Primary peritoneal and ovarian cancers: an epidemiological comparative analysis

Primary peritoneal serous carcinoma: a primer for radiologists

Primary peritoneal serous carcinoma (PPSC) is a rare primary peritoneal tumor characterized by a unique range of clinical features and imaging findings. Though it shares many clinical, histologic, and imaging features with serous ovarian carcinoma, it remains a distinct clinical entity. Although less common than its primary ovarian counterpart, PPSC is characterized by a prognosis that is often equally poor with presentations common in late stages of disease. Key imaging modalities used in the evaluation of PPSC include ultrasound, CT, MRI, and PET/CT. For radiologists, an understanding of the pertinent imaging findings, pathologic correlations, and clinical features of PPSC is essential for arriving at the correct diagnosis and guiding the subsequent appropriate management of this complex malignancy.

Ovarian Cancer Risk Factor Associations by Primary Anatomic Site: The Ovarian Cancer Cohort Consortium

BACKGROUND

Epithelial ovarian, fallopian tube, and primary peritoneal cancers have shared developmental pathways. Few studies have prospectively examined heterogeneity in risk factor associations across these three anatomic sites.

METHODS

We identified 3,738 ovarian, 337 peritoneal, and 176 fallopian tube incident cancer cases in 891,731 women from 15 prospective cohorts in the Ovarian Cancer Cohort Consortium. Associations between 18 putative risk factors and risk of ovarian, peritoneal, and fallopian tube cancer, overall and for serous and high-grade serous tumors, were evaluated using competing risks Cox proportional hazards regression. Heterogeneity was assessed by likelihood ratio tests.

RESULTS

Most associations did not vary by tumor site (P het ≥ 0.05). Associations between first pregnancy (P het = 0.04), tubal ligation (P het = 0.01), and early-adult (age 18-21 years) body mass index (BMI; P het = 0.02) and risk differed between ovarian and peritoneal cancers. The association between early-adult BMI and risk further differed between peritoneal and fallopian tube cancer (P het = 0.03). First pregnancy and tubal ligation were inversely associated with ovarian, but not peritoneal, cancer. Higher early-adult BMI was associated with higher risk of peritoneal, but not ovarian or fallopian tube, cancer. Patterns were generally similar when restricted to serous and high-grade serous cases.

CONCLUSIONS

Ovarian, fallopian tube, and primary peritoneal cancers appear to have both shared and distinct etiologic pathways, although most risk factors appear to have similar associations by anatomic site.

IMPACT

Further studies on the mechanisms underlying the differences in risk profiles may provide insights regarding the developmental origins of tumors arising in the peritoneal cavity and inform prevention efforts.

Breast Microcalcifications as the Only Imaging Manifestation of Metastatic Serous Peritoneal Adenocarcinoma in the Breast

We present a case of a 65 year old female with newly diagnosed primary peritoneal serous carcinoma who was found to have indeterminate segmental microcalcifications in the right upper outer quadrant with a mildly enlarged right axillary node on mammogram. There was no associated breast mass on ultrasound. Core biopsy of the right axillary lymph node and right upper outer quadrant breast microcalcifications confirmed the presence of breast metastases at both sites from primary peritoneal serous carcinoma. This case highlights the importance of histopathological correlation of any breast and axillary abnormalities in patient with primary extramammary malignancy. Imaging features of metastatic lesions to the breast are also reviewed.

Challenges and Opportunities in Studying the Epidemiology of Ovarian Cancer Subtypes

PURPOSE OF REVIEW

Only recently has it become clear that epithelial ovarian cancer (EOC) is comprised of such distinct histotypes--with different cells of origin, morphology, molecular features, epidemiologic factors, clinical features, and survival patterns-that they can be thought of as different diseases sharing an anatomical location. Herein, we review opportunities and challenges in studying EOC heterogeneity.

RECENT FINDINGS

The 2014 World Health Organization diagnostic guidelines incorporate accumulated evidence that high- and low-grade serous tumors have different underlying pathogenesis, and that, on the basis of shared molecular features, most high grade tumors, including some previously classified as endometrioid, are now considered to be high-grade serous. At the same time, several studies have reported that high-grade serous EOC, which is the most common histotype, is itself made up of reproducible subtypes discernable by gene expression patterns.

SUMMARY

These major advances in understanding set the stage for a new era of research on EOC risk and clinical outcomes with the potential to reduce morbidity and mortality. We highlight the need for multidisciplinary studies with pathology review using the current guidelines, further molecular characterization of the histotypes and subtypes, inclusion of women of diverse racial/ethnic and socioeconomic backgrounds, and updated epidemiologic and clinical data relevant to current generations of women at risk of EOC.

Challenges and Opportunities in Studying the Epidemiology of Ovarian Cancer Subtypes

Purpose of review

Only recently has it become clear that epithelial ovarian cancer (EOC) is comprised of such distinct histotypes--with different cells of origin, morphology, molecular features, epidemiologic factors, clinical features, and survival patterns-that they can be thought of as different diseases sharing an anatomical location. Herein, we review opportunities and challenges in studying EOC heterogeneity.

Recent findings

The 2014 World Health Organization diagnostic guidelines incorporate accumulated evidence that high- and low-grade serous tumors have different underlying pathogenesis, and that, on the basis of shared molecular features, most high grade tumors, including some previously classified as endometrioid, are now considered to be high-grade serous. At the same time, several studies have reported that high-grade serous EOC, which is the most common histotype, is itself made up of reproducible subtypes discernable by gene expression patterns.

Summary

These major advances in understanding set the stage for a new era of research on EOC risk and clinical outcomes with the potential to reduce morbidity and mortality. We highlight the need for multidisciplinary studies with pathology review using the current guidelines, further molecular characterization of the histotypes and subtypes, inclusion of women of diverse racial/ethnic and socioeconomic backgrounds, and updated epidemiologic and clinical data relevant to current generations of women at risk of EOC.

Challenges and Opportunities in Studying the Epidemiology of Ovarian Cancer Subtypes

PURPOSE OF REVIEW

Only recently has it become clear that epithelial ovarian cancer (EOC) is comprised of such distinct histotypes--with different cells of origin, morphology, molecular features, epidemiologic factors, clinical features, and survival patterns-that they can be thought of as different diseases sharing an anatomical location. Herein, we review opportunities and challenges in studying EOC heterogeneity.

RECENT FINDINGS

The 2014 World Health Organization diagnostic guidelines incorporate accumulated evidence that high- and low-grade serous tumors have different underlying pathogenesis, and that, on the basis of shared molecular features, most high grade tumors, including some previously classified as endometrioid, are now considered to be high-grade serous. At the same time, several studies have reported that high-grade serous EOC, which is the most common histotype, is itself made up of reproducible subtypes discernable by gene expression patterns.

SUMMARY

These major advances in understanding set the stage for a new era of research on EOC risk and clinical outcomes with the potential to reduce morbidity and mortality. We highlight the need for multidisciplinary studies with pathology review using the current guidelines, further molecular characterization of the histotypes and subtypes, inclusion of women of diverse racial/ethnic and socioeconomic backgrounds, and updated epidemiologic and clinical data relevant to current generations of women at risk of EOC.

Waldenström's macroglobulinemia masquerading as ovarian cancer with peritoneal carcinomatosis, ascites, and elevated CA-125

Waldenström's macroglobulinemia is a rare hematology malignancy which often presents with "B symptoms," anemia, and thrombocytopenia. A 46-year-old woman presented with 2 months of abdominal distension accompanied by an unintentional 20-lb weight loss. Her abdominal CT scan demonstrated diffuse carcinomatosis with bilateral ovarian lesions and screening labs revealed a markedly elevated CA-125, suggesting a diagnosis of ovarian cancer. Upon admission for workup, patient was found to have a significant protein gap, later attributed to a markedly elevated IgM. Omental and bone marrow biopsy confirmed the diagnosis of Waldenström's macroglobulinemia, with elevation in CA-125 thought to be secondary to peritoneal irritation. This patient has since been successfully treated with six cycles of bendamusine and rituximab with no evidence of disease on staging scans and normalization of both CA-125 and IgM. To our knowledge, this is the first documented case of Waldenström's macroglobulinemia presenting with symptoms classically associated with ovarian cancer and demonstrates the importance of maintaining a broad differential when evaluating patients with abdominal carcinomatosis.

The RENAPE observational registry: rationale and framework of the rare peritoneal tumors French patient registry

Background

Rare peritoneal cancers represent complex clinical situations requiring a specific and multidisciplinary management. Because of their rarity, lack of awareness and knowledge often leads to diagnostic delays and misdiagnosis. And patients are not systematically referred to expert centers as they should be. Clinicians and researchers also face unique challenges with these rare cancers, because it is hard to conduct adequately powered, controlled trials in such small patient population. This is how an observational patient registry constitutes a key instrument for the development of epidemiological and clinical research in the field of these rare cancers. It is the appropriate tool to pool scarce data for epidemiological research and to assess the impact of diagnostic and therapeutic strategies. We aimed to provide the outlines and the framework of the RENAPE observational registry and share our experience in the establishment of a national patient registry.

Results

The RENAPE observational registry has been launched in 2010 thanks to institutional supports. It concerns only patients with a histological diagnosis confirming a peritoneal surface malignancy. A web secured clinical database has been implemented based on data management procedures according to the principles of international recommendations and regulatory statements. A virtual tumor bank is linked in order to the conduct translational studies. Specialized working groups have been established to continuously upgrade and evolve the common clinical and histological data elements following the last classifications and clinical practices. They contribute also to standardize clinical assessment and homogenize practices.

Conclusions

The RENAPE Registry may improve awareness and understanding of the rare peritoneal tumors into the incidence, prevalence, recurrence, survival and mortality rates, as well as treatment practices thereby enabling therapeutic intervention to be evaluated and ultimately optimized.

Trial registration

ClinicalTrials.gov Identifier: NCT02834169

The Association between Endometriosis, Tubal Ligation, Hysterectomy and Epithelial Ovarian Cancer: Meta-Analyses

To investigate the association between endometriosis, tubal ligation, hysterectomy and epithelial ovarian cancer. Relevant published literatures were searched in PubMed, ProQuest, Web of Science and Medline databases during 1995-2016. Heterogeneity was evaluated by I² statistic. Publication bias was tested by funnel plot and Egger's test. Odds ratio and 95% CI were used to assess the association strength. The statistical analyses in this study were accomplished by STATA software package. A total of 40,609 cases of epithelial ovarian cancer and 368,452 controls in 38 publications were included. The result suggested that endometriosis was associated with an increased risk of epithelial ovarian cancer (OR = 1.42, 95% CI = 1.28-1.57), tubal ligation was associated with a decreased risk of epithelial ovarian cancer (OR = 0.70, 95% CI = 0.60-0.81), while hysterectomy show no relationship with epithelial ovarian cancer (OR = 0.97, 95% CI = 0.81-1.14). A stratified analysis showed there were associations between endometriosis and the increased risk of epithelial ovarian cancer for studies conducted in USA and Europe. Meanwhile, there were associations between tubal ligation and the decreased risk of epithelial ovarian cancer for studies conducted in USA, Asia, Europe and Australia. The result indicated that endometriosis was a risk factor of epithelial ovarian cancer whereas tubal ligation was a protective risk factor of epithelial ovarian cancer, hysterectomy may have no relationship with epithelial ovarian cancer.

Genetic landscape of a case of extraovarian peritoneal serous papillary carcinoma

The present report aimed to study genetic alterations underlying extraovarian peritoneal serous papillary carcinoma (EPSPC), which have not previously been systematically investigated. A case of EPSPC was identified, and its genetic alterations were assessed by combining comparative genomic hybridization and whole-exome sequencing technologies to investigate the genomic landscape, including copy number variations and mutations in EPSPC. It was found that a large number of germline mutations were present, which may have predisposed the patient to the occurrence of this disease. Copy number gains were found in a range of chromosomes, including 4q, 5q, 8q, 10q, 15q, 16p, 18q, 20p, 20q and Xq. Large-scale copy number loss occurred in chromosomes 2p, 13q, 16q, 17p and 17q. Through use of whole-exome sequencing, germline mutations were widely found that were associated with cancer development, including mutations in the BRCA1, DNA repair associated (BRCA1), BRCA2, tumor protein 53, erb-b2 receptor tyrosine kinase 2, matrix metalloproteinases and ADAM metallopeptidase domain-containing genes. In addition, 165 somatic mutations, including 52 missense mutations and 7 short insertions or deletions, were also identified. In summary, the EPSPC was undergoing profound genomic rearrangement and somatic mutation, which may have led to its initiation and development, and the present study discussed the genetic basis of this highly malignant cancer.

Serous ovarian and primary peritoneal cancers: A comparative analysis of clinico-pathological features, molecular subtypes and treatment outcome

OBJECTIVE

Primary peritoneal cancer is rare and considered equivalent to stage III/IV ovarian cancer, but questions remain concerning its underlying biology, prognosis and optimal management.

METHODS

Clinico-pathological and treatment details of primary peritoneal (n=120) and ovarian cancer (n=635) were obtained on women recruited to the Australian Ovarian Cancer Study. Log-rank test was used to compare survival and cox proportional hazards models were fitted to obtain hazard ratios and 95% confidence intervals, both unadjusted and adjusted for age, grade, FIGO stage, residual disease and treatment with neoadjuvant chemotherapy. Molecular subtype was determined by gene expression profiling using published data.

RESULTS

Compared with advanced serous ovarian cancer, primary peritoneal cancer patients were older (mean age 65.5 vs. 60.2years, p<0.001), more often treated with neoadjuvant chemotherapy (38.4% vs. 11.4%, p<0.001). Gene expression profiling classified a substantially higher proportion of primary peritoneal carcinomas as C1 (mesenchymal, reactive stromal infiltration) subtype (70.6% vs. 32.1%, p=0.029), which was associated with lower complete surgical resection rate. Women with primary peritoneal cancer had significantly shorter progression-free (11.6 vs. 13.6months, p=0.007) and overall survival (31.7 vs. 39.8months, p=0.012). In multivariate analysis, residual disease and neoadjuvant chemotherapy were both independently associated with increased risk of progression and death.

CONCLUSIONS

Primary peritoneal cancer patients were more frequently treated with neoadjuvant chemotherapy and had inferior survival. Different tumor biology characterized by activated stromal fibrosis in primary peritoneal cancer may underlie the differences in treatment and clinical outcome.

Tubal ligation and incidence of 26 site-specific cancers in the Million Women Study

BACKGROUND

Tubal ligation is known to be associated with a reduction in ovarian cancer risk. Associations with breast, endometrial and cervical cancers have been suggested. We investigated associations for 26 site-specific cancers in a large UK cohort.

METHODS

Study participants completed a questionnaire on reproductive and lifestyle factors in 1996-2001, and were followed for cancer and death via national registries. Using Cox regression models, we estimated adjusted relative risks (RRs) for 26 site-specific cancers among women with vs without tubal ligation.

RESULTS

In 1 278 783 women without previous cancer, 167 430 incident cancers accrued during 13.8 years' follow-up. Significantly reduced risks were found in women with tubal ligation for cancers of the ovary (RR=0.80, 95% CI: 0.76-0.85; P<0.001; n=8035), peritoneum (RR=0.81, 0.66-0.98; P=0.03; n=730), and fallopian tube (RR=0.60, 0.37-0.96; P=0.04; n=168). No significant associations were found for endometrial, breast, or cervical cancers.

CONCLUSIONS

The reduced risks of ovarian, peritoneal and fallopian tube cancers are consistent with hypotheses of a common origin for many tumours at these sites, and with the suggestion that tubal ligation blocks cells, carcinogens or other agents from reaching the ovary, fallopian tubes and peritoneal cavity.

Primary peritoneal adenocarcinoma as content of an incarcerated umbilical hernia: A case-report and review of the literature

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We report on a rare case of primary peritoneal carcinoma.

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During operation there was no sign of malignancy.

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The diagnosis of primary peritoneal carcinoma was made by routine histological examination.

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We recommend routine histological examination of resected tissue.

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An overview of the literature on primary peritoneal carcinoma is given.

Introduction

Umbilical hernia is a common finding in many cases, posing potentially life-threatening complications, such as incarceration or strangulation. The presence of malignancy in hernia sacs is, however, rather rare.

Presentation of case

Here we report on a case of primary peritoneal adenocarcinoma found through histological examination of omental tissue, resected due to an incarcerated umbilical hernia of an 84-years-old woman. There was no macroscopic sign of malignancy during operation; only after routine examination of histological sections the diagnosis was found.

Discussion

To our knowledge this is the first report of primary peritoneal cancer as content of an umbilical hernia. This is a rare neoplasm and histologically identical to epithelial ovarian carcinoma. For this reason, the diagnosis is usually based on the histological finding and exclusion of a primary ovarian tumor. Primary peritoneal cancer has a poor outcome in general. Early diagnosis is, therefore, essential for effective treatment.

Conclusion

Histological analysis of resected hernia sac or content should be performed routinely to discover malignant diseases in the background of a hernia.

When is it safe to omit surgery in primary peritoneal cancer with small volume disease?

Primary peritoneal cancer (PPC) is considered a very rare condition, with mesotheliomas deemed the only true PPC when considering the cellular content and embryological derivation of the peritoneum. However, in women, PPC are seen in much greater abundance than that in men and the type of cancer detected is often that of a serous epithelial carcinoma, histologically similar to serous ovarian carcinomas. The management is also similar, i.e. surgery and platin-based chemotherapy. The definition clinically of PPC is that of widespread carcinomatosis with normal-sized ovaries. The carcinomatosis is often extensive, and the only bulk disease may be within the omentum and achieving complete clearance of all disease at primary surgery unlikely. Thus, the concept of using chemotherapy as the main strategy is a reasonable approach and may well be the best single therapeutic option in some patients. This paper reviews the data on PPC and how this approach could be assessed.

Serous ovarian, fallopian tube and primary peritoneal cancers: a common disease or separate entities - a systematic review

OBJECTIVE

The aim of this systematic review is to analyze data on risk factors, epidemiology, clinicopathology and molecular biology from studies comparing primary peritoneal cancer, fallopian tube cancer and ovarian cancer of serous histology, in order to achieve a greater understanding of whether or not these disorders should be considered as separate entities.

METHODS

A systematic literature search was conducted in PubMed and MEDLINE. Case-control studies comparing primary serous peritoneal or fallopian tube carcinomas with primary serous ovarian carcinomas or a control group were included.

RESULTS

Twenty-eight studies were found eligible. Primary peritoneal cancer patients were older, had higher parity, were more often obese and had poorer survival compared to ovarian cancer patients. Differences in protein expression patterns of Her2/neu, estrogen and progestin receptors and frequency of loss of heterozygosity differed between primary peritoneal cancer and primary ovarian cancer patients. No major differences were found between primary fallopian tube cancer and primary ovarian cancer. The proportion of serous tubal intraepithelial carcinomas (STIC) was lower in primary peritoneal cancer and primary ovarian cancer compared to primary fallopian tube cancer.

CONCLUSION

Except from differences in the proportion of STIC only few differences between primary fallopian tube cancer and primary ovarian cancer have been found. In contrast, observed differences in risk factor profile, clinicopathologic and prognostic factors, as well as in the molecular patterns, indicate that peritoneal cancer and ovarian cancer may be linked to different carcinogenic pathways.

Demographic clinical and prognostic characteristics of primary ovarian, peritoneal and tubal adenocarcinomas of serous histology--a prospective comparative study

OBJECTIVES

Invasive serous adenocarcinomas may present as primary ovarian (POC), primary fallopian tube (PFC) or primary peritoneal (PPC) carcinomas. Whether they are variants of the same malignancy or develop through different pathways is debated.

METHODS

Population-based prospectively collected data on POC (n=1443), PPC (n=268) and PFC (n=171) cases was obtained from the Danish Gynecological Cancer Database (2005-2013). Chi-square, Fisher's or Wilcoxon-Mann-Whitney test, multivariate logistic regression, Kaplan-Meier and multivariate Cox-regression were used as appropriate. Statistical tests were 2-sided. P-values of <0.05 were considered statistically significant.

RESULTS

PPC cases were older (P<0.0001), had a later age at menarche (P=0.02), a higher percentage were multi-parous (≥two children vs. no children) OR 1.70 (1.01-2.49) and both PPC and PFC tended to have a higher BMI (>35 vs. >18.5-25) than POC cases. PFC cases were diagnosed in earlier stages (P<0.001). In advanced stages a lower proportion had preoperative carcinosis or ascites, and a higher percentage had macro-radical surgery or lymphadenectomy compared to POC. In contrast, more PPC cases had post-operative carcinosis; whereas a lower proportion had lymphadenectomy or macro-radical surgery compared to POC. PPC had a significantly lower overall survival than POC, HR=1.24 (1.04-1.47).

CONCLUSION

We found differences in risk pattern profiles among the three groups, especially for PPC. Furthermore, the severity of stage specific disease differed significantly according to location, resulting in a lower overall survival for PPC. These differences warrant further research to determine to what extent PPC is a distinct disease entity.

Primary peritoneal carcinoma: regional cancer institute experience

Primary peritoneal serous carcinoma (PPSC) is a rare malignancy that arises primarily from peritoneal surface epithelium. However there are limited studies on these tumors even in world literature. To study the clinical, pathologic profile, outcome and prognostic features of PPSC. A 5 year retrospective study of PPSC diagnosed and treated at our centre was conducted. The pathological specimen of PPSC diagnosed from January 2008 to December 2012 were reviewed by gynaeconcopathologists. The diagnosis was based on GOG criteria, complemented with IHC. Majority of the patients underwent upfront de-bulking surgery. Postoperatively, six cycles of combination chemotherapy with paclitaxel (175 mg/m(2)) and carboplatin (AUC 6) was administered every 3 weekly. These patients were analysed for progression free survival (PFS), this was correlated with stage and surgical adequacy. The median age of presentation was 56 years. The total number of ovarian cancers treated during study period was 374. The 30 cases were clinically suspected to have primary peritoneal carcinoma (PPC) on pre- and intra-operatve gross findings, but further evaluation with histopathological examination, IHC and GOG criteria revealed only 10 cases were genuine PPSC. The remaing 20 cases; 13 were found to poorly differentiated ovarian carcinomas, six were primary fallopian tube carcinoma and one was appendicular carcinoma. The 10 (2.7 %) cases of the 374 were eligible for the PPSC analysis. The two (20 %) of the 10 cases had family history of breast and ovarian cancers, two (20 %) cases were diagnosed as abdominal tuberculosis (TB) prior referral to our centre. Radiological presentation includes gross ascites, with omental caking and normal adenexa. The eight (80 %) of 10 cases presented with stage IIIC and other two cases (20 %) with stage IV disease. The eight (80 %) of 10 cases underwent upfront surgery; six (75 %) of these eight cases had optimal cytoreduction, i.e. residual disease (RD) <1 cm or no visible disease (R0) and other two (25 %) suboptimal cytoreduction. The two (20 %) of 10 cases with stage IV disease received neoadjuvant chemotherapy (NACT) followed by interval cytoreduction. After debulking surgery the most useful IHC marker include CK7+, CK20-, CA125+, WT-1+, and GCDFP- . At median follow up of 24 months (range 3-60 months), the median progression free survival (PFS) was 22 months, while the estimated 5 year PFS was 18 %. Stage IV disease and suboptimal surgery had poor outcome. The PPSC presents with advanced stage disease and are observed to be misdiagnosed abdominal TB in tropical countries. The GOG criteria and IHC complement the diagnosis. These have poor outcome despite optimal care, highlighting need for larger studies on this disease.

Extraovarian primary peritoneal carcinoma: staging with 18F-FDG PET/CT

A 69-year-old woman who presented with left lower quadrant abdominal pain and elevated serum cancer antigen 125 (CA-125) levels was referred for an MRI and an (18)F-FDG PET/CT to evaluate a suspicious abdominal mass seen on ultrasound. PET/CT showed extensive, intensely FDG-avid, omental and pelvic peritoneal thickening with no suspicious ovarian or colon masses. Based on the PET/CT results, the patient had extensive debulking surgery and histopathological evaluation revealed an extraovarian primary peritoneal carcinoma (EOPPC). (18)F-FDG PET/CT may be useful in differentiating EOPPC from other types of peritoneal carcinomatosis, and in determining the extent of the disease to better guide surgical management and improve long term outcomes.