Challenging gestational trophoblastic disease cases and mimics: An exemplar for the management of rare tumours

Appraisal of hydatidiform mole incidence and registration rates in Ireland following the establishment of a National Gestational Trophoblastic Disease Registry

AIMS

This study aimed to re-evaluate the incidence of hydatidiform mole (HM) and determine gestational trophoblastic disease (GTD) registration rates in Ireland following the establishment of the National GTD Registry in 2017.

METHODS

We performed a 3-year retrospective audit of HM cases (January 2017 to December 2019) reported in our centre. In 2019, we surveyed Irish pathology laboratories to determine the number of HMs diagnosed nationally and compared this data to that recorded in the National GTD Registry. Additionally, we compared both local and national HM incidence rates to those reported internationally.

RESULTS

In the 3-year local audit, we identified 87 HMs among 1856 products of conception (POCs) providing a local HM incidence rate of 3.92 per 1000 births. The 1-year pathology survey recorded 170 HMs in 6008 POCs, yielding a national incidence rate of 2.86 per 1000 births. Importantly, the local HM incidence rate exceeded the national incidence rate by 37% and the local partial HM incidence (1 in 296 births) was 64% higher than the nationally incidence rate (1 in 484 births). Notably, 42% of the HM and atypical POCs diagnosed nationally were not reported to the National GTD Registry.

CONCLUSIONS

Our study reveals increased HM incidence rates both locally and nationally compared with previous Irish studies. The higher local PHM incidence may reflect more limited access to ploidy analysis in other pathology laboratories nationally. Significantly, almost half of the women with diagnosed or suspected HM were not registered with the National GTD Centre.

Risk Stratification Tools to Aid Decisions on Adjuvant Chemotherapy Usage in Resected Soft Tissue Sarcomas: A Ten-Year Review of an Irish Sarcoma Center Experience

Background

Soft tissue sarcoma (STS) is comprised of approximately 80 subtypes, with an incidence of 4 - 5 per 100,000 annually in Europe. The National Comprehensive Cancer Network (NCCN) guidelines recommend consideration of neoadjuvant/adjuvant chemotherapy in tumors at high risk of recurrence based on the American Joint Committee on Cancer (AJCC) staging. Alternatively, the Sarculator is a risk prediction tool that has identified a threshold of risk, above which chemotherapy may provide an overall survival (OS) benefit. Using this nomogram, patients with a 10-year predicted OS < 60% are classified as high risk and should be considered for chemotherapy. The aim of this study was to assess the prognostic accuracy of these two risk prediction methods in an Irish population.

Methods

All newly diagnosed patients with resected STS discussed in the STS tumor board in Cork University Hospital between January 2012 and December 2021 were identified. Clinicopathological data were collected. Risk assessment using AJCC and Sarculator nomogram was performed on all patients with an extremity/trunk sarcoma. The OS was calculated including Kaplan-Meier method for time to event analysis.

Results

In total, 200 STS patients were reviewed, of whom 134 had truncal or extremity tumors. Sarculator score was calculated for 60 of these (well differentiated liposarcomas, desmoid tumors and dermatofibrosarcoma protuberans were excluded). Using the Sarculator nomogram to calculate 10-year predicted OS, 19 patients were categorized as high risk and 41 were categorized as low risk. Using AJCC staging, 25 patients were categorized as high risk and 35 as low risk. The 5-year OS rate in the Sarculator high-risk group was 60.2%, compared with 87.1% in the low-risk group (P = 0.009). The 5-year OS rate in the AJCC high-risk group was 67.6%, compared with 86.3% in the low-risk group (P = 0.083).

Conclusions

Our cohort is representative of the broad histological subtypes expected. In our population, Sarculator score results correlate with international outcomes and higher scores were associated with increased mortality. The Sarculator was more predictive of clinical outcome than AJCC staging, and its use would lower the proportion of patients being considered for adjuvant chemotherapy thereby sparing toxicity, which is important in the setting of uncertain clinical benefit.