A Comparison of Endometrial Cancer Outcomes in Ontario

Should Preoperative Pathology Be Used to Select Patients for Surgical Staging in Endometrial Cancer?

Introduction:

The decision to offer surgical staging in endometrial cancer is often based on preoperative histology and grade from endometrial biopsy or dilatation and curettage. The primary objective of this study was to evaluate the concordance between preoperative and final pathology from a population-based study of endometrial cancer to address whether preoperative biopsy is a reliable determinant in selecting patients for surgical staging.

Methods:

Retrospective cohort study in Ontario, Canada, from 1996 to 2000. The study included all women with a preoperative diagnosis of endometrioid adenocarcinoma on endometrial biopsy or dilatation and curettage, followed by definitive surgery. All other histological types were excluded. Surgical staging rates were compared according to preoperative pathology. Primary outcome measure was the concordance between preoperative and final pathology, expressed as a Spearman correlation coefficient (ρ). A multivariable logistic regression estimated the effects of demographic variables and grade on our outcome measure.

Results:

There were 1804 evaluable cases in this study. For preoperative grades 1, 2, and 3 endometrioid adenocarcinoma, surgical staging rates were 9.1%, 13.7%, and 25.6%, respectively. Concordance rates with final pathology were 73%, 52%, and 53%, respectively. There was only moderate concordance between preoperative and final pathology (ρ = 0.52). There was no significant difference in concordance rates according to age, year, or hospital volume, but lower concordance rates among teaching hospitals.

Conclusion:

Preoperative biopsy has only a moderate ability to predict final pathology in endometrial cancer, and therefore, additional factors should be considered in selecting patients for a surgical staging procedure.

Are there regional differences in gynecologic cancer outcomes in the context of a single-payer, publicly-funded health care system? A population-based study

BACKGROUND

Canada has a single-payer, publicly-funded health care system that provides comprehensive health care, and therefore significant disparities in health outcomes are not expected in our population. The objective of this study was to determine if differences exist in endometrial cancer outcomes across regions in Ontario.

METHODS

This was a population-based study of all endometrial (uterine) cancer cases diagnosed from 1996 to 2000 in Ontario and linked to various administrative databases. Univariate analyses examined trends in demographics (age, income, co-morbidities), treatment (surgical staging and adjuvant pelvic radiotherapy), and pathology (grade, histology, stage) across 14 geographic regions defined by local health integration networks (LHINs) in Ontario. Primary outcome was 5-year overall survival among LHINs, which were compared in a multilevel Cox regression model to account for clustering of patient data at the hospital level.

RESULTS

There were 3,875 evaluable cases with complete information on demographics, treatment, pathology, and outcomes. There was significant variation in patient demographics, treatment, and pathology across the 14 LHINs. Low income level and surgery at a low-volume, community hospital without gynecologic oncologists were not associated with a higher risk of death. There was a trend towards clustering of patients within hospitals. After adjustment for covariates, there was no significant difference in survival across LHINs.

CONCLUSIONS

In the context of a single-payer, publicly-funded health care system, we did not find significant regional differences in endometrial cancer outcomes.

Cost-effectiveness analysis of treatment strategies for Stage I and II endometrial cancer

OBJECTIVE

Practice patterns vary across Canada with respect to indications for surgical staging and adjuvant radiotherapy in early endometrial cancer. We evaluated the cost-effectiveness of two common strategies for managing early endometrial cancer as part of an Ontario population-based study.

METHODS

A decision-analytic model (DATA 4.5) was developed for Stage I and II endometrioid-type cancer using empiric data from Ontario. On the basis of preoperative biopsy grade, one of two surgical procedures was selected: (1) hysterectomy and bilateral salpingo-oophorectomy (HBSO) or (2) surgical staging (HBSO and pelvic +/- para-aortic lymphadenectomy). Adjuvant radiotherapy (RT) was administered according to final grade and stage. After HBSO, pelvic RT was indicated for Grades 1 and 2 if Stage IC, IIA with > 50% myometrial invasion (MI), or IIB, and for Grade 3 if Stage IB, IC, IIA, or IIB. After staging, pelvic RT was indicated for Grades 1 and 2 if Stage IIB, and for Grade 3 if Stage IC, IIA with > 50% MI, or IIB. Main outcome measures were quality-adjusted life-years (QALY) and incremental cost-effectiveness ratios (ICER). Sensitivity analyses were used to evaluate uncertainty around various parameters.

RESULTS

The most cost-effective (dominant) strategies were determined for each preoperative grade. For Grade 1, HBSO strongly dominated surgical staging. For Grade 2, neither strategy was dominant; surgical staging had an ICER of $5216 per QALY. For Grade 3, surgical staging strongly dominated HBSO. These results were stable over a wide range of estimates for costs and utilities (i.e., patient preferences for a particular health state).

CONCLUSION

The most cost-effective treatment strategies for early endometrial cancer in Ontario differ according to preoperative grade.

The impact of age on long-term outcome in patients with endometrial cancer treated with postoperative radiation

PURPOSE

Endometrial cancer is the most commonly diagnosed gynecologic malignancy in the United States. Age has been associated with worse outcome in univariate analysis. However, the patterns of failure and associated risk factors in older patients remain unclear. We reviewed our institution's experience to assess the effect of age in a population of endometrial cancer patients treated with surgery and adjuvant radiation therapy.

METHODS

From 1992-2002, 243 endometrial cancer patients underwent a total abdominal hysterectomy and adjuvant radiation. Forty-nine patients with stage I-II (occult) endometrial adenocarcinoma (no clear cell or serous papillary) were treated postoperatively with vaginal intracavitary high-dose rate (HDR) brachytherapy alone using Iridium-192 (median dose 30 Gy) to a median length of 4 cm. Forty-eight patients with stage I-III endometrial adenocarcinoma (no clear cell or papillary serous) were treated with postoperative pelvic RT (median dose 45 Gy) and intracavitary HDR brachytherapy (median dose 20 Gy). One hundred forty-six patients underwent postoperative whole abdomino-pelvic irradiation (WAPI) secondary to unfavorable histology (clear cell or serous papillary) or two of the following: deep myometrial invasion, grade 3, or FIGO stage III. Age was analyzed as a continuous and a categorical variable. The age of 63 year split the age group using various statistical analyses.

RESULTS

Median follow-up of all patients was 4.2 years. Patients grouped by age of < or =63 years or older had similar FIGO stage (P = 0.5), grade (P = 0.09), treatment modality (P = 0.7), and lymphovascular space invasion (LVSI) (P = 0.6). Twenty-five percent (60/243) of patients developed recurrence. Of these failures, 15% (15/102) were age < or =63 years and 32% (45/141) were age >63 years at diagnosis (P = 0.02). For all patients, the 5-year event-free survival (EFS), cause specific survival (CSS), and overall survival (OS) were 64%, 82%, and 72%, respectively. Five-year EFS for patients age < or =63 years and >63 years was 76% vs. 55% (P < 0.001). Five-year OS for age < or =63 years and >63 years was 85% vs. 63% (P < 0.001). Five-year CSS for age < or =63 years and >63 years was 91% vs. 75% (P = 0.003). Various factors were analyzed to determine an association with age. Older patients with stage III-IVA had significantly more failures than patients less than age 63 (P = 0.002). Older patients (>63 years) were found to have serous papillary histology (28%) more often than younger patients (15%) (P = 0.02). Greater depth of invasion was associated with older age (P = 0.01). On univariate analysis, older age (P = 0.003), LVSI (P = 0.002), FIGO stage (P < 0.001), grade (P < 0.001), and depth of invasion (P = 0.03) predicted for failure. On Cox multivariate analysis, older age (P = 0.006, HR 2.83), higher FIGO stage (P = 0.001, HR 1.96), and higher grade (P = 0.002, HR 2.66) were significant prognostic factors for recurrence. No difference was seen between the two age groups from date of surgery and start of radiation. The duration of therapy was not different between the two groups.

CONCLUSIONS

Older endometrial cancer (age >63 years) patients have a significantly decreased overall survival, cause-specific survival, and greater risk of recurrence following postoperative RT independent of other prognostic factors and/or treatment technique. The impact of treatment-related variables did not alter the age-related outcome.