Associations of illness perception and social support with fear of progression in young and middle-aged adults with digestive system cancer: A cross-sectional study

While Fear of progression (FoP) is a natural reaction in cancer, elevated FoP can impact life quality and social function. Our study aims to explore how illness perception, social support, and posttraumatic growth influence patients' FoP. This study enrolled 243 young and middle-aged adults with digestive system cancer at a hospital in Guangzhou from November 2022 to November 2023. In this study, the measurement instruments utilized included The Fear of Progression Questionnaire-Short Form, The Brief Illness Perception Questionnaire, The 12-item Perceived Social Support Scale, and The 21-item Posttraumatic Growth Inventory. Data was analyzed employing polynomial regression and response surface analyses. The mean score of FoP was 35.45 ± 10.05, and 59.3% of the cancers (scores≥34) had clinically dysfunctional levels of FoP. Regarding congruence, patients' FoP was higher when the levels of illness perception and social support were both low or high than when the levels were both intermediate. Regarding incongruence, patients' FoP was lower when the level of illness perception was low and social support was high compared with when the level of illness perception was high and social support was low. Additionally, posttraumatic growth moderated the (in)congruence effect of illness perception-social support on the FoP of patients. Low or high illness perception-social support congruence was detrimental to the FoP of patients. Low illness perception-high social support incongruence was beneficial to patients' FoP. Posttraumatic growth can be a positive factor for enhancing the impact of low illness perception-high social support incongruence on patients' FoP. •This is the first time to explore the FoP in young and middle-aged adults with digestive system cancer.•There were different (in)congruence effects of IP-SS on the FoP of patients.•PTG moderated the (in)congruence effect of IP-SS on the FoP of patients.•Providing a new perspective on alleviating patients' FoP.