To compare the prevalence, distress and impact of pelvic floor (PF) dysfunction (urinary incontinence (UI), faecal incontinence (FI) and pelvic organ prolapse (POP)) between women with and without breast cancer and to examine the associations between breast cancer and the presence, distress and impact of PF dysfunction.

Cross-sectional study

Women with and without breast cancer were invited to participate. For the cohort with breast cancer, we included women who had undergone primary treatment (surgery, radiotherapy, chemotherapy or endocrine therapy) and/or adjuvant therapy for a histologically confirmed breast tumour and were ≥ 18 years of age. They were recruited from outpatient clinics at a tertiary public hospital. For the control cohort, we included women with no history of breast cancer who were recruited from targeted women’s health groups on social media sites. Socio-demographic and medical variables were collected such as age, body mass index (BMI), parity, menopausal status, relationship status, social situation, educational level, employment, smoking, medical history and medications. Additional clinical data including breast cancer stage, treatment status and type were obtained from the cohort with breast cancer from medical records. The sample size calculation was based on an assumption of 20% difference in the prevalence of UI between groups1, 80% power and 95% confidence intervals. A sample size of 240 participants (120 per group) was needed to detect a difference in the prevalence of UI. The Pelvic Floor Distress Inventory (PFDI-20) and Pelvic Floor Impact Questionnaire (PFIQ-7) were used to quantify the prevalence, distress and impact of PF dysfunction. The presence of UI was established using an affirmative response to question 16 or 17 on the PFDI-20. An affirmative response to question 9 or 10 of the PFDI-20 established the presence of FI and question 3 established the presence of POP. The distress of PF dysfunction was quantified using PFDI-20 and the impact of PF dysfunction using PFIQ-7. These questionnaires were scored using the published scoring algorithm. Participant demographics, prevalence data and questionnaire summary scores were reported descriptively. Differences in participant demographics and questionnaire scores between the two groups were examined using appropriate bivariate tests e.g. independent t–tests or χ2 tests. Associations between PF outcomes in the two groups were examined using logistic and linear regressions while controlling for age, BMI and parity.

120 women with breast cancer, and 170 women without breast cancer were included. Women with breast cancer were older and had a higher BMI (mean age 53, SD=12; mean BMI  31 kg/m2, SD=7) than the cohort without breast cancer (mean age 40, SD=12; mean BMI 27 kg/m2, SD=7). Parity was similar in both cohorts. In women with breast cancer, cancer stage varied with representation across stage I (13%), II (36%), III (30%) and IV (23%). Sixty percent of women with breast cancer underwent chemotherapy (n=72), 27% underwent radiotherapy (n=32), 73% had at least one type of surgery (n=87) and 60% were currently taking endocrine therapy (n=72). Seventy-four percent of women with breast cancer (n=88) experienced any type of UI, compared to 57% in the control group (n=97) which was significantly different (p=0.0049). Women with breast cancer had slightly higher odds of experiencing UI (OR 1.10; 95%CI 0.59, 2.03) however, this association was not statistically significant (see Table 1). In contrast, they had lower odds of experiencing POP (OR 0.67; 95%CI 0.28, 1.48); again, not statistically significant. Both groups reported that urinary symptoms were the most distressing of all PF symptoms. Women with breast cancer had significantly higher distress scores in the urinary domain compared to the control cohort (p=0.0392). The impact of PF dysfunction was also higher in women with breast cancer compared to the control group, especially in the urinary domain (p<0.0001). Overall, having breast cancer was significantly associated with lower distress (β -0.36; 95%CI -0.63, -0.09) of PF dysfunction whilst having breast cancer (β 0.06; 95%CI -0.22, 0.33) was significantly associated with higher impact, demonstrating that women with breast cancer reported a higher impact of PF dysfunction than women in the control group (see Table 2).

Our findings indicate that women with breast cancer experience UI at higher rates than women without breast cancer. However, despite the higher prevalence, this association was not statistically significant once we adjusted for known risk factors of PF dysfunction. This may be because of other unmeasured risk factors (e.g. diet, physical activity levels, family history of UI) that were not captured in this dataset which may have affected the prevalence of UI. However, the absolute rate of UI in women with breast cancer observed in our study is higher than the pooled prevalence reported in a previous systematic review(1), suggesting that routine screening and management of UI may be important for this population. Furthermore, we found that women with breast cancer reported lower distress but a higher impact of PF dysfunction than women without breast cancer, particularly with urinary symptoms. The lower level of distress in the cohort of women with breast cancer may be related to their time since diagnosis; they were within the first five years (mean of 2.3 years) of diagnosis. Women with cancer may be more accepting of conditions unrelated to their cancer during the early phase of their cancer experience due to their focus on survival at this time(2). Despite the low distress, our results show that PF dysfunction was significantly associated with a greater impact on the activities of daily living of women with breast cancer compared with women without breast cancer. It is plausible that women reduce or avoid situations in their daily activities that would provoke UI, in order to cope and minimise the morbidity of PF dysfunction, thereby lowering distress; yet the impact of these modifications is felt as problematic, resulting in higher impact. Additionally, women with cancer tend to seek information and treatment on their ‘unmet needs’, such as menopausal symptoms caused by breast cancer treatments as they approach their 5 year survivorship milestone(3). Therefore, it is possible that women will prioritise treatment for PF dysfunction in later years once they meet their survivorship milestone. Further research to confirm this finding is warranted.

Women with breast cancer experience UI at higher rates than women without breast cancer. The presence of breast cancer was significantly associated with lower distress but higher impact of PF dysfunction. Routine screening and offer of treatment for PF dysfunction (such as PF muscle training) may be indicated in women with breast cancer.

Colombage, U., et al., Prevalence and impact of bladder and bowel disorders in women with breast cancer: a systematic review with meta-analysis Neurourology and Urodynamics, 2021. 40(1): 15-27.
Deimling, G.T., et al., Coping among older-adult, long-term cancer survivors. Psycho-Oncology, 2006. 15(2): p. 143-159.
Knobf, M.T., The Transition Experience to Breast Cancer Survivorship. Seminars in Oncology Nursing, 2015. 31(2): p. 178-182.