Aim:Having experienced previous traumatic events has been suggested to increase the risk of developing post-traumatic stress (PTS) symptoms following traumatic events later in life. We investigated the association between severity of PTS-symptoms related to a previous non-cancer traumatic event and the severity of breast cancer-related PTS-symptoms in two culturally distinct samples.
Methods: A total of 489 of 643 Palestinian women (mean age: 47.6 yrs) and 683 of 992 Danish women (mean age: 58.1 yrs) treated for breast cancer completed questions concerning “the most traumatic event other than cancer” together with two versions of the Impact of Event Scale-Revised (IES-R) with reference to their cancer (CA-IES) and the other traumatic event (OE-IES).
Results: Palestinian women had higher CA-IES-scores (M=39.85; SD=13.7) than Danish women (M=15.68; SD=21.73; p<0.001). A total of 175 (38.8%) Palestinian and 86 (20.5%) Danish women reported a non-cancer traumatic event before their diagnosis, with “war and combat” being the most frequent (34.3%) among Palestinians, and “death of a friend or loved one” (38.4%) the most frequent among Danes. The OE-IES scores related to these events were higher among Palestinian women (M=41.3; SD=12.6) than Danish (M=17.9; SD=17.4; p<0.001). Two hierarchical multiple regressions, adjusting for demographic and clinical variables, showed that for Palestinian women, OE-IES was a significant predictor of CA-IES (β= 0.54; p<0.001; CI(B): 0.48–0.71) together with older age, being married, having relapse, and tumorectory (p:0.001-0.039). Among Danish women, OE-IES did not predict CA-IES (β=-0.04;p=0.76; CI(B):-0.24–1.78), and only the number of affected lymph nodes reached statistical significance (β=0.36; p<0.001; CI(B): 0.41–1.82).
Conclusions: The severity of PTS-symptoms related to a previous non-cancer traumatic event was a strong predictor of breast cancer-related PTS-symptoms in Palestinian women, but not in Danish women. Our findings could be explained by between-sample differences in life circumstances, including the types of non-cancer traumatic events.