Lung Cancer (2005) 47, 1—8 Squamous and small cell carcinomas of the lung: similarities and differences concerning the role of tobacco smoking Eduardo De Stefani a,* , Paolo Boffetta b,c , Alvaro L. Ronco d , Paul Brennan b , Pelayo Correa e , Hugo Deneo-Pellegrini a , Luis Pi˜ neyro Guti´ errez f , Mar´ ıa Mendilaharsu a a Registro Nacional de C´ ancer, Avenida Brasil 3080 dep. 402, Montevideo, Uruguay b International Agency for Research on Cancer, Lyon, France c Division of Clinical Epidemiology, German Cancer Research Center (DKFZ), Heidelberg, Germany d Unidad de Oncolog´ ıa, Hospital Pereira Rossell, Montevideo, Uruguay e Department of Pathology, Louisiana State University Medical Center, New Orleans, LA, USA f Instituto de Neumolog´ ıa, Facultad de Medicina, Montevideo, Uruguay Received 21 January 2004; received in revised form 7 June 2004; accepted 10 June 2004 KEYWORDS Squamous cell carcinoma; Small cell carcinoma; Tobacco smoking; Intensity; Duration; Type of tobacco; Age at start Summary In the time period 1988—2000, a case—case study on environmental fac- tors and lung cancer risk was conducted in Montevideo, Uruguay. This study was de- signed in order the establish possible differences between squamous cell carcinomas (SCC) and small cell carcinomas (SCLC) of the lung in relation to tobacco smoking. Three hundred and ninety one (391) patients with small cell carcinoma were com- pared with 1187 patients with squamous cell carcinoma. Regarding sex, the study included a small number of women (26 with SCLC and 20 with SCC). SCLC was associ- ated with higher risks for smoking status, smoking intensity and cumulative exposure to tobacco smoking when compared with SCC. These three tobacco variables were significantly different between both cell types in men. Smoking duration was signif- icantly higher among SCLC compared with SCC only in women. With decreasing age at starting to smoke, the proportion of SCLC increases at the expense of SCC. Finally, Abbreviations: SCLC, Small cell carcinoma of the lung; SCC, Squamous cell carcinoma of the lung; OR, Odds ratios ∗ Corresponding author. Tel.: +598 2 708 2314; fax: +598 2 402 0810. E-mail address: estefani@adinet.com.uy (E.D. Stefani) 0169-5002/$ — see front matter © 2004 Elsevier Ireland Ltd. All rights reserved. doi:10.1016/j.lungcan.2004.06.013