ARID1A mutations in endometriosis-associated ovarian carcinomas

BACKGROUND

Ovarian clear-cell and endometrioid carcinomas may arise from endometriosis, but the molecular events involved in this transformation have not been described.

METHODS

We sequenced the whole transcriptomes of 18 ovarian clear-cell carcinomas and 1 ovarian clear-cell carcinoma cell line and found somatic mutations in ARID1A (the AT-rich interactive domain 1A [SWI-like] gene) in 6 of the samples. ARID1A encodes BAF250a, a key component of the SWI–SNF chromatin remodeling complex. We sequenced ARID1A in an additional 210 ovarian carcinomas and a second ovarian clear-cell carcinoma cell line and measured BAF250a expression by means of immunohistochemical analysis in an additional 455 ovarian carcinomas.

RESULTS

ARID1A mutations were seen in 55 of 119 ovarian clear-cell carcinomas (46%), 10 of 33 endometrioid carcinomas (30%), and none of the 76 high-grade serous ovarian carcinomas. Seventeen carcinomas had two somatic mutations each. Loss of the BAF250a protein correlated strongly with the ovarian clear-cell carcinoma and endometrioid carcinoma subtypes and the presence of ARID1A mutations. In two patients, ARID1A mutations and loss of BAF250a expression were evident in the tumor and contiguous atypical endometriosis but not in distant endometriotic lesions.

CONCLUSIONS

These data implicate ARID1A as a tumor-suppressor gene frequently disrupted in ovarian clear-cell and endometrioid carcinomas. Since ARID1A mutation and loss of BAF250a can be seen in the preneoplastic lesions, we speculate that this is an early event in the transformation of endometriosis into cancer. (Funded by the British Columbia Cancer Foundation and the Vancouver General Hospital–University of British Columbia Hospital Foundation.).

Survival effect of para-aortic lymphadenectomy in endometrial cancer (SEPAL study): a retrospective cohort analysis

BACKGROUND

In response to findings that pelvic lymphadenectomy does not have any therapeutic benefit for endometrial cancer, we aimed to establish whether complete, systematic lymphadenectomy, including the para-aortic lymph nodes, should be part of surgical therapy for patients at intermediate and high risk of recurrence.

METHODS

We selected 671 patients with endometrial carcinoma who had been treated with complete, systematic pelvic lymphadenectomy (n=325 patients) or combined pelvic and para-aortic lymphadenectomy (n=346) at two tertiary centres in Japan (January, 1986-June, 2004). Patients at intermediate or high risk of recurrence were offered adjuvant radiotherapy or chemotherapy. The primary outcome measure was overall survival.

FINDINGS

Overall survival was significantly longer in the pelvic and para-aortic lymphadenectomy group than in the pelvic lymphadenectomy group (HR 0.53, 95% CI 0.38-0.76; p=0.0005). This association was also recorded in 407 patients at intermediate or high risk (p=0.0009), but overall survival was not related to lymphadenectomy type in low-risk patients. Multivariate analysis of prognostic factors showed that in patients with intermediate or high risk of recurrence, pelvic and para-aortic lymphadenectomy reduced the risk of death compared with pelvic lymphadenectomy (0.44, 0.30-0.64; p<0.0001). Analysis of 328 patients with intermediate or high risk who were treated with adjuvant radiotherapy or chemotherapy showed that patient survival improved with pelvic and para-aortic lymphadenectomy (0.48, 0.29-0.83; p=0.0049) and with adjuvant chemotherapy (0.59, 0.37-1.00; p=0.0465) independently of one another.

INTERPRETATION

Combined pelvic and para-aortic lymphadenectomy is recommended as treatment for patients with endometrial carcinoma of intermediate or high risk of recurrence. If a prospective randomised or comparative cohort study is planned to validate the therapeutic effect of lymphadenectomy, it should include both pelvic and para-aortic lymphadenectomy in patients of intermediate or high risk of recurrence.

FUNDING

Japanese Foundation for Multidisciplinary Treatment of Cancer, and the Japan Society for the Promotion of Science.

Uterine papillary serous and clear cell carcinomas predict for poorer survival compared to grade 3 endometrioid corpus cancers

To compare the survival of women with uterine papillary serous carcinoma (UPSC) and clear cell carcinoma (CC) to those with grade 3 endometrioid uterine carcinoma (G3EC). Demographic, pathologic, treatment, and survival information were obtained from the Surveillance, Epidemiology, and End Results Program from 1988 to 2001. Data were analysed using Kaplan–Meier and Cox proportional hazards regression methods. Of 4180 women, 1473 had UPSC, 391 had CC, and 2316 had G3EC cancers. Uterine papillary serous carcinoma and CC patients were older (median age: 70 years and 68 vs 66 years, respectively; P<0.0001) and more likely to be black compared to G3EC (15 and 12% vs 7%; P<0.0001). A higher proportion of UPSC and CC patients had stage III–IV disease compared to G3EC patients (52 and 36% vs 29%; P<0.0001). Uterine papillary serous carcinoma, CC and G3EC patients represent 10, 3, and 15% of endometrial cancers but account for 39, 8, and 27% of cancer deaths, respectively. The 5-year disease-specific survivals for women with UPSC, CC and G3EC were 55, 68, and 77%, respectively (P<0.0001). The survival differences between UPSC, CC and G3EC persist after controlling for stage I–II (74, 82, and 86%; P<0.0001) and stage III–IV disease (33, 40, and 54; P<0.0001). On multivariate analysis, more favourable histology (G3EC), younger age, and earlier stage were independent predictors of improved survival. Women with UPSC and CC of the uterus have a significantly poorer prognosis compared to those with G3EC. These findings should be considered in the counselling, treating and designing of future trials for these high-risk patients.

Evaluation of monoclonal humanized anti-HER2 antibody, trastuzumab, in patients with recurrent or refractory ovarian or primary peritoneal carcinoma with overexpression of HER2: a phase II trial of the Gynecologic Oncology Group

PURPOSE

To evaluate the feasibility, toxicity, and efficacy of single-agent monoclonal antibody therapy targeting the human epidermal growth factor receptor 2 (HER2)/neu receptor in ovarian and primary peritoneal carcinoma.

PATIENTS AND METHODS

Eligible patients had measurable persistent or recurrent epithelial ovarian or primary peritoneal carcinoma with 2+ or 3+ HER2 overexpression documented by immunohistochemistry. Intravenous trastuzumab was administered initially at a dose of 4 mg/kg, then weekly at 2 mg/kg. Patients without progressive disease or excessive toxicity could continue treatment indefinitely. Those with stable or responding disease at 8 weeks were offered treatment at a higher weekly dose (4 mg/kg) at time of progression. Patient sera were analyzed for the presence of the soluble extracellular domain of HER2, host antibodies against trastuzumab, and trastuzumab pharmacokinetics.

RESULTS

A total of 837 tumor samples were screened for HER2 expression, and 95 patients (11.4%) exhibited the requisite 2+/3+ expression level. Forty-five patients, all of whom received prior chemotherapy, were entered, and 41 were deemed eligible and assessable. There were only mild expected toxicities and no treatment-related deaths. Although an elevated level of the soluble extracellular domain of HER2 was detected in eight of 24 patients, serum HER2 was not associated with clinical outcome. There was no evidence of host antitrastuzumab antibody formation. Serum concentrations of trastuzumab gradually increased with continued therapy. An overall response rate of 7.3% included one complete and two partial responses. Median treatment duration was 8 weeks (range, 2 to 104 weeks), and median progression-free interval was 2.0 months.

CONCLUSION

The clinical value of single-agent trastuzumab in recurrent ovarian cancer is limited by the low frequency of HER2 overexpression and low rate of objective response among patients with HER2 overexpression.

FIGO staging of endometrial cancer: 2023

INTRODUCTION

Many advances in the understanding of the pathologic and molecular features of endometrial cancer have occurred since the FIGO staging was last updated in 2009. Substantially more outcome and biological behavior data are now available regarding the several histological types. Molecular and genetic findings have accelerated since the publication of The Cancer Genome Atlas (TCGA) data and provide improved clarity on the diverse biological nature of this collection of endometrial cancers and their differing prognostic outcomes. The goals of the new staging system are to better define these prognostic groups and create substages that indicate more appropriate surgical, radiation, and systemic therapies.

METHODS

The FIGO Women's Cancer Committee appointed a Subcommittee on Endometrial Cancer Staging in October 2021, represented by the authors. Since then, the committee members have met frequently and reviewed new and established evidence on the treatment, prognosis, and survival of endometrial cancer. Based on these data, opportunities for improvements in the categorization and stratification of these factors were identified in each of the four stages. Data and analyses from the molecular and histological classifications performed and published in the recently developed ESGO/ESTRO/ESP guidelines were used as a template for adding the new subclassifications to the proposed molecular and histological staging system.

RESULTS

Based on the existing evidence, the substages were defined as follows: Stage I (IA1): non-aggressive histological type of endometrial carcinoma limited to a polyp or confined to the endometrium; (IA2) non-aggressive histological types of endometrium involving less than 50% of the myometrium with no or focal lymphovascular space invasion (LVSI) as defined by WHO criteria; (IA3) low-grade endometrioid carcinomas limited to the uterus with simultaneous low-grade endometrioid ovarian involvement; (IB) non-aggressive histological types involving 50% or more of the myometrium with no LVSI or focal LVSI; (IC) aggressive histological types, i.e. serous, high-grade endometrioid, clear cell, carcinosarcomas, undifferentiated, mixed, and other unusual types without any myometrial invasion. Stage II (IIA): non-aggressive histological types that infiltrate the cervical stroma; (IIB) non-aggressive histological types that have substantial LVSI; or (IIC) aggressive histological types with any myometrial invasion. Stage III (IIIA): differentiating between adnexal versus uterine serosa infiltration; (IIIB) infiltration of vagina/parametria and pelvic peritoneal metastasis; and (IIIC) refinements for lymph node metastasis to pelvic and para-aortic lymph nodes, including micrometastasis and macrometastasis. Stage IV (IVA): locally advanced disease infiltrating the bladder or rectal mucosa; (IVB) extrapelvic peritoneal metastasis; and (IVC) distant metastasis. The performance of complete molecular classification (POLEmut, MMRd, NSMP, p53abn) is encouraged in all endometrial cancers. If the molecular subtype is known, this is recorded in the FIGO stage by the addition of "m" for molecular classification, and a subscript indicating the specific molecular subtype. When molecular classification reveals p53abn or POLEmut status in Stages I and II, this results in upstaging or downstaging of the disease (IICmp53abn or IAmPOLEmut ).

SUMMARY

The updated 2023 staging of endometrial cancer includes the various histological types, tumor patterns, and molecular classification to better reflect the improved understanding of the complex nature of the several types of endometrial carcinoma and their underlying biologic behavior. The changes incorporated in the 2023 staging system should provide a more evidence-based context for treatment recommendations and for the more refined future collection of outcome and survival data.

Ovarian Cancer Risk Factors by Histologic Subtype: An Analysis From the Ovarian Cancer Cohort Consortium

PURPOSE

An understanding of the etiologic heterogeneity of ovarian cancer is important for improving prevention, early detection, and therapeutic approaches. We evaluated 14 hormonal, reproductive, and lifestyle factors by histologic subtype in the Ovarian Cancer Cohort Consortium (OC3).

PATIENTS AND METHODS

Among 1.3 million women from 21 studies, 5,584 invasive epithelial ovarian cancers were identified (3,378 serous, 606 endometrioid, 331 mucinous, 269 clear cell, 1,000 other). By using competing-risks Cox proportional hazards regression stratified by study and birth year and adjusted for age, parity, and oral contraceptive use, we assessed associations for all invasive cancers by histology. Heterogeneity was evaluated by likelihood ratio test.

RESULTS

Most risk factors exhibited significant heterogeneity by histology. Higher parity was most strongly associated with endometrioid (relative risk [RR] per birth, 0.78; 95% CI, 0.74 to 0.83) and clear cell (RR, 0.68; 95% CI, 0.61 to 0.76) carcinomas (P value for heterogeneity [P-het] < .001). Similarly, age at menopause, endometriosis, and tubal ligation were only associated with endometrioid and clear cell tumors (P-het ≤ .01). Family history of breast cancer (P-het = .008) had modest heterogeneity. Smoking was associated with an increased risk of mucinous (RR per 20 pack-years, 1.26; 95% CI, 1.08 to 1.46) but a decreased risk of clear cell (RR, 0.72; 95% CI, 0.55 to 0.94) tumors (P-het = .004). Unsupervised clustering by risk factors separated endometrioid, clear cell, and low-grade serous carcinomas from high-grade serous and mucinous carcinomas.

CONCLUSION

The heterogeneous associations of risk factors with ovarian cancer subtypes emphasize the importance of conducting etiologic studies by ovarian cancer subtypes. Most established risk factors were more strongly associated with nonserous carcinomas, which demonstrate challenges for risk prediction of serous cancers, the most fatal subtype.

Hormone-receptor expression and ovarian cancer survival: an Ovarian Tumor Tissue Analysis consortium study

BACKGROUND

Few biomarkers of ovarian cancer prognosis have been established, partly because subtype-specific associations might be obscured in studies combining all histopathological subtypes. We examined whether tumour expression of the progesterone receptor (PR) and oestrogen receptor (ER) was associated with subtype-specific survival.

METHODS

12 studies participating in the Ovarian Tumor Tissue Analysis consortium contributed tissue microarray sections and clinical data to our study. Participants included in our analysis had been diagnosed with invasive serous, mucinous, endometrioid, or clear-cell carcinomas of the ovary. For a patient to be eligible, tissue microarrays, clinical follow-up data, age at diagnosis, and tumour grade and stage had to be available. Clinical data were obtained from medical records, cancer registries, death certificates, pathology reports, and review of histological slides. PR and ER statuses were assessed by central immunohistochemistry analysis done by masked pathologists. PR and ER staining was defined as negative (<1% tumour cell nuclei), weak (1 to <50%), or strong (≥50%). Associations with disease-specific survival were assessed.

FINDINGS

2933 women with invasive epithelial ovarian cancer were included: 1742 with high-grade serous carcinoma, 110 with low-grade serous carcinoma, 207 with mucinous carcinoma, 484 with endometrioid carcinoma, and 390 with clear-cell carcinoma. PR expression was associated with improved disease-specific survival in endometrioid carcinoma (log-rank p<0·0001) and high-grade serous carcinoma (log-rank p=0·0006), and ER expression was associated with improved disease-specific survival in endometrioid carcinoma (log-rank p<0·0001). We recorded no significant associations for mucinous, clear-cell, or low-grade serous carcinoma. Positive hormone-receptor expression (weak or strong staining for PR or ER, or both) was associated with significantly improved disease-specific survival in endometrioid carcinoma compared with negative hormone-receptor expression, independent of study site, age, stage, and grade (hazard ratio 0·33, 95% CI 0·21-0·51; p<0·0001). Strong PR expression was independently associated with improved disease-specific survival in high-grade serous carcinoma (0·71, 0·55-0·91; p=0·0080), but weak PR expression was not (1·02, 0·89-1·18; p=0·74).

INTERPRETATION

PR and ER are prognostic biomarkers for endometrioid and high-grade serous ovarian cancers. Clinical trials, stratified by subtype and biomarker status, are needed to establish whether hormone-receptor status predicts response to endocrine treatment, and whether it could guide personalised treatment for ovarian cancer.

FUNDING

Carraresi Foundation and others.

Folate receptor alpha as a tumor target in epithelial ovarian cancer

OBJECTIVES

Folate receptor alpha (FRalpha) is a folate-binding protein overexpressed on ovarian and several other epithelial malignancies that can be used as a target for imaging and therapeutic strategies. The goal of this study is to improve historical data that lack specific information about FRalpha expression in rare histological subtypes, primary disease versus metastatic foci, and recurrent disease.

METHODS

FRalpha expression was analyzed by immunohistochemistry on 186 primary and 27 recurrent ovarian tumors, including 24 pairs of samples obtained from the same individuals at diagnosis and at secondary debulking surgery. For 20 of the 186 primaries, simultaneous metastatic foci were also analyzed. FRalpha staining was analyzed in light of disease morphology, stage, grade, debulking status, and time from diagnosis to recurrence and death.

RESULTS

FRalpha expression was apparent in 134 of 186 (72%) primary and 22 of 27 (81.5%) recurrent ovarian tumors. In 21 of 24 (87.5%) matched specimens, recurrent tumors reflected the FRalpha status detected at diagnosis. Metastatic foci were similar to primary tumors in FRalpha staining. FRalpha status was not associated with time to recurrence or overall survival in either univariate or multivariable analyses.

CONCLUSION

FRalpha expression occurs frequently, especially in the common high-grade, high-stage serous tumors that are most likely to recur. New findings from this study show that FRalpha expression is maintained on metastatic foci and recurrent tumors, suggesting that novel folate-targeted therapies may hold promise for the majority of women with either newly diagnosed or recurrent ovarian cancer.

Theories of endometrial carcinogenesis: a multidisciplinary approach

Historical observations have suggested that endometrial carcinomas vary in histopathologic appearance and clinical features. More recent, systematic studies have provided epidemiologic, clinicopathologic, and molecular support for these observations. Specifically, studies suggest that the most common type of endometrial carcinoma, endometrioid adenocarcinoma, develops from endometrial hyperplasia in the setting of excess estrogen exposure and usually pursues an indolent clinical course. In contrast, a minority of endometrial carcinomas, best represented by serous carcinoma, do not seem to be related to estrogenic risk factors or elevated serum hormone levels, and these tumors seem to develop from atrophic rather than hyperplastic epithelium. We have proposed that serous carcinomas develop from "endometrial intraepithelial carcinoma," a lesion representing malignant transformation of the endometrial surface epithelium. Whereas endometrioid carcinoma and endometrial hyperplasia are associated with microsatellite instability and ras and PTEN mutations, serous carcinoma and endometrial intraepithelial carcinoma are associated with p53 mutations and abnormal accumulation of p53 protein. Based on these data regarding the pathogenesis of endometrioid and serous carcinoma, we have proposed a dualistic model of endometrial carcinogenesis incorporating a "classic" estrogen-driven pathway and an "alternative" pathway seemingly unrelated to hormones. It is hoped that further studies may permit the extension and modification of this model and that these advances will lead to improved diagnosis, management, and prevention.

Interpretation of somatic POLE mutations in endometrial carcinoma

Pathogenic somatic missense mutations within the DNA polymerase epsilon (POLE) exonuclease domain define the important subtype of ultramutated tumours ('POLE-ultramutated') within the novel molecular classification of endometrial carcinoma (EC). However, clinical implementation of this classifier requires systematic evaluation of the pathogenicity of POLE mutations. To address this, we examined base changes, tumour mutational burden (TMB), DNA microsatellite instability (MSI) status, POLE variant frequency, and the results from six in silico tools on 82 ECs with whole-exome sequencing from The Cancer Genome Atlas (TCGA). Of these, 41 had one of five known pathogenic POLE exonuclease domain mutations (EDM) and showed characteristic genomic alterations: C>A substitution > 20%, T>G substitutions > 4%, C>G substitutions < 0.6%, indels < 5%, TMB > 100 mut/Mb. A scoring system to assess these alterations (POLE-score) was developed; based on their scores, 7/18 (39%) additional tumours with EDM were classified as POLE-ultramutated ECs, and the six POLE mutations present in these tumours were considered pathogenic. Only 1/23 (4%) tumours with non-EDM showed these genomic alterations, indicating that a large majority of mutations outside the exonuclease domain are not pathogenic. The infrequent combination of MSI-H with POLE EDM led us to investigate the clinical significance of this association. Tumours with pathogenic POLE EDM co-existent with MSI-H showed genomic alterations characteristic of POLE-ultramutated ECs. In a pooled analysis of 3361 ECs, 13 ECs with DNA mismatch repair deficiency (MMRd)/MSI-H and a pathogenic POLE EDM had a 5-year recurrence-free survival (RFS) of 92.3%, comparable to previously reported POLE-ultramutated ECs. Additionally, 14 cases with non-pathogenic POLE EDM and MMRd/MSI-H had a 5-year RFS of 76.2%, similar to MMRd/MSI-H, POLE wild-type ECs, suggesting that these should be categorised as MMRd, rather than POLE-ultramutated ECs for prognostication. This work provides guidance on classification of ECs with POLE mutations, facilitating implementation of POLE testing in routine clinical care. © 2019 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of Pathological Society of Great Britain and Ireland.

Clinicopathological and molecular characterisation of 'multiple-classifier' endometrial carcinomas

Endometrial carcinoma (EC) molecular classification based on four molecular subclasses identified in The Cancer Genome Atlas (TCGA) has gained relevance in recent years due to its prognostic utility and potential to predict benefit from adjuvant treatment. While most ECs can be classified based on a single classifier (POLE exonuclease domain mutations - POLEmut, MMR deficiency - MMRd, p53 abnormal - p53abn), a small but clinically relevant group of tumours harbour more than one molecular classifying feature and are referred to as 'multiple-classifier' ECs. We aimed to describe the clinicopathological and molecular features of multiple-classifier ECs with abnormal p53 (p53abn). Within a cohort of 3518 molecularly profiled ECs, 107 (3%) tumours displayed p53abn in addition to another classifier(s), including 64 with MMRd (MMRd-p53abn), 31 with POLEmut (POLEmut-p53abn), and 12 with all three aberrations (MMRd-POLEmut-p53abn). MMRd-p53abn ECs and POLEmut-p53abn ECs were mostly grade 3 endometrioid ECs, early stage, and frequently showed morphological features characteristic of MMRd or POLEmut ECs. 18/28 (60%) MMRd-p53abn ECs and 7/15 (46.7%) POLEmut-p53abn ECs showed subclonal p53 overexpression, suggesting that TP53 mutation was a secondary event acquired during tumour progression. Hierarchical clustering of TCGA ECs by single nucleotide variant (SNV) type and somatic copy number alterations (SCNAs) revealed that MMRd-p53abn tumours mostly clustered with single-classifier MMRd tumours (20/23) rather than single-classifier p53abn tumours (3/23), while POLEmut-p53abn tumours mostly clustered with single-classifier POLEmut tumours (12/13) and seldom with single-classifier p53abn tumours (1/13) (both p ≤ 0.001, chi-squared test). Finally, the clinical outcome of patients with MMRd-p53abn and POLEmut-p53abn ECs [stage I 5-year recurrence-free survival (RFS) of 92.2% and 94.1%, respectively] was significantly different from single-classifier p53abn EC (stage I RFS 70.8%, p = 0.024 and p = 0.050, respectively). Our results support the classification of MMRd-p53abn EC as MMRd and POLEmut-p53abn EC as POLEmut. © 2019 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of Pathological Society of Great Britain and Ireland.

Mouse model of human ovarian endometrioid adenocarcinoma based on somatic defects in the Wnt/beta-catenin and PI3K/Pten signaling pathways

One histologic subtype of ovarian carcinoma, ovarian endometrioid adenocarcinoma (OEA), frequently harbors mutations that constitutively activate Wnt/beta-catenin-dependent signaling. We now show that defects in the PI3K/Pten and Wnt/beta-catenin signaling pathways often occur together in a subset of human OEAs, suggesting their cooperation during OEA pathogenesis. Deregulation of these two pathways in the murine ovarian surface epithelium by conditional inactivation of the Pten and Apc tumor suppressor genes results in the formation of adenocarcinomas morphologically similar to human OEAs with 100% penetrance, short latency, and rapid progression to metastatic disease in upwards of 75% of mice. The biological behavior and gene expression patterns of the murine cancers resemble those of human OEAs with defects in the Wnt/beta-catenin and PI3K/Pten pathways.

Pathology and physiopathology of adenomyosis

Adenomyosis is defined by the presence of endometrial mucosa within the myometrium. This probably occurs by invagination of the basalis endometrium into the myometrium. The process of invagination and intramyometrial spreading may be facilitated by the non-cyclic, anti-apoptotic activity of the basalis associated with relative hyper-oestrogenic states. Most cases of adenomyosis are discovered in multiparous women during the 'transitional' years (40-50 years), and the condition is associated with menorrhagia, dysmenorrhoea, endometrial polyps and leiomyomata uteri. Endometrioid adenocarcinoma is often associated with adenomyosis, is frequently of early stage and low histological grade, is hormone-sensitive, and has an excellent prognosis. Extension of malignant growth into foci of adenomyosis has no adverse effect on prognosis. Definite diagnosis and treatment of adenomyosis are obtained by hysterectomy. Although adenomyotic endometrial glands are hormone-sensitive, exogenous progestogenic agents are ineffective for the treatment of adenomyosis. Anti-oestrogenic danazol and gonadotrophin-releasing hormone (GnRH) analogues induce suppression of adenomyosis, but their use must be of short duration. Surgical extirpation, therefore, is the best therapeutic option.

Molecular Classification of Grade 3 Endometrioid Endometrial Cancers Identifies Distinct Prognostic Subgroups

Our aim was to investigate whether molecular classification can be used to refine prognosis in grade 3 endometrial endometrioid carcinomas (EECs). Grade 3 EECs were classified into 4 subgroups: p53 abnormal, based on mutant-like immunostaining (p53abn); MMR deficient, based on loss of mismatch repair protein expression (MMRd); presence of POLE exonuclease domain hotspot mutation (POLE); no specific molecular profile (NSMP), in which none of these aberrations were present. Overall survival (OS) and recurrence-free survival (RFS) rates were compared using the Kaplan-Meier method (Log-rank test) and univariable and multivariable Cox proportional hazard models. In total, 381 patients were included. The median age was 66 years (range, 33 to 96 y). Federation Internationale de Gynecologie et d'Obstetrique stages (2009) were as follows: IA, 171 (44.9%); IB, 120 (31.5%); II, 24 (6.3%); III, 50 (13.1%); IV, 11 (2.9%). There were 49 (12.9%) POLE, 79 (20.7%) p53abn, 115 (30.2%) NSMP, and 138 (36.2%) MMRd tumors. Median follow-up of patients was 6.1 years (range, 0.2 to 17.0 y). Compared to patients with NSMP, patients with POLE mutant grade 3 EEC (OS: hazard ratio [HR], 0.36 [95% confidence interval, 0.18-0.70]; P=0.003; RFS: HR, 0.17 [0.05-0.54]; P=0.003) had a significantly better prognosis; patients with p53abn tumors had a significantly worse RFS (HR, 1.73 [1.09-2.74]; P=0.021); patients with MMRd tumors showed a trend toward better RFS. Estimated 5-year OS rates were as follows: POLE 89%, MMRd 75%, NSMP 69%, p53abn 55% (Log rank P=0.001). Five-year RFS rates were as follows: POLE 96%, MMRd 77%, NSMP 64%, p53abn 47% (P=0.000001), respectively. In a multivariable Cox model that included age and Federation Internationale de Gynecologie et d'Obstetrique stage, POLE and MMRd status remained independent prognostic factors for better RFS; p53 status was an independent prognostic factor for worse RFS. Molecular classification of grade 3 EECs reveals that these tumors are a mixture of molecular subtypes of endometrial carcinoma, rather than a homogeneous group. The addition of molecular markers identifies prognostic subgroups, with potential therapeutic implications.

p53 in endometrial cancer and its putative precursors: evidence for diverse pathways of tumorigenesis

To elucidate the role of p53 abnormalities in endometrial tumorigenesis, a diverse group of endometrial neoplasms and their putative precursors, atypical endometrial hyperplasia, and endometrial intraepithelial carcinoma (EIC) were studied using a conventional immunohistochemical technique. Immunostaining for p53 protein was detected in 24 (86%) of 28 serous carcinomas compared with nine (20%) of 45 endometrioid carcinomas (P < .001). Immunoreactivity was also detected in two (100%) of two clear cell carcinomas, five (83%) of six mixed endometrioid/serous carcinomas, and seven (70%) of 10 malignant mixed mesodermal tumors. Benign endometrial tissue and 12 examples of atypical endometrial hyperplasia were nonreactive. In 27 (79%) of 34 tumors containing EIC, both the tumor and EIC were immunoreactive for p53, whereas in 7 (21%) both were negative. Immunostaining for p53 highlighted small foci of EIC and showed the extent and distribution of the lesions. The strong association and similar p53 immunostaining pattern of EIC and serous carcinoma support the hypothesis that serous carcinomas develop from endometrial surface epithelium that demonstrates abnormal p53 protein expression in conjunction with transformation to EIC. Mutation of p53 seems unrelated to the development of endometrioid carcinoma from atypical endometrial hyperplasia but may be related to dedifferentiation in some of these neoplasms.

Pathologic features of endometrial carcinoma associated with HNPCC

BACKGROUND

Endometrial carcinoma is a common malignancy in hereditary nonpolyposis colorectal carcinoma (HNPCC). Like colon carcinoma, endometrial carcinoma is diagnosed at an earlier age in women with HNPCC. In contrast to colon carcinoma, the pathologic features of endometrial carcinoma in HNPCC have not been studied in detail. It was the purpose of this study to pathologically characterize a series of HNPCC associated endometrial carcinomas.

METHODS

Fifty women with HNPCC and endometrial carcinoma were analyzed from four different hereditary cancer registries. H&E stained slides and pathology reports were reviewed for clinically important pathologic features of endometrial carcinoma. These results were compared with those for two different groups of sporadic endometrial carcinoma--women younger than age 50 years (n = 42) and women of all ages with tumors demonstrating microsatellite instability (MSI-high) secondary to methylation of MLH1 (n = 26).

RESULTS

Nearly one-fourth of HNPCC patients in this study had endometrial tumors with pathologic features that would require adjuvant therapy after hysterectomy. There was a trend toward the HNPCC patients having more nonendometrioid tumors; all of these patients were carriers of MSH2 mutations. Such nonendometrioid tumors were extremely rare in the MLH1 methylated group. A subset of MLH1 methylated sporadic tumors demonstrated a unique, 'undifferentiated' histology that was not observed in HNPCC or the young group.

CONCLUSION

Data suggest a genotype-phenotype relation in which microsatellite instability resulting from MLH1 methylation is almost exclusively associated with classical or 'undifferentiated' endometrioid tumors, whereas microsatellite instability secondary to MSH2 mutation can result in a more variable histologic spectrum of endometrial carcinoma.

Indoleamine 2,3-dioxygenase is a novel prognostic indicator for endometrial cancer

Indoleamine 2,3-dioxygenase (IDO) is a tryptophan-catabolising enzyme inducing immune tolerance. The present study aimed to investigate IDO expression and its prognostic significance in endometrial cancer. Indoleamine 2,3-dioxygenase expression in endometrial cancer tissues (n = 80) was immunohistochemically scored as four groups (IDO-, 1+, 2+, and 3+). The high IDO expression (IDO2+ or 3+) in tumour cells was found in 37 (46.3%) of the 80 cases, and was positively correlated with surgical stage, myometrial invasion, lymph-vascular space involvement, and lymph node metastasis, but not with the histological grade. Patients with high IDO expression had significantly impaired overall survival and progression-free survival (PFS) (P = 0.002 and P = 0.001, respectively) compared to patients with no or weak expression of IDO (IDO- or 1+). The 5-year PFS for IDO-/1+, 2+, and 3+ were 97.7, 72.9, and 36.4%, respectively. Even in patients with early-stage disease (International Federation of Gynecology and Obstetrics I/II, n = 64), the PFS for IDO2+/3+ was significantly poor (P = 0.001) compared to that for IDO-/1+. On multivariate analysis, IDO expression was an independent prognostic factor for PFS (P = 0.020). These results indicated that the high IDO expression was involved in the progression of endometrial cancer and correlated with the impaired clinical outcome, suggesting that IDO is a novel and reliable prognostic indicator for endometrial cancer.

WT-1 assists in distinguishing ovarian from uterine serous carcinoma and in distinguishing between serous and endometrioid ovarian carcinoma

AIMS

It has been suggested that WT-1 is helpful in distinguishing a primary ovarian serous carcinoma (OSC) from a primary uterine serous carcinoma (USC). Since both neoplasms are often disseminated at diagnosis and since USC often spreads to the ovary and vice versa, it may be difficult to ascertain the primary site. This is important, since adjuvant therapies for OSC and USC may differ. WT-1 staining patterns also differ between OSC and ovarian endometrioid carcinoma and so it is possible that WT-1 may assist in the distinction of these two neoplasms, which is sometimes problematic, especially with poorly differentiated tumours. This study aims to document the value of WT-1 in these settings. Cases of ovarian borderline serous tumour, primary peritoneal serous carcinoma (PPSC) and uterine endometrioid carcinoma were also studied.

METHODS AND RESULTS

Cases of OSC (n = 38), USC (n = 25) (in five of these cases there was also a component of endometrioid adenocarcinoma), ovarian endometrioid carcinoma (n = 13), uterine endometrioid carcinoma (n = 7), ovarian borderline serous tumour (n = 16) and PPSC (n = 6) were stained with WT-1. Cases were scored on a scale of 0-3, depending on the percentage of positive cells. The intensity of staining was scored as weak, moderate or strong. There was positive nuclear staining of 36 of 38 (94.7%) OSC with WT-1. In most OSC (68.4%), >50% of cells stained positively and staining was usually strong. Five of 25 (20%) USC were positive with only two cases exhibiting staining of >50% of cells. All primary ovarian and uterine endometrioid carcinomas were negative. All PPSC were positive, usually with diffuse strong immunoreactivity. Fourteen of 16 borderline serous tumours exhibited positivity with WT-1.

CONCLUSIONS

WT-1 is useful in distinguishing OSC (characteristically diffuse strong nuclear positivity) from USC (characteristically negative). However, rarely OSC is negative and occasional cases of USC are positive. WT-1 may also be helpful in differentiating poorly differentiated OSC from poorly differentiated ovarian endometrioid carcinoma.

p53 immunohistochemistry is an accurate surrogate for TP53 mutational analysis in endometrial carcinoma biopsies

TP53 mutations are considered a surrogate biomarker of the serous-like 'copy number high' molecular subtype of endometrial carcinoma (EC). In ovarian carcinoma, p53 immunohistochemistry (IHC) accurately reflects mutational status with almost 100% specificity but its performance in EC has not been established. This study tested whether p53 IHC reliably predicts TP53 mutations identified by next-generation sequencing (NGS) in EC biopsy samples for all ECs and as part of a molecular classification algorithm after exclusion of cases harbouring mismatch repair defects (MMRd) or pathogenic DNA polymerase epsilon exonuclease domain mutations (POLEmut). A secondary aim assessed inter-laboratory variability in p53 IHC. From a total of 207 cases from five centres (37-49 cases per centre), p53 IHC carried out at a central reference laboratory was compared with local IHC (n = 164) and curated tagged-amplicon NGS TP53 sequencing results (n = 177). Following consensus review, local and central p53 IHC results were concordant in 156/164 (95.1%) tumours. Discordant results were attributable to both interpretive and technical differences in staining between the local and central laboratories. When results were considered as any mutant pattern versus wild-type pattern staining, however, there was disagreement between local and central review in only one case. The concordance between p53 IHC and TP53 mutation was 155/168 (92.3%) overall, and 117/123 (95.1%) after excluding MMRd and POLEmut EC. Three (3/6) discordant results were in serous carcinomas with complete absence of p53 staining but no detectable TP53 mutation. Subclonal mutant p53 IHC expression was observed in 9/177 (5.1%) cases, of which four were either MMRd or POLEmut. Mutant pattern p53 IHC was observed in 63/63 (100%) serous carcinomas that were MMR-proficient/POLE exonuclease domain wild-type. Optimised p53 IHC performs well as a surrogate test for TP53 mutation in EC biopsies, demonstrates excellent inter-laboratory reproducibility, and has high clinical utility for molecular classification algorithms in EC. © 2019 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Prognosis of papillary serous, clear cell, and grade 3 stage I carcinoma of the endometrium

OBJECTIVE

The purpose of this study was to evaluate patients with uterine papillary serous carcinoma (UPSC), clear cell (CC), and grade 3 endometrioid (G3) surgically stage I endometrial cancer.

METHODS

The 25th Annual Report (AR) of FIGO was used to identify patients with endometrial cancers who were surgically staged. For comparison, all cancers reported were evaluated with particular interest in patients with stage I UPSC, CC, and G3. Incidence, substage, post-surgical treatment, and survival were identified.

RESULTS

Of 5694 endometrial cancer patients reported to the AR, 3996 (70%) were surgically stage I. There were 148 UPSC, 59 CC, and 325 with G3 lesions. UPSC and CC represent 5.2% of all stage I cancers while 8.1% are G3. Although there were greater number of UPSC, CC, and G3 with extrauterine disease, about 50% of UPSC and CC were stage I. This compares to 81% for G1, 68% for G2, and only 42% for G3. There were more IA cancers with UPSC and CC than G3 (22%, 33%, and 17%, respectively). Survival (5 years) for UPSC and CC was 72% and 81%, respectively, compared to 76% for G3 lesions. Postoperative radiation improved survival somewhat (6-8%) but the difference was not significant.

CONCLUSION

UPSC and CC histotypes when diagnosed as stage I have a better survival than commonly perceived and equal to G3 endometrioid cancers. Postoperative radiation improves survival but not significantly so. The role of chemotherapy has not been defined.

Endometrial intraepithelial carcinoma: a distinctive lesion specifically associated with tumors displaying serous differentiation

Endometrial intraepithelial carcinoma (EIC) is a recently described lesion characterized by replacement of endometrial surface epithelium or glands by malignant cells resembling high-grade invasive endometrial carcinoma. EIC has been identified in a high proportion of uteri containing serous carcinoma, but its association with other endometrial tumors is unknown. To determine the strength and specificity of the association of EIC with tumors displaying serous differentiation, the appearance of the endometrium in 38 uteri with serous carcinoma, 113 with endometrioid carcinoma, and 34 with malignant mixed mesodermal tumor (MMMT) were compared. EIC was present in 34 (98%) uteri with serous carcinoma compared with 7 (6%) uteri removed for endometrioid carcinoma (P = .0001). Hyperplasia without atypia was found in only 2 (5%) of 38 serous carcinomas compared with 38 (34%) of 113 endometrioid carcinomas. Similarly, atypical hyperplasia was not found in any uterus with serous carcinoma, but was present in 14 (12%) uteri with endometrioid carcinoma (P = .02). The endometrium was inactive or atrophic in 29 (76%) patients with serous carcinoma compared with 33 (29%) with endometrioid carcinoma (P = .0001). EIC was found in five (56%) of nine MMMTs with a serous epithelial component (serous-MMMT) compared with one (4%) of 25 MMMTs woth an endometrioid epithelial component (endometrioid-MMMT). As with endometrioid and serous carcinomas, hyperplasia with and without atypia was more common with endometrioid-MMMTs as compared with serous-MMMTs. Hyperplasia was found in 25 (100%) and atypical hyperplasia in 8 (32%) of 25 endometrioid-MMMTs, but in none of the nine serous-MMMTs. This study shows that EIC is frequently and specifically associated with uterine tumors displaying serous differentiation. The findings suggest that EIC represents a form of intraepithelial tumor growth characteristic of serous carcinoma and serous MMMT and that EIC is the likely precursor of these neoplasms. In addition, the findings provide further evidence supporting the view that MMMTs represent variants of carcinoma not sarcoma.

beta-catenin expression pattern in stage I and II ovarian carcinomas : relationship with beta-catenin gene mutations, clinicopathological features, and clinical outcome

The immunohistochemical expression pattern of beta-catenin has been correlated with beta-catenin gene mutations, clinicopathological features, and disease outcome in 69 stage I and II ovarian carcinomas. beta-Catenin expression was localized in the nuclei, in addition to the cytoplasm and membrane, in 11 tumors (16%): nine endometrioid carcinomas with widespread nuclear expression and two serous carcinomas with focal nuclear expression. The remaining 58 carcinomas (84%) only had membranous beta-catenin expression. All but one of the endometrioid carcinomas with nuclear beta-catenin expression had considerable squamous metaplasia, and five of these cases had large areas of endometrioid tumor of low malignant potential. In addition, beta-catenin nuclear expression was observed in atypical epithelial cells in endometriotic glands adjacent to an endometrioid carcinoma. Sequencing was performed on 25 tumors and corresponding normal tissue: all 13 endometrioid tumors as well as 12 carcinomas of other histological types (four serous, two clear cell, two mucinous, and two mixed). There were oncogenic mutations in the phosphorylation sequence for GSK-3beta in exon 3 of the beta-catenin gene in seven endometrioid carcinomas with beta-catenin nuclear expression. Three mutations affected codon 32 (D32G, D32Y, and D32Y), one affected codon 33 (S33C), two affected codon 37 (S37C and S37F), and one affected codon 41 (T41A). No mutations were observed in the other 18 carcinomas analyzed, comprising two endometrioid and two serous carcinomas with beta-catenin nuclear expression, and 14 carcinomas of different histological types with only membranous expression. In the univariate and multivariate survival analyses, beta-catenin nuclear expression was selected as an indicator of good prognosis, because no patient whose tumor expressed beta-catenin in the nuclei showed relapses or died, in contrast to the 19 relapses and deaths among patients with tumors that only had beta-catenin membranous expression, including three of the four patients with endometrioid carcinomas. Oncogenic beta-catenin mutation is characteristic of a group of endometrioid carcinomas with a good prognosis, most of which originate from previous benign or borderline lesions. Endometrioid carcinomas with exclusively membranous expression of beta-catenin seem to represent a different subgroup of carcinomas that probably have a worse prognosis. In early-stage ovarian cancer, determination of the beta-catenin expression pattern could prove to be a useful marker for selecting low-risk patients.

Histologic transformation of benign endometriosis to early epithelial ovarian cancer

Between 1975 and 1990, 79 patients with Stage I epithelial ovarian cancer were treated at Massachusetts General Hospital. Patients were identified from the tumor registry and medical records were retrospectively reviewed. Pathological slides were evaluated for the presence of endometriosis, specifically looking for malignancy arising in endometriosis. Evidence of endometriosis was found in 22 of the 79 cases (28%). In the 23 cases of endometrioid histology, 9 cases (39%) were associated with endometriosis and, in the 17 cases of clear cell tumors, 7 (41%) were associated with endometriosis. All 8 cases of mixed histology had clear cell and/or endometrioid components and 4 cases (50%) were associated with endometriosis. Endometrioid adenocarcinoma accounted for 41% of the tumors associated with endometriosis, clear cell carcinoma 31%, mixed (endometrioid and/or clear cell types) 18%, and other types 9%. Among the 22 patients with associated endometriosis, we found 7 carcinomas (32%) arising in endometriosis. In these 7 cases a spectrum of benign and atypical endometriosis with a transition to clear cell or endometrioid adenocarcinoma were identified. These premalignant changes were characterized by cytologic atypia and architectural proliferation. Endometriosis was frequently encountered among patients with Stage I epithelial ovarian cancer of endometrioid and clear cell histologies. Endometriosis may play a role in the pathogenesis of some early stage malignant ovarian epithelial neoplasms.

Endometriosis and the neoplastic process

Endometriosis is a frequent disorder that commonly presents with infertility and pelvic pain. Although the precise aetiology of endometriosis is unclear, it is generally considered to involve multiple genetic, environmental, immunological, angiogenic and endocrine processes. Genetic factors have been implicated in endometriosis but the susceptibility genes remain largely unknown. Although endometriosis is a benign disorder, recent studies of endometriosis suggest endometriosis could be viewed as a neoplastic process. Evidence to support this hypothesis includes the increased susceptibility to develop ovarian clear-cell and endometrioid cancers in the presence of endometriosis, and molecular similarities between endometriosis and cancer. In this article we discuss (i) the evidence suggesting that endometriosis might be viewed as a neoplastic process, and (ii) the implications of this hypothesis for elucidating the pathogenesis of endometriosis and developing novel methods of diagnostic classification and individualised treatments.

Phase II trial of alternating courses of megestrol acetate and tamoxifen in advanced endometrial carcinoma: a Gynecologic Oncology Group study

OBJECTIVES

To estimate the objective response rate and toxicity associated with alternating megestrol acetate (MA) and tamoxifen citrate (T) in women with endometrial carcinoma.

METHODS

Consenting patients with measurable recurrent or advanced endometrial carcinoma were eligible if they had not received prior cytotoxic or hormonal treatment. MA 80 mg BID x 3 weeks alternating with T 20 mg BID x 3 weeks orally was given.

RESULTS

Of 61 patients entered, 56 eligible patients were evaluable for toxicity and response. Fifteen patients responded (12 complete, 3 partial) for an overall response rate of 27% (90% Confidence Interval: 17-38%). In 8 of 15 (53%) responders, response duration exceeded 20 months. The response rate was 38% in patients with histologic grade 1 tumors (n = 16), 24% in those with grade 2 disease (n = 17), and 22% among patients with grade 3 disease (n = 23). Women less than or equal to 60 years (n = 16) appear to have a better response rate than those >60 years (n = 40), 44% versus 20%. The response rate in patients with extra pelvic disease (n = 42) was 31% as compared to 14% in those with strictly pelvic and/or vaginal disease (n = 14). The median progression-free survival (PFS) was 2.7 months and median overall survival was 14.0 months. Two patients experienced a grade 4 thromboembolic event. Additional toxicities included one of each grade 3 gastrointestinal, grade 3 neurologic, and grade 3 genitourinary.

CONCLUSION

A regimen of alternating megestrol acetate and tamoxifen is active in treating endometrial cancer and may result in a prolonged complete response (CR) in some patients.