221(8.4%) patients screened were referred to colposcopy of whom 117 (53%) were less than 25 years of age similar to another Irish GU/STD clinic (56%) [8]. 1%, 3%, 5% had severe, moderate and, mild dyskaryosis, respectively, on cervical screening while 0.8%, 1.2%, 1.5% had CIN3, CIN2, CIN1 abnormalities, respectively, on biopsy with 3.5% showing no abnormality.
High grade lesions were found in 25% of mild, 41% of moderate and 61% of severe dyskaryosis. The literature reports that mild, moderate and severe dyskaryosis will give high grade lesions histologically (CIN2 and CIN3) in 50%, 50–75%, 80–90%, respectively, while CIN3 will have 5% invasion rate [11]. Any differences noted may be as a result of the age group of these patients being older or their sample selection. This study population has 37% of all those with high grade lesions (CIN2 +CIN3) <25 years while only 12% was seen in a US study [12]. Older patients (>25 yrs) had a higher prevalence of high grade lesions with 69%, 59%, 34% of CIN3, CIN2, CIN1 being >25 yrs, respectively.
It is accepted Progression, Regression and Persistence have been noted in mild dyskaryosis; 16%, 62%, 22%, moderate dyskaryosis; 35%, 50%,15% [13, 14], and regression of 46% [15] in severe dyskaryosis while progression from CIN1 to CIN3 in 26% was seen in a prospective study [16]. In this study the Progression, Regression and Persistence rates for mild dyskaryosis were; 21%, 51%, 28% and moderate dyskaryosis; 16%, 58%, 25% and regression of 60% in severe dyskaryosis. The lower grade lesions had higher persistence and progression while the higher grade lesions had a marginally lower rate of progression and persistence. This was not statistically significant.
Human Papilloma Virus (Type 16) has long been associated with cervical cancer. There is a 12% risk of recurrent abnormalities in women with low-risk HPV (non 16 or 18 subtypes) and up to a 50% risk of recurrence in women with certain types of HPV infection (especially subtypes 16 and 18). A change in the disease process in recent years is suggested in findings in the UK and Switzerland [17] where high risk HPV was seen in younger women and may lead to an increase in cervical cancer. In this study, where 28% of women have HPV infection and it is not feasible to type the HPV it is reasonable to postulate that at least 3% of all women seen are probably infected with high grade HPV as it is known that 11% of those with HPV have high grade HPV in China [18] and 7.2% in teenagers in the US where 15% had warts and 11% had Chlamydia trachomatis [19].
Transient HPV infection has been postulated for regression rates found. HPV associated changes have been reported in literature in 80% of women ≤ 25 years of age, 66% in the age group 26 to 35 years, 51% in the age group 36 to 45 years and 38% in women aged ≥ 46 years (p = 0.03). In this study there has been a high but not as high a rate of high grade lesions in the >25 year olds (35/54 = 65%) but the rates of progression, regression and persistence are the same in the <25 year olds as was reported by Wright et al in their study of teenagers with 18% having high grade lesions [20].
In this study RR of a high grade lesion with clinical HPV infection was 1.09 but 50% of high grade lesions had HPV. This RR is in agreement with the advice given to women on smear programmes that they do not need to come more often than the general population.
Other Sexually Transmitted Infections have been implicated in causing dyskaryosis especially Chlamydia trachomatis [21]. There is 11% prevalence of Chlamydia trachomatis in this clinic similar to 9.6% in a Dublin clinic [8]. 27% of biopsy proven CIN3 had Ct in this study and 80% of those were <25 years. However, the RR of having a high grade lesion at time of smear taking with Ct was 0.75 even though 13% of the study's patients with severe dyskaryosis had Ct.
Early sexual debut has not been audited in many studies [22, 23]. Younger onset of sexual activity [24] is established in Ireland and may contribute to the earlier age of onset of this cancer. In the 20 patients in this study with high grade lesions sexual debut was available in 8. 5 patients had first sexual intercourse at 14 years or less, one admitted child sexual abuse. Another was 15 and the other 2 were 18 and 19 years of age. These women had a mean number of 5.5 (range 1–20) sexual partners in their lives.
Recent analyses of cost-effectiveness suggest that the addition of molecular HPV DNA testing for women aged over 30 years may allow the screening interval to be lengthened to 3 years for most women but women at high risk for HPV infection and its associated cellular atypias warrant closer monitoring and follow-up. These patients would include organ transplant recipients, women exposed to diethylstilbestrol (DES) and HIV-infected women [25].37% of our patients with high grade lesions were <25 years and 43% of these had HPV and 13% Ct. Should patients at STI clinics be deemed at risk, too, as it was shown in the UK that they have a 10 fold increase in CIN3 (2.3%) [26] in 20–24 year olds compared to the general cervical smear population (0.24%) [27]?