression model of meta-analysis and systematic review.

METHODS

We performed a systematic review and a meta-analysis of the current literature to determine whether screening for lung cancer in a high-risk population with computed tomography improves outcomes. A search strategy using Medline was employed, studies selected based on preset criteria and application of exclusion criteria, and data collected and analyzed for statistical significance.

RESULTS

Screening for lung cancer using LDCT resulted in a significantly higher number of stage I lung cancers (odds ratio 3.9, 95% confidence interval [CI] 2.0-7.4), higher number of total non-small cell lung cancers (odds ratio 5.5, 95% CI 3.1-9.6), and higher total lung cancers (odds ratio 4.1, 95% CI 2.4-7.1). Screening using LDCT also resulted in increased detection of false-positive nodules (odds ratio 3.1, 95% CI 2.6-3.7) and more unnecessary thoracotomies for benign lesions (event rate 3.7 per 1000, 95% CI 3.5-3.8). For every 1000 individuals screened with LDCT for lung cancer, 9 stage I non-small cell lung cancer and 235 false-positive nodules were detected, and 4 thoracotomies for benign lesions were performed.

CONCLUSIONS

The baseline data from six randomized controlled trials offer no compelling data in favor or against the use of LDCT screening for lung cancer. We await the final results of these randomized controlled trials to improve our understanding of the effectiveness of LDCT in the screening for lung cancer and its effect on mortality.

Elucidation of relationship between tumor size and survival in non-small-cell lung cancer patients can aid early decision making in clinical drug development

Four non-small-cell lung cancer (NSCLC) registration trials were utilized to develop models linking survival to risk factors and changes in tumor size during treatment. The purpose was to leverage existing quantitative knowledge to facilitate future development of anti-NSCLC drugs. Eleven risk factors were screened using a Cox model. A mixed exponential decay and linear growth model was utilized for modeling tumor size. Survival times were described in a parametric model. Eastern Cooperative Oncology Group (ECOG) score and baseline tumor size were consistent prognostic factors of survival. Tumor size was well described by the mixed model. The parametric survival model includes ECOG score, baseline tumor size, and week 8 tumor size change as predictors of survival duration. The change in tumor size at week 8 allows early assessment of the activity of an experimental regimen. The survival model and the tumor model will be beneficial for early screening of candidate drugs, simulating NSCLC trials, and optimizing trial designs.

Estimated impact of LDCT-identified stage IA non-small-cell lung cancer on screening efficacy

About one-third of individuals radiographically diagnosed with surgical-pathological stage IA non-small-cell lung cancer (IA-NSCLC) harbor occult metastases that prove lethal. A comparison of the projected outcome of CT-diagnosed IA-NSCLC with actuarial figures for life expectancy of screenees suggests that about half of the remainder will succumb to alternative causes. CT screening can be efficacious if and only if it leads to an interdiction of potentially lethal cancers in the remaining one-third of sufficient magnitude that it offsets the surgical mortality and abbreviation of life expectancy in the two-thirds who are either understaged or overdiagnosed. Preliminary evidence from CT screening trials fails to support the premise that it diminishes the absolute number of advanced lung cancers.

Tumor Size Is a Determinant of Stage Distribution in T1 Non-Small Cell Lung Cancer

STUDY OBJECTIVE

Despite renewed interest in early detection of lung cancer, the relationship between tumor size and survival remains controversial. The objective of this study was to evaluate the relationship between size and stage in patients with T1 (< or = 3.0 cm) non-small cell lung cancer (NSCLC).

PATIENTS AND METHODS

A retrospective review of a lung cancer database from 1995 to 2003 identified 503 patients with completely resected invasive NSCLC with tumors < or = 3 cm. All clinical and pathologic characteristics were recorded. Univariate associations between nodal status and other prognostic factors were explored by chi2 and t tests. The independent effect of tumor size > 2 cm vs < or = 2 cm on the risk of nodal disease was analyzed using a logistic regression model.

RESULTS

Of the 503 patients, 324 patients (64.4%) had stage IA disease, 52 patients (10.3%) had stage IB disease, 37 patients (7.4%) had stage IIA disease, 15 patients (3%) had stage IIB disease, 43 patients (8.6%) had stage IIIA disease, 24 patients (4.8%) had stage IIIB disease, and 8 patients (1.6%) had stage IV disease. One hundred patients (19.9%) had nodal metastases. The mean (+/- SD) tumor size of cases without nodal disease was 1.90 +/- 0.67 cm, compared to 2.18 +/- 0.69 cm for node-positive tumors (p = 0.0003; 95% confidence interval [CI] for mean difference, 0.13 to 0.43). Forty-eight of 308 patients (15.6%) with smaller carcinomas (< or = 2.0 cm) compared to 52 of 195 patients (26.7%) with carcinomas > 2.0 cm had nodal metastases (p = 0.002). Exploratory multivariate analysis revealed that only tumor size (< or = 2.0 cm [referent] vs > 2.0 cm) affected nodal status and thus stage (adjusted odds ratio, 2.0; 95% CI, 1.3 to 3.1; p = 0.002).

CONCLUSIONS

Primary invasive NSCLC > 2.0 cm was twice as likely to have nodal metastases than carcinomas < or = 2.0 cm. Our results suggest that in lung cancer smaller lesions may represent earlier stage disease. These results also suggest the need for further subclassification by tumor size within the current International Union Against Cancer/American Joint Committee on Cancer stage I, with tumors < 2 cm in size contained in a separate substage. This refinement may help to better clarify which patients might benefit from novel adjuvant or neoadjuvant therapeutic interventions.

The effect of tumor size on curability of stage I non-small cell lung cancers

OBJECTIVE

The objective of this study was to determine the relationship between tumor size and curability of stage I non-small cell lung cancer.

METHODS

From the Surveillance, Epidemiology, and End Results registry 2003, we identified all primary non-small cell lung cancer cases that were diagnosed prior to autopsy. Among these cases, we narrowed the focus to those diagnosed in 1988 or later, and to 7,620 patients who had undergone curative surgical resection. Kaplan-Meier survival curves were obtained for these stage I malignancies for five tumor size categories (ie, 5 to 15 mm, 16 to 25 mm, 26 to 35 mm, 36 to 45 mm, and > 45 mm). The 12-year Kaplan-Meier estimator of survival was used as a measure of lung cancer cure rate.

RESULTS

Among 7,620 stage I cancers, cure rates decreased with increasing tumor size. The 12-year survival rates for patients with tumors 5 to 15 mm in diameter was 69% (95% confidence interval [CI], 64 to 74%), 63% for those with tumors 16 to 25 mm in diameter (95% CI, 60 to 67%), 58% for those with tumors 26 to 35 mm in diameter (95% CI, 54 to 61%), 53% for those with tumors 36 to 45 mm in diameter (95% CI, 48 to 57%), and 43% for those with tumors > 45 mm in diameter (95% CI, 39 to 48%). Cure rates were statistically significantly different for all tumor size categories (p < 0.05) except for the groups with tumors 26 to 35 mm and 36 to 45 mm in diameter (p = 0.10).

CONCLUSIONS

Smaller tumor size at diagnosis is associated with improved curability within stage I non-small cell lung cancers. These results suggest that further subclassification by size within stage I may be important.

Population screening for lung cancer

The feasibility of diagnosing small stage 1 lung cancers using low-dose chest computed tomography in asymptomatic at-risk individuals has been demonstrated in multiple studies. However, it has yet to be proved that the introduction of a chest computed tomography screening programme would do more good than harm at an acceptable cost.

[Stage I nonsmall cell lung cancer up to 3 cm in diameter. Prognostic factors]

OBJECTIVE

To assess the prognostic value of a series of clinicopathological variables in stage I nonsmall cell lung cancer, for tumors up to 3 cm in diameter.

PATIENTS AND METHOD

The study included 271 patients. Survival was analyzed with the Kaplan-Meier method. The Cox model was used for multivariate analysis.

RESULTS

Five- and ten-year survival were 78.63% and 67.59%, respectively. Survival did not significantly depend on sex, age, extent of resection, histology, visceral pleural invasion, level of bronchial invasion or T1 versus T2. The decade in which resection was performed did affect survival (P=.0037). Five-year survival was 58% for operations between 1970 and 1980, 77% for operations between 1981 and 1990, and 84% for operations between 1991 and 2000. Tumor size also affected survival (P=.0046), which was 86% for patients with tumors of less than or equal to 2 cm in diameter and 73% for those with tumors of more than 2 cm in diameter. In the multivariate analysis both variables entered into regression, remaining predictive of survival.

CONCLUSION

We found evidence for a prognostic stage migration (Will Rogers phenomenon) according to the decade in which resection was performed and that tumor size affected survival in our population. Finally, the current system of TNM staging fails in conforming groups of patients with a homogenous prognosis.

Tumor size predicts survival within stage IA non-small cell lung cancer

STUDY OBJECTIVES

The basic premise of CT screening is that size is an important determinant of survival in lung cancer. We sought to examine this hypothesis within stage IA non-small cell lung cancer (NSCLC).

METHODS

A retrospective analysis of all patients with pathologically confirmed stage IA NSCLC resected from 1991 to 2001 was conducted. All but seven patients underwent anatomic lung resection and mediastinal lymph node dissection. Kaplan-Meier survival analysis was performed to estimate the 5-year overall and disease-specific survival probability stratified by tumor size. The influence of age, gender, histology, and tumor size on survival was also analyzed using a Cox proportional hazards regression model.

RESULTS

There were 244 patients (mean age, 66.7 years; 45.1% were men). Lobectomy was performed in 229 patients, segmentectomy in 8 patients, and wedge resection in 7 patients. Operative mortality was 0.4%. Histologic breakdown was as follows: adenocarcinoma (59.4%), squamous (18.9%), bronchoalveolar (15.2%), large cell (4.5%), and poorly differentiated (2.0%). The median follow-up time for all patients was 2.6 years. The 5-year survival probability for all patients was 71.1% (95% confidence interval [CI], 63.6 to 78.6%). For 161 patients with tumor sizes < or = 2.0 cm, the 5-year survival probability was 77.2% (95% CI, 68.6 to 85.8%) in comparison with 60.3% (95% CI, 46.7 to 73.8%) in 83 patients with tumor size > 2.0 cm (p = 0.03 by log-rank test). The overall 5-year disease-specific survival was 74.9% (95% CI, 67.6 to 82.2%). Disease-specific survival was 81.4% (95% CI, 73.3 to 89.4%) for patients with tumors < or = 2.0 cm and 63.4% (95% CI, 49.6 to 77.1%) for patients with tumors > 2.0 cm.

CONCLUSIONS

These data suggest that size within stage IA is an important predictor of survival and that further substaging should be considered.

Staging in lung cancer: is 3 cm a prognostic threshold in pathologic stage I non-small cell lung cancer? A multicenter study of 1,020 patients

INTRODUCTION

Since 1974, a tumor size of 3 cm in diameter has been regarded as the prognostic threshold in the staging of bronchogenic carcinoma.

OBJECTIVE

To study the prognostic behavior of surgical-pathologic tumor size in non-small cell lung cancer (NSCLC) with complete resection.

DESIGN

Four-year multi-institutional prospective study from 1993 to 1997.

PATIENTS

Consecutive cases of NSCLC in pathologic stages IA-IB (pIA-pIB) treated surgically with complete resection in hospitals belonging to the Bronchogenic Carcinoma Co-operative Group of the Spanish Society of Pneumology and Thoracic Surgery (GCCB-S).

METHODS

The Schoenfeld procedure was used to identify different prognostic groups, considering 1 cm as the measurement unit.

RESULTS

Based on the 1,020 cases evaluated, four prognostic groups were identified: 0 to 2 cm (group A; n = 147), 2.1 to 4 cm (group B; n = 448), 4.1 to 7 cm (group C; n = 336), and > 7 cm (group D; n = 89). At 5 years, survival was 0.63 (95% confidence interval [CI], 0.58 to 0.68), 0.56 (95% CI, 0.53 to 0.59), 0.49 (95% CI, 0.46 to 0.52), and 0.38 (95% CI, 0.32 to 0.44) for groups A, B, C, and D, respectively. Differences between paired groups (log-rank) were significant: 0.0074 between groups A and B, 0.0048 between groups B and C, and 0.0034 between groups C and D.

CONCLUSIONS

In initial stages (pIA-pIB) of NSCLC, the 3-cm value was not found to behave as a prognostic threshold; in this study, four surgical-pathologic tumor size groups were identified with strong prognostic differences: from 0 to 2 cm, from 2.1 to 4 cm, from 4.1 to 7 cm, and > 7 cm.

Therapy for stage I and stage II non-small cell lung cancer

Despite complete resection of what seems to be all evident tumor, one third to three quarters of patients with stages I and II NSCLC ultimately succumb to this neoplasm. Patients who are cured of an original NSCLC or small cell cancer remain at risk for a new primary lung cancer. Although the importance of lifelong surveillance is clear, the extent and timing of optimal follow-up remain undefined. Although clinicians refer to the development after treatment of clinically discernible sites of tumor as "recurrence," it is probably more accurate to consider these foci as "persistence"--that is, the locoregional site was not sterilized by surgery, and the distant implants were present from the outset but undetected. Although data are sparse, induction and improved adjuvant therapy for early NSCLC may be helpful. Much further experience is needed. Further study and application of biologic indicators in addition to TNM staging likely will help identify patients at high risk for surgical failure who may benefit by combination treatment.