The role of adjuvant treatment for early-stage uterine clear cell carcinomas.

BACKGROUND: Uterine clear cell carcinoma is a rare and aggressive subtype of endometrial carcinoma. Prospective clinical trials have not been feasible for this rare tumor, and data regarding the optimal adjuvant treatment regimen for early-stage uterine clear cell carcinomas is limited. Our study's objective was to determine if adjuvant chemotherapy or radiation therapy improves patients' outcomes in stage I and II uterine clear cell carcinoma. METHODS: Patients with stage I and II uterine clear cell carcinoma were identified at a single institution. All cases were reviewed by a gynecologic pathologist. Both pure and mixed non-serous uterine clear cell carcinomas were included. Primary outcomes were recurrence free survival and overall survival. RESULTS: A total of 71 patients were identified including 39 (55%) pure and 32 (45%) mixed clear cell carcinoma. Most patients were FIGO stage IA (77.5%). Most patients (n = 58, 82%) received adjuvant therapy, including 43 (61%) receiving chemotherapy, 50 (70%) receiving radiation therapy, and 35 (49%) receiving both. Recurrence free survival was not significantly different among patients receiving no or <6 cycles of chemotherapy versus patients receiving 6 cycles of chemotherapy (p = 0.39). However, median OS was significantly different among patients receiving no or <6 cycles of chemotherapy versus 6 cycles of chemotherapy (p = 0.004). On univariable analysis, 6 cycles of chemotherapy was significantly associated with improved OS (HR 0.1, 95% CI 0.01-0.07). Presence of LVSI, mutated p53, number of pelvic and para-aortic lymph nodes assessed, adjuvant chemotherapy (any number of cycles), and >2 medical co-morbidities were not significant predictors of OS on univariable analysis. On multivariable analysis, 6 cycles of adjuvant chemotherapy remained a significant predictor of improved OS (HR 0.1, 95% CI 0.01-0.8). CONCLUSIONS: In this study, administration of 6 cycles of chemotherapy appears to significantly improve OS. This finding suggests consideration of 6 cycles of adjuvant chemotherapy in patients with early-stage uterine clear cell carcinoma, however clinical trials are needed to confirm these findings.

Is Substantial Lymphovascular Space Invasion Prognostic for Clinical Outcomes in Type II Endometrial Cancer?

AIMS: Substantial lymphovascular space invasion (LVSI) compared with none or focal LVSI is predictive of lymph node involvement and worse clinical outcomes in endometrioid-type endometrial carcinoma. We aimed to quantify the incidence of substantial LVSI in type II (clear cell and serous) endometrial cancer and correlate the extent of LVSI with clinical outcomes. MATERIALS AND METHODS: A retrospective review was conducted on type II endometrial cancer patients who underwent surgical management from July 2017 to December 2019 using the three-tier LVSI scoring system. Binary logistic regression and Cox regression were used to analyse predictors of lymph node involvement or survival outcomes, respectively. The Kaplan-Meier method and Log-rank test were used to analyse differences in locoregional disease-free survival (LR-DFS), distant metastasis disease-free survival (DM-DFS) and overall survival between patients with substantial versus none/focal LVSI. RESULTS: In 79 patients with type II endometrial carcinoma, no LVSI, focal LVSI and substantial LVSI was present in 48.1%, 15.2% and 36.7% of patients, respectively. Lymph nodes were involved in 0.0% with no LVSI, 20.0% with focal LVSI and 60.0% with substantial LVSI (P < 0.001). The median follow-up was 22.2 months. In patients with none/focal versus substantial LVSI, the 2-year LR-DFS and DM-DFS rates were 91.5% versus 71.4% (P = 0.01) and 90.2% versus 63.8% (P = 0.005), respectively. On univariate analysis, myometrial invasion ≥50%, tumour size ≥3.6 cm, substantial versus none/focal LVSI, lymph node involvement and omission of adjuvant radiotherapy were significant predictors for worse LR-DFS and DM-DFS (P < 0.05). DISCUSSION: Substantial LVSI has a high incidence in type II pathology at our institution and predicts for lymph node involvement and worse clinical outcomes.

Cost-effectiveness analysis of tumor molecular classification in high-risk early-stage endometrial cancer.

PURPOSE: Tumor molecular analyses in endometrial cancer (EC) includes 4 distinct subtypes: (1) POLE-mutated, (2) mismatch repair protein (MMR) deficient, (3) p53 mutant, and (4) no specific molecular profile. Recently, a sub-analysis of PORTEC-3 demonstrated notable differences in treatment response between molecular classification (MC) groups. Cost of testing is one barrier to widespread adoption of MC. Therefore, we sought to determine the cost-effectiveness of MC in patients with stage I and II high-risk EC. METHODS: A Markov decision model was developed to compare tumor molecular classification (TMC) vs. no testing (NT). A healthcare payor's perspective and 5-year time horizon were used. Base case data were abstracted from PORTEC-3 and the molecular sub-analysis. Cost and utility data were derived from public databases, peer-reviewed literature, and expert input. Strategies were compared using the incremental cost-effectiveness ratio (ICER) with effectiveness in quality-adjusted life years (QALYs) and evaluated with a willingness-to-pay threshold of $100,000 per QALY gained. Sensitivity analyses were performed to test model robustness. RESULTS: When compared to NT, TMC was cost effective with an ICER of $25,578 per QALY gained; incremental cost was $1780 and incremental effectiveness was 0.070 QALYs. In one-way sensitivity analyses, results were most sensitive to the cost of POLE testing, but TMC remained cost-effective over all parameter ranges. CONCLUSIONS: TMC in early-stage high-risk EC is cost-effective, and the model results were robust over a range of parameters. Given that MC can be used to guide adjuvant treatment decisions, these findings support adoption of TMC into routine practice.

Regional Control and Chemoradiotherapy Dose Response for Clinically Involved Lymph Nodes in Patients with Locally Advanced Endometrial Cancers Who are Not Candidates for Upfront Surgical Staging Extrafascial Hysterectomy.

AIMS: There are limited data in endometrial cancer for nodal control and appropriate treatment volume for non-surgically resected nodes treated with chemoradiotherapy (CRT) for patients who are not candidates for upfront extrafascial hysterectomy. MATERIALS AND METHODS: Patients (n = 105) with clinical stage ≥ II endometrial cancer who were not candidates for upfront extrafascial hysterectomy treated with preoperative CRT were retrospectively reviewed. CRT included pelvic nodes to the common iliac for node-negative disease and para-aortic nodes to the renal vessel for any node-positive disease. Involved nodes most commonly received a boost of 55 Gy in 25 fractions ± additional 4-6 Gy sequential boost for nodes >2 cm. RESULTS: Of the included 95 patients, 55 patients were node positive, with a total of 300 positive nodes. At a median follow-up of 25 months (interquartile range 9-46), the 3-year regional control was 91%. The 3-year involved nodal control rate was 96%. Involved nodal control was significantly higher in type I histology, nodes <2 cm and by radiation dose (75% for <55 Gy, 98% for 55 Gy in 25 fractions and 89% for >55 Gy, P = 0.03). The 3-year para-aortic failure rate for node negative patients treated with pelvis-only CRT was significantly higher with positron emission tomography/computed tomography (PET/CT) versus computed tomography (CT)-based staging (0% versus 20%). CONCLUSION: This is the largest study examining regional control rates of involved lymph nodes with CRT for patients who were not candidates for upfront extrafascial hysterectomy. Nodal failure was low following CRT and dose ≥55 Gy in 25 fractions seems to be adequate for involved nodes.

Early outcomes after definitive chemoradiation therapy with Vienna/Venezia hybrid high-dose rate brachytherapy applicators for cervical cancer: A single-institution experience.

PURPOSE: The Vienna and Venezia (Elekta) are hybrid intracavitary/interstitial brachytherapy (BT) applicators for cervical cancers unsuitable for intracavitary BT alone to improve target coverage or reduce critical organ dose. There is limited outcome data with the use of these applicators outside published experience of the EMBRACE group. We report feasibility and early outcomes with the use of these hybrid applicators at our institution. METHODS AND MATERIALS: Hybrid applicators were used to treat 61 patients with cervical cancer from November 2011 to December 2019. Indications for hybrid applicator use were involvement of the vagina in 10 patients (16%), residual central or parametrial disease in 46 patients (75%), and a narrow introitus in 5 patients (9%). Toxicities were graded using the CTCAE v4.0. Outcomes were assessed with the Kaplan-Meier method. RESULTS: Median follow-up was 16 months (IQR 9-32 mos). Median HRCTV volume was 31.6 cm3 (IQR 25-48 cm3). Median HRCTV D90 was 86.1 Gy (IQR 84.3-88.0 Gy). In 54 patients with follow-up PET/CT at 3 months, complete initial imaging response locally was seen in 46 patients.Estimated 12-month Kaplan-Meier overall survival, locoregional control, distant control, and recurrence-free survival estimates were 86.9%, 80.6%, 73.8%, and 65.9%, respectively. The 12-month incidence of Grade 3+ GI/GU chronic toxicities was 5.7%, consisting of vesicovaginal fistula, rectovaginal fistula, and ureterovesical fistula. CONCLUSIONS: Our single-institution data support the use of the hybrid applicators, as an alternative to traditional BT applicators when clinically warranted. Use of hybrid applicators is feasible with adequate coverage of disease in the vagina and parametrium.

Pathologic and clinical tumor size discordance in early-stage cervical cancer: Does it matter?

OBJECTIVE: The objective of this study was to assess the rate of discordance between clinical and pathologic tumor size for women with stage IB1 cervical cancer (FIGO 2009 criteria), assess risk factors for discordance, and determine the impact of discordance on oncologic outcomes. METHODS: This was a secondary analysis of a prior multi-institutional retrospective review of patients diagnosed with stage IB1 (FIGO 2009 staging) cervical cancer undergoing radical hysterectomy between 2010 and 2017. Demographic, clinicopathologic, and oncologic data were collected. Pathologic upstaging was defined as having a preoperative diagnosis of stage IB1 cervical cancer with pathology demonstrating a tumor size >4 cm. Demographic and clinicopathologic data was compared using chi-square, fisher exact or 2-sided t-test. Survival was estimated using the Kaplan-Meier method. RESULTS: Of the 630 patients, 77 (12%) were upstaged. Patients who were upstaged had lower rates of preoperative conization (p < .001) or preoperative tumor sizes ≤2 cm (p < .001). Upstaged patients had increased odds of deep stromal invasion, lymphovascular space invasion, positive margins and positive lymph nodes. Almost 88% of upstaged patients received adjuvant therapy compared to 29% of patients with tumors ≤4 cm (odds 18.49, 95% CI 8.99-37.94). Finally, pathologic upstaging was associated with an increased hazard of recurrence (hazard ratio [HR] 1.95, 95% CI 1.03-3.67) and all-cause death (HR 2.31, 95% CI 1.04-5.11). CONCLUSIONS: Pathologic upstaging in stage IB1 cervical cancer is relatively common. Upstaging is associated with an 18-fold increased risk of receipt of adjuvant therapy. Patients undergoing preoperative conization and those with tumors <2 cm had lower risks of upstaging. Improvement in preoperative assessment of tumor size may better inform primary treatment decisions.

Is the risk of substantial LVSI in stage I endometrial cancer similar to PORTEC in the North American population? - A single-institution study.

OBJECTIVES: A pooled analysis of PORTEC-1 & 2 identified substantial lymphovascular space invasion (LVSI) in 4.8% of patients, which predicted for pelvic recurrence, distant metastasis, and overall survival. Our institution implemented the PORTEC three-tier system of LVSI reporting (absent, focal, or substantial). We aimed to quantify the incidence of substantial LVSI in a North American population and to correlate extent of LVSI with lymph node (LN) involvement. METHODS: A retrospective review was conducted on patients with clinically uterine-confined, endometrioid type endometrial cancer who underwent surgical staging and were found to have pT1a-b disease. Binary logistic regression was used to assess predictors of LN involvement (defined as ITC, micrometastases, or macrometastases). RESULTS: In total, 438 patients with pT1a-b disease were identified. In the overall cohort and in the subset meeting PORTEC-1 inclusion criteria (n = 195), no LVSI was present in 67.4% and 50.8%; focal LVSI was present in 16.7% and 24.1%; and substantial LVSI was present in 16.0% and 25.1%, respectively. Among patients who underwent surgical LN assessment (79.2%, n = 347), LNs were involved in 3.3% without LVSI, 7.5% with focal LVSI (OR 2.4), and 15.2% with substantial LVSI (OR 5.3) (p = .005), with a similar trend in the PORTEC-1 cohort. Extent of LVSI correlated with disease burden in LN metastases. CONCLUSION: Our incidence of substantial LVSI was three to five times higher than reported by PORTEC and correlated with LN involvement. This questions the reproducibility of the three-tier LVSI reporting system and emphasizes the need for multi-institutional data outside PORTEC for confirmation of our findings.

Human papillomavirus infection mediates response and outcome of vulvar squamous cell carcinomas treated with radiation therapy.

PURPOSE: Human papillomavirus (HPV) is implicated as a causative factor in vulvar squamous cell carcinoma (VSCC). This study evaluates if p16-positivity, a surrogate for HPV, predicts for better response rates to chemoradiation therapy and survival. MATERIALS AND METHODS: We conducted a retrospective chart review of women treated with neoadjuvant or definitive chemoradiation (CRT) therapy from 2000 to 2016 for VSCC. p16 stain-positivity was defined as diffuse strong "block" immunoreactivity within invasive tumor. RESULTS: Seventy-three women with median follow-up of 13.4 months were analyzed. Thirty-three (45.2%) had p16+ tumors. Median age was 73 years (range: 37-89); with p16+ tumors, the median age was 60 years vs 73 years for women with p16- tumors (p < 0.001). The distribution of tumor size and stage by p16-status were similar. The complete clinical response (cCR) rate for p16+ tumors was 63.6% vs 35.0% for p16- tumors (p = 0.014). The pathologic complete response (pCR) rate for women treated neoadjuvantly was 53.8% vs 31.4% for p16+ vs p16-, respectively (p = 0.067). The combined complete response (cCR orpCR [CCR]) rate was 63.6% for p16+ and 30.0% for p16- (p = 0.004). Two-year vulvar control (VC) for women with p16+ tumors was 75.5% vs. 49.5% for p16- (p = 0.008). In women with p16+ tumors who achieved CCR, 2-year VC was 92.3% vs 52.1% for CIR (p = 0.009). For p16- tumors, 2-year VC was 67.3% vs 41.1% for CCR and CIR (p = 0.072). No woman with a p16+ tumor developed distant metastases vs. 7 with p16- tumor (p = 0.013). OS was not statistically different between p16+ cohorts, but was improved for p16- patients with CR vs CIR, 72.9% vs 18.8% (p = 0.026). CONCLUSIONS: p16-positive tumors appear to have better clinical and pathologic response rates and clinical outcomes.

Survival advantage associated with multimodal therapy in women with node-positive (stage-IIIC) uterine papillary serous carcinoma: a National Cancer Database study.

OBJECTIVE: Uterine papillary serous carcinoma (UPSC) is an aggressive subtype of endometrial cancer. Adjuvant chemotherapy (CT) has become standard care in treatment of women with advanced-stage UPSC, but the role of consolidative radiotherapy (RT) is unclear. This study aims to evaluate survival outcomes of multimodal therapy. DESIGN: Retrospective cohort study using a National Cancer Database (NCDB). SETTING: United States of America. SAMPLE: A total of 1816 women diagnosed with UPSC. METHODS: All women diagnosed with surgically staged FIGO (International Federation of Gynecology and Obstetrics) stage-IIIC UPSC were identified in the NCDB from January 1998 to December 2010. Overall survival (OS) was estimated using the Kaplan-Meier method. Univariate and multivariable analyses were performed to identify and control for prognostic factors. MAIN OUTCOME MEASURE: Overall survival. RESULTS: A total of 398 057 cases of uterine cancer were identified, 22 106 of which were UPSC. Of these women, 14 093 underwent lymph-node examination, 2902 (20.6%) were found to have stage-IIIC disease, and 1816 received chemotherapy. Younger age and higher number of total lymph nodes examined were independently predictive of receiving multimodality (CT + RT) therapy, compared with CT only. Median OS was 33.6 and 42.6 months, for the CT and CT + RT groups, respectively (P < 0.0005). Exploratory univariate analyses found age, comorbidity index, tumour size, and number of dissected and positive lymph nodes to be also associated with survival. Multivariable analysis controlling for the above found the use of consolidative radiotherapy to be independently predictive of improved OS, with a hazard ratio of 0.69 (95% confidence interval, 95% CI 0.56-0.84). CONCLUSIONS: Patients with stage-IIIC UPSC may benefit from multimodal treatment that includes adjuvant radiotherapy in addition to chemotherapy. TWEETABLE ABSTRACT: In this study of 1816 women with uterine papillary serous cancer, adjuvant radiotherapy increased survival.

Comparison of outcomes in patients treated with multi-agent regiments of cisplatin, adriamycin, and VP-16 versus carboplatin and paclitaxel for advanced and recurrent endometrial cancer.

OBJECTIVE: The objective of this study was to compare the efficacy of two multi-agent chemotherapeutic regiments that were previously used at the Institution for treatment of advanced and recurrent endometrial cancer. METHODS: A retrospective review of patients with Stage III, IV, and recurrent endometrial cancer who received adjuvant chemotherapy at Roswell Park Cancer Institute over a period of 21 years. Two patient groups were defined based on treatment received: cisplatin, adriamycin, and VP-16 with or without megace (PAV-M), or carboplatin and paclitaxel (CT). RESULTS: Forty-two patients with advanced or recurrent endometrial cancer were included in this review based on regimen received. Median duration of follow up was 55 months. Treatment with PAV-M resulted in more dose modifications compared to CT group (42% vs 11%, respectively). There were no significant differences in disease-free survival or overall survival. CONCLUSIONS: PAV/PAV-M is active in patients with advanced or recurrent endometrial cancer. However, toxicity associated with this triplet regimen may limit clinical use.

Phase II trial of erlotinib in women with squamous cell carcinoma of the vulva.

OBJECTIVE: To evaluate the efficacy and toxicity of erlotinib in the management of squamous cell carcinoma (SCC) of the vulva. METHODS: Patients with vulvar lesions amenable to surgery or chemoradiation (cohort 1) or those with metastatic measurable disease (cohort 2) received erlotinib 150 mg daily. Patients were monitored for toxicity. Responses were determined by digital photography or RECIST 1.1. Cohort 1 underwent pre and post treatment biopsies. EGFR immunohistochemistry (IHC), fluorescence in-situ hybridization (FISH), and mutational analysis were performed. RESULTS: 41 patients were enrolled: 17 in cohort 1 and 24 in cohort 2. Notable grade 3 or 4 toxicities included allergic reaction (1), diarrhea/electrolyte abnormalities (3), ischemic colitis (1), and renal failure (3) and electrolyte abnormalities (n=2). Mean number of cycles for cohort 2 was 3.3. Overall clinical benefit rate was 67.5% with 11 (27.5%) partial responses (PR), 16 (40.0%) stable disease (SD), and 7 (17.5%) progressive disease. Responses were of short duration. All pre and post treatment biopsies exhibited 2-3+ EGFR staining. 5 of 14 patients (35%) were found to have EGFR amplification (n=3) or high polysomy/trisomy (n=2). These five patients had either a PR (n=3) or SD (n=2). Gain of function mutations were not been identified. CONCLUSIONS: This is the first reported controlled trial evaluating erlotinib for the management of vulvar carcinoma. Toxicities were acceptable given the lack of treatment options for these patients. Given the observed clinical benefits erlotinib may represent one of the most active agents available to treat vulvar SCC.

Three-dimensional high dose rate intracavitary image-guided brachytherapy for the treatment of cervical cancer using a hybrid magnetic resonance imaging/computed tomography approach: feasibility and early results.

AIMS: To evaluate the feasibility and outcome of image-guided brachytherapy (IGBT) for treating cervical cancer using magnetic resonance imaging (MRI)-based planning for the first fraction followed by computed tomography (CT)-based planning for subsequent fractions. MATERIALS AND METHODS: Forty-four patients with cervical cancer were treated with three-dimensional high dose rate IGBT. The brachytherapy dose was 5.0-6.0 Gy × five fractions. All but five patients received concurrent weekly cisplatinum at 40 mg/m(2). All patients received external beam radiotherapy (EBRT) with a median dose of 45Gy over 25 fractions. Total doses for the high-risk clinical target volume (HRCTV) and organs at risk, including the rectum, bladder and sigmoid, from EBRT and brachytherapy were summated and normalised to a biologically equivalent dose of 2Gy per fraction (EQD(2)). At 3 months after therapy, any early response was assessed with positron emission tomography (PET)/CT imaging. RESULTS: The mean D(90) for the HRCTV was 83.3 (3.0) Gy. The mean 2 cm (3) dose to the bladder, rectum and sigmoid colon organs was 79.7 (5.1), 57.5 (4.4) and 66.8 (5.7) Gy, respectively. All but one (2.3%) patient had a complete response. Follow-up PET/CT was carried out in 41 (93.0%) patients, of whom 38 (92.5%) had a complete response. Of the 38 patients with a complete response on PET/CT, two had local recurrences at 6 and 8 months, respectively. Actuarial 2 year local control, disease-specific and overall survival rates were 88, 85 and 86%, respectively. CONCLUSION: This is the first report of three-dimensional high dose rate IGBT for the treatment of cervical cancer using a hybrid MRI/CT approach. Early results have shown the feasibility of this approach with excellent local control. Additional studies are needed to assess long-term outcomes of local control and associated morbidities.

A comparison of outcome in patients with stage 1 clear cell and grade 3 endometrioid adenocarcinoma of the endometrium with and without adjuvant therapy.

OBJECTIVE: To determine the outcomes in patients with Stage I uterine clear cell carcinoma (UCCC) treated with and without adjuvant therapy, and to compare the outcomes in these patients to that of matched controls, patients with Stage I, grade 3, endometrioid adenocarcinoma of the endometrium (EC). METHODS: Patients with FIGO Stage I UCCC who underwent comprehensive surgical staging between January 1996 and January 2007 were identified. Cases (UCCC) were matched by age, stage, adjuvant therapy, and year of diagnosis to controls consisting of patients with grade 3 EC. Recurrence and survival were analyzed using the Kaplan-Meier method. RESULTS: 25 patients with Stage I UCCC were identified of whom 13 (52%) received no adjuvant therapy and 12 (48%) received adjuvant radiation therapy (XRT). The 5-year disease-free survival and overall survival rates for the observation and the XRT groups were 78% and 75%, (p = 0.7) and 85% and 82% (p = 0.1), respectively. When compared to controls, the 5-year disease-free survival rates and overall survival rates of patients with Stage I UCCC were not significantly different, 77% vs 75% (p = 0.8) and 84% vs 88% (p = 0.5), respectively. CONCLUSIONS: In patients with Stage I UCCC tumors there was no clear benefit to adjuvant radiation given the absence of improvement in recurrence risk or any survival benefit. These data question the benefit of radiation therapy in UCCC patients with disease confined to the uterus.

Impact of bowel obstruction at the time of initial presentation in women with ovarian cancer.

OBJECTIVE: To determine whether the presence of bowel obstruction at the time of initial presentation has any prognostic significance in these women. DESIGN: Retrospective cohort study. SETTING: Dedicated gynaecological oncology service of a large tertiary institution. POPULATION: Women who had a bowel obstruction as part of their initial presentation of ovarian cancer were identified between 1995 and 2007. Each woman was matched with four control women (with disease but no obstruction). METHODS: Women with disease were compared with controls to determine the impact, if any, of bowel obstruction at presentation. Several prognostic variables including bowel obstruction were also evaluated in a Cox proportional hazard model. MAIN OUTCOME MEASURES: Progression-free survival (PFS) and overall survival (OS). RESULTS: Forty-eight women with disease and 192 controls were identified during the study period. The median follow-up period was 19 months among women with disease versus 20 months in controls. No differences were seen in demographics and clinical characteristics of the women. Optimal cytoreduction rate was similar between the two groups (75% versus 78%, P = 0.7). Patients with bowel obstruction had a shorter PFS and OS compared with controls [19 months versus 21 months (P = 0.01) and 22 versus 35 months (P = 0.008)], respectively. Bowel obstruction at presentation was an independent prognostic variable with a hazard ratio of 1.5 (P = 0.009). Other prognostic variables were age, stage and extent of surgical cytoreduction. CONCLUSIONS: Bowel obstruction at the time of initial presentation is an adverse prognostic factor in women with ovarian cancer.

Isolated fetal echogenic intracardiac foci or golf balls: is karyotyping for Down's syndrome indicated?

OBJECTIVE: To determine the prevalence of isolated echogenic intracardiac foci and the subsequent risk for Down's syndrome at 18-23 weeks in an unselected obstetric population. DESIGN: Prospective study. SETTING: A district general hospital serving a routine obstetric population. PARTICIPANTS: 16,917 pregnant women who underwent a routine ultrasound screening at 18-23 weeks of gestation between November 1994 and August 1998. METHODS: All women were offered screening for Down's syndrome by nuchal translucency or maternal serum biochemistry. The prevalence of isolated echogenic intracardiac foci was determined and the relative risk for Down's syndrome was calculated for different ultrasound findings. RESULTS: The combined sensitivity of age, nuchal translucency and maternal serum biochemistry for Down's syndrome was 84% (27/32). The relative risk for Down's syndrome was 0.17 (95% CI 0.07-0.41) for the women with normal scan findings at 18-23 weeks. The prevalence of isolated echogenic intracardiac foci at 18-23 weeks was 0.9% (144/16,917). None of these pregnancies were affected by Down's syndrome. CONCLUSION: The significance of the association between isolated echogenic intracardiac foci and Down's syndrome is a matter of ongoing debate. The data of this study suggest that in an unselected obstetric population with prior, effective, routine Down's syndrome screening, the association between isolated echogenic intracardiac foci and Down's syndrome is no longer significant.