Cervical Cancer: Preventable Deaths Among American Indian/Alaska Native Communities

American Indian/Alaska Native (AI/AN) individuals have twice the mortality rate of cervical cancer than the general US population. Participation in prevention programs such as cervical cancer screening and human papillomavirus (HPV) vaccination are under-utilized in this population. There are high rates of established cervical cancer risk factors among this community, with AI/AN people having a higher likelihood of infection with high-risk HPV strains not included in the 9-valent vaccine. There is a need for more robust and urgent prevention and treatment efforts in regard to cervical cancer in the AI/AN community.

Persistent cervical cancer disparities among American Indian/Alaska Native women: a systematic scoping review exploring the state of the science in this population

PURPOSE

American Indian/Alaska Native (AI/AN) populations experience significantly higher incidence and mortality rates of cervical cancer. The objective of this systematic scoping review is to characterize the volume and nature of research being conducted specific to the AI/AN population regarding cervical cancer and related clinical themes.

METHODS

This scoping review was conducted in collaboration with the Pacific Northwest Evidence-based Practice Center. Search strategies identified eligible publications from 1990 through 4 February 2022. Two reviewers independently abstracted study data, including clinical area, number of participants and percent inclusion of AI/AN, intervention or risk factor, outcomes reported, Indian Health Service (IHS) Region, and funding source. We used published algorithms to assess study design.

RESULTS

Database searches identified 300 unique citations. After full-text evaluation of 129 articles, 78 studies and 9 secondary publications were included (total of 87). Approximately 74% of studies were observational in design, with cross-sectional methodology accounting for 42.7% of all included studies. The most common clinical theme was cervical cancer screening. The most common intervention/exposure was risk factor, typically race (AI/AN compared with other groups) (69%). For studies with documented funding sources, 67% were funded by the US Government.

CONCLUSION

Of the small number of publications identified, the majority are funded through government agencies, are descriptive and/or cross-sectional studies that are hypothesis generating in nature, and fail to represent the diversity of the AI/AN populations in the US. This systematic scoping review highlights the paucity of rigorous research being conducted in a population suffering from a greater burden of disease.

Ultrasonographic evaluation of endometrial stripe thickness is insufficient to rule out uterine serous carcinoma

PURPOSE

Uterine serous carcinoma (USC) is a rare endometrial cancer representing less than 10% of uterine cancers but contributing to up to 50% of the mortality. Delay in diagnosis with this high-grade histology can have significant clinical impact. USC is known to arise in a background of endometrial atrophy. We investigated endometrial stripe (EMS) thickness in USC to evaluate current guidelines for postmenopausal bleeding in the context of this histology.

METHODS

Retrospective chart review was conducted using ICD-9 and ICD-10 codes over an 18-year period. We included 139 patients with USC and compared characteristics of patients with EMS ≤ 4 mm and EMS > 4 mm. Chi-square or Fisher's exact tests were used to compare proportions and two-tailed t-tests to compare means. A p-value of < 0.05 was considered statistically significant.

RESULTS

Most patients were white, obese, and multiparous. Thirty-two (23%) had an EMS ≤ 4 mm; 107 (77%) had an EMS > 4 mm. There were no statistically significant differences in age at diagnosis or presenting symptoms between groups, and postmenopausal bleeding was the most common symptom in each group.

CONCLUSION

Nearly 25% of patients with USC initially evaluated with transvaginal ultrasound were found to have an EMS ≤ 4 mm. If transvaginal ultrasound is used to triage these patients, one in four women will potentially experience a delay in diagnosis that may impact their prognosis.

Success Rates of Sentinel Lymph Node Mapping for Endometrial Cancer in Patients with Body Mass Index < 45 Compared with Body Mass Index ≥ 45

STUDY OBJECTIVE

The objective is to evaluate the rate of sentinel lymph node (SLN) mapping in patients with body mass index (BMI [kg/m2]) BMI ≥ 45 compared with < 45.

DESIGN

A retrospective chart review.

SETTING

Three urban referral-based settings-1 academic and 2 community based.

PATIENTS

Patients age ≥ 18 years, with endometrial intraepithelial neoplasia or clinical stage 1 endometrial cancer who underwent robot-assisted total laparoscopic hysterectomy with attempted SLN mapping between January 2015 and December 2021.

INTERVENTIONS

Robot-assisted total laparoscopic hysterectomy with attempted SLN mapping.

MEASUREMENTS AND MAIN RESULTS

A total of 933 subjects were included: 795 (85.2%) with BMI < 45 and 138 (14.8%) with BMI ≥ 45. Comparing the BMI < 45 with BMI ≥ 45 group, bilateral mapping was successful in 541 (68.1%) vs 63 (45.7%), respectively. Unilateral mapping was successful in 162 (20.4%) vs 33 (23.9%), respectively. Failure to map occurred in 92 (11.6%) vs 42 (30.4%) (p <.001), respectively. Exploratory analysis also suggested an inverse relationship between success rate of bilateral SLN mapping and BMI, with patients with BMI < 20 having bilateral SLN mapping rates of 86.5% and patients with BMI ≥ 61 having rates of 20.0%. The steepest decline in bilateral SLN mapping rates was from BMI group 46 to 50 compared to 51 to 55, at 55.4% to 37.5%, respectively. Adjusted odds ratio (compared with those with BMI < 30) for those in the BMI 30 to 44 group was 0.36 (95% confidence interval 0.21-0.60) and for those in the BMI ≥ 45 group was 0.10 (95% confidence interval 0.06-0.19).

CONCLUSION

There is a statistically significant lower rate of SLN mapping in patients with a BMI ≥ 45 than BMI < 45. Understanding the success of SLN mapping in patients with morbid obesity is essential for preoperative counseling, surgical planning, and developing a risk-appropriate postoperative treatment plan.

Ovarian preservation compared to oophorectomy in premenopausal women with early-stage, low-grade endometrial Cancer: A cost-effectiveness analysis

OBJECTIVES

Standard treatment for endometrial cancer is a hysterectomy, bilateral salpingo-oophorectomy, and lymph node assessment. In premenopausal women, removal of the ovaries may not be necessary and could increase the risk of all-cause mortality. We sought to estimate the outcomes, costs, and cost-effectiveness of oophorectomy versus ovarian preservation in premenopausal women with early-stage, low-grade endometrial cancer.

METHODS

A decision-analytic model was designed using TreeAge software comparing oophorectomy to ovarian preservation in premenopausal women with early-stage, low-grade endometrial cancer. We used a theoretical cohort of 10,600 women to represent our population of interest in the United States in 2021. Outcomes included cancer recurrences, ovarian cancer diagnoses, deaths, rates of vaginal atrophy, costs, and quality-adjusted life years (QALYs). The cost-effectiveness threshold was set at $100,000/QALY. Model inputs were derived from the literature. Sensitivity analyses were conducted to evaluate the robustness of the results.

RESULTS

Oophorectomy resulted in more deaths and higher rates of vaginal atrophy, while ovarian preservation resulted in 100 cases of ovarian cancer. Ovarian preservation resulted in lower costs and higher QALYs making it cost effective when compared to oophorectomy. Sensitivity analyses demonstrated the probability of cancer recurrence after ovarian preservation and probability of developing ovarian cancer were the most impactful variables in our model.

CONCLUSION

Ovarian preservation is cost-effective in premenopausal women with early-stage, low-grade endometrial cancer when compared to oophorectomy. Ovarian preservation may prevent surgical menopause, which may improve quality of life and overall mortality without compromising oncologic outcomes, and should be strongly considered in premenopausal women with early stage disease.

Adjuvant Human Papillomavirus Vaccination After Excisional Procedure for Cervical Intraepithelial Neoplasia: A Cost-Effectiveness Analysis

OBJECTIVE

To examine the cost effectiveness of human papillomavirus (HPV) vaccination after excisional procedure compared with no vaccination.

METHODS

We constructed a decision-analytic model (TreeAge Pro 2021) to compare outcomes between patients who underwent an excisional procedure followed by nonavalent HPV vaccination to those who underwent an excisional procedure without vaccination. Our theoretical cohort contained 250,000 patients, the approximate number undergoing excisional procedures annually in the United States. Our outcomes were costs, quality-adjusted life-years (QALYs), recurrence events, number of surveillance Pap tests with co-testing, number of colposcopies, and second excisional procedures. Probabilities of recurrence were based on a recently published meta-analysis. All values were derived from the literature, and QALYs were discounted at a rate of 3%. Outcomes were applied for 4 years after the initial excisional procedure. Our cost-effectiveness threshold was $100,000 per QALY. Sensitivity analyses were performed to evaluate the robustness of the model.

RESULTS

In our theoretical cohort of patients who underwent an excisional procedure, the HPV vaccination strategy was associated with 17,281 fewer recurrences of cervical intraepithelial neoplasia (CIN) (8,360 fewer cases of CIN 1 and 8,921 fewer cases of CIN 2 or 3), 26,203 fewer Pap tests (1,025,368 vs 1,051,570), 17,281 fewer colposcopies (20,588 vs 37,869), and 8,921 fewer second excisional procedures (4,779 vs 13,701). The vaccination strategy was associated with a higher cost of $135 million. Vaccination was a cost-effective strategy, with an incremental cost-effectiveness ratio of $29,181 per QALY, compared with no vaccination. In our sensitivity analyses, the HPV vaccination strategy remained cost effective until the cost of the three-dose HPV vaccine series reached $1,899 or the baseline (nonvaccinated) probability of recurrence was less than 4.8%.

CONCLUSION

In our model, HPV vaccination for patients with a prior excisional procedure led to improved outcomes and was cost effective. Our study suggests that clinicians should consider offering the three-dose HPV vaccine series to patients who have undergone an excisional procedure to decrease the risk of CIN recurrence and its sequelae.

Persistent disparities of cervical cancer among American Indians/Alaska natives: Are we maximizing prevention tools?

BACKGROUND

Cervical cancer incidence and mortality disparities experienced by American Indian/Alaska Native (AI/AN) women have persisted for decades. Pap smear screening and HPV vaccination are powerful tools to prevent cervical cancer. We evaluated the utilization of these tools among AI/ANs living in the Pacific Northwest (PNW).

METHODS

The Indian Health Service (IHS) National Data Warehouse's Epi Data Mart was analyzed using all healthcare visits from 2010 to 2020 from IHS, Tribal, and Urban Indian clinics in the PNW. Women ages 21-64 were included and considered up-to-date on pap smears if they had either cytology within 3 years or cytology with HPV testing within 5 years of the most recent clinical encounter. HPV vaccination rates for both sexes were calculated for individuals ages 9-26. HPV vaccination was considered complete if: two vaccines were received prior to age 15 or after three vaccinations if initiated after age 15.

FINDINGS

Cervical cancer screening rates are below the national average of 73.5% ranging between 57.1% - 65.0%. Sub-analysis of age groups shows substantially lower rates of up-to-date pap smear screening in the 50-64 age group. HPV vaccination rates have increased over time for both sexes across all age groups. However, the current vaccination rate of 58.6% is well below the Healthy People 2030 goal of 84.3%.

INTERPRETATION

Cervical cancer screening and HPV vaccination are the cornerstones of cervical cancer prevention and early detection. These tools are underutilized and public health efforts can be strengthened to improve cervical cancer disparities in AI/AN women.

FUNDING

Author ASB: Funding for this project has been provided through the Robert Wood Johnson Foundation Harold Amos Minority Faculty Development Grant and the National Cancer Institute K08 Mentored Clinical Scientist Development Award.

Hysterectomy with a General Gynecologist vs. Gynecologic Oncologist in the Setting of Endometrial Intraepithelial Neoplasia: A Cost-Effectiveness Analysis

BACKGROUND

Standard treatment for patients with endometrial intraepithelial neoplasia (EIN) is a hysterectomy, which has a 43% risk of concomitant endometrial cancer on final pathology. General gynecologists and gynecologic oncologists perform hysterectomies; however, patients who have a hysterectomy for EIN with a general gynecologist and are found to have cancer may require a second surgery by a gynecologic oncologist to complete staging. There is current ongoing discussion regarding whether patients with EIN should be provided the option to receive the initial hysterectomy with a gynecologic oncologist.

OBJECTIVE

To better understand if patients with EIN should be initially referred to a gynecologic oncologist for treatment, we examined the cost-effectiveness of hysterectomy by general gynecologists versus gynecologic oncologists for patients with EIN.

STUDY DESIGN

We created a decision-analytic model using TreeAge Pro software to compare outcomes between patients with EIN undergoing hysterectomy by a general gynecologist versus a gynecologic oncologist. Our theoretical cohort contained 200,000 patients, an estimate of the number of individuals diagnosed with EIN each year in the United States. Outcomes included costs, quality-adjusted life years (QALYs), primary lymph node dissection (LND), secondary LND, surgical site infection, and perioperative mortality. We assumed that surgical morbidity and mortality were the same under generalist and specialist care and applied costs of travel and lost work for those seeing a gynecologic oncologist. We performed univariable sensitivity analyses as well as multivariable probabilistic sensitivity analysis to assess the model's robustness given the uncertainty of model inputs.

RESULTS

In our theoretical cohort of 200,000 patients with EIN, hysterectomy with a gynecologic oncologist was associated with a decrease in 10,811 second surgeries for LND, 87 surgical site infections, and 9 perioperative mortalities. When hysterectomy was performed by a general gynecologist, 9 fewer patients had a LND due to perioperative mortalities that occurred prior to LND with a gynecologic oncologist. Hysterectomy with a gynecologic oncologist was the dominant, cost-effective strategy as it saved $116 million and increased QALYs by 180. In our univariable analyses, hysterectomy with a gynecologic oncologist was cost-saving and increased QALYs over a wide range of probabilities and costs for LND, surgical site infection, and perioperative mortality. However, hysterectomy with a gynecologic oncologist is only a cost-effective and cost-saving saving strategy in just over 50% of multivariable simulations, demonstrating that that there is significant uncertainty in the model's cost-effectiveness.

CONCLUSIONS

In our model, hysterectomy with a gynecologic oncologist for patients with EIN was associated with cost savings and increased QALYs. Our study supports that patients undergoing hysterectomy for EIN at institutions using Mayo criteria to determine need for lymphadenectomy may benefit from surgery with a gynecologic oncologist rather than a general gynecologist to reduce costs and adverse events associated with a second surgery.

Cervical Cancer Screening in Postmenopausal Women: Is It Time to Move Toward Primary High-Risk Human Papillomavirus Screening?

Background: Cervical cytology in postmenopausal women is challenging due to physiologic changes of the hypoestrogenic state. Misinterpretation of an atrophic smear as atypical squamous cells of uncertain significance (ASCUS) is one of the most common errors. We hypothesize that high-risk human papillomavirus (hrHPV) testing may be more accurate with fewer false positive results than co-testing of hrHPV and cervical cytology for predicting clinically significant cervical dysplasia in postmenopausal women. Materials and Methods: We conducted a retrospective analysis of 924 postmenopausal and 543 premenopausal women with cervical Pap smears and hrHPV testing. Index Pap smear diagnoses (ASCUS or greater vs. negative for intraepithelial lesion) and hrHPV testing results were compared with documented 5-year clinical outcomes to evaluate sensitivity and specificity of hrHPV compared with co-testing. Proportions of demographic factors were compared between postmenopausal women who demonstrated hrHPV clearance versus persistence. Results: The prevalence of hrHPV in premenopausal and postmenopausal women was 41.6% and 11.5%, respectively. The specificity of hrHPV testing (89.6% [87.4-91.5]) was significantly greater compared with co-testing (67.4% [64.2-70.4]) (p < 0.05). A greater proportion of women with persistent hrHPV developed cervical intraepithelial lesion 2 or greater (CIN2+) compared with women who cleared hrHPV (p = 0.012). No risk factors for hrHPV persistence in postmenopausal women were identified. Conclusion: Our data suggest that hrHPV testing may be more accurate than co-testing in postmenopausal women and that cytology does not add clinical value in this population. CIN2+ was more common among women with persistent hrHPV than those who cleared hrHPV, but no risk factors for persistence were identified in this study.

Gynecologic cancer incidence and mortality among American Indian/Alaska Native women in the Pacific Northwest, 1996-2016

OBJECTIVES

Compare the incidence and mortality of gynecologic cancers among American Indian/Alaska Native (AI/AN) women to the Non-Hispanic White (NHW) population in the Pacific Northwest.

METHODS

Age-adjusted cancer incidence (1996-2016) and mortality (2006-2016) rates were calculated from population-based state cancer registry and death certificate data obtained from Washington, Oregon, and Idaho, and corrected for AI/AN misclassification. Incidence and mortality rate ratios (RR) were calculated to compare AI/AN and NHW women with gynecologic cancers.

RESULTS

Across all gynecologic cancer sites, AI/AN women were diagnosed at a younger age compared to NHW women. AI/AN women had a higher incidence of cervical cancer compared to NHW women with a RR of 1.53 (95% CI: 1.34, 1.75). For all age groups, AI/AN women had a higher incidence of cervical cancer and the disparity was greatest in the 50-64 age group with a RR of 1.76 (95% CI: 1.36, 2.30). Cervical cancer mortality was greater among AI/AN women, with an all-ages RR of 1.79 (95% CI: 1.30, 2.46); the disparity was greatest in the 50-64 age group (RR: 2.88, 95% CI: 1.89, 4.38). For uterine cancer, AI/AN women had similar incidence rates as NHW women but higher mortality rates (RR: 1.35, 95% CI: 1.03-1.75). Incidence and mortality for ovarian cancer were similar between groups.

CONCLUSION

Our analysis of gynecologic cancers among AI/AN in the PNW found significant disparities relative to NHW women in cervical cancer incidence and mortality. These disparities persist despite advances in prevention strategies.

A contemporary framework of health equity applied to gynecologic cancer care: A Society of Gynecologic Oncology evidenced-based review

Health disparities are defined as the preventable difference in the burden of disease, injury, and violence, or opportunity to achieve optimal health that socially disadvantaged populations experience compared to the population as a whole. Disparities in incidence and cancer outcomes for women with gynecologic malignancies have been well described particularly for American women of Black race. The etiology of these disparities has been tied to socio-economics, cultural, educational and genetic factors. While access to high quality treatment has been primarily linked to survival from cervical and ovarian cancer, innate biologic distinctions have been principally cited as reasons for differences in incidence and mortality in cancers of the uterine corpus. This article will update the framework of disparities to incorporate a broader understanding of the social determinants of health and how they affect health equity by addressing the root causes of disparities within the health care system. Special populations are identified who are at risk for health inequities which include but are not limited to Black race, underserved racial and ethnic minorities (e.g. indigenous peoples, low English fluency), trans/gender nonconforming people and rural populations. Each of these populations at risk have unique structural barriers within the healthcare system impacting gynecologic cancer outcomes. The authors provide practical recommendations for practitioners aimed at eliminating cancer related outcome disparities.

Clinical Challenges Associated with Universal Screening for Lynch Syndrome-Associated Endometrial Cancer

Universal testing for Lynch syndrome is now a routine component of the diagnostic work-up of endometrial cancer patients. The purpose of this study was to identify prospectively the barriers to universal screening based on a tissue testing approach [microsatellite instability (MSI) analysis, IHC for DNA mismatch repair proteins, and MLH1 methylation analysis]. Endometrial carcinoma patients (n = 213) prospectively underwent microsatellite instability and IHC testing for expression of DNA mismatch repair (MMR) proteins. Patients with low (MSI-L) or high (MSI-H) levels of tumor MSI or immunohistochemical loss of MLH1 (and absent MLH1 methylation), MSH2, MSH6, or PMS2 were referred to a genetic counselor for consideration of germline testing. Six discordances (3.1% of tested cases) between IHC and MSI were identified. Half of these exhibited heterogeneous immunohistochemical loss of MLH1/PMS2 and were microsatellite stable (MSS). Of the remaining cases, one was MSS with immunohistochemical loss of MSH6, one was MSS with immunohistochemical loss of MLH1/PMS2 and absent MLH1 promoter methylation, and one was MSI-H with intact expression of DNA MMR proteins. Four patients had MSI-L tumors with intact immunohistochemical protein expression; the clinical significance of MSI-L in endometrial cancer is unclear. Eight patients did not have germline mutations despite tissue testing suggesting Lynch syndrome. Including cases with insufficient tissue for testing and patients declining tissue or germline testing, we encountered significant barriers to universal screening in 13.6% of screened patients (29/213) that preclude designation of a tumor as sporadic or hereditary. Cancer Prev Res; 10(2); 108-15. ©2016 AACR.

Germline multi-gene hereditary cancer panel testing in an unselected endometrial cancer cohort

Hereditary endometrial carcinoma is associated with germline mutations in Lynch syndrome genes. The role of other cancer predisposition genes is unclear. We aimed to determine the prevalence of cancer predisposition gene mutations in an unselected endometrial carcinoma patient cohort. Mutations in 25 genes were identified using a next-generation sequencing-based panel applied in 381 endometrial carcinoma patients who had undergone tumor testing to screen for Lynch syndrome. Thirty-five patients (9.2%) had a deleterious mutation: 22 (5.8%) in Lynch syndrome genes (three MLH1, five MSH2, two EPCAM-MSH2, six MSH6, and six PMS2) and 13 (3.4%) in 10 non-Lynch syndrome genes (four CHEK2, one each in APC, ATM, BARD1, BRCA1, BRCA2, BRIP1, NBN, PTEN, and RAD51C). Of 21 patients with deleterious mutations in Lynch syndrome genes with tumor testing, 2 (9.5%) had tumor testing results suggestive of sporadic cancer. Of 12 patients with deleterious mutations in MSH6 and PMS2, 10 were diagnosed at age >50 and 8 did not have a family history of Lynch syndrome-associated cancers. Patients with deleterious mutations in non-Lynch syndrome genes were more likely to have serous tumor histology (23.1 vs 6.4%, P=0.02). The three patients with non-Lynch syndrome deleterious mutations and serous histology had mutations in BRCA2, BRIP1, and RAD51C. Current clinical criteria fail to identify a portion of actionable mutations in Lynch syndrome and other hereditary cancer syndromes. Performance characteristics of tumor testing are sufficiently robust to implement universal tumor testing to identify patients with Lynch syndrome. Germline multi-gene panel testing is feasible and informative, leading to the identification of additional actionable mutations.

Defective DNA Mismatch Repair Influences Expression of Endometrial Carcinoma Biomarkers

Endometrial endometrioid carcinomas are related to estrogen excess and express estrogen and progesterone receptors. However, hormone receptor expression can be variable from tumor to tumor, and this variability is not always explained by differences in tumor grade. Variable expression of other biomarkers that may be used in the diagnostic work-up of endometrial cancer has also been noted. We hypothesized that mismatch repair (MMR) defects may contribute to this variability. A total of 411 unselected endometrial carcinomas were evaluated for immunohistochemical expression of DNA MMR proteins and MLH1 methylation. Loss of immunohistochemical expression of MLH1, MSH2, MSH6, or PMS2 was defined as MMR deficient; positive expression was defined as MMR intact. A case-control cohort of 80 Grade 2 endometrioid carcinomas was selected from this set (40 MMR deficient, 40 MMR intact). Cases were matched for histotype, grade, and age. Estrogen receptor, progesterone receptor, CK7(+), CK20, and Pax-8 immunohistochemistry was evaluated. The median percentage of CK7 tumor cells was significantly lower in the MMR deficient group compared with the MMR intact group. The mean percentage of tumor cells exhibiting estrogen receptor expression was similar in both the MMR-deficient and MMR intact groups. However, there was greater variability in the MMR-deficient group. Our study shows that MMR defects influence the expression of clinically important biomarkers for endometrioid-type endometrial carcinoma as decreased cytokeratin 7 expression is more commonly associated with MMR deficiency.

Utility of MLH1 methylation analysis in the clinical evaluation of Lynch Syndrome in women with endometrial cancer

Clinical screening criteria, such as young age of endometrial cancer diagnosis and family history of signature cancers, have traditionally been used to identify women with Lynch Syndrome, which is caused by mutation of a DNA mismatch repair gene. Immunohistochemistry and microsatellite instability analysis have evolved as important screening tools to evaluate endometrial cancer patients for Lynch Syndrome. A complicating factor is that 15-20% of sporadic endometrial cancers have immunohistochemical loss of the DNA mismatch repair protein MLH1 and high levels of microsatellite instability due to methylation of MLH1. The PCR-based MLH1 methylation assay potentially resolves this issue, yet many clinical laboratories do not perform this assay. The objective of this study was to determine if clinical and pathologic features help to distinguish sporadic endometrial carcinomas with MLH1 loss secondary to MLH1 methylation from Lynch Syndrome-associated endometrial carcinomas with MLH1 loss and absence of MLH1 methylation. Of 337 endometrial carcinomas examined, 54 had immunohistochemical loss of MLH1. 40/54 had MLH1 methylation and were designated as sporadic, while 14/54 lacked MLH1 methylation and were designated as Lynch Syndrome. Diabetes and deep myometrial invasion were associated with Lynch Syndrome; no other clinical or pathological variable distinguished the 2 groups. Combining Society of Gynecologic Oncology screening criteria with these 2 features accurately captured all Lynch Syndrome cases, but with low specificity. In summary, no single clinical/pathologic feature or screening criteria tool accurately identified all Lynch Syndrome-associated endometrial carcinomas, highlighting the importance of the MLH1 methylation assay in the clinical evaluation of these patients.

Consequences of universal MSI/IHC in screening ENDOMETRIAL cancer patients for Lynch syndrome

OBJECTIVE

Determine factors impacting the uptake of genetic counseling and results of genetic testing following universal tumor testing for Lynch syndrome in patients with endometrial cancer.

METHODS

The study population consisted of two unselected cohorts of endometrial cancer patients, 408 identified retrospectively and 206 identified prospectively. Immunohistochemistry for mismatch repair protein expression and/or microsatellite instability analysis was performed on these tumors. MLH1 methylation analysis was performed on tumors with loss of MLH1 protein. Tumor studies were considered suggestive of Lynch Syndrome if they showed immunohistochemical loss of MSH2, MSH6 or PMS2, loss of MLH1 without MLH1 promoter methylation, and/or microsatellite instability. Participants with suggestive tumor studies were contacted and offered genetic counseling and testing.

RESULTS

In the retrospective cohort, 11% had tumor studies suggestive of Lynch syndrome, and 42% was seen for genetic counseling. A germline mutation was detected in 40%, and one had a variant of uncertain significance. In the prospective cohort, 8.7% of patients had tumor testing suggestive of Lynch syndrome; 72% were seen for genetic counseling. Germline mutations were found in 40%, and one had a variant of uncertain significance. Common challenges included timing of re-contact, age, perceived lack of relevance, inability to travel and limited insurance coverage.

CONCLUSIONS

There are several barriers to genetic counseling and testing follow-up after universal tumor testing, and uninformative genetic test results present a management challenge. It is important to consider these limitations when implementing an approach to screening endometrial cancer patients for Lynch syndrome.

Evaluation of clinical criteria for the identification of Lynch syndrome among unselected patients with endometrial cancer

Clinical criteria, primarily young age of cancer onset and family history of signature cancers, have been developed to identify individuals at elevated risk for Lynch syndrome with the goals of early identification and cancer prevention. In 2007, the Society of Gynecologic Oncology (SGO)-codified criteria for women presenting with gynecologic cancers. These criteria have not been validated in a population-based setting. For 412 unselected endometrial cancers, immunohistochemical expression of DNA mismatch repair proteins and MLH1 methylation were assessed to classify tumors as sporadic or probable Lynch syndrome (PLS). In this cohort, 10.5% of patients were designated as PLS based on tumor testing. The sensitivity and specificity of the SGO criteria to identify these same cases were 32.6% [95% confidence interval (CI), 19.2-48.5] and 77% (95% CI, 72.7-81.8), respectively. With the exception of tumor location in the lower uterine segment, multivariate analysis of clinical features, family history, and pathologic variables failed to identify significant differences between the sporadic and PLS groups. A simplified cost-effectiveness analysis demonstrated that the SGO clinical criteria and universal tissue testing strategies had comparable costs per patient with PLS identified. In conclusion, the SGO criteria successfully identify PLS cases among women with endometrial cancer who are young or have significant family history of signature tumors. However, a larger proportion of patients with PLS who are older and have less significant family history are not detected by this screening strategy. Universal tissue testing may be necessary to capture more individuals at risk for having Lynch syndrome.

Abstract 4855: Poor performance of published clinical screening criteria for the population-based identification of endometrial cancer patients with Lynch Syndrome

Objective: Clinically based risk assessment tools, targeting those with young age of cancer onset and family history of specific cancers, have been used to identify individuals with Lynch Syndrome (LS). Women with LS are equally likely to develop endometrial carcinoma (EC) as they are colorectal carcinoma (CRC). To identify women presenting with EC at risk for LS, the Society of Gynecologic Oncology (SGO) published recommendations in 2007 regarding which patients would benefit from further genetic evaluation for LS. These criteria are comparable to the Revised Bethesda Guidelines. The primary objective of this study was to evaluate SGO criteria's ability to predict women at risk for LS in the EC population and to ascertain if alternative criteria exist that can better identify high-risk patients.

Methods: 408 sequential EC cases were evaluated for immunohistochemical expression of four DNA mismatch repair (MMR) proteins. Tumors with loss of MSH2, MSH6 or PMS2 were designated as probable Lynch Syndrome (PLS). Tumors with loss of MLH1 and absence of MLH1 promoter methylation were also designated PLS. Clinical and pathologic data were collected from the electronic medical record.

Results: Of the 408 EC cases, 43 (10.5%) of the patients were defined as probable Lynch Syndrome (PLS). 97/408 (23.7%) of EC cases met SGO criteria, but only 14 of these 97 cases (14.4%) were PLS. Of the 43 PLS cases, 29/43 (67.4%) did not meet SGO criteria. Comparison of clinical and pathologic characteristics, including age of cancer diagnosis and family history of EC and/or CRC, revealed no statistically significant differences between sporadic and PLS tumors with the exception of tumors arising from the lower uterine segment. Tumors with this sight of origin are more likely to be associated with PLS. The sensitivity and specificity of SGO criteria was 32.6% and 77.2%, respectively.

Conclusions: Existing clinical guidelines for detecting endometrial carcinoma patients at elevated risk for having Lynch Syndrome perform poorly in an unselected patient population. With the exception of tumors arising from the lower uterine segment, there are no statistically significant clinical or pathological differences between sporadic tumors and PLS tumors. Lower uterine segment EC occurs in only 3% of all EC cases and is not a useful screening tool. SGO clinical criteria correctly identified 32.6% of women with PLS, which results in missed CRC screening opportunities for 67% of women with increased risk profiles. These results suggest that the SGO guidelines are inadequate for identifying LS. Given the lack of effective clinical or pathological screening tools, MMR IHC and MLH1 methylation testing of all endometrial cancer patients may be the best way to identify women at risk for having Lynch Syndrome.

Citation Format: Amanda S. Bruegl, Bojana Djordjevic, Bryan M. Fellman, Diana L. Urbauer, Raja Luthra, Karen H. Lu. Poor performance of published clinical screening criteria for the population-based identification of endometrial cancer patients with Lynch Syndrome. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 4855. doi:10.1158/1538-7445.AM2013-4855

An alternative approach to identify women at risk for colorectal cancer

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Background: Hereditary colorectal cancer (CRC) is preventable; however, identification of individuals at sufficiently high risk to warrant heightened surveillance is difficult. Lynch Syndrome (LS) is an inherited cancer syndrome due to germline mutation in a DNA mismatch repair gene. For women with LS, the lifetime risk of endometrial cancer (EC) is 64% and CRC is 54%. Fifty percent of women with LS will present with EC or ovarian cancer prior to CRC. Therefore, women with LS associated EC represent an ideal group for CRC prevention. The optimal method to identify women with LS associated EC is not known. The purpose of this study was to determine the utility of Amsterdam II and Society of Gynecologic Oncology (SGO) Criteria (modified Bethesda criteria that use EC as the sentinel cancer) in identifying women with LS associated EC. Our ultimate goal is to identify women at increased risk of CRC. Methods: Immunohistochemistry (IHC) for DNA mismatch repair proteins and MLH1 methylation analyses were used to identify LS associated EC among 388 women. EC was designated as LS if there was loss of mismatch repair protein expression. Absence of MLH1 methylation was required to confirm LS in tumors with MLH1 protein loss. Results: Fifty-nine (15.2%) of the EC patients tested had LS. These patients are summarized in the table. Conclusions: Clinical criteria to detect LS identify 17/59 (29%) - 44/59 (74%) of women who present with EC first. EC with MSH2 loss is most likely to occur in younger women and women with positive family history of EC and CRC, features classically associated with LS. In general, the MSH6 mutation is associated with older age at diagnosis and fewer familial CRCs, however, we found a large number of MLH1 (50%) and PMS2 (86%) cases diagnosed at greater than 50 years with no family history of CRC. Our data suggest that classic clinical screening criteria are inadequate to detect patients with LS who present with EC, potentially missing up to 25% of these patients. [Table: see text]

Phenotypic screening of Escherichia coli K-12 Tn5 insertion libraries, using whole-genome oligonucleotide microarrays

Complete genome sequences in combination with global screening methods allow parallel analysis of multiple mutant loci to determine the requirement for specific genes in different environments. In this paper we describe a high-definition microarray approach for investigating the growth effects of Tn5 insertions in Escherichia coli K-12. Libraries of insertion mutants generated by a unique Tn5 mutagenesis system were grown competitively in defined media. Biotin-labeled runoff RNA transcripts were generated in vitro from transposon insertions in each population of mutants. These transcripts were then hybridized to custom-designed oligonucleotide microarrays to detect the presence of each mutant in the population. By using this approach, the signal associated with 25 auxotrophic insertions in a 50-mutant pool was not detectable following nine generations of growth in glucose M9 minimal medium. It was found that individual insertion sites could be mapped to within 50 bp of their genomic locations, and 340 dispensable regions in the E. coli chromosome were identified. Tn5 insertions were detected in 15 genes for which no previous insertions have been reported. Other applications of this method are discussed.