Based on a survey of the literature, a summary of the etiology of endometrial cancer (EC) is presented. The effect of a number of expositions on the risk of developing EC, expressed as odds ratio or relative risk, are indicated. Combining these with the prevalence of the specific exposition allows calculation of the etiologic fraction (EF) for each risk factor. The etiologic fraction indicates the proportion of EC that would disappear if the exposition were eliminated. Obesity increases the risk of EC with a factor three to four. One quarter of Danish women of 60-70 years of age have a relative weight exceeding 1.2 times the ideal weight. The corresponding EF is 41%. Oestrogen substitution therapy is connected with an odds ratio of EC of 3.8 and an EF of 8%, anticipating that the lifetime prevalence of pure oestrogen substitution is 3%. On the other hand, oral contraceptives imply a reduction in EC of 14%, parity of 37% and cigarette smoking of 26%. It appears that the etiology of EC is multifactorial, and that a number of disposing and protecting factors are identified and quantified. The greatest prophylactic potential seems to be in reducing weight among obese women.
In an attempt to clarify the correlation between the spread of a local anesthetic and a radiographic contrast medium in the epidural space, a lumbar epidural catheter was inserted in 21 cancer patients. In group 1,10 patients, a single dose of bupivacaine 0.5%, 8 ml, was injected. The epidural block was evaluated by assessing loss of pin-prick sensation. The following day a contrast medium, iohexol 180 mg I/ml, 1.2 ml, was injected and the position of the catheter determined. A second dose of iohexol 180 mg I/ml, 8 ml, was injected and epidurograms were taken. The vertebral spread was measured in cephalad and caudad directions from the catheter tip. Group II, 11 patients, underwent the same procedures as group I with the exception of the volumes injected. On the first day they were given bupivacaine 0.5%, 16 ml, and on the second day iohexol 180 mg I/ml, 1.2 ml, followed by 16 ml. In both groups the position of the patients was supine and the speed of injection standardized. In group I there was no statistically significant correlation between the spread of contrast medium and the extension of the epidural block either in the cephalad or in the caudad direction. In group II there was a statistically significant correlation in both the cephalad and caudad direction. It is concluded that epidurography can provide an estimate of the epidural block, but cannot predict the exact segmental distribution of the block.
