Urinary incontinence was highly prevalent at diagnosis in women with early-stage breast cancer, a prospective, observational study has found. These findings were reported in the Journal of the National Comprehensive Cancer Network.1
In addition, there is some evidence supporting an increased prevalence of urinary incontinence in women with breast cancer who were treated with endocrine therapy and those at high-risk of the disease who received endocrine therapy as chemoprevention.
Nevertheless, many of the studies investigating the impact of systemic therapy for breast cancer on bladder symptoms were population-based studies in which preexisting urinary incontinence arising from causes other than breast cancer therapy was not evaluated.
This study enrolled women with stage I to III breast cancer diagnosed at a tertiary cancer center between 2015 and 2017. Eligibility criteria included planned treatment with neoadjuvant or adjuvant chemotherapy or systemic therapy.
Prior to and 3 months following the initiation of systemic therapy, study patients completed 2 quality of life (QOL) measures for the assessment of urinary incontinence — the Incontinence Impact Questionnaire (IIQ-7) and the Urogenital Distress Inventory.
Urinary incontinence was considered to be present if the patient reported being bothered by at least 1 urinary symptom, The level of urinary incontinence was classified as high, moderate, or low if the patient reported being “greatly bothered,” “moderately bothered,” or “slightly bothered,” respectively, and the impact of urinary incontinence was classified as major, moderate, or no impact. In addition, urinary incontinence was defined as prevalent, incident, or stable if it was present at baseline, new or worse following 3 months of treatment, or present at baseline and unchanged after 3 months of treatment, respectively.
Baseline characteristics of the 203 patients in the study who completed QOL questionnaires prior to initiation of systemic therapy included mean age, 54.5 years; mean body mass index (BMI), 29.0 kg/m2; and approximately 17% were nulliparous. The study population was racially and ethnically diverse with 55.2% classified as non-white Hispanic, 18.7% as Hispanic, 15.3% as Asian, and 5.4% as black. Nearly three-quarters of patients reported being never smokers.
A key study finding was that approximately 80% of patients had prevalent urinary incontinence at baseline. Overactive bladder, stress incontinence, and mixed incontinence were reported in 29.1%, 10.8%, and 39.9% of patients, respectively. Although BMI was significantly associated with the level of urinary incontinence (P <.05), parity and smoking history were not. In patients reporting prevalent urinary incontinence, 13.6%, 29.6%, and 56.8% classified it as major, moderate, or having no impact on QOL, respectively.
Of the 163 patients who completed QOL assessments at baseline and 3 months following the start of systemic therapy, 44.2% received endocrine therapy, with 35.8% and 17.8% of patients treated with taxane-based and anthracycline-based chemotherapy, respectively. For the 131 patients in this group with prevalent urinary incontinence, incident urinary incontinence developed in 27 patients, with the remaining 94 patients reporting stable urinary incontinence following systemic therapy. In addition, 12 of the 32 patients without prevalent urinary incontinence at baseline reported incident urinary incontinence following treatment with endocrine or chemotherapy. Of note, compared with prevalent or stable urinary incontinence, the impact of incident urinary incontinence on QOL was lower (odd ratio [OR], 0.40; 95% CI, 0.17–0.94; P =.036).
“The incidence [of urinary incontinence] we observed seems higher than one would expect of women in this age group without breast cancer,” noted the study authors. “This frequency raises the question of whether risk factors for developing breast cancer overlap with those for developing [urinary incontinence], an extremely common problem in breast cancer survivors.”
They further identified a need for management approaches for patients with cancer experiencing urinary incontinence, given that survivorship guidelines from the National Comprehensive Cancer Network (NCCN) do not currently address this issue.2
1. Chung CP, Behrendt C, Wong L, Flores S, Mortimer JE. Serial assessment of urinary incontinence in breast cancer survivors undergoing (neo)adjuvant therapy. J Natl Compr Canc Netw. 2020;18(6):712-716.
2. National Comprehensive Cancer Network. NCCN Clinical Practice Guidelines in Oncology (NCCN Guidelines®) Survivorship V1.2020 — March 17, 2020. Accessed June 26, 2020. https://www.nccn.org/professionals/physician_gls/pdf/survivorship.pdf