PTEN protein expression has role in predicting disease-free-interval in endometrioid endometrial carcinoma

OBJECTIVES

To determine the significance of tumour PTEN protein expression in endometrioid endometrial carcinoma (EEC) and it is correlation with tumour characteristics.

METHODS

A total of 30 eligible archived paraffin-embedded tissue blocks from 61 EEC cases (January 2015-December 2017) were retrieved from the Histopathology Laboratory in Universiti Kebangsaan Malaysia Medical Centre (UKMMC) following institutional ethic approval. For PTEN protein detection, immunohistochemistry (IHC) staining was performed and the data was correlated with clinicopathologic parameters.

RESULTS

Fourteen samples (46.7%) showed positive PTEN protein expression, while 16 (53.3%) were negative. The mean age was 62.00 ± 9.51 years old, while the mean Body Mass Index (BMI) was 27.28 ± 7.16 kg/m². There was no significant difference between age (p=0.27, 95% CI: -10.98 to 3.21) and BMI (p=0.67, 95% CI: -4.30 to 6.58) with PTEN protein expression. There were significant correlation between PTEN protein expression with myometrial invasion (p=0.010), but not with lymphovascular space invasion (p=0.743), grade (p=0.532), stage (p=0.733) and CA-125 level (p=0.47). The higher stage correlates with the presence of LVSI (p=0.002). PTEN positive associated with longer disease-free-interval (p=0.025), but not improving the overall survival (p=0.38).

CONCLUSIONS

Positive PTEN protein expression correlates with less myometrial invasion.

Ovarian and uterine leiomyosarcoma: which one is the primary?

Uterine leiomyosarcoma (LMS) is rare but primary ovarian LMS is even rarer constituting less than 0.1% of all gynecologic disorders. Neither histologic features nor immunohistochemistry could be utilized to distinguish between uterine or ovarian origin. We illustrate a clinical case of metastatic LMS to the ovary in a woman with underlying uterine fibroid presenting with anemia with heavy menses.

Targeted Next-Generation Sequencing Identifies Actionable Targets in Estrogen Receptor Positive and Estrogen Receptor Negative Endometriod Endometrial Cancer

Endometrioid endometrial cancer (EEC) is the commonest form of endometrial cancer and can be divided into estrogen receptor (ER) positive and negative subtypes. The mutational profiles of EEC have been shown to aid in tailoring treatment; however, little is known about the differences between the gene mutation profiles between these two subtypes. This study aims to investigate the gene mutation profile in ER positive and negative EEC, and to further elucidate the role of WHSC1 mutations in this cancer. EEC and normal endometrial tissues were obtained from 29 patients and subjected to next-generation sequencing (NGS) using Ion Ampliseq Comprehensive Cancer PanelTM targeting 409 cancer related. A total of 741 non-synonymous alterations were identified from 272 genes in ER positive subtype while 448 non-synonymous variants were identified from 221 genes in ER negative subtype. PTEN is the most frequently altered gene in ER positive subtype (64%, 7/11) while ARID1A is the most frequently altered gene in ER negative subtype (50%, 4/8). We also identified alterations in ERRB3 (36%, 4/11), GNAS (36%, 4/11), and WHSC1 (27%, 3/11) in the ER positive subtype. WHSC1 R1126H and L1268P were shown to significantly increase cell viability, proliferation, migration, and survival. In addition, reduction in ER expression sensitized EEC-1 cell with WHSC1 L1268P mutant to Fulvestrant treatment. We revealed the mutational spectra of ER positive and ER negative EEC that could lead to better understanding of the biological mechanisms of endometrial cancer and may ultimately result in improvement of treatment options and patient prognosis.

Molecular characterization of serous ovarian carcinoma using a multigene next generation sequencing cancer panel approach

BACKGROUND

High grade serous ovarian cancer is one of the poorly characterized malignancies. This study aimed to elucidate the mutational events in Malaysian patients with high grade serous ovarian cancer by performing targeted sequencing on 50 cancer hotspot genes.

RESULTS

Nine high grade serous ovarian carcinoma samples and ten normal ovarian tissues were obtained from Universiti Kebangsaan Malaysia Medical Center (UKMMC) and the Kajang Hospital. The Ion AmpliSeq™ Cancer Hotspot Panel v2 targeting "mutation-hotspot region" in 50 most common cancer-associated genes was utilized. A total of 20 variants were identified in 12 genes. Eleven (55%) were silent alterations and nine (45%) were missense mutations. Six of the nine missense mutations were predicted to be deleterious while the other three have low or neutral protein impact. Eight genes were altered in both the tumor and normal groups (APC, EGFR, FGFR3, KDR, MET, PDGFRA, RET and SMO) while four genes (TP53, PIK3CA, STK11 and KIT) were exclusively altered in the tumor group. TP53 alterations were present in all the tumors but not in the normal group. Six deleterious mutations in TP53 (p.R175H, p.H193R, p.Y220C, p.Y163C, p.R282G and p.Y234H) were identified in eight serous ovarian carcinoma samples and none in the normal group.

CONCLUSION

TP53 remains as the most frequently altered gene in high grade serous ovarian cancer and Ion Torrent Personal Genome Machine (PGM) in combination with Ion Ampliseq™ Cancer Hotspot Panel v2 were proven to be instrumental in identifying a wide range of genetic alterations simultaneously from a minute amount of DNA. However, larger series of validation targeting more genes are necessary in order to shed a light on the molecular events underlying pathogenesis of this cancer.