Rural vs urban inequalities in stage at diagnosis for lung cancer.

OBJECTIVES

Early diagnosis of lung cancer increases the chance of survival. The aim of this study was to measure the relationship between geographic residence in Saskatchewan and stage of lung cancer at the time of diagnosis.

MATERIALS AND METHODS

Retrospective cohort analysis of 2,972 patients with a primary diagnosis of either non-small cell cancer (NSCLC) or small cell lung cancer (SCLC) between 2007 and 2012 was performed. Incidence proportion of early and advanced stage cancer, and relative risk of being diagnosed with advanced-stage lung cancer relative to early-stage was calculated.

RESULTS

Compared to urban Saskatchewan, rural Saskatchewan lung cancer patients had a higher relative risk of advanced stage NSCLC (relative risk [RR] = 1.11, 95% confidence interval [CI]: 1.01-1.22). Rural Saskatchewan was further subdivided into north and south. The relative risk of advanced stage NSCLC in rural north Saskatchewan compared to urban Saskatchewan was even greater (RR = 1.17, 95% CI: 1.03-1.31). Although not statistically significant, there was a trend for a higher incidence of advanced stage SCLC in rural and rural north vs urban Saskatchewan (RR = 1.16, 95% CI: 0.95-1.43 and RR = 1.22; 95% CI: 0.94-1.58, respectively). There was a higher incidence proportion of advanced stage NSCLC in rural areas relative to urban (31.6-34.4 vs 29.5 per 10,000 people).

CONCLUSION

Patients living in rural Saskatchewan have higher incidence proportion of and were more likely to present with advanced stage NSCLC in comparison to urban Saskatchewan patients at time of diagnosis. This inequality was even greater in rural north Saskatchewan.