Anti-Mullerian hormone levels in female cancer patients of reproductive age in Indonesia: A cross-sectional study

Introduction

Reproductive preservation efforts for cancer patients have become an important aspect of cancer management. Of all female cancer cases worldwide, 10% of cases occur during reproductive age¹. Most cancer patients do not have an opportunity to preserve reproductive function prior to cancer treatment, and decline in reproductive function is known to occur after exposure to cancer treatments, whether it be chemotherapy or radiotherapy. In total, 68% of cancer survivors of reproductive age who have undergone anti-cancer treatments experience infertility, amenorrhea, reduction of ovarian reserves, and premature ovarian failure. Ovarian reserves also decrease with increasing age^2,3, therefore, the American Society of Clinical Oncology (ASCO), and the American Society for Reproductive Medicine (ASRM) have recommended that consultation on fertility preservation methods prior to cancer therapy should be provided⁴. However, there is an ongoing debate on whether the ovarian reserves of cancer patients could be reduced long before exposure to anti-cancer therapy.

The measurement of the anti-Müllerian hormone (AMH) levels is known to be the best parameter for predicting ovarian reserves, which represent reproductive function⁵. Low AMH levels reflect a low ovarian reserve^6,7.

Several studies have shown that in breast cancer and lymphoma patients, ovarian reserves are already decreased prior to cancer therapy. However, other studies have shown that a decreased ovarian reserve is only associated with increasing age. It is, therefore, important to know whether the ovarian reserves in cancer patients decrease before or after therapy. This will help predict the reproductive function in such cases and the effectiveness of ovarian preservation efforts.

Methods

Results

The 88 subjects participated in this study, with similar characteristics between the two arms. The mean age for cancer and non-cancer groups was the same, 28 years. For the cancer patient menarche age was 11 years. Body mass index for cancer patients was 20.7 ± 3.89, and non-cancer patients 19.5 ± 2.561. Both groups have the same parity average of 0. The mean AMH level for cancer patients was 1.11 ng/ml (0.08–4.65 ng/ml), and for non-cancer patients 3.99 ng/ml (1.19–8.7 ng/ml). The biological age for cancer patients based on an AMH level of 1.1 ng/ml was 38 years old, and for non-cancer patients 3.99 ng/ml corresponded to 28 years old. Characteristics of research subjects can be seen in Table 1. Of all the cancer patients recruited in the study, 14 subjects were gynecologic cancer patients and 30 subjects were non-gynecologic cancer patients, the distribution of cancer cases can be seen in Table 2.

Overall, the AMH levels were abnormally distributed (Kolmogorov-Smirnov test for normality, p-value <0.001) with a median level of AMH 2.06 ng/ml (0.08–8.78 ng/ml). AMH levels in the cancer group were lower than that of the non-cancer group (1.11 [0.08–4.65] ng/ml vs. 3.99 [1.19–8.7]; p-value <0.001). This study also showed that there were no statistically significant differences between the AMH levels of the gynecologic cancer patients 0.965 ng/ml (0.08–2.65 ng/ml) and the non-gynecological cancer patients before treatments 1.49 ng/ml (0.08–4.65 ng/ml); p-value 0.162.

Discussion

In line with advances in cancer therapy, the survival rate of cancer patients also increases. Unfortunately, this rate of improvement does not coincide with an increased quality of life, especially in regards to reproductive function. Currently, one of the best parameter to measure ovarian reserves is by measuring serum AMH levels; AMH levels can also help predict biological age, which is of more importance when assessing reproductive function.

There are several types of cancer known to be associated with decreased ovarian reserves prior to cancer therapy, such as Hodgkin and Non-Hodgkin’s lymphoma, and breast cancer. Lawrenz et al. demonstrated that the AMH levels of lymphoma patients were lower than that in non-cancer patients, with mean AMH levels of 2.06 ng/ml vs. 3.20 ng/dl (p- value <0.05)⁹. Su et al. conducted a similar study wherein the AMH levels of the breast cancer patients were lower than that of the non-cancer patients, 0.6 ng/ml vs. 1.1 ng/ml (p- value <0.001)¹⁰. Van et al. also conducted a broader study in 2014 comparing the AMH levels in young cancer patients (<18 years) before treatment with non-cancer patients (age-matched). The results showed that AMH levels in the cancer group were significantly lower than that of the non-cancer group, 1.4 mg/l vs. 3.0 mg/l (p- value <0.001)¹¹. The results of these three studies were similar to that of our study; the AMH levels of the 44 reproductive age cancer patients prior to cancer treatment were lower than that of the non-cancer patients (1.11 [0.08–4.65] ng/ml vs. 3.99 [1.19–8.7] ng/ml; p- value <0.001).

Although some studies have shown that the ovarian reserves of reproductive-age cancer patients before treatment are lower than that of the non-cancer patients, the factors that directly affect AMH levels are still unknown. Several studies have suggested genetic mutations, such as BRCA gene mutations, may affect ovarian reserves in breast cancer patients^12–14; the effects of high cytokines in lymphoma patients indirectly affect the ovarian reserves as well^15,16. In non-cancer populations, Jung et al. has proven that only the age of menarche affected the concentration of AMH (age of menarche <12 years vs. ≥14 years, 0.90 ng/mL vs. 1.12 ng/mL), while ethnicity, BMI, education level, smoking status, height, and menstrual cycle are not associated with AMH concentrations. There was no significant variations in AMH concentrations between Asian women and white women (age-adjusted model ; p < 0.77, multivariable model ; p < 0.62)¹⁷. Bleil et al. found there was a statistically significant race/ethnicity-by-linear age interaction among healthy and regularly cycling women, indicating that differences in AMH levels between race/ethnic groups varied as a function of age¹⁸. Su et al. found that age, BMI, parity, and smoking status are not associated with decreased levels of AMH in patients with breast cancer¹⁰. The differences result between previous studies may arise from the varying environment conditions, and heterogeneous character of the populations studied. Serum AMH levels may be influenced by genetic and environmental factors. Our study found that the decreasing level of AMH in cancer group before therapy was related to older of biological age. The result of biological age from both groups were adjusted by Indonesian Kalkulator of Oocytes (IKO) and referred to previous study from Wiweko et al. among Indonesian women who went through AMH level test. By using data from this study as reference, we could exclude racial differences of AMH¹⁹.

In contrast to other types of non-gynecological cancers, reproductive preservation in gynecological cancers is not widely discussed. This is related to the fact that the genital organs themselves are involved in the cancer and the local treatments of such cancers are destructive to the organs of reproduction²⁰. Therefore, in this study, we compared the AMH levels of gynecologic patients of reproductive age before receiving cancer treatment with the non-gynecological cancer patients, and we found no significant difference between AMH levels (0.965 ng/dl vs. 1.49 ng/dl; p- value 0.162). However, the unequal size of the gynecological and non-gynecological cancers subject groups in our study may have affected the results. With increasing age the capability of a woman to produce appropriate quality oocytes, and quantity of oocytes decreases; this process, called ovarian aging, is defined as a gradual decrease in both the quantity and quality of the oocytes. The decrease in the quality and quantity of these oocytes is related to chronological age and biological age²¹. Chronological age is determined by the passage of time from birth, while the biological age is determined by physiology²². Biological age affects the reproductive function more than chronological age, besides that ovarian reserve is a good marker for representing the biological age of the ovary. In this study, the biological age of the cancer group was 10 years higher than that of the non-cancer group, indicating that ovarian aging occurs earlier in cancer patients. This would indicate that reproductive preservation methods should be offered long before cancer patients undergo therapy.

There is a hypothesis that reported a decreased number of ovarian follicles and an increased gonadotropin level which caused an inflammatory environment and changing epithelial cell surface and the development of tumors in the ovary²³. Other studies have suggested genetic mutations were associated with ovarian aging. Johnson et al. observed BRCA2 carriers had significantly lower AMH levels compared to healthy, low-risk women and had increased odds of having a low AMH (OR 3.69, 95% 1.34–10.19, p=0.012). BRCA 2 as tumor suppressor genes which involved in the regulation of follicular pool through impairment of DNA repair pathway and affected ovarian reserves in breast cancer patients²⁴. A study in lymphoma patients showed significantly lower AMH levels than in the control group. There is a strong negative correlation between AMH with SIL-2R, IL-6, and IL-8 cytokines exists¹⁵. The impairment of DNA repair mechanisms may affect the granulosa cell function. This condition cause AMH decreased independently in childhood cancer¹¹.

There are many reproductive preservation techniques; however, one of technique for cancer patients is ovarian cryopreservation. This technique consists of two methods: the slow cooling method and vitrification ovary. Based on the research conducted by Wiweko et al., ovarian vitrification techniques are superior to the slow cooling method²⁵. Ovarian vitrification does not alter the morphology of the granulosa cells, or the stromal and ovarian collagen components¹⁹. It has also been shown to not change the morphology of the pre-antral follicle nor does it increase the risk of cell apoptosis^19,25. Other options that may still be offered to cancer patients of reproductive age are oocyte cryopreservation and embryo cryopreservation. In patients who already have a partner or are married, embryo cryopreservation can be offered, however, this may delay cancer therapy due to the ovarian stimulation process required for this technique. In addition to this, estrogen exposure given at the time of ovarian stimulation may have an adverse effect in estrogen sensitive tumors. Unlike embryo cryopreservation, cryopreservation of the oocytes can be used for single women who can undergo the stimulation cycle, but the effectiveness of this technique is very low. The pregnancy and delivery rates range from 1 to 5% per frozen oocyte²⁶. The current weakness of this study is that the other gynecological abnormalities that may affect AMH levels in both groups were not included in the screening criteria for exclusion, such as genetic factors and the type/stage of cancer or other diseases which may affect the levels of AMH, were also not studied.

Conclusions

This study showed that the AMH levels in reproductive age patients before receiving therapy were lower in contrast to that in the non-cancer patients (1.11 ng/ml vs. 3.99 ng/ml; p- value <0.001). In addition to this, there was no significant difference in the AMH levels between the gynecologic and non-gynecologic cancer groups before treatment (0.965 ng/dl vs. 1.49 ng/dl; p- value 0.162).

Data availability

F1000Research: Dataset 1. All raw data and demographic information obtained from subject during the present study, https://doi.org/10.5256/f1000research.15728.d229186²⁷.