Chest
Volume 117, Issue 6, June 2000, Pages 1568-1571
Journal home page for Chest

Clinical Investigations
CANCER
Correlation of Tumor Size and Survival in Patients With Stage IA Non-small Cell Lung Cancer

https://doi.org/10.1378/chest.117.6.1568Get rights and content

Objective

The purpose of this study was to determine the relationship between tumor size and survival in patients with stage IA non-small cell lung cancer (non-small cell lung cancer; ie, lesions < 3 cm).

Method

Five hundred ten patients with pathologic stage IA (T1N0M0) non-small cell lung cancer were identified from our tumor registry over an 18-year period (from 1981 to 1999). There were 285 men and 225 women, with a mean age of 63 years (range, 31 to 90 years). The Cox proportional model was used to examine the effect on survival. Tumor size was incorporated into the model as a linear effect and as categorical variables. The Kaplan-Meier product limit estimator was used to graphically display the relationship between the tumor size and survival.

Results

The Cox proportional hazards model did not show a statistically significant relationship between tumor size and survival (p = 0.701) as a linear effect. Tumor size was then categorized into quartiles, and again there was no statistically significant difference in survival between groups (p = 0.597). Tumor size was also categorized into deciles, and there was no statistical relationship between tumor size and survival (p = 0.674).

Conclusions

This study confirms stratifying patients with stage IA non-small cell lung cancer in the same TNM classification, given no apparent difference in survival. Unfortunately, these data caution that improved small nodule detection with screening CT may not significantly improve lung cancer mortality. The appropriate prospective randomized trial appears warranted.

Section snippets

Patients

The Thoracic Oncology and Comprehensive Cancer Center tumor registries at our institution retrospectively identified 510 consecutive patients, 285 men and 225 women, with a mean age of 63 years (range, 31 to 90 years) with surgically resected, pathologic stage IA (T1N0M0) non-small cell lung cancer. The surgical and pathologic reports were reviewed to ensure that appropriate size, histology, and stage were recorded.

One hundred ninety-five patients (38%) had squamous cell carcinoma, 235 patients

Linear Effects of Tumor Size

Tumor size was incorporated into the Cox proportional hazards model as a linear effect on survival, and was not found to be statistically significant (regression coefficient, 1.08; standard error of estimate, 0.196; likelihood ratio test p value, 0.701). The distribution of tumor size is shown in Figure 1 .

Effect of Tumor Size Categorized Into Four Strata

Tumor size was then classified into quartiles. The tumor size category, number of patients, and number of deaths are shown in Table 1 . The Cox model did not show a statistically significant

Discussion

Despite continued advances in diagnostic techniques, treatment protocols, and tumor biology, the survival rate for lung cancer has shown only minimal improvements over the past several decades. Most patients still present with advanced disease, at which time therapeutic options are less than optimal.1

One strategy directed at improving outcome is screening and early detection. It has been suggested that if lesions are discovered when small, patients will have an earlier stage of disease, and

References (26)

  • K Ebeling et al.

    Screening for lung cancer: results from a case-control study

    Int J Cancer

    (1987)
  • TA Sellers et al.

    Evidence for Mendelian inheritance in the pathogenesis of lung cancer

    J Natl Cancer Inst

    (1990)
  • K Mori et al.

    Utility of low-dose helical CT as a second step after plain chest radiography for mass screening for lung cancer

    J Thorac Imaging

    (1997)
  • Cited by (0)

    View full text