Asian ethnicity is a favorable prognostic factor for overall survival in non-small cell lung cancer (NSCLC) and is independent of smoking status.
BACKGROUND
We previously showed that Asian ethnicity was an independent favorable prognostic factor in non-small cell lung cancer (NSCLC). Many Asian NSCLC patients were never-smokers, and never-smokers had improved survival than ever-smokers. We investigated whether Asian ethnicity is a favorable prognostic factor independent of smoking status.


METHODS
Retrospective population-based study of NSCLC cases from the cancer surveillance programs of three Southern California counties from 1991 to 2005.


RESULTS
A total of 20,140 NSCLC patients with known smoking status were analyzed of which 9.1% were never-smokers and 6.5% were Asians. There was a threefold increase in the percentage of Asian never-smokers as compared with ever-smokers. Asians had the highest overall survival (OS) among the 4 major ethnicities (p < 0.0001) and never-smokers had improved OS over ever-smokers (p = 0.0183) by univariate analyses. By multivariate analyses, Asian ethnicity was an independent and favorable prognostic factor for OS (versus non-Asian; hazard ratio [HR] = 0.861, 95% confidence interval [CI]: 0.808-0.918, p < 0.0001), among smokers (versus non-Asian; HR = 0.867, 95% CI: 0.807-0.931, p < 0.0001), and among never-smokers (versus non-Asian; HR = 0.841, 95% CI: 0.728-0.971, p = 0.0180). Never-smoker was a favorable prognostic factor if ethnicity was not accounted for (versus ever-smoker; HR = 0.936, 95% CI: 0.886-0.988, p = 0.0169) but was no longer an independent favorable prognostic factor (versus ever-smoker; HR = 0.953, 95% CI: 0.902-1.007, p = 0.0861) after accounting for ethnicity.


CONCLUSIONS
Asian ethnicity is an independent favorable prognostic factor for OS in NSCLC regardless of smoking status.
Ou
Sai-Hong Ignatius
SH
Chao Family Comprehensive Cancer Center, Division of Hematology/Oncology, Department of Medicine, University of Irvine Medical Center, Orange, California 92868-3298, USA. Ignatius.ou@uci.edu
Ziogas
Argyrios
A
Zell
Jason A
JA
D000368:Aged; D000369:Aged, 80 and over; D044466:Asian People; D002289:Carcinoma, Non-Small-Cell Lung / Q000208:ethnology* / Q000401:mortality / Q000473:pathology / Q000628:therapy; D005260:Female; D006801:Humans; D008175:Lung Neoplasms / Q000208:ethnology* / Q000401:mortality / Q000473:pathology / Q000628:therapy; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D011379:Prognosis; D012189:Retrospective Studies; D012907:Smoking / Q000009:adverse effects*; D012959:Socioeconomic Factors