How preventable is invasive cervical cancer? A community study of preventable factors

Spontaneous Screening for Cervical Cancer and Diagnostic Histories of Incident Cases

Cytologic and colposcopic histories of cases of invasive cervical cancer and cervical intraepithelial neoplasia grade III (CIN III) registered in Ravenna (northern Italy) between 1986 and 1990 were evaluated. During the 5 years prior to diagnosis, 10/49 invasive cancer patients and 25/61 CIN III patients had had at least one pap smear reported as negative. At the time of the most recent false-negative report, 9/10 and 17/25 of these cases had been recommended for a repeat smear within 2 to 6 months. Of the 9 patients with invasive cancer, 5 had also undergone an inconclusive colposcopy (with biopsy unperformed). Among invasive cancer patients aged under 50, half of incident cases (7/14) and most of those with some cytologic experience (7/8) had had a false-negative report; each of these patients (7/7) had been recommended for an early repeat smear. For invasive cancer patients as well as for CIN III patients, the suggested intervals for the early repeat were largely exceeded. Median delay in diagnosis was about 2 years. Although the frequency of negative reports recommending repeat smears within a few months was estimated to be some 10 % of total screening patients, current concepts in cervical cytology suggest that cancer cases with such false-negative reports should be regarded as follow-up failures rather than laboratory errors. In fact, they passed quite unnoticed. In unplanned (spontaneous) cervical screening practice, sensitivity needs to be maximized, but even the occurrence of false-negative cases is not monitored. The present study points out what may result from such a contradiction.

Multimodal hyperspectral imaging for the noninvasive diagnosis of cervical neoplasia

OBJECTIVE

To determine the ability of Multimodal Hyperspectral Imaging (MHI) to noninvasively detect, localize and diagnose cervical neoplasia.

MATERIALS AND METHODS

The cervical epithelium was interrogated by MHI using tissue fluorescence and reflectance measurements after the probe was placed on the ectocervix. A Papanicolaou smear was taken, and a colposcopic examination was performed and cervical histologic specimens were collected, when indicated. MHI and Pap smear sensitivity and specificity data were compared with colposcopic and histologic results.

RESULTS

Nineteen patients had CIN2 or higher, 30 had CIN1, 34 had benign cellular changes or metaplasia, and 28 were normal by both Pap smear and colposcopic examination. At equal specificity (70%) for both tests, the sensitivity of MHI was 97%, compared to 72% for the Pap smear.

CONCLUSION

MHI detected cervical cancer precursors at a rate greater than that obtained by a simultaneously collected Pap smear.

Screening test results associated with cancer diagnoses in 287 women with cervical squamous cell carcinoma

CONTEXT

The limitations of newer cervical screening tests are still being studied.

OBJECTIVE

To investigate those limitations, we conducted a retrospective review of 287 cases of cervical squamous cell carcinoma (SCC).

DESIGN

A search through 5 years of records identified 287 women with cervical SCC diagnoses. Clinical history, histopathology, and liquid-based cytology (ThinPrep) and Hybrid Capture 2 (HC2) high-risk human papillomavirus (HPV) results were documented. Polymerase chain reaction HPV tests were performed on SCC tissues with prior negative HC2 results.

RESULTS

Of 287 women, 156 (54.4%) had abnormal cytology results, and 75 (26.1%) had abnormal clinical findings triggering tissue diagnoses of SCC. Among 156 patients with abnormal Papanicolaou (Pap) test results, more-seriously abnormal Pap test results were reported in 142 women (91.1%). Among 31 women with Pap and HC2 HPV cotesting within 1 year of SCC diagnoses, 28 (90%) were Pap⁺/HPV⁺, 2 (15.5%) were Pap⁺/HPV⁻, and 1 (3%) was Pap⁻/HPV⁻. Two of 3 women with negative HC2 results before SCC diagnosis had abnormal Pap results; 1 had negative Pap reports with questionable lesional cells mimicking atrophy. In all 3 cases of SCC with negative HC2 results, HPV-18 was detected; in 2 cases (66%), HPV-16 was also detected.

CONCLUSIONS

Although abnormal cytology preceded most SCC diagnoses, about one-third of patients were referred for diagnostic testing because of clinical suspicion alone. Among 31 SCC cases with liquid-based cytology and high-risk HPV cotest results less than 1 year before SCC diagnoses, 2 patients (6.5%) had Pap⁺/HPV⁻ results, and 1 patient (3.2%) had Pap⁻/HPV⁻ results. Polymerase chain reaction detected high-risk HPV DNA in tumor tissues of 3 SCC cases with recent HC2⁻ results.

Significance and possible causes of false-negative results of reflex human papillomavirus infection testing

BACKGROUND

The objective of this study was to assess the rate and possible reasons for false-negative (FN) reflex human papillomavirus (HPV)-DNA tests.

METHODS

The authors reviewed all ThinPrep cervical specimens that were submitted for reflex HPV-DNA testing using the Digene Hybrid Capture II (HC2) method from January 2002 to January 2004. Follow-up biopsies were reviewed. The results were considered HPV-FN if the HPV-DNA test was negative and the biopsy was positive for grade > or =2 cervical intraepithelial neoplasia (CIN2+), and the results were considered true positive (HPV-TP) if the HPV-DNA test was positive and the biopsy showed CIN2+. HPV-FN cases were compared with HPV-TP cases regarding the grade and extent of CIN, the number of abnormal cells on the original ThinPrep slide, and the presence of amplifiable, viral DNA on biopsy.

RESULTS

In total, 1520 (66%) of 2309 patients who had diagnoses of atypical squamous cells of undetermined significance (ASCUS) were negative for HPV DNA and 789 patients of 2309 patients (34%) were positive for HPV DNA. Three hundred sixteen women (40%) who had a positive HPV-DNA test underwent a biopsy. Of those, 36 biopsies (11%) showed CIN2+ (HPV-TP), and 154 biopsies (66%) showed CIN1. Cervical tissue was available for review from 82 women who had negative HPV-DNA tests; of these, 6 tissue samples (7%) showed CIN2+ (HPV-FN), and 13 tissue samples (16%) showed CIN1. Therefore, in the total ASCUS population that was triaged with reflex HPV testing, there were at least 42 women who were diagnosed with CIN2+, for an estimated CIN2+ FN fraction of 14% (6 of 42 women). HPV-FN lesions were smaller (but the difference was not statistically significant) and shed significantly fewer abnormal cells than HPV-TP cases. Polymerase chain reaction testing for viral DNA in the biopsy was detected in 3 of 6 women who had HPV-FN results; none of those positive results demonstrated a viral type that was not included in the Digene probes.

CONCLUSIONS

Although the rate of FN high-grade lesions was significantly higher than that reported in the ASCUS/Low-grade Squamous Intraepithelial Lesion Triage trial, most missed lesions were small and shed few abnormal cells. It was assumed that those lesions were either in early stages or in regressing stages, which made their clinical significance uncertain.

Family physicians' knowledge of risk factors for cervical cancer

BACKGROUND

A woman's risk for cervical cancer has been used by physicians to guide the initiation and frequency of a Pap smear. The aim of this study was to determine family physicians' knowledge of risk factors for cervical cancer and perceived importance of risk in screening women.

METHODS

The self-administered questionnaire was mailed to 5000 randomly selected active members of the American Academy of Family Physicians (AAFP).

RESULTS

Data from 2748 usable questionnaires indicated the mean number of risks considered for cervical cancer was 4.5. Physician's age and the number of reported risks were inversely correlated (p = 0.0001). Female physicians reported significantly more risk factors than male physicians (p = 0.05). The number of Pap smears performed per month was positively correlated with the number of risk factors reported (p = 0.001). Only 10% of the physicians indicated that they perform a Pap smear at the same interval regardless of the risk of the woman.

CONCLUSIONS

This sample of family physicians has a limited understanding of the risk factors for cervical cancer. This was true regardless of the age, gender, training, race, geographic location, or practice setting of the responding physician. Yet the usual practice of screening for cervical cancer reported by these physicians would suggest that knowledge and use of risk factors would be a critical aspect of screening for cervical cancer.

Prospective study of PAPNET: review of 25,656 Pap smears negative on manual screening and rapid rescreening

In this prospective study, 27,014 Pap smears were selected for PAPNET review on the request of the referring practitioner or patient. Smears that were negative on routine manual screening were submitted for rapid rescreening. Smears considered normal after these two manual screens (n = 25,656) were reviewed using the PAPNET testing system. Routine manual screening identified 1340 (4.96%) of the smears as abnormal, and a further 18 (0.07%) abnormalities were detected by rapid rescreening. PAPNET review identified an additional 102 (0.4%) abnormal smears, including 10 histologically confirmed high grade lesions. The use of PAPNET testing following routine manual screening and rapid rescreening in tandem, enables cytologists to detect additional diagnostically significant abnormalities and reduce the rate of false-negative smears.

Screening for cervical cancer--should the routine be challenged?

Despite the extensiveness of cervical cancer screening programs, certain major issues are still at stake: (a) substantial false negative rates are common, mostly due to impaired test quality, (b) the optimal length of interval between screenings is uncertain, being a function of available resources and the physicians' attitude, (c) the postmenopausal population, in which incidence is highest, is inadequately tapped. Efforts must be made to optimise the process through more stringent control measures, and a more comprehensive cover of the target population.

Efficacy of cervical cancer screening

The earlier optimistic predictions that invasive carcinoma of the uterine cervix could be totally eradicated by means of Pap screening have failed. Experiences from different countries give evidence, however, that a considerable reduction of incidence and mortality can be gained with this type of secondary prevention. Improved knowledge of the epidemiology of carcinoma of the uterine cervix and of its natural history could be anticipated to give a better basis for the planning of preventive measures. Maintenance of a high laboratory standard, a good technique for taking of smears, and improved communications between laboratories and the doctor or nurse taking the smear and the doctor or clinic performing the treatment and an adequate reaction to the report from the laboratory with adequate treatment of the precancerous stages is supposed to improve the effect of the screening programmes.

An evaluation of cervical smears consisting of spatula and Cytobrush samples

Analysis of 100 paired spatula and Cytobrush cervical smear samples taken and evaluated by one person showed that the combined smear was excellent for sampling the transformation zone and for detecting lesions. However, care in obtaining and evaluating smears are still vital if false-negative smears are to be eliminated. The greater use of the 2-sample smear is advocated.

The Pap smear revisited

Papanicolaou smear screening for cervical cancer has become an established practice in most developed countries. This is because the cervix is relatively accessible to investigation and treatment, and early stages in the morphogenesis of cervical cancer are both recognizable and easily treated. The Pap smear is a valid test. It is simple, relatively inexpensive, reliable, and free of risk. Although the test has far from perfect sensitivity, it has high specificity, and false-positive results are rare. In most reported series, the majority of false-negative results have been found to be attributable to collection errors rather than laboratory errors. Despite the importance of Pap smear screening, controlled prospective trials have not been undertaken to determine its efficiency in reducing cervical cancer incidence and mortality. However, countries with well-organized programmes, wide population coverage and correct follow-up appear to have had some impact on mortality from cervical cancer. Nevertheless, coverage of high-risk groups, particularly women over 40 years of age, remains the greatest problem. Recommendations on the frequency of testing vary considerably. Statistical models indicate triennial testing may deliver almost all of the effectiveness of annual testing at a substantially reduced cost, but the numerous reports of false-negative results argue strongly in favour of annual screening. It is possible that these problems may be solved in the future by increasing the sensitivity of the test and/or by the use of additional tests.

Evaluation of the pulse wash sampling technique for screening of uterine cervical carcinoma

The efficacy of a new sampling technique performed for early detection of cervical carcinoma is compared with Pap smears with the swab-and-wooden spatula technique in 312 women. In this new method, sampling of cytologic material is achieved by using a pulse wash instrument described in a previous article. Cells are rinsed and detached by liquid jets of 0.2 mm in diameter which are produced by a spray nozzle connected with a pressure hose to a high pressure pump. The liquid molecules pass through the spray nozzle at a speed of 20 m/s thus creating a successful rinsing effect on cervical epithelium due to high kinetic energy. Rinsed cells are mixed with the small amount of the flushing liquid. The suspension of cells and liquid accumulated in the speculum is then transported to a small container by a suction pump. The results of this work suggest that the pulse wash technique gives a more representative cell sample than the Pap smear sampling technique, thus offering a simple method to decrease false negative diagnoses in the detection of carcinoma of the uterine cervix. Samples by the new technique give an abundance of cells for slide preparation for cytodiagnostic techniques as well as for additional cytochemical, immunocytochemical and microbiologic diagnostic techniques.

Potential limits of physical examination and breast self-examination in detecting small cancers of the breast. An unselected population-based study of 1302 cases

Neither a change in the average or median size of breast cancers, nor in the extent of axillary lymph node involvement, was seen in a total, unselected population study before and after an intensive public and professional education project in San Diego County. Comparison of these data with those from the Breast Cancer Detection Demonstration Project lends strong support for the greatly increased use of mammography if it is to be possible to detect the smaller, more curable cancers of the breast.

A retrospective review of cervical cytology in women developing invasive squamous cell carcinoma

The records of 93 women who presented with invasive squamous cell carcinoma were searched for evidence of cervical cytology during the years preceding this diagnosis; a search was also made through the files of local laboratories and contact was made with general practitioners and relevant hospital departments. Only 26 (28%) of these 93 women had had a cervical smear at any time before the diagnosis of invasive cancer, and only 11 (12%) had had regular cytological surveillance. Fifteen (60%) had had a smear taken and reported as negative within the previous 5 years, six (6%) within the previous year. Eleven of these 15 slides were obtained for review: three were regarded as positive and three more were re-classed as too scanty for conclusive assessment. In nine of the 67 women who had never had a smear, a gynaecological or obstetric examination was known to have been performed or indicated within the previous 5 years, thereby representing a missed opportunity for screening. In three patients cytological abnormalities had been reported within the previous 3 years but no action had been taken.

High-risk factors in gynecologic cancer

Cervical cancer retains its character as a venereal disease associated with infections and multiple sexual partners, but poverty also is important. Precise incidence figures for cervical and endometrial cancer are almost nonexistent because in areas with precise case counts there is rarely accurate knowledge of hysterectomy prevalence. For endometrial cancer little recent attention has been paid to any risk factor except exogenous estrogen. It is now suggested that a low pregnancy rate is a cause, not a consequence, of ovarian pathology leading to cancer. Some progress has been made in separating the epidemiologies of various kinds of ovarian and uterine cancer. A few clues are available regarding the epidemiology of fallopian tube cancers and vaginal cancers other than those produced by maternal stilbestrol. Vulvar cancer becomes common only after the age of 75 and so has been neglected epidemiologically.

Effects of observer variation in population screening for cervical carcinoma

A stratified random sample of 100 cervical smears was taken from routine population screening material and graded by three cytological laboratories. The sensitivity of the smear test for detecting cervical malignancies varied from 72 to 88%-a difference of 16%; for all serve epithelial abnormalities the sensitivity varied from 52 to 71% (a difference of 19%). The histological material pertaining to these smears was re-examined ;blindly' and then sent for diagnosis to a second pathologist. Using each set of histodiagnoses as reference, the sensitivity of the test for detecting cervical malignancies varied from 77 to 85%-a difference of 8%; the sensitivity for all epithelial abnormalities varied from 62 to 76% (a difference of 14%). The significance of these observer variations on the efficacy of screening for cervical carcinoma is discussed.