Suggested Excess of Occupational Cancers in Norwegian Offshore Workers: Preliminary Results from the Cancer Registry Offshore Cohort

Objective The aim of this communication was to report the overall incidence of cancer in a cohort of male Norwegian offshore oil workers. Methods The Offshore Cohort was comprised of > 25 000 men who were employed at installations in the North Sea in the period 1965-1999, and who responded to a questionnaire that included work history offshore, other occupational experience, education, leisure-time activities, and lifestyle factors. Calculating standardized incidence ratios (SIR), we compared the number of prospective incident cancers diagnosed between 1999 and 2005 with those expected for age-, gender-and period-specific rates in the general Norwegian population. Results The overall cancer incidence did not differ from that of the reference population [SIR=1.0, 95% confidence interval (95% CI) 1.0-1.1, N=695]. There were indications of excess risks of acute myeloid leukemia (SIR= 2.0,95% CI 1.0-3.7) and cancer of the pleura (SIR=2.2,95% CI 0.9-4.6). No data on occupational history was used in these preliminary analyses. Conclusions The cohort was relatively young and an extended observation period would be important for in-depth analyses. The suggested excess of leukemia and cancer of the pleura may be linked to occupational exposure during employment offshore; this issue needs to be addressed in further studies.