Chemoradiation for cervical cancer treatment portends high risk of pelvic floor dysfunction

Abstract

Goal: To assess the impact of chemoradiation on pelvic floor (PF) muscle function after the treatment of cervical cancer (CC).

Methods: We performed a prospective cohort study of women between the ages of 20 and 70 years old who had a diagnosis of CC. Patients were treated with chemoradiation at the Barretos Cancer Hospital (BCH), between August 2016 and July 2017. We performed three evaluations at different time points after chemoradiation treatment to compare changes in muscle function. Pelvic floor muscle function was assessed through perineometry (PNM) and surface electromyography (EMG) at the following time points: Pretreatment Moment 1 (M1): evaluated before chemoradiation; Moment 2 (M2): at the first follow-up medical visit (usually 3 to 4 months after treatment); and Moment 3 (M3): at the second follow-up medical visit (usually after 6 to 9 months after treatment). Mean vaginal squeeze pressure levels were determined by PNM and muscle electromyographic activity by EMG and the results were evaluated by Generalized Linear Model comparisons.

Results: Forty-nine patients were evaluated at M1; 35 at M2; and 32 at M3, so that 32 patients had all three muscle evaluations performed. There was a statistically significant increase in the frequency of women with urgency urinary incontinence at the M2 evaluation time (41.9%), compared to pretreatment M1 (18.6%), p<0.001. The means of the vaginal squeeze pressures reduced through M1 to M3 in the phasic (M1: 17.7 mmHg; M3: 11.27mmHg) and tonic contractions (M1: 10.56 mmHg; M3: 7.52mmHg), p = 0.01 and p = 0.03 respectively. There was no difference in pelvic floor function in the three evaluations M1-M3, measured by EMG. The pelvic floor strength assessed by PMN and their interactions with anthropometric, parity and hormonal status variables, showed that a high body mass index (BMI) significantly influenced decreases in pelvic floor muscle function before and after treatment.

Conclusion: These results show that chemoradiation causes reduction of muscle function of the pelvic floor, especially in the late phase after the end of treatment. Both the high BMI and urgent urinary incontinence symptoms were related to decreased muscle strength.

Fig 1. Recruitment flowchart and evaluation moments of study patients.

IC: Informed Consent; EMG: Surface electromyography; M1: Evaluation at Moment 1 (before treatment); M2: Evaluation at Moment 2 (from 90 to 120 days after the end of the treatment); M3: Evaluation at Moment 3 (from 200 to 270 days after the end of the treatment.

Fig 2. Means of phasic and tonic contractions measured through PNM and surface EMG, in the three moments of evaluation.

A—Means of phasic contractions measured by PNM at moments of evaluation. B—Means of tonic contractions measured by PNM at moments of evaluation. C—Means of phasic contractions measured by EMG at moments of evaluation. D—Means of tonic contractions measured by EMG at moments of evaluation.