Advance Cytology: a Tool for Patient Care

Title: Advance Cytology: A tool for patient care

Author(s): Yogesh Murti, Vijay Sharma, Sameer Rastogi and Deepa Pathak

Address: Rajiv Academy for Pharmacy,

N.H. # 2, Delhi-Mathura Bye-pass, P.O. Chhatikara, Mathura- 281001

India

Mobile: 09412627553

E-mail: ymurti@rediffmail.com

Introduction

The word cytology is derived from the Greek words kytos meaning hollow vessel and logos meaning discourse, so literally cytology is the study of hollow vessels or the study of cells. Since Robert Hooke first established that organisms are made up of individual cells. The cells that are examined in cytological samples usually originate from epithelial, or epithelial like tissues, and are most simply obtained as the epithelium exfoliates. These cells may be naturally exfoliated as in sputa or urine, or mechanically obtained by brushing or scraping, or by the use of fine needle aspiration (FNA). Cytological specimens are usually divided into gynecological and non-gynecological samples. The former are from well women within cervical screening programmes, the latter generally being diagnostic samples from patients with suspected disease, providing a cytological diagnosis.

Automation in cytology

Despite the overwhelming interest in the development of several computer-based technologies in the last several years, the role of automation in cytology has remained controversial. The potential of these technologies in the reduction of false negative results in pap smears is well recognized. However, there is still remarkable confusion as how to incorporate automation in the routine practice of cytology. This prompted the New Technology Task Force of the George Papanicolaou Society of Cytopathology to design a survey to seek the opinion of those engaged in cervicovaginal cytology screening regarding the value of automation in cytology. In 1996, a ten-question survey was sent to 1800 cytopathology laboratories throughout the nation. The response rate was 23% (416/1800). The responders represented laboratories varying from those with less than 5,000 pap smears to those with over 100,000 cases per year. The majority of the responders did not believe that automation is essential for cervicovaginal cytology. This was evidenced by the fact that only 12% of the laboratories were engaged in automated cytology and predominantly used it for quality control measures. The inability of small laboratories to absorb the extra expense involved in the integration of automated cytology in their practice, particularly in the current era of managed care was a major concern. There was also concern about the potential for compromise of patient care by the drive for corporate profits and the dissemination of wrong information to the public and physicians. Suggestions most frequently proposed included appropriate patient and physician education about the merits and pitfalls of the pap smear, and also endorsing an affordable universal fee for pap smears Partnership with larger cytology laboratories, creation of cytology consortiums with shared resources to provide regionalized automated rescreening services were also strongly suggested. This survey clearly indicates the need for further evaluation of automation in cytopathology and a focused attention to various issues surrounding cervicovaginal cytology screening1.

Advancement in cytology

Recent advances in bladder cancer

Transitional cell carcinoma of the bladder is a significant cause of morbidity and mortality worldwide. Many tumor markers have been evaluated for detecting and monitoring of the disease in serum, bladder washes, and urinary specimens. However, none of these biomarkers reported to date has shown sufficient sensitivity and specificity for the detection of the whole spectrum of bladder cancer diseases in routine clinical practice. The advent of high-throughput microarrays is accelerating the identification process of the molecular events characteristic of bladder tumors’ phenotype and subsequent clinical behavior. The information provided by these analyses is resulting not only in the identification of novel therapeutic targets for bladder cancer, but also in the development of diagnostic tools2.

Recent advances in cervical cytology

The field of cytology automation, through long investigation, trial and error, and finally, commercial success and failure, has arrived at the first levels of the “grail” of improvements in accuracy and productivity in cervical cytology screening. Will commercial ventures or academic institutions continue to support investigations to further the applications that have been developed to date? This remains to be seen and is directly dependent on parallel processes that are detailed elsewhere in this issue. Will HPV vaccines eliminate the need for screening? Possibly, but probably not for many years. Will more sensitive and specific genetic or protein markers (or combinations thereof) be found to be more accurate and cost-effective? Certainly the possibility of mass screening by high-risk HPV DNA testing, as a viable alternative, is being discussed at present. Despite all of these uncertainties, the present (or nearly available) technology has the potential to improve the practice of cervical cytology. Improvements in accuracy that is necessary to provide the highest possible level of patient care and to protect practitioners from unreasonable levels of medico-legal risk are a reality3.

Recent advances in age-specific detection of high risk HPV DNA in cytologically normal, computer-imaged ThinPrep Pap samples

Recent cervical cancer screening guidelines for women over age 30 seek to improve the sensitivity of cytology by incorporating high-risk (HR) human papillomavirus (HPV) DNA testing into the screening algorithm, a recommendation based largely on data that utilized the conventional Pap smear and were not stratified by patient age. The objective of this study was to determine the rate of HR HPV DNA positivity in women ages 30 and over with a cytologically negative liquid-based Pap test result. Consecutive residual ThinPrep Pap samples from women with a cytologically negative result following computer-assisted screening were tested for HR HPV using the Hybrid Capture 2 (HC2) method. All HC2-positive samples were additionally tested with the Linear Array (LA) HPV Genotyping Test4.

Recent advances in potential applications of oral brush cytology with liquid-based technology:

Fifty healthy volunteers were studied to assess the potential applications of oral brush sampling using liquid-based cytology. Three specimens from the buccal mucosa and lateral border of tongue were collected from each subject by using cervical brushes and brooms. The brush was immersed in a preservative fluid. The sample in the preservative fluid was processed according to the manufacturer’s directions (SurePath™, UK). Slides were stained by the Papanicolaou method and assessed for squamous cell adequacy by the same criteria used for cervical cytology screening. Immunocytochemical staining for FHIT (Fragile Histidine Triad) was applied in liquid-based preparations following the streptavidin-biotin-peroxidase method. Human papillomavirus (HPV) detection was performed using the Hybrid Capture 2 assay (Digene) and the PCR-based Roche AMPLICOR HPV Test. LBC preparation slides showed good sample preservation, specimen adequacy and visualization of cell morphology. The AMPLICOR Roche Test detected samples with positive results for high-risk HPVs. The method may also have applications for research and practice in the field of oral cancer and precancer5.

Recent advances in brush cytology, and the oral brush biopsy

Studies have demonstrated that the survival and cure rate dramatically increase when oral cancer is detected in its precancerous stage or at an early asymptomatic stage. Advances in the early detection of oral cancer are unfolding and analogous to those made in the advances for cervical cancer.

Exfoliative cytology was thought of as a technique that could facilitate and accelerate clinical and histopathologic recognition of oral cancer. The use of oral cytology for large, advanced and obviously malignant lesions is limited since such growths always require a definitive biopsy-obtained diagnosis. The use of oral cytology has been shown to accelerate biopsy of these clinically harmless-appearing cancers that would have otherwise been neglected. Furthermore, oral cytology has been demonstrated repeatedly to reveal carcinoma in patients whose initial noncancerous diagnosis was based upon false negative biopsy results.

Brush biopsies are utilized routinely in the detection of precancer and cancer in other organ systems. Examples of well-known applications of brush biopsies include fiberoptic bronchoscopy (bronchial), ureteral retrograde brush biopsy (renal or ureter tissue), cholangiography (bile duct stricture), pancreatic ductal brush biopsies and others, including endometrial, nasopharynx, and GI tract applications (rectal, gastric, esophageal, colon). Their use in the oral cavity has only recently been introduced as OralCDx testing. The diagnosis of an oral cancer is, accordingly, made when an oral lesion is suspicious enough that it causes the dentist to refer the lesion for biopsy. For example, clinical features and symptoms of a suspicious lesion include large size, ulceration, and pain, and although these are all indications for immediate biopsy, an oral cancer that exhibits any of these features, all too often, is already considered advanced.

The results of brush biopsy studies demonstrate that the tool can be reliably utilized on oral lesions as a method of confirming their benign nature and more importantly, revealing those that are precancerous and cancerous when they are not clinically suspected. The role for OralCDx is to help determine the true nature of lesions which would not otherwise receive any further testing, i.e. lesions which are not judged to be sufficiently suspicious on visual inspection to be referred for immediate biopsy. Thus, the brush biopsy is a method of detecting a precancerous lesion, which can prevent oral cancer from ever developing, and it is a method of identifying unsuspected oral cancers at early and curable stages6.

Recent advances in brush cytology for pancreatic carcinoma

Despite recent advances in cytology brush design, yield of endoscopic brush cytology in suspected pancreatic carcinoma remains low. It was evaluated 32 such patients by ERCP to analyze differences in yield based on anatomic location of the pancreatic stricture, and the role of concurrent biliary stricture brush cytology, in improving the overall yield. Endoscopic brush cytology was performed on all strictures following ERCP. The yield of endopancreatic brush cytology is related to the location of malignancy, with overall yield enhanced by concurrent brushing of bile duct strictures7.

Recent advances in thin-layer cytology

ThinPrep system has found broad acceptance in non-gynecologic cytopreparation. Many laboratories have successfully applied this technique to body fluids (e.g. urine, pleural effusions), brushing samples (e.g. gastrointestinal tract, lung) and fine-needle aspiration. Most comparative studies have shown the ThinPrep system to perform as well as or better than conventional preparations in nongynecologic cytology; plus, the residual cells within the vial can be used for DNA analysis or immunohistochemical and other special studies. Recently, the ThinPrep 2000 system has been approved for use in gynecologic cytology. This approval was based on a large, multicenter clinical study that showed the ThinPrep system to be favored over the conventional Pap smear for the detection of low-grade squamous intraepithelial lesions, or more severe lesions. At screening centers the improved rate of detecting low grade squamous intraepithelial lesions (LSIL) or more severe diagnosis was up to 73%, with an average improvement of 65% as compared to the conventional Pap smears. This multicenter clinical trial demonstrates the ThinPrep 2000 system was more effective than the conventional Pap smear for the detection of atypical cells and cervical cancer and its precursor lesions. In addition, by collecting cells in a liquid-based medium the opportunity is present to improve the Pap test by adjunctive testing for Human Papilloma Virus or other procedures. This creates the opportunity for improved triage and management of patients with cervical abnormalities8.

Conclusion

The Screening Programs have made enormous strides and continues to incorporate evidence- based advances. A great deal of effort has resulted in a quality-assured programme, regarded by some as the best in the world, yet accessible to all patients in this country, although a significant proportion still do not take up the invitation. It seems likely that, despite expected preventative vaccine programmes coming on stream within 10 years, screening is likely to be required for several decades yet.

Automation should not lead to a reduction in standards nor expose the patient to any increased risk. Supervisory personnel should continue a visual quality control on a percentage of slides diagnosed as normal, and recognition should be made that human expert opinion represents the gold standard. The setting of performance criteria should remain the responsibility of the regulatory authorities, and not the manufacturers, and the professional cytology community should participate in the development of procedures that improve decision-making.

References

1. http://www3.interscience.wiley.com/cgibin/abstract/39111/ABSTRACT?CRETRY=1&SRETRY=0

2. http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6TDD-4CRWHPH-7&_user=10&_coverDate=07%2F31%2F2004&_alid=594377989&_rdoc=2&_fmt=summary&_orig=search&_cdi=5196&_sort=d&_docanchor=&view=c&_ct=11&_acct=C000050221&_version=1&_urlVersion=0&_userid=10&md5=a35655019e9ba6322952b2c02611df24

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4. http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6WG6-4MH2BNV-5&_user=10&_coverDate=03%2F31%2F2007&_rdoc=1&_fmt=&_orig=search&_sort=d&view=c&_acct=C000050221&_version=1&_urlVersion=0&_userid=10&md5=4e394d12ddf16cc4d3178cb6006093d3

5. http://www.ncbi.nlm.nih.gov/sites/entrez?cmd=Retrieve&db=PubMed&list_uids=16458571&dopt=Abstract

6. http://www.oralcancerfoundation.org/diagnosis/detailed_brush_cytology.htm

7. http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6WFY-4HBSHRB-G&_user=10&_coverDate=09%2F30%2F1996&_alid=594377989&_rdoc=9&_fmt=summary&_orig=search&_cdi=6807&_sort=d&_docanchor=&view=c&_ct=11&_acct=C000050221&_version=1&_urlVersion=0&_userid=10&md5=b1ef548169d3d476be9caf213cec33b7

8. http://www3.interscience.wiley.com/cgibin/abstract/39108/ABSTRACT?CRETRY=1&SRETRY=0

About Authors:

Yogesh Murti

Lecturer, Deptt. of Pharmaceutical Chemistry

Rajiv Academy for Pharmacy, Mathura

Vijay Sharma

Lecturer, Deptt. of Pharmaceutics

Rajiv Academy for Pharmacy, Mathura

Sameer Rastogi

Lecturer, Deptt. of Pharmaceutical Chemistry

Rajiv Academy for Pharmacy, Mathura

Deepa Pathak

Lecturer, Deptt. of Pharmaceutics

Rajiv Academy for Pharmacy, Mathura