Body mass index trends and quality of life from breast cancer diagnosis through seven years’ survivorship

BACKGROUNDWeight gain is a potential negative outcome of breast-cancer treatment,occurringin 50%-to-96%of breast-cancer patients,although the amount of weight gain isinconsistently reported in the literature.Research has also shown a relationshipbetween overweight/obesity and breast-cancer mortality.Correspondingly,weight management is a self-care approach known to benefit quality of life(QOL).These research questions and analysis add to existing literature byexamining participants’body mass index(BMI)trend and its relationship withQOL indicators over seven years.AIMTo examine:(1)BMI trends among breast cancer survivors;and(2)The trends’relationship to QOL indicators over seven years.METHODSDuring the Breast Cancer and Lymphedema Project,378 patients’weight andheight were recorded by nurses prior to or just after beginning breast cancertreatment and repeated at quarterly-to-semiannual intervals over seven years.Additionally,participants annually completed the 36-Item Short Form HealthSurvey(SF-36),a valid and reliable tool assessing QOL and health concepts,including physical function,pain,and emotional well-being.BMI trends,changein BMI,and change in SF-36 subscales over seven years were calculated using arandom-intercept repeated-measures regression.Patients were placed into BMIcategories at each time point:Normal,Overweight and Obese.As patients’weights changed,they were categorized accordingly.RESULTSDuring the seven-year study and while controlling for age and residence,participants gained an average of 0.3534 kg/m^2(P=0.0009).This amountremained fairly consistent across BMI categories with those in the normal-weight category(n=134)gaining 0.4546 kg/m^2(P=0.0003);Overweight(n=190)gaining 0.2985 kg/m^2(P=0.0123);and obese(n=199)gaining 0.3147 kg/m^2,(P=0.0649).Age(under or over 55)and region(metro/micro vs small/rural)weresignificantly associated with BMI increase in both the normal and obesecategories.There were statistically significant(P<0.0100)changes in five of theeight SF-36 domains;however,the directions of change were different andsomewhat divergent from that hypothesized.Controlling for age and region,these five were statistically significant,so there were no change or differencesbetween the micropolitan/metropolitan and small town/rural groups.CONCLUSIONAlthough only modest increases in mean BMI were observed,mean BMI changewas associated with selected QOL indicators,suggesting the continued need forself-care emphasis during breast cancer survivorship.