Retrospective cohort study of surgical staging for ovarian low malignant potential tumors

Borderline Ovarian Tumors: Fifteen Years' Experience at a Scottish Tertiary Cancer Center

OBJECTIVES

Since the recognition of borderline ovarian tumors (BOTs) in the 1970s, the management of this subset of epithelial ovarian tumors has presented a challenge to clinicians. The majority present at an early stage, but their diagnosis is often only made following surgery, hence the heterogeneity of surgical management. Borderline ovarian tumors are morphologically diverse, and their behavior is subsequently also heterogeneous. We aimed to assess recurrence rates and the rate of malignant transformation in patients diagnosed with BOT. Secondary objectives included a review of current management and assessment of tumor markers, stage, cyst dimensions, and the presence of micropapillary features as prognostic indicators of recurrence.

METHODS

This retrospective cohort study included all patients treated with BOT between 2000 and 2015 in the southeast region of Scotland. Clinical, surgicopathological, and follow-up data were collated. Data were analyzed with reference to recurrence and malignant transformation.

RESULTS

Two hundred seventy-five patients underwent treatment for BOT in the study period. Surgical management was highly variable. A diagnosis of recurrent/persistent BOT or ovarian malignancy following initial treatment of BOT was rare, with only 12 (4%) of 275 cases. There were 7 cases (3%) of ovarian malignancy. Advanced International Federation of Gynecology and Obstetrics stage was the most prominent prognostic factor. Elevated preoperative serum CA-125 and the presence of micropapillary features correlated with advanced stage at presentation. With a lack of clear guidance, follow-up was highly variable with a median of 43 months (0-136 months).

CONCLUSIONS

To our knowledge, this study is the largest BOT cohort in the United Kingdom. Recurrent disease is rare in optimally staged, completely resected, early-stage BOT, without high-risk features. Caution is needed in women electing not to undergo completion staging after diagnosis and in those opting for a fertility-preserving approach. Thorough informed consent and clear plans for surveillance and follow-up are needed with consideration of delayed completion surgery as appropriate.

Staging for low malignant potential ovarian tumors: a global perspective

OBJECTIVE

We describe current evidence for staging low malignant potential ovarian tumors and their conformity to current consensus guidelines and practice from an international perspective.

DATA SOURCES

A search of MEDLINE, EMBASE, and SCOPUS databases was conducted for articles published between January 1990 and April 2015.

STUDY ELIGIBILITY CRITERIA

Studies on low malignant potential ovarian tumors that evaluated the prognostic value of disease stage, staging vs no staging, complete vs incomplete staging, or discrete components of staging were eligible. Studies that described only crude survival rates were excluded.

STUDY APPRAISAL AND SYNTHESIS METHODS

Eligible studies were categorized according to their outcome (disease stage, staging procedure, or discrete staging elements). Data were abstracted using a standard form. Inconsistencies on data abstraction were resolved by consensus among the authors. Risk of bias was assessed using the Newcastle-Ottawa Scale.

RESULTS

Of 1116 studies, 702 were excluded for irrelevance and 364 for not meeting inclusion criteria. Nine studies were excluded for describing crude survival rates without a comparative conclusion. We found that studies supporting the value of defining disease stage or staging procedures (mostly conducted in northern Europe) included more patients than studies that did not find disease stage or staging useful (predominantly from North America, 4072 vs 3951). Disease stage correlated with survival in 13 of 25 studies, whereas none of the studies that evaluated the value of staging found it beneficial (9 studies, 1979 patients). Studies that evaluated isolated components of staging found no benefit to these procedures. Regional guidelines and consensus reviews drew conclusions based on a limited number of studies that generally originated from the same region.

CONCLUSIONS

Although the correlation of stage with survival was mixed, performing staging procedures for low malignant potential ovarian tumors is not supported by the best available evidence. Guidelines in support of staging based their recommendations on a few regional studies and conflict with better-quality data that do not support staging procedures. An international consensus statement is needed to standardize the surgical management of low malignant potential ovarian tumors.

Intraoperative frozen section analysis for the diagnosis of early stage ovarian cancer in suspicious pelvic masses

BACKGROUND

Women with suspected early-stage ovarian cancer need surgical staging which involves taking samples from areas within the abdominal cavity and retroperitoneal lymph nodes in order to inform further treatment. One potential strategy is to surgically stage all women with suspicious ovarian masses, without any histological information during surgery. This avoids incomplete staging, but puts more women at risk of potential surgical over-treatment.A second strategy is to perform a two-stage procedure to remove the pelvic mass and subject it to paraffin sectioning, which involves formal tissue fixing with formalin and paraffin embedding, prior to ultrathin sectioning and multiple site sampling of the tumour. Surgeons may then base further surgical staging on this histology, reducing the rate of over-treatment, but conferring additional surgical and anaesthetic morbidity.A third strategy is to perform a rapid histological analysis on the ovarian mass during surgery, known as 'frozen section'. Tissues are snap frozen to allow fine tissue sections to be cut and basic histochemical staining to be performed. Surgeons can perform or avoid the full surgical staging procedure depending on the results. However, this is a relatively crude test compared to paraffin sections, which take many hours to perform. With frozen section there is therefore a risk of misdiagnosing malignancy and understaging women subsequently found to have a presumed early-stage malignancy (false negative), or overstaging women without a malignancy (false positive). Therefore it is important to evaluate the accuracy and usefulness of adding frozen section to the clinical decision-making process.

OBJECTIVES

To assess the diagnostic test accuracy of frozen section (index test) to diagnose histopathological ovarian cancer in women with suspicious pelvic masses as verified by paraffin section (reference standard).

SEARCH METHODS

We searched MEDLINE (January 1946 to January 2015), EMBASE (January 1980 to January 2015) and relevant Cochrane registers.

SELECTION CRITERIA

Studies that used frozen section for intraoperative diagnosis of ovarian masses suspicious of malignancy, provided there was sufficient data to construct 2 x 2 tables. We excluded articles without an available English translation.

DATA COLLECTION AND ANALYSIS

Authors independently assessed the methodological quality of included studies using the Quality Assessment of Diagnostic Accuracy Studies tool (QUADAS-2) domains: patient selection, index test, reference standard, flow and timing. Data extraction converted 3 x 3 tables of per patient results presented in articles into 2 x 2 tables, for two index test thresholds.

MAIN RESULTS

All studies were retrospective, and the majority reported consecutive sampling of cases. Sensitivity and specificity results were available from 38 studies involving 11,181 participants (3200 with invasive cancer, 1055 with borderline tumours and 6926 with benign tumours, determined by paraffin section as the reference standard). The median prevalence of malignancy was 29% (interquartile range (IQR) 23% to 36%, range 11% to 63%). We assessed test performance using two thresholds for the frozen section test. Firstly, we used a test threshold for frozen sections, defining positive test results as invasive cancer and negative test results as borderline and benign tumours. The average sensitivity was 90.0% (95% confidence interval (CI) 87.6% to 92.0%; with most studies typically reporting range of 71% to 100%), and average specificity was 99.5% (95% CI 99.2% to 99.7%; range 96% to 100%).Similarly, we analysed sensitivity and specificity using a second threshold for frozen section, where both invasive cancer and borderline tumours were considered test positive and benign cases were classified as negative. Average sensitivity was 96.5% (95% CI 95.5% to 97.3%; typical range 83% to 100%), and average specificity was 89.5% (95% CI 86.6% to 91.9%; typical range 58% to 99%).Results were available from the same 38 studies, including the subset of 3953 participants with a frozen section result of either borderline or invasive cancer, based on final diagnosis of malignancy. Studies with small numbers of disease-negative cases (borderline cases) had more variation in estimates of specificity. Average sensitivity was 94.0% (95% CI 92.0% to 95.5%; range 73% to 100%), and average specificity was 95.8% (95% CI 92.4% to 97.8%; typical range 81% to 100%).Our additional analyses showed that, if the frozen section showed a benign or invasive cancer, the final diagnosis would remain the same in, on average, 94% and 99% of cases, respectively.In cases where the frozen section diagnosis was a borderline tumour, on average 21% of the final diagnoses would turn out to be invasive cancer.In three studies, the same pathologist interpreted the index and reference standard tests, potentially causing bias. No studies reported blinding pathologists to index test results when reporting paraffin sections.In heterogeneity analyses, there were no statistically significant differences between studies with pathologists of different levels of expertise.

AUTHORS' CONCLUSIONS

In a hypothetical population of 1000 patients (290 with cancer and 80 with a borderline tumour), if a frozen section positive test result for invasive cancer alone was used to diagnose cancer, on average 261 women would have a correct diagnosis of a cancer, and 706 women would be correctly diagnosed without a cancer. However, 4 women would be incorrectly diagnosed with a cancer (false positive), and 29 with a cancer would be missed (false negative).If a frozen section result of either an invasive cancer or a borderline tumour was used as a positive test to diagnose cancer, on average 280 women would be correctly diagnosed with a cancer and 635 would be correctly diagnosed without. However, 75 women would be incorrectly diagnosed with a cancer and 10 women with a cancer would be missed.The largest discordance is within the reporting of frozen section borderline tumours. Investigation into factors leading to discordance within centres and standardisation of criteria for reporting borderline tumours may help improve accuracy. Some centres may choose to perform surgical staging in women with frozen section diagnosis of a borderline ovarian tumour to reduce the number of false positives. In their interpretation of this review, readers should evaluate results from studies most typical of their population of patients.

Surgical staging and prognosis in serous borderline ovarian tumours (BOT): a subanalysis of the AGO ROBOT study

BACKGROUND

Incomplete surgical staging is a negative prognostic factor for patients with borderline ovarian tumours (BOT). However, little is known about the prognostic impact of each individual staging procedure.

METHODS

Clinical parameters of 950 patients with BOT (confirmed by central reference pathology) treated between 1998 and 2008 at 24 German AGO centres were analysed. In 559 patients with serous BOT and adequate ovarian surgery, further recommended staging procedures (omentectomy, peritoneal biopsies, cytology) were evaluated applying Cox regression models with respect to progression-free survival (PFS).

RESULTS

For patients with one missing staging procedure, the hazard ratio (HR) for recurrence was 1.25 (95%-CI 0.66-2.39; P=0.497). This risk increased with each additional procedure skipped reaching statistical significance in case of two (HR 1.95; 95%-CI 1.06-3.58; P=0.031) and three missing steps (HR 2.37; 95%-CI 1.22-4.64; P=0.011). The most crucial procedure was omentectomy which retained a statistically significant impact on PFS in multiple analysis (HR 1.91; 95%-CI 1.15-3.19; P=0.013) adjusting for previously established prognostic factors as FIGO stage, tumour residuals, and fertility preservation.

CONCLUSION

Individual surgical staging procedures contribute to the prognosis for patients with serous BOT. In this analysis, recurrence risk increased with each skipped surgical step. This should be considered when re-staging procedures following incomplete primary surgery are discussed.

Current surgical management of ovarian cancer

Surgical management of ovarian cancer requires excellent judgment and mastery of a wide array of procedures. Involvement of a gynecologic oncologist improves outcomes. Staging of apparent stage I disease is important. Minimally invasive techniques provide advantages. Primary debulking surgery provides the best long-term survival of any strategy in advanced ovarian cancer. Aggressive surgical paradigms have the greatest success. Further cytoreductive surgery may be appropriate. Most relapsed patients require management of bowel obstruction at some point. Palliative intervention can enhance quality of life. Surgical correction may extend survival. For end-stage patients with progressive disease, the treating gynecologic oncologist must manage expectations.

Fertility preserving options in patients with gynecologic malignancies

A proportion of reproductive age women are affected by gynecologic malignancies. This patient population is faced with difficult decisions, related to their cancer care and treatment, as well as future childbearing potential. Therefore, it is important for gynecologists to be familiar with fertility sparing management options in patients with cervical, ovarian, and endometrial cancer. In addition to understanding the surgical approaches available, providers should be able to counsel patients regarding their eligibility for and the indications and limitations of fertility sparing therapy for gynecologic cancer, allowing for appropriate referrals. A comprehensive PUBMED literature search was conducted using the key words "fertility preservation," "cervical cancer," "endometrial cancer," "ovarian cancer," "borderline tumor of the ovary," "germ cell tumor," "obstetrical outcomes," "chemotherapy," and "radiation." The following review summarizes fertility sparing options for patients with cervical, ovarian and endometrial cancer, with an emphasis on appropriate patient selection, oncologic, and obstetric outcomes.

Laparoscopy in the treatment of ovarian tumours of low malignant potential

Laparoscopy is increasingly used by gynaecologists for the investigation of adnexal masses. Uncertainty exists whether ovarian tumours of low malignant potential can effectively be treated by laparoscopy, whether staging bears a benefit for all patients, whether port-site metastases are a problem and how long patients need to be followed up after surgery. This review summarises the evidence to address these important questions.