Evaluation of the effectiveness of combination therapy utilizing laser-mediated photodynamic therapy in patients with combined hormone-dependent pathology: endometrial hyperplasia and adenomyosis

In recent decades, the incidence of hormone-dependent diseases, including endometrial hyperplasia and endometriosis, has been increasing in many countries worldwide. These two conditions are often diagnosed in the same patient, that significantly complicates treatment. Pathophysiological studies have confirmed that adenomyosis is an estrogen-dependent disorder similar to endometrial hyperplasia (EH) in terms of changes in the hormonal status in patients. Thus, prolonged exposure to endogenous estrogen (for example, early menarche between the ages of 9 and 11, or late menopause) is a risk factor for endometriosis, while the risk of EH increases both with relative endogenous hyperestrogenism associated with obesity and ovulatory dysfunction, and the use of exogenous estrogens, for example, in assisted reproductive technology cycles. Currently, due to an unprecedented level of obesity, we observe the signs of a shift toward increased incidence of EH among women in premenopause and perimenopause [1–4]. Adenomyosis and EH have common risk factors, such as menstrual and reproductive history, smoking, diet, and environmental exposures. Both conditions contribute to infertility. EH is associated with decreased area and height of pinopodia, a two-fold decrease in the expression of leukemia inhibitory factor (LIF) by glandular and stromal cells, that demonstrates decreased endometrial receptivity and is a predictor of implantation failure. Uterine factor infertility is associated both with EH and endometriosis. It is known that in different locations of genital endometriosis the incidence of infertility is approximately 3-4 times higher than in the general population [5–7].

At the same time, there is evidence that matrix metalloproteinase-9 (MMP-9) expression in EH is enhanced depending on the level of estrogen receptor expression, while increased expression of MMP-2 or MMP-9 can be an important factor for the development of adenomyosis, promoting the invasion of endometrial tissue into the myometrium and angiogenesis in adenomyotic foci [8, 9].

A conservative approach to therapy in combination with surgical treatment of external genital endometriosis, which is often found in this category of patients (enucleation of endometrioid cysts, coagulation of endometriotic foci, and others), has demonstrated the highest level of success. However, the rate of disease progression, significant impact on quality of life and fertility dictate the search for new approaches to therapy.

The issues of EH recurrence, limitations for the use of long-term medications, diminished ovarian reserve, formation of intrauterine adhesions or high prevalence of chronic endometritis due to multiple intrauterine interventions in this group of patients remain unresolved. This determines the relevance of searching for new, more effective organ-sparing minimally invasive strategies [10–12].

The use of photodynamic therapy (PDT) for treatment of adenomyosis coexisting with EH is a safe, selective approach that can limit side effects. PDT can be used in combination with other treatment approaches and can help prevent hyperthermia or Asherman's syndrome recurrence by reducing the invasive potential of the endometrium, and thereby preventing subsequent disease progression. Moreover, numerous studies emphasize that PDT is a safe treatment modality for reproductive outcomes [2, 13–17].

The objective of the study was to evaluate the effectiveness of combination of photodynamic therapy (PDT) and traditional hormone therapy on reproductive outcomes, the frequency of clinical manifestations, and the recurrence rate in women of reproductive age with EH and adenomyosis.

Materials and methods

This retrospective single-center comparative study included 48 female patients aged 25–45 years, who were admitted to the Clinic of Professor Pasman with the established diagnoses of adenomyosis and non-atypical EH.

Inclusion criteria in the study were clinically and instrumentally confirmed diagnoses of adenomyosis and EH, which were histologically verified. Exclusion criteria were atypical EH, large uterine fibroids (over 4 cm), malignant neoplasms, male factor infertility.

The dynamics of clinical parameters, the results of laboratory and instrumental examination, as well as histological and immunohistochemical analysis of endometrial biopsies were assessed. The severity of chronic endometritis was determined based on the results of histological and immunohistochemical examinations (including assessment of Syndican-1 (CD 138) expression).

Primary endpoints were reproductive outcomes – the length of time before the onset of pregnancy and getting pregnant during a 36-month follow-up. Secondary endpoints included the frequency of clinical manifestations of adenomyosis and EH (abnormal uterine bleeding (AUB)), heavy menstrual bleeding (HMB), dysmenorrhea, dyspareunia, and the recurrence of EH.

In accordance with the indicated therapy two clinical groups were formed:  group 1 – hormone therapy (n=21) and group 2 – combination therapy using endometrial PDT (n=27). Assessment of reproductive outcomes included pregnancy rate, the length of time before getting pregnant, clinical symptoms before and after treatment, and the recurrence of EH based on follow-up histology of endometrial biopsy specimens. The follow-up period was up to 36 months.

After receiving the results of endometrial biopsy in the outpatient setting and using non-steroidal anti-inflammatory agents or intravenous anesthesia during hysteroscopy (Fig.), the patients with the established diagnosis of chronic endometritis, who had previously signed informed consent, underwent laser-mediated endometrial PDT (the patent for invention RU 2 692 999 C2). For this purpose, photosensitization of the endometrium was performed by intrauterine administration of Radachlorin at a dose of 3.5 mg with exposure time 60–90 minutes. Then uterine walls were irradiated with multi-spot positioning laser at a wave length of 662 nm for 11–13-minutes in non-contact mode until energy density reached 30-40 J/cm² at radiation power of 0.3–0.4 W using a quartz-polymer light guide connected to the Latus semiconductor laser generator [18].

Assessment of reproductive outcomes included the occurrence of pregnancy and the length of time (months) before getting pregnant after surgery with a maximum follow-up period of 36 months. The effectiveness of treatment was assessed based on clinical data, sonographic findings, and morphological examination of tissue samples obtained by endometrial aspiration biopsy.

Statistical analysis

Statistical data processing was performed using JASP statistics package. The quantitative indicators were represented as the median (Me) and interquartile range [Q1; Q3]. The Mann–Whitney U test was used for intergroup comparisons. The categorical variables were presented as n/N (%); Pearson’s chi-squared test was used for intergroup comparisons. Two-sided Fisher's exact test was used for small numbers of frequencies. For binary outcomes relative risk (RR) and 95% confidence interval (95% CI) were calculated. The differences were considered statistically significant at p<0.05.

Results

There was no statistically significant difference between the groups in the median age of patients at the beginning of treatment – 38 [35; 42] years in the hormone therapy group and 37 [35; 40,5] years in the combination therapy group, that indicated comparability between the groups by age (p=0.446).

The groups were comparable by the beginning of the menstrual function (p=0.258). The normal age for menarche prevailed in both groups.

No statistically significant difference was found between the groups in the incidence of external genital diseases (p>0.05 for all diseases), that indicates comparability between the groups by somatic status of patients.

Multiparous women, who had given birth to ≥2 babies were most often observed in the hormone therapy group – 10/21 (47.6%), whereas the number of women who had given birth to 1 baby prevailed in the combination therapy group – 17/27 (63%). Reproductive profile was unfavorable in group 2 – spontaneous miscarriages were most common (p=0.008).

No statistically significant differences in the incidence of gynecological and external genital pathologies were found between the groups (p>0,05). In group 2, infertility, external genital endometriosis and low ovarian reserve, as well as burdened surgical history we observed more often (Table 1), that can indicate a more severe baseline profile of patients in the combination therapy group. The intergroup differences in the frequency of the diagnosed chronic endometritis based on morphological examination were comparable between the groups (p=0.390).

Combination therapy including PDT led to significantly higher pregnancy rate compared with hormone therapy alone. The length of time before the onset of pregnancy among the women who had got pregnant was not significantly different.

The frequency of clinical manifestations after treatment reduced in both groups. Despite lower frequency of AUB, HMB, and dysmenorrhea in the combination therapy group, no statistically significant intergroup differences were found in these parameters.  The patients in both groups did not have dyspareunia after treatment.

Reccurrence of EH was less common among the patients who underwent control morphological examination in the combination therapy group. However, no statistically significant differences were found between the groups (Table 2).

Discussion

The patients in both groups were predominantly of late reproductive age (36–45 years) (Table 1). Probably due to a higher percentage of anovulatory cycles and, as a result, relative progesterone deficiency – a key factor in the pathogenesis of EH [19], as well as the diagnostic features at this age, endometrial biopsy is generally performed after the age of 40. In late reproductive age, women experience longer menstrual periods, that means the prolonged exposure to estrogen. Also, adenomyosis is traditionally most commonly diagnosed in women of advanced reproductive age and in multiparous women, as is published in epidemiological reviews and population data [2, 3, 20, 21].

Despite the fact that some authors reported relationship between early menarche and EH or adenomyosis [3, 20–22], in our study the average age of menarche was most common (Table 1). This confirms that the age at menarche is not a mandatory or universal risk factor for adenomyosis or EH. The absence of a shift toward early menarche in these patients can lead to low clinical suspicion and late verification of the disease, and, consequently, the start of therapy. The researchers report that it takes on average up to 10 years from the occurrence of adenomyosis to its diagnosis and treatment initiation [23, 24].

A history of already realized reproductive function is associated with more favorable chances for subsequent pregnancy and live birth, that is confirmed in the studies by other authors [24, 25] and emphasizes low probability of pregnancy in group 2, despite more successful results obtained in our study.

High infertility rate, low ovarian reserve, and external genital endometriosis are comparable with the data reported by other authors in patients with hormone-dependent pathology [7, 26, 27]. In addition, in the studied patient groups, risk factors were identified for the diseases that also contribute to infertility (menstrual irregularities, overweight or obesity, multiple surgeries leading to premature ovarian failure or diminished ovarian reserve due to external genital endometriosis, and chronic endometritis as a result of intrauterine surgical manipulations) (Table 1) [28–31]. A high incidence of chronic endometritis in both groups reflects the clinical characteristics of patients with combined hormone-dependent pathology as a risk factor for the occurrence and recurrence of hyperplastic processes, impaired endometrial receptivity, and reduced implantation potential.

The obtained data demonstrate the advantages of combination therapy using  PDT for realization of reproductive function (p=0.002) in the group of patients with EH and adenomyosis.  However, the length of time before the occurrence of pregnancy did not significantly differ among the women who got pregnant (p=0.750). Combined hormone-dependent pathology is accompanied by impaired endometrial receptivity, chronic inflammation, altered angiogenesis and local hormonal dysregulation [2, 5–7]. Given the unresolved issues related to the etiology of chronic endometritis, it is suggested that the anti-inflammatory, immunomodulatory, and antibacterial effects of PDT can be a promising, additional pathogenetic therapeutic approach to treatment of  this group of patients. In view of the pathogenetic theory of using PDT, it can be suggested that exposure of the endometrium to free oxygen radicals leads to oxidative stress.

After photosensitizer is localized in the uterine cavity, radiation penetrates the tissue and activates mitochondria, that promotes an increase in cellular ATP. In response to oxidative stress, AMP-activated protein kinase (AMPK) is activated, that in turn suppresses mTOR and stimulates autophagy. This can reduce cyclooxygenase 2 levels, since mTOR plays a role in activating inflammatory responses, as has been demonstrated in numerous studies [32–34]. Helping to reduce inflammation, combination of PDT with traditional therapy for adenomyosis, can improve reproductive outcomes in this group of patients and have a better anti-relapse effect due to the impact on chronic endometritis, the main risk factor for the recurrence of EH.

The frequency of clinical manifestations of combined hormone-dependent pathology in both groups reduced after treatment. Despite the absence of statistically significant intergroup differences in the incidence of persistent symptoms after treatment, low incidence of HMB was in the combination therapy group, and the difference in this indicator was borderline significant (p=0.073). This results seems to be clinically significant, since HMB is one of the leading factors associated with reduction in quality of life, development of anemia and reproductive impairments in patients with EH and adenomyosis [28, 29].

Conclusion

In patients with EH and adenomyosis, combination therapy using PDT was associated with higher pregnancy rate compared with hormone therapy alone. The trend was observed in favor of combination therapy with PDT regarding the recurrence rate of EH and persistence of clinical symptoms after treatment. However, no statistically significant intergroup differences were found for these indicators. The obtained results confirm the potential of including PDT in the complex treatment of patients with combined hormone-dependent pathology and justify the need for further research using large samples.