THE SAFETY OF TENS ON CERVICALCANCER PATIENTS
X. SUN1, S. WANG 1,J. WANG 2;
1Dept. Ob Gyn, Peking Univ.People's Hosp., Beijing, China, 2Peking Univ. people'sHosp., Beijing, China.
Introduction: There is nearly131.5 thousands new cases of cervical cancer (CC) per year in China,account for 28.8% all over the world. With the popularity of cervicalcancer screening, the proportion of early stages cervical cancer isgetting higher & higher. Class III radical hysterectomy pluspelvic lymphadenectomy is the standard surgery for early stagecervical cancer patients with the 5 year survival rate about 90%.But postoperative pelvic floor disorders especially bladderdysfunction is common due to the damaged vessels & nerve fibersduring the surgery which significantly deceased their lifequality. Transcutaneous low frequency electrical stimulation(TENS) treatment is a non-pharmacological method which is currentlyused by many clinics in many areas including pain relief &function improvement . It is proved to be effectively on treatinglower urinary tract symptoms (LUTS) . Recently some doctors use TENSto treat voiding problems for CC patients after class III radicalhysterectomy. They believed that TENS can shorten the duration ofindwelling catheter & improve voiding function. But would thepulse electrical field (PEF) caused by electrical stimulation enhancethe proliferation of cancer cell thus lead to the recurrence andmetastasis? What's the effect of such PEF on cervical cancer & isit safe for these patients? No clinical or experimental data wasfound by now.
Objective: To determine the effect of PEF oncervical cancer cells & to investigate the safety of TENS oncervical cancer patients
Methods: 1. In vitro experiment:PEF device is designed to imitate TENS which is commonly used inclinic with the frequency 1/4/1HZ & pulse-width 230/270/230μs.Cervical cancer SiHa cells in logarithmic growth period were treatedwith microsecond PEF for 30 mins. According to the different electriccurrent intensity, cells were divided into four groups: 20 mA,40mA,60 mA group & control group(no electrical stimulation). Cellsgrowth ability & migration ability were determined by using CCK-8proliferation assay & Transwell chamber Matrigel migration assay.2. In vivo experiment: Mice cancer model was established bysubcutaneous implanting of human cervical squamous cancer SiHa cells.Mice were divided into TENS group & control group randomly with 5in each group. TENS treatment was performed to mice in TENS group for20 minutes after the tumor grow to 0.4-0.5cm in diameter. Theparameters used was frequency 1/4/1HZ, pulse-width 230/270/230μs ¤t intensity 20mA. Mice in control group received the sametreatment unless the electrical stimulation. The growth trend of thetumor & the tumor volume was compared between the two groups withthe cut-off time 28 d after PEF treatment. The proliferation &apoptosis of the tumor was determined by immunohistochemistrymethod.
Results: (1) CCK-8 proliferation assay showed nodifference of the cell proliferation after treated 4h, 24h, 48h &72h with 0 mA, 20mA, 40mA & 60mA of PEF stimulation(4h:F=3.357,P=0.076; 24h:F=1.285, P=0.344; 48h:F=1.047,P=0.423; 72h:F=0.277, P=0.841). (2) Cellsmigration ability had no difference among the groups (F=0.364,P=0.779). (3) Tumor growth speed, the tumor size & tumorweight had no significant difference between the two groups. (4)Expression of VEGF and CD34 showed that there had no significantlydifference between the two groups. The apoptosis antibody ofcaspase-3 & proliferation antibody Ki-67 also showed nosignificant difference between the two groups.
Conclusions:In vitro experimental results indicate that microsecond PEF had noeffect on the proliferation & migration of cervical cancer SiHacells. Also it had no siginificanly influence in the tumor growth,tumor cell apoptosis & proliferation.
References: 1.Chinese Journal of Obstetrics & Gynecology &Pediatrics,2015,11(02):1-62. 2. Obstet. Gynecol. 1986; 68: 111-120.3. Int Urogynecol J,2012,23:993-1005