Prolactin as a local growth promoter in patients with locally advanced tongue cancer: GCRI experience

Serum Prolactin Contributes to Enhancing Prolactin Receptor and pJAK2 in Type I Endometrial Cancer Cells in Young Women Without Insulin Resistance

Elevated levels of serum prolactin and a high expression of prolactin receptor (PRLR) in cancer cells was recently identified in patients with endometrial cancer (EC). However, the impact of prolactin on EC remains unknown. The aim of this study was to elucidate the clinical and immunohistochemical characteristics of hyperprolactinemic patients with EC according to the pathogenetic types, type I and type II. EC patients were retrospectively divided into a high prolactin (HP) group and a low prolactin (LP) group by a serum prolactin level of 20 ng/mL and were compared between 2 groups. The expression of PRLR, phosphorylated Janus-kinase 2 (pJAK2), estrogen receptor-α, progesterone receptor, and PTEN in cancer tissue were evaluated by immunohistochemistry. Ninety-nine patients were identified. In the type I group, HP group was significantly younger (45.2 vs. 52.2, P=0.028) and their insulin resistance was significantly lower (1.6 vs. 2.5, P=0.033) than those in LP group, and the expression of PRLR and pJAK2 in the HP group was significantly higher than that in the LP group (immunoreactive score: 6.8 vs. 3.9, P=0.003; 5.7 vs. 2.6, P<0.001, respectively). In the type 2 group, there were no differences between all the term. In the type I group, the rate of loss of PTEN in the HP group was significantly lower than the LP group (25.0% vs. 60.7%, P=0.024). Prolactin-PRLR signaling may play a crucial role for the progression of type I EC without involving the PTEN mutation in young hyperprolactinemic women without insulin resistance.

A review of the most promising biomarkers for early diagnosis and prognosis prediction of tongue squamous cell carcinoma

BACKGROUND

There is a great interest in developing biomarkers to enhance early detection and clinical management of tongue squamous cell carcinoma (TSCC). However, the developmental path towards a clinically valid biomarker remains extremely challenging. Ideally, the initial key step in moving a newly discovered biomarker towards clinical implementation is independent replication. Therefore, the focus of this review is on biomarkers that consistently showed clinical relevance in two or more publications.

METHODS

We searched PubMed database for relevant papers across different TSCC sample sources, i.e., body fluids (saliva, serum/plasma) and tissues. No restriction regarding the date of publication was applied except for immunohistochemistry (IHC); only studies published between 2010 and June 2017 were included.

RESULTS

The search strategy identified 1429 abstracts, of which 96 papers, examining 150 biomarkers, were eventually included. Of these papers, 66% were exploratory studies evaluating single or a panel of biomarkers in one publication. Ultimately, based on studies that had undergone validation for their clinical relevance in at least two independent studies, we identified 10 promising candidates, consisting of different types of molecules (IL-6, IL-8, and Prolactin in liquid samples; HIF-1α, SOX2, E-cadherin, vimentin, MALAT1, TP53, and NOTCH1 in tissue biopsies) CONCLUSIONS: Although more exploratory research is needed with newer methods to identify biomarkers for TSCC, rigorous validation of biomarkers that have already shown unbiased assessment in at least two publications should be considered a high priority. Further research on these promising biomarkers or their combination in multi-institutional studies, could provide new possibilities to develop a specific panel for early diagnosis, prognosis, and individualized treatments.

Domperidone use and risk of primary liver cancer in the Clinical Practice Research Datalink

BACKGROUND

Pronounced sex-disparity in liver cancer suggests a role for hormones, one of which could be prolactin. Stimulation of prolactin production in mice via domperidone has been reported to decrease hepatocarcinogenesis, thus may have chemopreventive potential. To study the effect of domperidone in humans, a large medical records study was conducted.

METHODS

Based in the Clinical Practice Research Datalink, 1921 liver cancer cases and 7681 controls were identified. Conditional logistic regression was employed to estimate odds ratios (OR) and 95% confidence intervals (CI). Domperidone use was analyzed overall, and by number of prescriptions and cumulative dose.

RESULTS

Comparing ever- versus never-use, there was no association between domperidone and liver cancer among men (OR = 1.06, 95% CI: 0.76-1.48) or women (OR = 1.21, 95% CI: 0.82-1.76). Among men, there was no association with dose or number of prescriptions, while among women who received the highest doses (OR_{2700 mg vs. 0 mg} = 2.52, 95% CI: 1.18-5.41, p-trend = 0.02) and greatest number of prescriptions (OR_{≥11 Rx vs. 0 Rx} = 3.17, 95% CI: 1.07-9.40, p-trend = 0.02) there was a significantly increased risk, although there was no evidence of heterogeneity in the results by gender.

CONCLUSION

Domperidone use was not associated with decreased liver cancer risk among all study participants. Among women, an increased risk at highest levels of exposure warrants further study.

Administration of Cabergoline Contributes to Preserving Fertility in Young Hyperprolactinemic Patients With Endometrial Cancer Treated With Medroxyprogesterone Acetate

Background

An association between high levels of serum prolactin and endometrial cancer (EC) has been reported. However, the effect of antiprolactin drugs on hyperprolactinemic patients with EC has not been determined. The aim of this study was to confirm the effect of cabergoline on young hyperprolactinemic patients treated with medroxyprogesterone acetate (MPA) for the preservation of fertility.

Methods

A retrospective observational study was conducted to identify patients with atypical endometrial hyperplasia or early-stage EC aged 40 years or younger who were treated with oral MPA in Kumamoto University Hospital between 1998 and 2016.

Results

Thirty-four patients were identified and divided into two groups of 17 patients each, including a nonadministration of cabergoline group (noncabergoline group) and an administration of cabergoline group (cabergoline group). The ratio of pathological diagnoses of EC in the noncabergoline group was significantly lower than that in the cabergoline group (29.4% vs 70.6%, P = 0.016). The mean serum prolactin levels showed a significant decrease after the administration of cabergoline in the cabergoline group (25.2 [24.0] vs 5.2 [4.2] ng/mL, P = 0.003), and this decreased level was also significantly lower than that in the noncabergoline group (5.2 [4.2] vs 12.0 [5.0] ng/mL, P < 0.001). Kaplan-Meier analysis conducted for 150 months revealed that the estimated mean period until hysterectomy in the noncabergoline group was significantly shorter than that in the cabergoline group (83.5 vs 140.8 months, P = 0.007). Significant differences were observed in EC but not atypical endometrial hyperplasia based on histological classification (25.6 vs 138.0 months, P = 0.001).

Conclusions

The administration of cabergoline may contribute to preserving fertility in young hyperprolactinemic patients with EC who were treated with MPA.

Breast carcinoma associated with prolactinoma: A case report

We report a 28-year-old woman who presented with a 6-year history of milk-like discharge from both of her nipples and was diagnosed with prolactinoma based on computed tomography (CT) findings and serum prolactin level. Further breast examination revealed a mass located in the upper outer region of the left breast. She underwent subtotal pituitary tumor resection. Thereafter, modified radical mastectomy was performed for left breast cancer. Twelve years after treatment, prolactinoma recurrence was detected, and bromocriptine therapy was administered. No recurrence of breast cancer was discovered. Based on this case report, we stress the importance of prolactin levels due to their possible biologic effects on breast cancer induction or growth.

Differentiated thyroid cancer in patients with prolactinoma

BACKGROUND/AIM

Increasing evidence is available about the role of prolactin in the development of various cancers. The purpose of this study is to evaluate the frequency of thyroid cancer in patients with prolactinoma followed at a single site.

MATERIALS AND METHODS

The medical records of 182 patients diagnosed with prolactinoma were reviewed retrospectively. Serum prolactin, antithyroglobulin, antithyroid peroxidase antibody, thyroid-stimulating hormone, free T4, and free T3 values and pituitary gland magnetic resonance imaging and thyroid ultrasound reports were evaluated.

RESULTS

Forty-five (39.5%) patients were found to have a thyroid nodule (13 solitary, 32 multiple). Ten patients were administered a thyroidectomy, and differentiated thyroid cancer (DTC) was detected in 6 of these patients (6/114, 5.3%). One patient had lung metastasis. The control group consisted of 113 individuals (101 females, 12 males with a mean age of 32.1 ± 9.1). In the ultrasound reports, 28 of these individuals (24.8%) had a thyroid nodule (5 solitary, 23 multiple), and one individual (1/113, 0.8%) had DTC.

CONCLUSION

When compared to the control group, thyroid volume and thyroid nodularity were significantly higher in patients with prolactinoma (P < 0.001, P = 0.018, respectively); however, no statistically significant difference existed for the incidence of thyroid cancer (P = 0.196).

The prolactin receptor as a therapeutic target in human diseases: browsing new potential indications

INTRODUCTION

Prolactin (PRL) signaling has emerged as a relevant target in breast and prostate cancers. This has encouraged various laboratories to develop compounds targeting the PRL receptor (PRLR). As the latter is widely distributed, it is timely to address whether other conditions could also benefit from such inhibitors.

AREAS COVERED

The authors briefly overview the two classes of PRLR blockers, which involve: i) PRL-core based analogs that have been validated as competitive antagonists in various preclinical models, and ii) anti-PRLR neutralizing antibodies that are currently in clinical Phase I for advanced breast and prostate cancers. The main purpose of this review is to discuss the multiple organs/diseases that may be considered as potential targets/indications for such inhibitors. This is done in light of reports suggesting that PRLR expression/signaling is increased in disease, and/or that systemic or locally elevated PRL levels correlate with (or promote) organ pathogenesis.

EXPERT OPINION

The two immediate challenges in the field are i) to provide the scientific community with potent anti-prolactin receptor antibodies to map prolactin receptor expression in target organs, and ii) to take advantage of the availability of functionally validated PRLR blockers to establish the relevance of these potential indications in humans.

Cancer risk in hyperprolactinemia patients: a population-based cohort study

OBJECTIVE

Experimental evidence indicates that prolactin might play a role in tumorigenesis of several human cancers, but data on cancer risk in hyperprolactinemia patients are sparse. The aim of this study was to investigate cancer risk in hyperprolactinemia patients. Design A population-based matched cohort study in Sweden.

METHODS

The hyperprolactinemia cohort consisted of patients hospitalized for hyperprolactinemia from 1987 to 1995 identified in the National Patient Register (n=585) and a hospital cohort of prolactinoma patients at Karolinska University Hospital (n=384). For each patient, ten matched individuals were identified via the Register of Population. Cancer occurrence was ascertained via the Swedish Cancer Registry. Hazard ratios (HRs) were estimated by Cox proportional hazards regression.

RESULTS

Seventy-three malignant tumors were identified in the hyperprolactinemia patients and 660 tumors in the comparison group (HR 1.31; 95% confidence interval (CI): 1.02-1.68), mainly attributed to an increased risk of upper gastrointestinal cancer in both males and females (HR 3.69; 95% CI: 1.70-8.03) and hematopoietic cancer in females (HR 3.51; 95% CI: 1.06-11.6). Twelve breast cancers occurred in the female patients, corresponding to an HR of 1.09 (95% CI: 0.60-1.99). Prostate cancer risk in hyperprolactinemia men was reduced (HR 0.40; 95% CI: 0.16-0.99).

CONCLUSIONS

An increased overall cancer risk was found in hyperprolactinemia patients, but no increased risk of breast cancer in women and a reduced risk of prostate cancer in men. These findings warrant further investigations and to be confirmed in larger studies but may indicate the importance of an active treatment strategy and follow-up of hyperprolactinemia patients.

Prolactin receptor is a negative prognostic factor in patients with squamous cell carcinoma of the head and neck

Background:

The influence of human prolactin (hPRL) on the development of breast and other types of cancer is well established. Little information, however, exists on the effects of hPRL on squamous cell carcinomas of the head and neck (SCCHNs).

Methods:

In this study, we evaluated prolactin receptor (PRLR) expression in SCCHN cell lines and assessed by immunohistochemistry the expression in 89 patients with SCCHNs. The PRLR expression was correlated with clinicopathological characteristics as well as clinical outcome. The effect of hPRL treatment on tumour cell growth was evaluated in vitro.

Results:

Immunoreactivity for PRLR was observed in 85 out of 89 (95%) tumours. Multivariate COX regression analysis confirmed high levels of PRLR expression (>25% of tumour cells) to be an independent prognostic factor with respect to overall survival (HR=3.70, 95% CI: 1.14–12.01; P=0.029) and disease-free survival (P=0.017). Growth of PRLR-positive cancer cells increased in response to hPRL treatment.

Conclusion:

Our data indicate that hPRL is an important growth factor for SCCHN. Because of PRLR expression in a vast majority of tumour specimens and its negative impact on overall survival, the receptor represents a novel prognosticator and a promising drug target for patients with SCCHNs.

Serum prognostic markers in head and neck cancer

PURPOSE

Recognized prognostic factors do not adequately predict outcomes of head and neck cancer (HNC) patients after their initial treatment. We identified from the literature nine potential serum prognostic markers and assessed whether they improve outcome prediction.

EXPERIMENTAL DESIGN

A pretreatment serum sample was obtained from 527 of the 540 HNC patients who participated in a randomized controlled trial. During follow-up, 115 had a HNC recurrence, 110 had a second primary cancer (SPC), and 216 died. We measured nine potential serum prognostic markers: prolactin, soluble interleukin-2 (IL-2) receptor-alpha, vascular endothelial growth factor, IL-6, squamous cell carcinoma antigen, free beta-human choriogonadotropin, insulin-like growth factor-I, insulin-like growth factor binding protein-3, and soluble epidermal growth factor receptor. Cox regression was used to identify a reference predictive model for (a) HNC recurrence, (b) SPC incidence, and (c) overall mortality. Each serum marker was added in turn to these reference models to determine by the likelihood ratio test whether it significantly improved outcome prediction. We controlled for the false discovery rate that results from multiple testing.

RESULTS

IL-6 was the only serum marker that significantly improved outcome prediction. Higher levels of IL-6 were associated with a higher SPC incidence. The hazard ratio comparing the uppermost quartile to the lowest quartile of IL-6 was 2.68 (95% confidence interval, 1.49-4.08). IL-6 was also associated with SPC-specific mortality but not with mortality due to other causes. No marker improved outcome prediction for cancer recurrence or overall mortality.

CONCLUSIONS

IL-6 significantly improves outcome prediction for SPC in HNC patients.

Increase of hypophyseal hormone levels in male head and neck cancer patients

Head and neck squamous cell carcinoma (HNSCC) develops in at least 80% of cases in men with a history of smoking and heavy alcohol consumption, still it is only diagnosed in a small proportion of alcoholics. Endocrine milieu is an important factor in carcinogenesis and prognosis of several cancer types. The aim of our study was to investigate sex steroid and hypophyseal hormone status of male HNSCC patients in comparison to healthy volunteers and to patients with alcoholic liver disease, to determine possible hormonal alterations characteristic of cancer. Liver function (GGT level), and serum levels of gonadotropic hormones (FSH, LH, prolactin), sex steroids (estradiol, progesterone, testosterone) and sex hormone-binding globulin (SHBG) were compared in 130 male HNSCC patients, 54 patients with alcoholic liver disease but no known cancer, and 56 healthy controls. We found abnormal values of liver function in both HNSCC patients and alcoholics compared to healthy controls, suggesting the presence of alcoholic liver disease in the former group as well. On the other hand, a significant elevation in the level of DHEA, FSH and LH was observed in cancer patients exclusively. As a conclusion, abnormal alterations in sex steroid hormone levels can frequently be found in HNSCC patients, which may be caused in part by the alcoholic liver damage accompanying the disease. The significant increase in FSH and LH serum levels, observed only in the cancer patients, indicates that these hormones may play a role in the development and/or progression of HNSCC.

Progression of head and neck squamous cell cancer

Squamous cell cancer in the head and neck region (HNSC) is unique concerning its progression since it remains locoregional for long time and visceral metastases develop only in a later stage of the disease. Accordingly, molecular markers of the local invasion and the lymphatic dissemination both have critical importance. HNSC progression is associated with deregulated control of cell proliferation and apoptosis but it seems equally significant the disregulation of the proteolytic machineries. Here we outline the lymphatic metastatic cascade for HNSC to depict key molecular determinants as possible prognostic factors or therapeutic targets identifying immunological selection as a major feature. Unlike in local spreading, invasive potential of cancer cells seems to be less significant during lymphatic dissemination due to the anatomical properties of the lymphatic vessels and tissues. There is a general believe that HNSC is one disease however, data indicate that the anatomical localization of the tumor (the "soil") such as oral, lingual, glottic or pharyngeal has a significant effect on the gene expression profile and corresponding biological behavior of HNSC. Furthermore, even the endocrine milieu of the host was proved to be influential in modulating the progression of HNSC. Gene expression profiling techniques combined with proteomics could help to define and select usefull genetic and biomarkers of progression of HNSC, some of them could well be potential novel therapeutic target.

Ectopic production of prolactin by colorectal adenocarcinoma

PURPOSE

This study assessed the role of prolactin in patients with Dukes B and C colorectal carcinoma.

METHODS

Circulating prolactin and carcinoembryonic antigen were assayed using immunoradiometric assay and radioimmunoassay kits, respectively, in preoperative blood (n = 98) and tumor-draining venous blood (n = 34) samples of colorectal carcinoma patients. Immunohistochemical localization of prolactin (n = 98), carcinoembryonic antigen (n = 98), and prolactin receptors (n = 56) was performed. The expression of prolactin messenger ribonucleic acid (n = 50) and prolactin receptor messenger ribonucleic acid (n = 50) was studied by reverse transcriptase polymerase chain reaction. Further, prolactin amplimer was sequenced.

RESULTS

Preoperative prolactin and carcinoembryonic antigen levels were significantly higher in patients with colorectal carcinoma than in controls (prolactin, P = 0.001; carcinoembryonic antigen, P = 0.0001). Univariate survival analysis showed that Dukes stage, histologic grade, and circulating prolactin were significant prognostic factors for determining overall survival (Dukes stage, P = 0.00001; histologic grade, P = 0.005; prolactin, P = 0.001). In multivariate analysis, besides Dukes stage, circulating prolactin emerged as the most significant independent prognostic factor influencing overall survival. Preoperative prolactin levels showed excellent significant correlation with response to therapy and progression of disease. A significant tenfold higher mean concentration of prolactin was observed in tumor-draining venous blood than in peripheral blood (P = 0.0001). Diffuse cytoplasmic staining for prolactin was seen in 51 percent (50/98) of the colorectal carcinomas. Prolactin messenger ribonucleic acid expression was seen in 88 percent (44/50) of the colorectal carcinomas. Sequence analysis of the 234-bp prolactin amplimer revealed that the sequence was homologous to exon 5 of pituitary prolactin messenger ribonucleic acid.

CONCLUSION

These multiple approaches confirmed that prolactin is produced by colorectal carcinoma cells. Looking at its prognostic value and correlation with disease activity, it may provide new insights into treatment for patients with colorectal carcinoma.