Control of cancer of the uterine cervix by cytologic screening

Impact of Widespread Cervical Cancer Screening: Number of Cancers Prevented and Changes in Race-specific Incidence

OBJECTIVES

With recent approval of standalone HPV testing and increasing uptake of HPV vaccination, some have postulated that we are moving toward a "post-Pap" era of cervical cancer prevention. However, the total number cases that have been prevented by Pap smear screening as well as its impact on racial disparities are unknown.

METHODS

We estimated national cervical cancer incidence from 1976 to 2009 using the Surveillance, Epidemiology, and End Result database. Screening data were obtained from the literature and National Cancer Institute Progress Reports. We examined early, late, and race-specific trends in cancer incidence, and calculated the estimated number of cancers prevented over the past 3 decades.

RESULTS

From 1976 to 2009, there was a significant decrease in the incidence of early-stage cervical cancer, from 9.8 to 4.9 cases per 100,000 women (P<0.001). Late-stage disease incidence also decreased, from 5.3 to 3.7 cases per 100,000 women (P<0.001). The incidence among black women decreased from 26.9 to 9.7 cases per 100,000 women (P<0.001), a greater decline compared with that of white women and women of other races. After adjusting for "prescreening era" rates of cervical cancer, we estimate that Pap smears were associated with a reduction of between 105,000 and 492,000 cases of cervical cancer over the past 3 decades in the United States.

CONCLUSIONS

A large number of early-stage and late-stage cervical cancers were prevented and racial disparity in cancer rates were reduced during an era of widespread Pap smear screening.

Direct-to-vial comparison of a new liquid-based cytology system, liqui-PREP™ versus the conventional Pap smear

The objective of the study was to assess the clinical utility of a liquid-based cytology system on cervicovaginal screening in a clinical commercial laboratory. Twenty-six thousand, one hundred and seventy eight cervicovaginal specimens were prepared by the Liqui-PREP (LGM International Inc., Ft. Lauderdale, FL) with a direct-to-vial comparison to 218,548 cases of the conventional direct smear from August 2005 through December 2005. Biopsy data was obtained to confirm the sensitivity for each method. Liqui-PREP showed a marked increase in HSIL+ detection compared to the conventional smear ( P = 0.001). The rate of LSIL and AGC detection was higher with Liqui-PREP ( P equals; 0.001 for both). The percentage of ASCUS specimens was higher than with conventional smear due to cleaner slides and easier detection of suspicious cells. The WNL rate was lower for Liqui- PREP ( P = 0.001) consistent with increased HSIL+ and ASCUS. The unsatisfactory rate was lower for Liqui-PREP ( P = 0.017). The histological predictive value of Liqui-PREP was slightly higher than the conventional smear (94.1% versus 89.9%). The Liqui-PREP system similar to other reported LBC technologies shows an increased detection of squamous intraepithelial lesions, and gives higher-quality slides for interpretation than the conventional smear. Histological results confirm that this increase in cytological findings are clinically significant. LGM's new LBC technology is a more sensitive screening tool when compared with the conventional smear.

Cost-effectiveness analyses in gynecologic oncology: methodological quality and trends

OBJECTIVES

To evaluate methodological quality and trends of cost-effectiveness analyses (CEA) published in gynecologic oncology.

METHODS

A medical literature search of articles from 1966 through 2002 was performed to identify original, English-language articles that included economic analyses in gynecologic oncology. We included articles that were cost-effectiveness or cost-benefit analyses or performed these analyses as part of their study. Ten methodological principles that should be incorporated in CEAs were assessed for each study. Each article was given a score of 0, 1, or 2 for each of the 10 methodological principles (max score = 20). Data were analyzed using the Student t test, ANOVA, and linear regression.

RESULTS

We screened 693 articles to identify 68 that met our inclusion criteria. The articles focused on cervical cancer (n = 53; 78%), ovarian cancer (n = 11; 16%), uterine cancer (n = 2; 3%), and general perioperative care (n = 2; 3%). The mean (+/-SD) methodological principle score was 16.1 (+/-4.1) and we observed a significant improvement in the total score over time (P = 0.01). Primary CEA's (CEA identified as the objective of the study) were of higher quality than secondary CEA's (primary objective of the study was not CEA but CEA was included in the study; total scores 18.2 vs. 11.6, respectively; P<0.0001). Studies with at least one investigator in public health or healthcare economies also had higher quality (mean total score 17.7 vs. 15.2; P=0.006). The most common limitations of published CEAs were in methodology or presentation of incremental analyses, sensitivity analyses, and discounting.

CONCLUSIONS

Cost-effectiveness analyses in gynecologic oncology showed significant improvement in quality over the last two decades. Despite this progress, methodological improvement is still needed in the areas of incremental comparisons and sensitivity analysis. Understanding the methodology of cost-effectiveness analysis is critical for researchers, editors, and readers to accurately interpret results of the growing body of CEA articles.

Treatment and survival in 631 patients with invasive carcinoma of the cervix

From 1951 to 1972, a total of 631 cases of invasive carcinoma of the cervix were diagnosed in Frederiksberg, Copenhagen, Denmark. Treatment was either by surgery or radiotherapy, a combination of both being rarely used. The crude five-year survival rates were 99 per cent in stage Ia, 79 per cent in stage Ib, 67 per cent in stage IIa, 45 per cent in stage IIb, 23 per cent in stage III, 5 per cent in stage IV and 63 per cent for all stages. The relative survival rates were respectively 100 per cent, 81 per cent, 73 per cent, 48 per cent, 26 per cent, 5 per cent and 66 per cent. Radical hysterectomy were found more effective than radiotherapy in stage Ib carcinoma of the cervix. This difference was not explained by age but other factors possibly playing a role are considered. The combination of surgery and radiotherapy is discussed and only seems indicated for patients with stage Ib carcinoma and lymph node metastases.