Clinicopathological Determinants of Recurrence Risk and Survival in Mucinous Ovarian Carcinoma

Mucinous ovarian carcinoma: A survey of practice in Australia and New Zealand

BACKGROUND

Mucinous ovarian carcinoma (MOC) is a rare ovarian cancer with limited evidence to support clinical care.

AIMS

We undertook a clinician survey to better understand current practice in treating MOC in Australia and New Zealand, and to determine any features associated with variation in care. In addition, we aimed to understand future research priorities.

METHODS

A RedCap survey was distributed to clinician members of the Australia New Zealand Gynaecological Oncology Group (ANZGOG). Questions included respondent demographics, three case studies and future research priorities. Clinicians were asked questions specific to their speciality.

RESULTS

Respondents (n = 47) were commonly experienced gynae-oncology specialists, most often surgical (38%) or medical (30%) oncologists. There was good consensus for surgical approaches for stage I disease; however, variation in practice was noted for advanced or recurrent MOC. Variation was also observed for medical oncologists; in early-stage disease there was no clear consensus on whether to offer chemotherapy, or which regimen to recommend. For advanced and recurrent disease a wide range of chemotherapy options was considered, with a trend away from an ovarian-type toward gastrointestinal (GI)-type regimens in advanced MOC. This practice was reflected in future research priorities, with 'Is a GI chemotherapy regimen better than an ovarian regimen?' the most highly ranked option, followed by 'Should stage 1C patients receive chemotherapy?'

CONCLUSIONS

Although the number of respondents limited the analyses, it was clear that chemotherapy selection was a key point of divergence for medical oncologists. Future research is needed to establish well-evidenced guidelines for clinical care of MOC.

The survival benefit associated with complete macroscopic resection in epithelial ovarian cancer is histotype specific

BACKGROUND

Complete macroscopic resection is a key factor associated with prolonged survival in ovarian cancer. However, most evidence derives from high-grade serous ovarian carcinoma, and the benefit of complete macroscopic resection in other histotypes is poorly characterized. We sought to determine which histotypes derive the greatest benefit from complete macroscopic resection to better inform future decisions on radical cytoreductive efforts.

METHODS

We performed multivariable analysis of disease-specific survival across 2 independent patient cohorts to determine the magnitude of benefit associated with complete macroscopic resection within each histotype.

RESULTS

Across both cohorts (Scottish: n = 1622; Surveillance, Epidemiology, and End Results [SEER]: n = 18 947), complete macroscopic resection was associated with prolonged disease-specific survival; this was more marked in the Scottish cohort (multivariable hazard ratio [HR] = 0.44, 95% confidence interval [CI] = 0.37 to 0.52 vs HR = 0.59, 95% CI = 0.57 to 0.62 in SEER). In both cohorts, clear cell ovarian carcinoma was among the histotypes to benefit most from complete macroscopic resection (multivariable HR = 0.23 and HR = 0.50 in Scottish and SEER cohorts, respectively); high-grade serous ovarian carcinoma patients demonstrated highly statistically significant and clinically meaningful survival benefit, but this was of lower magnitude than in clear cell ovarian carcinoma and endometrioid ovarian carcinoma across both cohorts. The benefit derived in low-grade serous ovarian carcinoma is also high (multivariable HR = 0.27 in Scottish cohort). Complete macroscopic resection was associated with prolonged survival in mucinous ovarian carcinoma patients in the SEER cohort (multivariable HR = 0.65), but the association failed to reach statistical significance in the Scottish cohort.

CONCLUSIONS

The overall ovarian cancer patient population demonstrates clinically significant survival benefit associated with complete macroscopic resection; however, the magnitude of benefit differs between histotypes.

Development and validation of a nomogram to predict cancer-specific survival of mucinous epithelial ovarian cancer after cytoreductive surgery

BACKGROUND

Mucinous epithelial ovarian cancer (mEOC) is a relatively uncommon subtype of ovarian cancer with special prognostic features, but there is insufficient research in this area. This study aimed to develop a nomogram for the cancer-specific survival (CSS) of mEOC based on Surveillance, Epidemiology, and End Results (SEER) database and externally validate it in National Union of Real World Gynecological Oncology Research and Patient Management (NUWA) platform from China.

METHODS

Patients screened from SEER database were allocated into training and internal validation cohort in a ratio of 7: 3, with those from NUWA platform as an external validation cohort. Significant factors selected by Cox proportional hazard regression were applied to establish a nomogram for 3-year and 5-year CSS. The performance of nomogram was assessed by concordance index, calibration curves and Kaplan-Meier (K-M) curves.

RESULTS

The training cohort (n = 572) and internal validation cohort (n = 246) were filtered out from SEER database. The external validation cohort contained 186 patients. Baseline age, tumor stage, histopathological grade, lymph node metastasis and residual disease after primary surgery were significant risk factors (p < 0.05) and were included to develop the nomogram. The C-index of nomogram in training, internal validation and external validation cohort were 0.869 (95% confidence interval [CI], 0.838-0.900), 0.839 (95% CI, 0.787-0.891) and 0.800 (95% CI, 0.738-0.862), respectively. The calibration curves of 3-year and 5-year CSS in each cohort showed favorable agreement between prediction and observation. K-M curves of different risk groups displayed great discrimination.

CONCLUSION

The discrimination and goodness of fit of the nomogram indicated its satisfactory predictive value for the CSS of mEOC in SEER database and external validation in China, which implies its potential application in different populations.

Distinct histopathological features are associated with molecular subtypes and outcome in low grade serous ovarian carcinoma

Low grade serous ovarian carcinoma (LGSOC) demonstrates unique clinical and molecular features compared to other ovarian cancer types. The relationship between common histological features of LGSOC and molecular events, such as hormone receptor expression patterns and MAPK gene mutation status, remains poorly understood. Recent data suggest some of these molecular features may be biomarkers of response to recently introduced biologically-targeted therapies, namely endocrine therapy and MEK inhibitors. We utilize a cohort of 63 pathologically-confirmed LGSOC cases with whole exome sequencing and hormone receptor expression data to investigate these relationships. LGSOC cases demonstrated uniformly high oestrogen receptor (ER) expression, but variable progesterone receptor (PR) expression intensity. 60% and 37% of cases demonstrated micropapillary and macropapillary patterns of stromal invasion, respectively. 63% of cases demonstrated desmoplasia, which was significantly associated with advanced disease stage and visible residual disease after cytoreductive surgery. MAPK-mutant cases (KRAS, BRAF, NRAS) more frequently demonstrated macropapillary stromal invasion, while Chr1p loss was associated with desmoplasia and low PR expression. Presence of micropapillary stromal invasion and low PR expression were associated with significantly poorer survival after accounting for stage and residual disease status. Together, these data identify novel relationships between histopathological features and molecularly-defined subgroups in LGSOC.

Molecular characteristics and clinical behaviour of epithelial ovarian cancers

Ovarian carcinoma (OC) is an umbrella term for multiple distinct diseases (histotypes), each with their own developmental origins, clinical behaviour and molecular profile. Accordingly, OC management is progressing away from a one-size-fits all approach, toward more molecularly-driven, histotype-specific management strategies. Our knowledge of driver events in high grade serous OC, the most common histotype, has led to major advances in treatments, including PARP inhibitor use. However, these agents are not suitable for all patients, most notably for many of those with rare OC histotypes. Identification of additional targeted therapeutic strategies will require a detailed understanding of the molecular landscape in each OC histotype. Until recently, tumour profiling studies in rare histotypes were sparse; however, significant advances have been made over the last decade. In particular, reports of genomic characterisation in endometrioid, clear cell, mucinous and low grade serous OC have significantly expanded our understanding of mutational events in these tumour types. Nonetheless, substantial knowledge gaps remain. This review summarises our current understanding of each histotype, highlighting recent advances in these unique diseases and outlining immediate research priorities for accelerating progress toward improving patient outcomes.

Update on Prognostic and Predictive Markers in Mucinous Ovarian Cancer

This review includes state-of-the-art prognostic and predictive factors of mucinous ovarian cancer (MOC), a rare tumor. Clinical, pathological, and molecular features and treatment options according to prognosis are comprehensively discussed. Different clinical implications of MOC are described according to the The International Federation of Gynecology and Obstetrics (FIGO) stage: early MOC (stage I-II) and advanced MOC (stage III-IV). Early MOC is characterized by a good prognosis. Surgery is the mainstay of treatment. Fertility-sparing surgery could be performed in patients who wish to become pregnant and that present low recurrence risk of disease. Adjuvant chemotherapy is not recommended, except in patients with high-risk clinical and pathological features. Regarding the histological features, an infiltrative growth pattern is the major prognostic factor of MOC. Furthermore, novel molecular biomarkers are emerging for tailored management of early-stage MOC. In contrast, advanced MOC is characterized by poor survival. Radical surgery is the cornerstone of treatment and adjuvant chemotherapy is recommended, although the efficacy is limited by the intrinsic chemoresistance of these tumors. Several molecular hallmarks of advanced MOC have been described in recent years (e.g., HER2 amplification, distinct methylation profiles, peculiar immunological microenvironment), but target therapy for these rare tumors is not available yet.

Case report: Long-term clinical benefit of pyrotinib therapy following trastuzumab resistance in HER2-amplification recurrent mucinous ovarian carcinoma

Advanced or recurrent mucinous carcinoma of the ovary minimally responds to current cytotoxic treatments and has a poor prognosis. Despite multimodal treatment with chemotherapy and surgery, most patients ultimately progress and require palliative systemic therapy. Anti-HER2 therapy has been demonstrated to be an effective strategy for the treatment of HER2-positive breast cancer. However, the role of anti-HER2 therapy in ovarian cancer remains largely unknown. Here, we report the case of a young woman with FIGO Stage IIIc recurrent mucinous ovarian carcinoma (MOC) who developed trastuzumab resistance and disease progression following cross-treatment with trastuzumab combined with pertuzumab. HER2 amplification was discovered using next-generation sequencing (NGS). The patient then received bevacizumab, and pyrotinib (an irreversible HER2 antagonist) plus capecitabine treatment, and achieved a long-term clinical benefit for 22 months. Pyrotinib combined with bevacizumab is a potential treatment for MOC patients who are heavily pretreated and harbor a HER2 amplification. Our case may provide valuable treatment information for patients with advanced or recurrent MOC.

Outcome-based Validation of Confluent/Expansile Versus Infiltrative Pattern Assessment and Growth-based Grading in Ovarian Mucinous Carcinoma

The growth pattern (confluent/expansile versus infiltrative) in primary ovarian mucinous carcinoma (OMC) is prognostically important, and the International Collaboration on Cancer Reporting (ICCR) currently recommends recording the percentage of infiltrative growth in this tumor type. Histologic grading of OMC is controversial with no single approach widely accepted or currently recognized by the World Health Organization Classification of Tumours. Since ovarian carcinoma grade is often considered in clinical decision-making, previous literature has recommended incorporating clinically relevant tumor parameters such as growth pattern into the OMC grade. We herein validate this approach, termed Growth-Based Grade (GBG), in an independent, well-annotated cohort from 2 institutions. OMCs with available histologic material underwent review and grading by Silverberg, International Federation of Obstetrics and Gynecology (FIGO), and GBG schema. GBG categorizes OMCs as low-grade (GBG-LG, confluent/expansile growth, or ≤10% infiltrative invasion) or high-grade (GBG-HG, infiltrative growth in >10% of tumor). The cohort consisted of 74 OMCs, 53 designated as GBG-LG, and 21 as GBG-HG. Using Silverberg grading, the cohort had 42 (57%) grade 1, 28 (38%) grade 2, and 4 (5%) grade 3 OMCs. Using FIGO grading, 50 (68%) OMCs were grade 1, 23 (31%) grade 2, and 1 (1%) grade 3. Follow-up data was available in 68 patients, of which 15 (22%) had cancer recurrence. GBG-HG tumors were far more likely to recur compared with GBG-LG tumors (57% vs. 6%; χ2P<0.0001). Silverberg and FIGO grading systems also correlated with progression-free survival in univariate analysis, but multivariate analysis showed only GBG to be significant (hazard ratio: 10.9; Cox proportional regression P=0.0004). Seven patients (10%) died of disease, all of whom had GBG-HG (log-rank P<0.0001). Multivariate analysis showed that the percentage of infiltrative growth was the only factor predictive of disease-specific survival (hazard ratio: 25.5, Cox P=0.02). Adding nuclear atypia to GBG categories did not improve prognostication. Our study validates the prognostic value of the GBG system for both disease-free survival and disease-specific survival in OMC, which outperformed Silverberg and FIGO grades in multivariate analysis. Thus, GBG should be the preferred method for tumor grading.