Table 15

Regression Analysis of the Main Effects of Independent
Variables for Breast Cancer



Variable df F p


Age 1 0.49 .4885
Race 1 2.01 .1611
Stage 4 2.11 .0912
Histology 2 0.73 .4840
Initial treatment 15 0.98 .4909
Subsequent treatment 13 2.93 .0025


 Of the independent variables tested, only the main

effect of subsequent treatment was significant [ F (13,59) =

2.93, p = .0025]. The variable stage was also retained for

further study because of the relatively low value of p.

 The second regression analysis included the same six

main effects as well as the following interactions: Age x

Stage, Age x Histology, Age x Initial Treatment, Age x

Subsequent Treatment, Race x Stage, Stage x Initial

Treatment, and Age x Stage x Initial Treatment. This

regression model was not statistically significant ( p =

.0586) and none of the interactions tested were significant

at the .05 level.

 These findings were used to develop two additional

regression models with fewer independent variables. As noted

previously for the lung cancer cases, at this point the

dependent variable was transformed by taking its natural log.