Fit-for-Purpose Ki-67 Immunohistochemistry Assays for Breast Cancer.

New therapies are being developed for breast cancer, and in this process, some "old" biomarkers are reutilized and given a new purpose. It is not always recognized that by changing a biomarker's intended use, a new biomarker assay is created. The Ki-67 biomarker is typically assessed by immunohistochemistry (IHC) to provide a proliferative index in breast cancer. Canadian laboratories assessed the analytical performance and diagnostic accuracy of their Ki-67 IHC laboratory-developed tests (LDTs) of relevance for the LDTs' clinical utility. Canadian clinical IHC laboratories enrolled in the Canadian Biomarker Quality Assurance Pilot Run for Ki-67 in breast cancer by invitation. The Dako Ki-67 IHC pharmDx assay was employed as a study reference assay. The Dako central laboratory was the reference laboratory. Participants received unstained slides of breast cancer tissue microarrays with 32 cases and performed their in-house Ki-67 assays. The results were assessed using QuPath, an open-source software application for bioimage analysis. Positive percent agreement (PPA, sensitivity) and negative percent agreement (NPA, specificity) were calculated against the Dako Ki-67 IHC pharmDx assay for 5%, 10%, 20%, and 30% cutoffs. Overall, PPA and NPA varied depending on the selected cutoff; participants were more successful with 5% and 10%, than with 20% and 30% cutoffs. Only 4 of 16 laboratories had robust IHC protocols with acceptable PPA for all cutoffs. The lowest PPA for the 5% cutoff was 85%, for 10% was 63%, for 20% was 14%, and for 30% was 13%. The lowest NPA for the 5% cutoff was 50%, for 10% was 33%, for 20% was 50%, and for 30% was 57%. Despite many years of international efforts to standardize IHC testing for Ki-67 in breast cancer, our results indicate that Canadian clinical LDTs have a wide analytical sensitivity range and poor agreement for 20% and 30% cutoffs. The poor agreement was not due to the readout but rather due to IHC protocol conditions. International Ki-67 in Breast Cancer Working Group (IKWG) recommendations related to Ki-67 IHC standardization cannot take full effect without reliable fit-for-purpose reference materials that are required for the initial assay calibration, assay performance monitoring, and proficiency testing.

Mesonephric-like adenocarcinoma of the female genital tract: novel observations and detailed molecular characterisation of mixed tumours and mesonephric-like carcinosarcomas.

AIMS: To report novel observations in five mesonephric-like adenocarcinomas (MLAs) of the female genital tract. METHODS AND RESULTS: We report two endometrial MLAs in association with endometrioid carcinoma and atypical hyperplasia and three (one endometrial, two ovarian) cases with a sarcomatoid component (mesonephric-like carcinosarcoma). Pathogenic KRAS mutations, which are characteristic of MLA, were identified in all cases although interestingly, in one of the mixed carcinomas, this was confined to the endometrioid component. The concurrent MLA, endometrioid carcinoma and atypical hyperplasia components in one case harboured identical EGFR, PTEN and CCNE1 mutations, suggesting that the atypical hyperplasia gave rise to a Müllerian carcinoma with both endometrioid and mesonephric-like components. The carcinosarcomas all contained a component of MLA and a sarcomatous component with chondroid elements. In the ovarian carcinosarcomas, the coexisting epithelial and sarcomatous components shared some mutations including KRAS and CREBBP, suggesting that they are clonally related. Furthermore, in one case CREBBP and KRAS mutations detected in the MLA and sarcomatous components were also detected in an associated undifferentiated carcinoma component, suggesting that it was clonally related to the MLA and sarcomatous components. CONCLUSIONS: Our observations provide additional evidence that MLAs have a Müllerian origin and characterise mesonephric-like carcinosarcomas in which chondroid elements appear to be characteristic. In reporting these findings, we provide recommendations for distinction between a mesonephric-like carcinosarcoma and a MLA with a spindle cell component.

Genomic profiling of dedifferentiated endometrial carcinomas arising in the background of high-grade carcinoma: a targeted next-generation sequencing study.

AIMS: Our understanding of dedifferentiated endometrial carcinoma (DEC), a rare and aggressive malignancy, mainly reflects undifferentiated carcinomas (UC) arising in the setting of low-grade endometrial cancer (DEC-LG). However, cases of UC arising in the setting of high-grade EC (DEC-HG) have been noted in the literature. Our knowledge of the genomics of DEC-HG is limited. To characterise the molecular landscape of DEC-HC, targeted genomic sequencing and immunohistochemical analysis was carried out on seven DEC-HG and four DEC-LG. METHODS AND RESULTS: DEC-HG and DEC-LG, including undifferentiated and differentiated components, both showed a similar frequency and spectrum of mutations. ARID1A mutations were identified in 6/7 (86%) DEC-HG and 4/4 (100%) DEC-LG, while SMARCA4 mutations were present in 4/7 (57%) DEC-HG and in 1/4 (25%) DEC-LG. Concurrent SMARCA4/BRG1 protein loss by immunohistochemistry was observed in 3/4 and 1/1 SMARCA4 mutated DEC-HG and DEC-LG, respectively. Neither genomic alterations nor protein loss in SMARCB1/INI1 were observed in any of our cases. TP53 mutations were detected in 4/7 (57%) DEC-HG and in 2/4 (50%) DEC-LG, while mutation-pattern p53 immunohistochemistry expression was observed in 2/7 (29%) DEC-HG and none of the DEC-LG. MLH1 mutations were observed in 1/7 (14%) DEC-HG and 1/4 (25%) DEC-LG. MSH2 and MSH6 mutations were each detected in 1/7 (14%) DEC-HG, but neither was associated with corresponding loss of protein expression. CONCLUSION: The findings support expanding the definition of DEC to include DEC-HG, a previously under-recognised phenomenon with genomic similarities to DEC-LG.

Budget impact analysis of molecular subtype profiling in endometrial cancer.

OBJECTIVE: This study evaluated the costs associated with four approaches to classifying endometrial cancer (EC), including histomorphological, histomorphological with ancillary immunohistochemical assays, histomolecular and selective molecular classification. METHODS: Direct costs were determined per EC sample from the hospital's perspective. A budget impact analysis and sensitivity analysis were conducted to estimate the mean, minimum and maximum costs per sample and annual institutional costs in adjusted 2022 Canadian dollars. A provincial cost forecast was projected based on expected 2022 EC biopsies. RESULTS: In 2018, our institution performed 190 EC biopsies. The mean cost per biopsy was $158 ($156-$212) for histomorphological classification, $384 ($360-$514) for histomorphological classification with immunohistochemistry and $1297 ($1265-1833) for histomolecular classification. Total annual institutional cost for histomorphological classification was $29,980 and $72,950 with immunohistochemistry. For histomolecular classification, the first year cost was $246,521, accounting for initial educational learning curve, and $233,461 thereafter, assuming a consistent number of biopsies per year. Targeted implementation of histomolecular classification among high-grade, p53 abnormal and/or MMR-deficient ECs (56% of cases) cost $169,688 in the first year and $162,418 annually thereafter. With a projected 3400 EC biopsies in Ontario in 2022, histomorphological classification would annually cost $537,078 and $1,305,677 with immunohistochemistry. Histomolecular classification would cost $4,410,203 in the first year and $4,176,737 annually once established. Selective molecular classification would lead to a cost of $3,044,178 in the first year and $2,913,443 thereafter. CONCLUSIONS: The study highlights the need for informed decision-making when implementing molecular classification in clinical practice, given the substantial incremental healthcare costs associated with these approaches.

Long-term outcomes of women with large DCIS lesions treated with breast-conserving therapy.

PURPOSE: The paucity of data on women with large (≥ 40 mm) DCIS tumors lead to uncertainty on the safety of breast-conserving surgery (BCS) for these patients. We evaluated the impact of large tumor size on local recurrence (LR) among women with DCIS treated with BCS ± radiotherapy (RT). METHODS: Treatment and outcomes were ascertained through administrative databases for all women with DCIS in Ontario from 1994 to 2003 treated with BCS ± RT with negative margins; 82% had pathology review. Cox proportional hazards model was used to evaluate the impact of tumor size on LR. 10- and 15-year LR-free survival (LRFS) were calculated using Kaplan-Meier method. RESULTS: The cohort includes 2049 women treated by BCS (N = 1073 with RT). Median follow-up is 14 years (IQR 9-17 years). Referenced to tumors ≤ 10 mm, the risk of LR following BCS was significantly higher for larger tumors: HR ≥ 40 mm = 3.67 (95% CI 2.13, 6.33; p < 0.001), HR 26-39 mm = 2.27 (95% CI 1.47, 3.50, p < 0.001), and HR 11-25 mm = 1.42 (95% CI 1.06, 1.92, p = 0.02). However, for individuals with BCS + RT, large tumor size was not associated with a significantly increased risk of LR (HR ≥ 40 mm = 1.92 (95% CI 0.97, 3.79); HR 26-39 mm = 1.81 (95% CI 1.09-2.99)). For women with tumors ≥ 40 mm, 10-year LRFS risk for those treated by BCS alone, BCS + RT without boost, and BCS + RT with boost was 58.9%, 82.8%, and 83.9%. CONCLUSION: Large DCIS lesions ≥ 40 mm are associated with higher risks of LR following BCS, but high long-term LRFS rates can be achieved with the addition of breast RT.

Systematically higher Ki67 scores on core biopsy samples compared to corresponding resection specimen in breast cancer: a multi-operator and multi-institutional study.

Ki67 has potential clinical importance in breast cancer but has yet to see broad acceptance due to inter-laboratory variability. Here we tested an open source and calibrated automated digital image analysis (DIA) platform to: (i) investigate the comparability of Ki67 measurement across corresponding core biopsy and resection specimen cases, and (ii) assess section to section differences in Ki67 scoring. Two sets of 60 previously stained slides containing 30 core-cut biopsy and 30 corresponding resection specimens from 30 estrogen receptor-positive breast cancer patients were sent to 17 participating labs for automated assessment of average Ki67 expression. The blocks were centrally cut and immunohistochemically (IHC) stained for Ki67 (MIB-1 antibody). The QuPath platform was used to evaluate tumoral Ki67 expression. Calibration of the DIA method was performed as in published studies. A guideline for building an automated Ki67 scoring algorithm was sent to participating labs. Very high correlation and no systematic error (p = 0.08) was found between consecutive Ki67 IHC sections. Ki67 scores were higher for core biopsy slides compared to paired whole sections from resections (p ≤ 0.001; median difference: 5.31%). The systematic discrepancy between core biopsy and corresponding whole sections was likely due to pre-analytical factors (tissue handling, fixation). Therefore, Ki67 IHC should be tested on core biopsy samples to best reflect the biological status of the tumor.

The effect of complete surgical staging and adjuvant chemotherapy on survival in stage I, grade 1 and 2 endometrioid ovarian carcinoma.

OBJECTIVES: To assess the effect of complete surgical staging and adjuvant chemotherapy on survival in stage I, low grade endometrioid ovarian cancer. METHODS: This retrospective study was conducted at two cancer centers from July 2001 to December 2019. Inclusion criteria were all stage I, grade 1 and 2 endometrioid ovarian cancer patients. Patients with mixed histology, concurrent endometrial cancer, neoadjuvant chemotherapy, and patients who did not undergo follow-up at our centers were excluded. Clinical, pathologic, recurrence, and follow-up data were collected. Cox proportional hazard model evaluated predictive factors. Recurrence-free survival and overall survival were calculated using the Kaplan-Meier method. RESULTS: There were 131 eligible stage I patients: 83 patients (63.4%) were stage IA, 5 (3.8%) were stage IB, and 43 (32.8%) were stage IC, with 80 patients (61.1%) having grade 1 and 51 (38.9%) patients having grade 2 disease. Complete lymphadenectomy was performed in 34 patients (26.0%), whereas 97 patients (74.0%) had either partial (n=22, 16.8%) or no (n=75, 57.2%) lymphadenectomy. Thirty patients (22.9%) received adjuvant chemotherapy. Median follow-up was 51.5 (95% CI 44.3 to 57.2) months. Five-year recurrence-free survival was 88.0% (95% CI 81.6% to 94.9%) and 5 year overall survival was 95.1% (95% CI 90.5% to 99.9%). In a multivariable analysis, only grade 2 histology had a significantly higher recurrence rate (HR 3.42, 95% CI 1.03 to 11.38; p=0.04). There was no difference in recurrence-free survival (p=0.57) and overall survival (p=0.30) in patients with complete lymphadenectomy. In stage IA/IB, grade 2 there was no benefit of adjuvant chemotherapy (p=0.19), and in stage IA/IB, low grade without complete surgical staging there was no benefit of adjuvant chemotherapy (p=0.16). Twelve patients (9.2%) had recurrence; 3 (25%) were salvageable at recurrence and are alive with no disease. CONCLUSIONS: Patients with stage I, low grade endometrioid ovarian cancer have a favorable prognosis, and adjuvant chemotherapy and staging lymphadenectomy did not improve survival.

Oncologic and pregnancy outcomes after fertility-sparing surgery for stage I, low-grade endometrioid ovarian cancer.

OBJECTIVE: To evaluate oncologic outcomes in patients with stage I endometrioid ovarian cancer treated with fertility-sparing compared with conventional surgery and to describe reproductive outcomes. METHODS: A retrospective cohort study was carried out of patients aged 18-45 with stage I, grade 1 and 2 (low-grade) endometrioid ovarian cancer treated at two cancer centers between July 2001 and December 2019. Clinical and pathologic characteristics were compared using Fisher's exact test for categorical and the Mann-Whitney U test for continuous variables. Recurrence-free and overall survival were calculated from Kaplan-Meier curves and compared for fertility-sparing and conventional surgery using the log rank test. Pregnancy outcomes are described. RESULTS: There were 230 patients with endometrioid ovarian cancer. After exclusion of patients with stage greater than I and those older than 45 years, there were 31 patients with stage I cancer aged 18-45. Of these patients, 11 (35.5%) underwent fertility-sparing surgery and 20 (64.5%) underwent conventional surgery. The median follow-up was 6.0 years (range 1.8-17.3). The median age was 36 years (range 26-42) in the fertility-sparing group and 42 years (range 35-45) in the conventional surgery group (p=0.001), with no difference in other clinical and pathologic characteristics. The 5-year recurrence-free survival was 90.9% (95% CI 73.9% to 100%) for the fertility-sparing group and 84.0% (95% CI 67.3% to 100%) for the conventional surgery group (p=0.65). The 5-year overall survival was 100% for patients in the fertility-sparing group and 92.6% (95% CI 78.7% to 100%) for patients treated with conventional surgery (p=0.49). Four (12.9%) patients had disease recurrence: three (15%) after conventional surgery and one (9.1%) in the contralateral ovary after fertility-sparing surgery and embryo cryopreservation. After fertility-sparing surgery, seven (63.6%) patients attempted pregnancy, of which five (71.4%) conceived with four (57.1%) using in vitro fertilization. Of the five patients who conceived, there were three spontaneous abortions and five live births. CONCLUSION: Fertility-sparing surgery appears safe and may be considered in young women with stage I, low-grade endometrioid ovarian cancer when fertility preservation is desired.

Case of epithelioid hemangioendothelioma occurring in the postradiation setting for breast cancer.

Epithelioid hemangioendothelioma (EHE) is a rare malignant vascular tumor, which is typically characterized by recurrent fusion genes. EHEs most commonly occur in the lung, liver, bone, and internal organs. EHE has rarely been reported to occur in the post-radiotherapeutic setting, the breast site or in association with breast cancer. The differential diagnosis for radiation-associated vascular lesions of the breast is classically limited to atypical vascular lesion and angiosarcoma and does not include EHE. We present the case of a woman with a history of breast cancer and post-surgical radiotherapy who went on to develop an EHE of the chest wall skin within 3 years of the completion of radiotherapy. Microscopically, the lesion was infiltrative and composed of anastomosing nests of epithelioid-to-spindled cells with eosinophilic and vacuolated cytoplasm. By immunohistochemistry, the cells were positive for ERG, D2-40, and CD31. The diagnosis was confirmed by identification of a characteristic WWTR1-CAMTA1 fusion gene using RNA sequencing. This case expands our understanding of radiation-associated tumors.

Quantitative single-cell analysis of immunofluorescence protein multiplex images illustrates biomarker spatial heterogeneity within breast cancer subtypes.

BACKGROUND: The extent of cellular heterogeneity in breast cancer could have potential impact on diagnosis and long-term outcome. However, pathology evaluation is limited to biomarker immunohistochemical staining and morphology of the bulk cancer. Inter-cellular heterogeneity of biomarkers is not usually assessed. As an initial evaluation of the extent of breast cancer cellular heterogeneity, we conducted quantitative and spatial imaging of Estrogen Receptor (ER), Progesterone Receptor (PR), Epidermal Growth Factor Receptor-2 (HER2), Ki67, TP53, CDKN1A (P21/WAF1), CDKN2A (P16INK4A), CD8 and CD20 of a tissue microarray (TMA) representing subtypes defined by St. Gallen surrogate classification. METHODS: Quantitative, single cell-based imaging was conducted using an Immunofluorescence protein multiplexing platform (MxIF) to study protein co-expression signatures and their spatial localization patterns. The range of MxIF intensity values of each protein marker was compared to the respective IHC score for the TMA core. Extent of heterogeneity in spatial neighborhoods was analyzed using co-occurrence matrix and Diversity Index measures. RESULTS: On the 101 cores from 59 cases studied, diverse expression levels and distributions were observed in MxIF measures of ER and PR among the hormonal receptor-positive tumor cores. As expected, Luminal A-like cancers exhibit higher proportions of cell groups that co-express ER and PR, while Luminal B-like (HER2-negative) cancers were composed of ER+, PR- groups. Proliferating cells defined by Ki67 positivity were mainly found in groups with PR-negative cells. Triple-Negative Breast Cancer (TNBC) exhibited the highest proliferative fraction and incidence of abnormal P53 and P16 expression. Among the tumors exhibiting P53 overexpression by immunohistochemistry, a group of TNBC was found with much higher MxIF-measured P53 signal intensity compared to HER2+, Luminal B-like and other TNBC cases. Densities of CD8 and CD20 cells were highest in HER2+ cancers. Spatial analysis demonstrated variability in heterogeneity in cellular neighborhoods in the cancer and the tumor microenvironment. CONCLUSIONS: Protein marker multiplexing and quantitative image analysis demonstrated marked heterogeneity in protein co-expression signatures and cellular arrangement within each breast cancer subtype. These refined descriptors of biomarker expressions and spatial patterns could be valuable in the development of more informative tools to guide diagnosis and treatment.

Clinical outcomes and prognostic biomarkers among pregnant, post-partum and nulliparous women with breast cancer: a prospective cohort study.

PURPOSE: To compare clinical-pathologic characteristics and outcomes of pregnancy-associated, post-partum (PP) and nulliparous (NP) breast cancer (BC) patients and explore mediators of the poor prognosis associated with post-partum BC. METHODS: A prospective database of 233 women ≤ 40 years of age diagnosed with BC between February 2008 and January 2015 was analysed. Clinical-pathologic characteristics and outcomes among pregnant, PP and NP patients were compared using chi-square or Kruskal-Wallis tests. The Kaplan-Meier method was used to estimate disease-free survival (DFS), distant DFS and overall survival (OS). Survival curves were compared using the log-rank test. Univariable Cox proportional hazards regression models were used to evaluate factors that were potentially prognostic for the clinical outcomes of interest; a multivariable Cox model was constructed using a forward stepwise selection process. Androgen receptor (AR), GATA3, PDL1 status and the presence/absence of tumour-infiltrating lymphocytes (TILs) were assessed when possible. Pre-treatment neutrophil and lymphocyte counts were abstracted retrospectively. Statistical significance was defined as a p value ≤ 0.05. RESULTS: Women ≤ 2 years PP had a numerically higher incidence of lymph node-positive and high-grade disease and were significantly more likely to have estrogen receptor-negative BC compared to NP controls. With a median follow-up of 7.2 years, increasingly poor outcomes were observed among NP (longest OS), > 2 years PP, ≤ 2 years PP and pregnant (shortest OS) patients, but these differences were not statistically significant. The ≤ 2 years PP group had significantly lower AR expression, a strong trend toward higher PDL1 expression and a higher expression of stromal TILs compared to NP women. CONCLUSIONS: PPBC patients had numerically lower DFS and OS compared to NP controls. Higher PDL1 and stromal TILs in PPBC suggest that adjuvant immunotherapy may be effective in the post-partum BC subgroup.

Interobserver variability in the assessment of stromal tumor-infiltrating lymphocytes (sTILs) in triple-negative invasive breast carcinoma influences the association with pathological complete response: the IVITA study.

High stromal tumor-infiltrating lymphocytes (sTILs) in triple-negative breast cancer (TNBC) are associated with pathological complete response (pCR) after neoadjuvant chemotherapy (NAC). Histopathological assessment of sTILs in TNBC biopsies is characterized by substantial interobserver variability, but it is unknown whether this affects its association with pCR. Here, we aimed to investigate the degree of interobserver variability in an international study, and its impact on the relationship between sTILs and pCR. Forty pathologists assessed sTILs as a percentage in digitalized biopsy slides, originating from 41 TNBC patients who were treated with NAC followed by surgery. Pathological response was quantified by the MD Anderson Residual Cancer Burden (RCB) score. Intraclass correlation coefficients (ICCs) were calculated per pathologist duo and Bland-Altman plots were constructed. The relation between sTILs and pCR or RCB class was investigated. The ICCs ranged from -0.376 to 0.947 (mean: 0.659), indicating substantial interobserver variability. Nevertheless, high sTILs scores were significantly associated with pCR for 36 participants (90%), and with RCB class for eight participants (20%). Post hoc sTILs cutoffs at 20% and 40% resulted in variable associations with pCR. The sTILs in TNBC with RCB-II and RCB-III were intermediate to those of RCB-0 and RCB-I, with lowest sTILs observed in RCB-I. However, the limited number of RCB-I cases precludes any definite conclusions due to lack of power, and this observation therefore requires further investigation. In conclusion, sTILs are a robust marker for pCR at the group level. However, if sTILs are to be used to guide the NAC scheme for individual patients, the observed interobserver variability might substantially affect the chance of obtaining a pCR. Future studies should determine the 'ideal' sTILs threshold, and attempt to fine-tune the patient selection for sTILs-based de-escalation of NAC regimens. At present, there is insufficient evidence for robust and reproducible sTILs-guided therapeutic decisions.

Budget Impact Analysis of Preoperative Radioactive Seed Localization.

BACKGROUND: This study models costs in implementing a radioactive seed localization (RSL) program for nonpalpable breast lesions at a large Canadian tertiary hospital to replace existing wire-guided localization (WGL). METHODS: All direct and indirect operating costs of localization per lesion from the hospital's perspective were determined by retrospectively reviewing patient data and costs from January 2014 to December 2016. A budget impact analysis and sensitivity analysis were performed to calculate the mean cost per lesion, the minimum and maximum cost per lesion, operational costs, and initial costs. RESULTS: There were 265 WGL lesions in 2014 and 170 RSL lesions in 2016 included in cost calculation. The mean cost per localization was $185 CAD for WGL ($148-$311) and $283 CAD ($245-$517) for RSL using preloaded seeds, adjusted to 2016 Canadian dollars. The annual operational expenditure including all localizations and overhead costs was $49,835 for WGL and $80,803 for RSL. Initial costs for RSL were $22,000, including external training and new equipment purchases. CONCLUSIONS: Our budget impact analysis shows that RSL using preloaded radioactive seeds was more expensive than WGL when considering per-lesion localization costs and specific costs related to radiation safety. Manually loading radioactive seed could be a cost-saving alternative to purchasing preloaded seeds. Our breakdown of costs can provide a framework for other centres to determine which localization method best suit their departments.

Risk of second malignancy in patients with ovarian clear cell carcinoma.

OBJECTIVE: Ovarian clear cell carcinoma has unique clinical and molecular features compared with other epithelial ovarian cancer histologies. Our objective was to describe the incidence of second primary malignancy in patients with ovarian clear cell carcinoma. METHODS: Retrospective cohort study of patients with ovarian clear cell carcinoma at two tertiary academic centers in Toronto, Canada between May 1995 and June 2017. Demographic, histopathologic, treatment, and survival details were obtained from chart review and a provincial cancer registry. We excluded patients with histologies other than pure ovarian clear cell carcinoma (such as mixed clear cell histology), and those who did not have their post-operative follow-up at these institutions. RESULTS: Of 209 patients with ovarian clear cell carcinoma, 54 patients developed a second primary malignancy (25.8%), of whom six developed two second primary malignancies. Second primary malignancies included: breast (13), skin (9), gastrointestinal tract (9), other gynecologic malignancies (8), thyroid (6), lymphoma (3), head and neck (4), urologic (4), and lung (4). Eighteen second primary malignancies occurred before the index ovarian clear cell carcinoma, 35 after ovarian clear cell carcinoma, and 7 were diagnosed concurrently. Two patients with second primary malignancies were diagnosed with Lynch syndrome. Smoking and radiation therapy were associated with an increased risk of second primary malignancy on multivariable analysis (OR 3.69, 95% CI 1.54 to 9.07, p=0.004; OR 4.39, 95% CI 1.88 to 10.6, p=0.0008, respectively). However, for patients developing second primary malignancies after ovarian clear cell carcinoma, radiation therapy was not found to be a significant risk factor (p=0.17). There was no significant difference in progression-free survival (p=0.85) or overall survival (p=0.38) between those with second primary malignancy and those without. CONCLUSION: Patients with ovarian clear cell carcinoma are at increased risk of second primary malignancies, most frequently non-Lynch related. A subset of patients with ovarian clear cell carcinoma may harbor mutations rendering them susceptible to second primary malignancies. Our results may have implications for counseling and consideration for second primary malignancy screening.

Interobserver variability in upfront dichotomous histopathological assessment of ductal carcinoma in situ of the breast: the DCISion study.

Histopathological assessment of ductal carcinoma in situ, a nonobligate precursor of invasive breast cancer, is characterized by considerable interobserver variability. Previously, post hoc dichotomization of multicategorical variables was used to determine the "ideal" cutoffs for dichotomous assessment. The present international multicenter study evaluated interobserver variability among 39 pathologists who performed upfront dichotomous evaluation of 149 consecutive ductal carcinomas in situ. All pathologists independently assessed nuclear atypia, necrosis, solid ductal carcinoma in situ architecture, calcifications, stromal architecture, and lobular cancerization in one digital slide per lesion. Stromal inflammation was assessed semiquantitatively. Tumor-infiltrating lymphocytes were quantified as percentages and dichotomously assessed with a cutoff at 50%. Krippendorff's alpha (KA), Cohen's kappa and intraclass correlation coefficient were calculated for the appropriate variables. Lobular cancerization (KA = 0.396), nuclear atypia (KA = 0.422), and stromal architecture (KA = 0.450) showed the highest interobserver variability. Stromal inflammation (KA = 0.564), dichotomously assessed tumor-infiltrating lymphocytes (KA = 0.520), and comedonecrosis (KA = 0.539) showed slightly lower interobserver disagreement. Solid ductal carcinoma in situ architecture (KA = 0.602) and calcifications (KA = 0.676) presented with the lowest interobserver variability. Semiquantitative assessment of stromal inflammation resulted in a slightly higher interobserver concordance than upfront dichotomous tumor-infiltrating lymphocytes assessment (KA = 0.564 versus KA = 0.520). High stromal inflammation corresponded best with dichotomously assessed tumor-infiltrating lymphocytes when the cutoff was set at 10% (kappa = 0.881). Nevertheless, a post hoc tumor-infiltrating lymphocytes cutoff set at 20% resulted in the highest interobserver agreement (KA = 0.669). Despite upfront dichotomous evaluation, the interobserver variability remains considerable and is at most acceptable, although it varies among the different histopathological features. Future studies should investigate its impact on ductal carcinoma in situ prognostication. Forthcoming machine learning algorithms may be useful to tackle this substantial diagnostic challenge.

Molecular Evaluation of Breast Ductal Carcinoma in Situ with Oncotype DX DCIS.

A subset of patients with ductal carcinoma in situ (DCIS) of the breast develop ipsilateral invasive breast cancer after breast-conserving surgery with or without adjuvant radiotherapy. Risk assessment and prediction of adverse outcomes for individual patients based on traditional clinical and pathological parameters are limited. The Oncotype DCIS Score is a commercially available multigene assay that has been independently validated in a prospective clinical trial and a population-based cohort. The score helps to identify a subset of women >50 years old with unifocal disease that carries <10% risk of any local recurrence after breast-conserving surgery alone. In this population, individual patients and physicians may consider omitting adjuvant radiotherapy. In this article, we review the literature and summarize the evidence regarding the role of the Oncotype DCIS Score in estimating the risk of ipsilateral local recurrence and ipsilateral invasive breast cancer recurrence. The available data on clinical utility and cost-effective analysis for optimizing decisions on adjuvant treatments are discussed.

Histological grading of ovarian mucinous carcinoma - an outcome-based analysis of traditional and novel systems.

AIMS: Grading of primary ovarian mucinous carcinoma (OMC) is inconsistent among practices. The International Collaboration on Cancer Reporting recommends grading OMC using the International Federation of Gynecology and Obstetrics (FIGO) system for endometrial endometrioid carcinoma, when needed. The growth pattern (expansile versus infiltrative), a known prognostic variable in OMC, is not considered in any grading system. We herein analysed the prognostic value of various grading methods in a well-annotated cohort of OMC. METHODS AND RESULTS: Institutional OMCs underwent review and grading by the Silverberg and FIGO schemes and a novel system, growth-based grading (GBG), defined as G1 (expansile growth or infiltrative invasion in ≤10%) and G2 (infiltrative growth >10% of tumour). Of 46 OMCs included, 80% were FIGO stage I, 11% stage II and 9% stage III. On follow-up (mean = 52 months, range = 1-190), five patients (11%) had adverse events (three recurrences and four deaths). On univariate analysis, stage (P = 0.01, Cox proportional analysis), Silverberg grade (P = 0.01), GBG grade (P = 0.001) and percentage of infiltrative growth (P < 0.001), but not FIGO grade, correlated with disease-free survival. Log-rank analysis showed increased survival in patients with Silverberg grade 1 versus 2 (P < 0.001) and those with GBG G1 versus G2 (P < 0.001). None of the parameters evaluated was significant on multivariate analysis (restricted due to the low number of adverse events). CONCLUSIONS: Silverberg and the new GBG system appear to be prognostically significant in OMC. Pattern-based grading allows for a binary stratification into low- and high-grade categories, which may be more appropriate for patient risk stratification. Despite current practices and recommendations to utilise FIGO grading in OMC, our study shows no prognostic significance of this system and we advise against its use.

Undifferentiated endometrial carcinoma arising in the background of high-grade endometrial carcinoma - Expanding the definition of dedifferentiated endometrial carcinoma.

Dedifferentiated endometrial adenocarcinoma (DEC) is defined by the coexistence of undifferentiated carcinoma with low-grade (FIGO grade 1 or 2) endometrioid carcinoma. Few cases of DEC arising in the background of high-grade carcinoma (DEC-HG) have been reported, however, this phenomenon is poorly characterized. In this study we describe the morphologic, immunohistochemical and clinico-pathologic characteristics of DEC-HG. 18 DECs were diagnosed at our institution between 2008-2019, and in 11 (61%), the undifferentiated component was associated with high-grade carcinoma (8 endometrioid FIGO grade 3, 2 with ambiguous features, 1 serous). The remaining 7 (39%) represented DEC-LG (3 FIGO grade 1 and 4 FIGO grade 2). 7/11 (64%) patients with DEC-HG presented with advanced stage (FIGO stage III/IV), whereas most with DEC-LG (6/7, 86%) were stage I. On follow up, 2 patients in the DEC-HG group died of disease and 2 had progressive disease within 2 months of surgery. There was only one recurrence in the DEC-LG, 6 months post-surgery. The DEC component in both groups showed similar morphology and immunophenotype, with predominantly focal or complete loss of expression of pan-keratin, EMA, E-cadherin, CK8/18, PAX8 and ER. The DEC component in the DEC-HG group had wild-type p53 expression in 8/11 (73%) cases, loss of MLH1 and PMS2 in 6/11 (55%) and loss of SMARCA4 in 3/9 (33%). Although numbers are small, we show that DEC-HG is a previously under-recognized phenomenon, with morphologic and immunophenotypic similarities to DEC-LG, which supports expanding the definition of DEC to include DEC-HG. DEC-HG may be more aggressive than DEC-LG.

The prognostic role of horizontal and circumferential tumor extent in cervical cancer: Implications for the 2019 FIGO staging system.

OBJECTIVE: The FIGO 2019 update on cervical cancer staging removed horizontal tumor extent (HZTE) as a staging variable. Evidence is needed to substantiate this change. The prognostic significance of HZTE and a related variable, circumferential tumor extent (%CTE), is similarly unknown. We aimed to investigate the association of HZTE and %CTE with survival outcomes in cervical cancer patients. METHODS: We identified patients treated with primary surgery for stage I cervical cancer in a single institution during a 9-year period. HZTE and, when available, %CTE were obtained from pathology records. Cases were staged using 2019 FIGO staging. Correlations between HZTE, %CTE and FIGO stage with recurrence-free (RFS) and disease-specific survival (DSS) were determined using univariable and multivariable analyses. RESULTS: 285 patients were included with a median follow-up of 48 (range 7-123) months. HZTE was statistically associated with RFS and DSS on univariate and multivariate analysis. None of the 168 stage IA patients in our series had tumor recurrence or death during follow-up, including 42 with HZTE ≥7 mm. None of the patients with a tumor horizontal extent <7 mm experienced recurrence or death. %CTE correlated only with RFS on univariate analysis. 2019 FIGO stage did not independently correlate with RFS or DSS in our sample. CONCLUSIONS: HZTE is an independent predictor of survival in cervical carcinoma. In stage IA tumors, however, HZTE does not offer superior prognostic value, supporting the 2019 FIGO recommendations to remove this variable from staging in these cases. HZTE may be useful in larger tumors in which staging depends on maximum tumor size. %CTE is not an independent prognostic variable in cervical cancer, and we advise against its use.

Ischemic necrosis of the breast following septic shock: A case report.

Fat necrosis of the breast is a common and benign entity, often secondary to trauma, surgery, radiation therapy, or unknown etiologies. Critically ill patients with septic shock may experience end-organ hypoperfusion and tissue infarction and necrosis, which may result in breast fat necrosis, however, to the best of our knowledge this has not been previously described. We report a case of biopsy-proven breast fat necrosis secondary to septic shock following an emergency surgery in a postmenopausal female.