CORRESPONDENCE

Re: Natural History of Dysplasia of the Uterine Cervix

Istvan Nyirjesy

Correspondence to: Istvan Nyirjesy, M.D., 5301 Westbard Circle #5, Bethesda, MD 20816

Holowaty et al. (1) should be commended for undertaking the nearly impossible task of determining the natural course of dysplasia. However, their recent report on the outcome of cytologically suggested dysplasia in women who were not treated with hysterectomy and who were not "censored" for specific (e.g., hysterectomy) or vague (e.g., "other gynecologic treatments" or incomplete requisition forms) events should not have been given the misleading title of "Natural History of Cervical Dysplasia." Dysplasia and its grade are defined on the basis of histology, and cytologic categories that suggest a grade of dysplasia correlate poorly with the final diagnosis (2-5). However, even if cytologic definitions are accepted and used, the inclusion of patients with smears suggesting "minimal dysplasia," a term without universal definition, may have greatly diluted the mild dysplasia group with an expected result of underestimation of progression. Furthermore, the confusing "Materials and Methods" section, with the exclusion of over 50 000 records (29 228 records that suggested minimal dysplasia or worse) and the use of ill-defined terms such as "censoring" and "eliminated records," suggests a strong possibility of selection bias.

Since the natural history of a disease is its course without interference, the lack of precise information on the number of biopsies and other local procedures that may modify a natural course raises further questions about the prestudy state and the selection of those studied. If the authors had to eliminate 21% of the records because the patient's date of birth was missing, is it not possible that information on prior biopsy and treatment was also incompletely recorded? Does the sentence, "Records were censored at treatment or at the end of the screening history," mean that outcome (progression or regression) was determined before performing a biopsy or applying treatment? Was the outcome diagnosis (carcinoma in situ or invasive cancer) also based on cytology; if so, what criteria were used to differentiate severe dysplasia from carcinoma in situ?

These missing answers and the development of potentially fatal and preventable invasive carcinoma in 138 women in the Ontario sample (64 cases in women originally diagnosed with mild cytologic dysplasia) clearly indicate the underestimation of risks by this study, as well as the failure of "conservative management" (meaning really nonmanagement) to prevent cancer. Practicing physicians are responsible to their patients for the detection and treatment of preventable and curable diseases. Such a goal cannot be accomplished without verification of the nature of cytologic abnormalities by more definitive methods, namely a gynecologic evaluation that includes colposcopy and biopsy when indicated. The development of innovative laboratory procedures, such as liquid-based cytologic analysis and human papillomavirus testing (2-6), may change future management, but their current ability to replace a human specialist has not yet been proven.

REFERENCES

1 Holowaty P, Miller AB, Rohan T, To T. Natural history of cervical dysplasia. J Natl Cancer Inst 1999;91;252-8.[Abstract/Free Full Text]

2 Hatch KD, Schneider A, Abdel-Nour MW. An evaluation of human papillomavirus testing for intermediate- and high-risk types as triage before colposcopy. Am J Obstet Gynecol 1995;172:1150-7.[Medline]

3 Ferenczy A, Franco E, Arseneau J, Wright TC, Richart RM. Diagnostic performance of Hybrid Capture human papillomavirus deoxyribonucleic acid assay combined with liquid-based cytologic study. Am J Obstet Gynecol 1996;175:651-6.[Medline]

4 Kaufman RH. Atypical squamous cells of undetermined significance and low-grade squamous intraepithelial lesion: diagnostic criteria and management. Am J Obstet Gynecol 1996:175:1120-8.[Medline]

5 Nyirjesy I, Billingsley FS, Forman MR. Evaluation of atypical and low-grade cervical cytology in private practice. Obstet Gynecol 1998;92:601-7.[Abstract/Free Full Text]

6 Critchlow CW, Kiviat NB. Old and new issues in cervical cancer control [editorial]. J Natl Cancer Inst 1999;91;200-1.[Free Full Text]



             
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