Is there a 'cancer corridor' in Louisiana?

Cancer mortality rates in South Louisiana are higher than the national averages, leading to the area's designation as a "cancer corridor". This study was conducted to assess whether incidence data substantiate the reputation derived from mortality statistics. Age-adjusted cancer incidence rates for 1983-1987 were calculated for South Louisiana as a whole, for five regional divisions of it, and for the combined nine areas of the Surveillance, Epidemiology, and End Results (SEER) program. Significantly lower (p < 0.0001) incidence rates were found in South Louisiana among white females, black males, and black females for cancers of all sites combined; among women of both races for cancer of the breast; among men of both races for cancers of the colon and prostate; and among whites of both sexes for melanoma and rectal cancer. South Louisiana incidence rates were significantly higher than the SEER rates only for lung and larynx cancers in white males. The excess of lung cancer was statistically significant in four out of five regions while the laryngeal cancer excess was significant only in the New Orleans area. The excessive mortality rates reported for South Louisiana are not the result of excessive incidence. These results indicate poorer cancer prognosis in this region, a phenomenon that deserves more scrutiny by the health profession.