Plasma concentrations of micronutrients during a nine-month clinical trial of beta-carotene in women with precursor cervical cancer lesions

A Scoping Review of Complementary and Alternative Medicine for Human Papillomavirus Infections and Cervical Dysplasia

OBJECTIVE

The goal of this scoping review is to synthesize clinically relevant scientific literature on current complementary and alternative medications that address human papillomavirus (HPV) infections and cervical dysplasia.

MATERIALS AND METHODS

A systematic search of published studies was performed December 2021 for the following concepts: human papilloma virus, cervical dysplasia, and complementary and alternative medicine (CAM). Relevant publications were identified by searching Ovid MEDLINE ALL, Embase, Cochrane Library, AMED, and MEDLINE databases, in addition to clinical trial databases. Data were extracted based on specific study selection criteria and analyzed by 3 authors independently using Covidence software.

RESULTS

A total of 2324 studies were identified of which 56 met inclusion criteria. Treatment outcomes measured regression of HPV, improvement of cervical cytology, and/or regression of histopathology with varied definitions of success across all studies. The CAM therapies found to have the most clinical benefit and best supporting data via randomized control trials were topical mushroom ( Coriolus versicolor) gel, oral and topical selenium therapies, and oral indol-3-carbinol. Adverse events were reported in only 28/56 (50%) of included studies.

CONCLUSIONS

The evidence for treating HPV and cervical dysplasia with CAM is of low quality because of lack of standardized, clinically relevant treatment outcomes, lack of standardization of products, and minimal reporting on adverse and long-term effects. Future large, randomized control trials are needed to further assess efficacy and safety of CAM therapies to address HPV and cervical dysplasia.

Human papillomavirus in the setting of immunodeficiency: Pathogenesis and the emergence of next-generation therapies to reduce the high associated cancer risk

Human papillomavirus (HPV), a common sexually transmitted virus infecting mucosal or cutaneous stratified epithelia, is implicated in the rising of associated cancers worldwide. While HPV infection can be cleared by an adequate immune response, immunocompromised individuals can develop persistent, treatment-refractory, and progressive disease. Primary immunodeficiencies (PIDs) associated with HPV-related disease include inborn errors of GATA, EVER1/2, and CXCR4 mutations, resulting in defective cellular function. People living with secondary immunodeficiency (e.g. solid-organ transplants recipients of immunosuppression) and acquired immunodeficiency (e.g. concurrent human immunodeficiency virus (HIV) infection) are also at significant risk of HPV-related disease. Immunocompromised people are highly susceptible to the development of cutaneous and mucosal warts, and cervical, anogenital and oropharyngeal carcinomas. The specific mechanisms underlying high-risk HPV-driven cancer development in immunocompromised hosts are not well understood. Current treatments for HPV-related cancers include surgery with adjuvant chemotherapy and/or radiotherapy, with clinical trials underway to investigate the use of anti-PD-1 therapy. In the setting of HIV co-infection, persistent high-grade anal intraepithelial neoplasia can occur despite suppressive antiretroviral therapy, resulting in an ongoing risk for transformation to overt malignancy. Although therapeutic vaccines against HPV are under development, the efficacy of these in the setting of PID, secondary- or acquired- immunodeficiencies remains unclear. RNA-based therapeutic targeting of the HPV genome or mRNA transcript has become a promising next-generation therapeutic avenue. In this review, we summarise the current understanding of HPV pathogenesis, immune evasion, and malignant transformation, with a focus on key PIDs, secondary immunodeficiencies, and HIV infection. Current management and vaccine regimes are outlined in relation to HPV-driven cancer, and specifically, the need for more effective therapeutic strategies for immunocompromised hosts. The recent advances in RNA-based gene targeting including CRISPR and short interfering RNA (siRNA), and the potential application to HPV infection are of great interest. An increased understanding of both the dysregulated immune responses in immunocompromised hosts and of viral persistence is essential for the design of next-generation therapies to eliminate HPV persistence and cancer development in the most at-risk populations.

Human Papillomavirus, Smoking, and Cancer

Background:

The effect of smoking on human papillomavirus (HPV) activity and subsequent dysplasia and neoplasia remains controversial

Objective:

To determine any reported effects of smoking on either HPV activity or HPV-related dysplasia/cancer using retrospective analysis of the literature from 1966 through 1998 via Toxline and PubMed to search for “smoking,” “papillomavirus,” and “cancer.”

Conclusion:

Several recent large studies demonstrated that smoking was associated with a greater incidence of cervical, vulvar, penile, anal, oral, and head and neck cancer in a dose-dependent fashion, while other studies did not show any correlation between smoking and cervical dysplasia after multivariate adjustment. Recent studies have also indicated that smoking may be more closely related to high-grade lesions of the cervix and vulva. These data provide evidence of an association between HPV, smoking, and cancer. Progression of dysplasia likewise seems to be associated with smoking. Several groups have attempted to discern whether the connection between smoking and cervical cancer is from local immunosuppression and/or from direct carcinogenic effects.

Systematic review of studies investigating the association between dietary habits and cutaneous malignant melanoma

OBJECTIVE

Several papers have dealt with diet as a risk factor for cutaneous malignant melanoma (CMM). This study aimed to synthesize available data on the topic.

STUDY DESIGN

A systematic review of observational studies assessing the association between dietary habits and CMM was performed.

METHODS

Electronic databases were used to identify eligible articles. Quality was assessed through the Newcastle-Ottawa scale. Case-control and cohort studies evaluating the intake of food/nutrients through the assessment of dietary habits and the occurrence of CMM were considered eligible. Data comparing the highest and lowest levels of consumption were collected from single studies and described qualitatively as data combination was not possible. Results were reported as percentages on the basis of relative risks and odds ratios.

RESULTS

Eighteen studies reported in 21 articles were selected. Cohort studies showed better quality than case-control studies. Most articles did not detect any significant association between food/nutrient intake and CMM, except for limited evidence of a protective role associated with fish, vegetables and fruit. Risk reduction was shown to be 35-37%, 40-57% and 34-46%, respectively, in studies reporting significant results. Similarly, few articles showed protective roles of beta-carotene and vitamins A, C, D and E, with risk reduction of 64%, 37-43%, 41%, 15-39% and 50-66%, respectively.

CONCLUSION

A trend towards reduced risk of CMM associated with higher intake of fish, vegetables and fruit, as well as beta-carotene and vitamins A, C, D and E, has been shown but further research is needed to provide decisive data.

Antioxidant vitamins and chemoprevention

Free radicals play an important role in human carcinogenesis and the mechanism of their counteraction by antioxidant vitamins has been reviewed. It seems more likely that these vitamins work in concert rather than acting singly. Currently available data are compatible with the notion that these vitamins act as chemopreventives against some important cancers, e.g. carotenoids for lung cancer, ascorbic acid for salivary gland cancer, tocopherols for head and neck cancers etc. Thus, a greater consumption of fruits and vegetables should be encouraged as they are the natural sources of these chemopreventive, antioxidants along with other protective factors packaged by nature. However, much work still remains to be done to establish the role of antioxidant vitamins in carcinogenesis.

Vitamin A and risk of cervical cancer: a meta-analysis

OBJECTIVE

To conduct a systematic review with meta-analysis of studies assessing the association of vitamin A (retinol, carotene and other carotenoids) intake or blood (serum or plasma) levels of vitamin A (retinol and carotene) with risk of cervical cancer.

METHODS

We evaluated the studies published in English and Chinese on diet or blood vitamin A for the risk of cervical cancer. We also reviewed reference lists from retrieved articles. Meta-analysis was applied to calculate the combined effect values and their 95% confidence intervals. The risk of bias was assessed by the Egger regression asymmetry test.

RESULTS

As many as 11 articles on dietary vitamin A and 4 articles on blood vitamin A were selected according to the eligibility criteria and were included in the meta-analysis, for a total of 12,136 participants. The pooled odds ratios (ORs) of cervical cancer were 0.59 (95% CI, 0.49-0.72) for total vitamin A intake and 0.60 (95% CI, 0.41-0.89) for blood vitamin A levels. The combined ORs of cervical cancer were 0.80 (95% CI, 0.64-1.00), 0.51 (95% CI, 0.35-0.73) and 0.60 (95% CI, 0.43-0.84) for retinol, carotene and other carotenoid intake, and 1.14 (95% CI, 0.83-1.56) and 0.48 (95% CI, 0.30-0.77) for blood retinol and carotene.

CONCLUSIONS

Vitamin A intake and blood vitamin A levels were inversely associated with the risk of cervical cancer in this meta-analysis.

Plasma micronutrients and the acquisition and clearance of anal human papillomavirus infection: the Hawaii HPV cohort study

Anal human papillomavirus (HPV) infection is common among women and the cause of most anal malignancies. The incidence of anal cancer has been increasing among U.S. women, yet few cofactors for the natural history of anal HPV infection have been identified. We examined the hypothesis that plasma carotenoid, retinol, and tocopherol concentrations are associated with the acquisition and clearance of anal HPV infection in a cohort of 279 Hawaiian residents followed at 4-month intervals for a mean duration of 16 months. At each visit, interviews were conducted and biological specimens were obtained, including anal cell specimens for HPV DNA detection and genotyping, and a fasting blood sample to measure 27 micronutrients. Cohort participants acquired 189 anal HPV infections, 113 of which cleared during the study period. The most frequently acquired HPV genotypes were HPV-52, -53, -84, and -16. Women in the highest quartile of trans-zeaxanthin, trans -anhydro-lutein, and trans-, cis-, and total β-carotene had significant 43% to 50% reduction in the risk of acquisition of any HPV infection compared with women in the lowest quartile. Few associations were observed between micronutrient levels and clearance of transient (≤ 150 days) anal HPV infections. However, clearance of persistent (> 150 days) infections was associated with higher levels of β-tocopherol + γ-tocopherol and lower levels of carotenoids and retinol. Our findings suggest that several carotenoids can reduce the risk and clearance of anal HPV infections that contribute to anal cancer.

The role of retinoid deficiency and estrogens as cofactors in cervical cancer

Persistent infection with high-risk human papillomaviruses (HR-HPVs) is involved in cervical cancer (CC), a major cause of cancer mortality worldwide. Infection occurs primarily at the transformation zone (TZ), the most estrogen- and retinoid-sensitive region of the cervix. Development of CC affects a small percentage of HR-HPV-infected women and often takes decades after infection, suggesting that HR-HPV is a necessary but not sufficient cause of CC. Thus, other cofactors are necessary for progression from cervical HR-HPV infection to cancer such as long-term use of hormonal contraceptives, multiparity, smoking, as well as micronutrient depletion and in particular retinoid deficiency, which alters epithelial differentiation, cellular growth and apoptosis of malignant cells. Therefore, early detection of HR-HPV and management of precancerous lesions together with a profound understanding of additional risk factors could be a strategy to avoid this disease. In this review we focus on the synergic effect of estrogens, retinoid deficiency and HR-HPVs in the development of CC. These risk factors may act in concert to induce neoplastic transformation in squamous epithelium of the cervix, setting the stage for secondary genetic or epigenetic events leading to cervical cancer.

The U.S. Food and Drug Administration's evidence-based review for qualified health claims: tomatoes, lycopene, and cancer

Several studies have reported an inverse association between tomato and/or lycopene intake and the risk of some types of cancer. In 2004, the U.S. Food and Drug Administration (FDA) received two petitions for qualified health claims regarding tomatoes, lycopene, and the risk reduction for some forms of cancer. Health claims that characterize the relationship between a food or food component and a disease or health-related condition require premarket approval by FDA to be included on the labels of conventional foods and dietary supplements. Here we describe FDA's review of the scientific data for tomato and/or lycopene intake with respect to risk reduction for certain forms of cancer. The FDA found no credible evidence to support an association between lycopene intake and a reduced risk of prostate, lung, colorectal, gastric, breast, ovarian, endometrial, or pancreatic cancer. The FDA also found no credible evidence for an association between tomato consumption and a reduced risk of lung, colorectal, breast, cervical, or endometrial cancer. The FDA found very limited evidence to support an association between tomato consumption and reduced risks of prostate, ovarian, gastric, and pancreatic cancers.

Hawaii cohort study of serum micronutrient concentrations and clearance of incident oncogenic human papillomavirus infection of the cervix

The degree to which the resolution of human papillomavirus (HPV) infection parallels exposure to other factors, particularly those related to nutritional status, is a relatively unexplored area of research. We established a cohort of women for long-term follow-up to examine the association of serum retinol, carotenoid, and tocopherol concentrations with the clearance of incident cervical HPV infection. Interviews and biological specimens were obtained at baseline and at 4-month intervals. At each visit, a cervical cell specimen for HPV DNA analysis and cytology and a fasting blood sample to measure micronutrient levels were collected. A Cox proportional hazards model was used to study the relationship between clearance of 189 incident (type-specific) oncogenic HPV infections and the levels of 20 serum micronutrients among 122 women. Higher circulating levels of trans-zeaxanthin, total trans-lutein/zeaxanthin, cryptoxanthin (total and beta), total trans-lycopene and cis-lycopene, carotene (alpha, beta, and total), and total carotenoids were associated with a significant decrease in the clearance time of type-specific HPV infection, particularly during the early stages of infection (<or=120 days). HPV clearance time was also significantly shorter among women with the highest compared with the lowest serum levels of alpha-tocopherol and total-tocopherol, but significant trends in these associations were limited to infections lasting <or=120 days. Clearance of persistent HPV infection (lasting >120 days) was not significantly associated with circulating levels of carotenoids or tocopherols. Results from this investigation support an association of micronutrients with the rapid clearance of incident oncogenic HPV infection of the uterine cervix.

Associations between serum carotenoids and tocopherols and type-specific HPV persistence: the Ludwig-McGill cohort study

Although oncogenic HPV infections have been established as the necessary cause of cervical cancer, most HPV infections are transient and rarely progress to cervical lesions. Current research is focused on identifying factors associated with viral persistence and clearance, such as nutritional status. We evaluated the association between serum antioxidant nutrients (retinol, 10 carotenoids and 3 tocopherols) and type-specific HPV persistence over 4 visits among 405 women participating in the Ludwig-McGill cohort study. We measured circulating carotenoids and tocopherol at 4 different clinical visits for each woman. We report the results from different analytic approaches (a case-control approach at both the woman and viral level, and a prospective approach based on persistent events) that examined the association between these micronutrients and type-specific oncogenic and nononcogenic HPV persistence. In the case-control analysis at the viral level, midcirculating levels of alpha-tocopherol were inversely associated with nononcogenic HPV persistent infection (adjusted odds ratio (AOR) = 0.28, 95% CI 0.14-0.57), while high levels were marginally associated (AOR = 0.59, 95% CI 0.28-1.19). Similarly, utilizing generalized estimating equation models, circulating levels of alpha- and delta-tocopherol in the middle or upper tertiles were inversely associated with type-specific nononcogenic HPV persistence (AOR = 0.44, 95% CI 0.19-0.97 and AOR = 0.46, 95% CI 0.19-1.11, respectively). Our study among Brazilian women suggests that serum levels of tocopherols may be protective against nononcogenic HPV persistence. However, we did not find a strong protective effect (as hypothesized) of other serum antioxidant nutrients and type-specific oncogenic HPV persistence measured over 4 clinical visits.

Lower red blood cell folate enhances the HPV-16-associated risk of cervical intraepithelial neoplasia

OBJECTIVE

We previously reported that higher circulating concentrations of folate are independently associated with a lower likelihood of becoming positive for high-risk human papillomaviruses (HR-HPVs) and of having a persistent HR-HPV infection and a greater likelihood of becoming HR-HPV negative (Cancer Res 2004;64:8788-93). In the present study conducted in the same study population, we tested whether circulating folate concentrations modify the risk of cervical intraepithelial neoplasia (CIN) > or =2 associated with specific types of HR-HPV.

METHODS

Multiple logistic regression models were used to assess associations (odds ratio with 95% confidence intervals) across HR-HPV, folate, and rigorously reviewed cervical histology of each subject.

RESULTS

HPV-16-positive women with low red blood cell folate were significantly more likely to be diagnosed with CIN > or =2 than were HPV-16-negative women with higher red blood cell folate (odds ratio 9, 95% confidence interval 3.3-24.8).

CONCLUSION

To our knowledge, this is the first study reporting an independent association of folate with risk of having CIN > or =2 in a population tested extensively for HR-HPV and CIN that also adequately controlled for several other micronutrients and known risk factors for CIN. Our findings suggest that improving the folate status in HR-HPV-infected women may reduce the risk of CIN and thus the risk of cervical cancer. Folate supplementation should be tested as a means of reducing the risk of developing CIN > or =2 in women exposed to HR-HPV, especially HPV-16.

Determination of lycopene and β-carotene by high-performance liquid chromatography using sudan I as internal standard

A new method, using sudan I as internal standard to determine the content of lycopene or beta-carotene in samples, was developed. According to UV-vis absorption spectra, sudan I, lycopene and beta-carotene all had absorption peaks at 450 nm. They could be separated absolutely by high-performance liquid chromatography (HPLC) with retention time of 2.7, 6.6 and 10.1 min, respectively. The related equations between sudan I and lycopene or beta-carotene content were obtained and verified by determining the content of lycopene or beta-carotene in Blakeslea trispora cells. The relative error was below 1.4% for determining lycopene content and below 1.9% for beta-carotene. Intra-day variability for lycopene determination was less than 3.4% and for beta-carotene was less than 1.4%. The mean recovery of lycopene or beta-carotene was 96.1 and 97.9%, respectively.

The role of diet and nutrition in cervical carcinogenesis: A review of recent evidence

Our objective was to provide an update on recent epidemiologic evidence about the role of diet and nutrition on the risk of human papillomavirus (HPV) persistence and cervical neoplasia, taking HPV into account. We conducted a systematic review and qualitative classification of all observational studies controlling for HPV infection published between March 1995 and November 2003 and of all randomized clinical trials published between January 1991 and November 2003. Scientific evidence was classified as convincing, probable, possible or insufficient, as used in a previous study on diet and cancer. Thirty-three studies were eligible for this review (10 clinical trials, 8 observational prospective studies and 15 case-control studies). The few studies on HPV persistence showed a possible protective effect of fruits, vegetables, vitamins C and E, beta- and alpha-carotene, lycopene, luterin/zeaxanthin and cryptoxanthin. Evidence for a protective effect of cervical neoplasia was probable for folate, retinol and vitamin E and possible for vegetables, vitamins C and B12, alpha-carotene, beta-carotene, lycopene, lutein/zeaxanthin and cryptoxanthin. Evidence for an increased risk of cervical neoplasia associated with high blood homocysteine was probable. Results did not differ between studies looking at preneoplastic and invasive lesions or between retrospective and prospective studies. The available evidence for an association between diet and nutritional status and cervical carcinogenesis taking HPV infection into account is not yet convincing. Large cohort studies are needed to adequately assess the role of foods and nutrients in cervical HPV carcinogenesis.

Folate Is Associated with the Natural History of High-Risk Human Papillomaviruses

Several micronutrients have been implicated in cervical carcinogenesis. However, their mode of action is still a matter of speculation. In particular, it is unclear whether certain nutrients reduce the probability of acquiring high-risk human papillomavirus (HPV) or whether they facilitate the clearance of high-risk HPV. We conducted a 24-month prospective follow-up study to test the hypothesis that systemic concentrations of folate are associated with the occurrence and duration of high-risk HPV infections after controlling for other micronutrients (vitamins B(12), A, E, and C, total carotene) and known risk factors for high-risk HPV infections and cervical cancer. Circulating concentrations of these micronutrients and risk factors for cervical cancer were determined in a cohort of 345 women who were at risk of developing cervical intraepithelial neoplasia. Using the hybrid capture 2 (HC-2) assay, high-risk HPV status was evaluated at 6-month intervals up to 24 months. All women had at least three consecutive visit high-risk HPV test results. Higher folate status was inversely associated with becoming HC-2 test-positive [odds ratio (OR): 0.27; 95% confidence interval (CI), 0.08-0.91; P = 0.04]. Women with higher folate status were significantly less likely to be repeatedly HC-2 test-positive (OR: 0.33; 95% CI, 0.13-0.86; P = 0.02) and more likely to become test-negative during the study (OR: 2.50; 95% CI, 1.18-5.30; P = 0.02). To our knowledge, this is the first long-term prospective follow-up study reporting an independent protective role of higher folate status on several aspects of the natural history of high-risk HPV after controlling for known risk factors and other micronutrients. Improving folate status in subjects at risk of getting infected or already infected with high-risk HPV may have a beneficial impact in the prevention of cervical cancer.

Relation between deranged antioxidant system and cervical neoplasia

The purpose of this study was to compare the plasma levels of the anti-oxidant system and oxidative stress between a cervical neoplasia group and a normal control group and to investigate the relationship between the levels of micronutrients of antioxidant system and various clinicopathological parameters of cervical carcinoma. A cross-sectional sample of 180 women, including 90 normal controls, was recruited from November 2000 to January 2001. Plasma concentration of malondialdehyde (MDA) was spectrophotometrically measured as the parameter of lipid peroxidation. Plasma levels of antioxidant vitamins were analyzed with the help of reverse-phase, high-pressure liquid chromatography, whereas glutathione peroxidase activity was evaluated by using coupled enzyme procedure. While the activity of glutathione peroxidase and the plasma levels of antioxidant vitamins, such as lutein, beta-carotene, lycopene, and zeaxanthin, were all significantly lower, the concentration of MDA was significantly higher in women with cervical intraepithelial neoplasia (CIN) or invasive cervical cancer, compared to those of the normal control group. The status of the plasma antioxidant system showed no significant correlation with the prognostic factors of cervical cancer. These findings suggest a potential role of oxidative stress-induced lipid peroxidation and the impairment of the anti-oxidant system in the pathogenesis of CIN and carcinoma of the uterine cervix.

Chapter 4: Genital tract infections, cervical inflammation, and antioxidant nutrients--assessing their roles as human papillomavirus cofactors

Cervical infections by approximately 15 human papillomavirus (HPV) types are the necessary cause of cervical cancer and its immediate precursor lesions. However, oncogenic HPV infections are usually benign and usually resolve within 1-2 years. A few of these infections persist and progress to cervical precancer and cancer. A number of cervical factors, such as infection by sexually transmitted pathogens other than HPV, cervical inflammation, and antioxidant nutrients, may influence the natural history of HPV infection along the pathways of persistence and progression or resolution. We examine the possible roles of these HPV cofactors in cervical carcinogenesis and discuss new methodologies that may enable researchers to measure relevant markers of the cervical microenvironment in which these cofactors may be active.

Plasma concentrations of coenzyme Q10 and tocopherols in cervical intraepithelial neoplasia and cervical cancer

Cervical intraepithelial neoplasia (CIN) may, at times, unpredictably progress to invasive carcinoma of the cervix. Epidemiological nutritional studies suggest that higher dietary consumption and circulating levels of certain micronutrients may be protective against cervical cancer. However, a preventive role of dietary antioxidants in CIN is not well established. The purpose of this cross-sectional study was to investigate the comparative plasma concentrations of three potent antioxidants, coenzyme Q(10,) alpha-tocopherol and gamma-tocopherol, in women with normal Pap smears and patients with a biopsy-confirmed histopathological lesion diagnosed as CIN or cervical cancer. Plasma concentrations of coenzyme Q(10,) alpha-tocopherol and gamma-tocopherol were measured by high-pressure liquid chromatography in both normal women without any history of abnormal Pap smears (n=48), and patients with histopathologically confirmed diagnoses of: (a) CIN I, n=98; (b) CIN II, n=49; (c) CIN III, n=10; and (d) cervical cancer, n=25. The mean plasma levels of coenzyme Q(10), alpha-tocopherol and gamma-tocopherol were significantly lower (P<0.001,<0.001, and<0.001, respectively by Kruskal-Wallis test) in patients with various grades of CIN and cervical cancer compared with controls. After controlling for age and smoking, an inverse association between histological grades of epithelial lesions and both plasma coenzyme Q(10) and alpha-tocopherol concentrations was observed. The low plasma concentrations of coenzyme Q(10) may be due to deficient dietary intake or a decrease in endogenous coenzyme Q(10) biosynthesis that may reflect increased utilization as a result of free radical reactive oxygen species induced oxidative stress. Further molecular studies on the mechanistic role of antioxidants in women with precancer cervical lesions are needed.

Management of precursor lesions of cervical carcinoma: history, host defense, and a survey of modalities

Before the initiation of screening and treatment for cervical cancer precursors, approximately 3% to 4% of women were destined to eventually develop cervical cancer. During the last 50 years the rate of cervical cancer incidence and mortality has decreased by more than 75% primarily because of the widespread availability of cervical cytologic screening and of treatment for documented cervical precancer. Successful screening of the entire population and appropriate treatment of lesions could theoretically reduce this risk to one tenth of the risk of an unscreened population [7,28]. The relatively recent understanding of the etiology of cervical cancer precursor lesions and of the immune response to them has given new direction to management options that incorporate healthy habits and dietary measures as part of traditional ablative or excisional treatment options. As we look to the future we can expect that new markers that more specifically identify individuals at-risk for cervical precancer and cancer will be developed and take precedence in cervical screening. At the same time, treating the cause of these lesions, rather than the result, should provide less traumatic and more successful therapies. To this end, harnessing the immune system through immune response modifiers and HPV vaccines seems to be on the horizon, as do new chemopreventative approaches. Of all human cancers, only cervical cancer, once the second most common cancer among women, stands on the threshold of being virtually eliminated.

Management of women with cervical cancer precursor lesions

An understanding of the natural history of HPV-induced precancer and cancer, and of the immune response to HPV and to these lesions, has significantly changed the management of lower genital tract neoplasia. New management guidelines incorporate this understanding, providing a more rational approach to diagnosis and treatment. Understanding that low-grade HPV-induced lesions are not true cervical cancer precursor has fostered expectant management of women with these lesions; however, management approaches are still hampered by the inability to better predict who is at risk for high-grade intraepithelial neoplasia and cancer and who is not; this is particularly problematic in the expectant management of CIN 1. In addition, the decision whether or not to treat these low-grade lesions may depend on a number of complex factors that take into account the woman's preferences and reliability for follow-up, as well as a host of issues related to costs and the reliability of the original diagnosis and the tests used for follow-up. Management options for high-grade cervical cancer precursor lesions are much more definitive, because the option of expectant management is given except in pregnancy and for adolescents with CIN 2. New markers that better predict which women with high-risk HPV are at highest risk for subsequent development of a true cervical cancer precursor lesion appear to be on the horizon and may make the management of low-grade lesions as clear as present guide lines for their high-grade cousins. Until that time, understanding all the issues involved in expectant and in active management of cervical HPV-induced lesions will help provide women with the best care possible.

Advanced-stage cervix cancer: rapid tumour growth rather than late diagnosis

Either diagnostic delay or tumour biology are possible factors governing the degree of spread at diagnosis of cervical cancer. To try to identify the most important parameter contributing to advanced stage, the duration of symptoms were recorded from patients scheduled for radiotherapy (n = 141) or radical hysterectomy (n = 36). In 146 cases tumour proliferation rates were evaluated following in vivo labelling with the DNA precursor BrdUrd. For symptomatic patients there was no association between duration of symptoms and stage at presentation. There was a significant trend for patients with increasing tumour stage to have more rapidly proliferating tumours with higher mean labelling index (LI) measurements (P = 0.001) and a shorter mean potential doubling time (Tpot) (P = 0.023). Socio economic deprivation may be associated with shorter Tpot values. The conclusion from this data is that stage at diagnosis is more dependent on the biological behaviour of the tumour, as expressed by proliferation rates, than delay in presentation.

Smoking, diet, pregnancy and oral contraceptive use as risk factors for cervical intra-epithelial neoplasia in relation to human papillomavirus infection

Smoking, nutrition, parity and oral contraceptive use have been reported as major environmental risk factors for cervical cancer. After the discovery of the very strong link between human papillomavirus (HPV) infection and cervical cancer, it is unclear whether the association of these environmental factors with cervical cancer reflect secondary associations attributable to confounding by HPV, if they are independent risk factors or whether they may act as cofactors to HPV infection in cervical carcinogenesis. To investigate this issue, we performed a population-based case-control study in the Vasterbotten county of Northern Sweden of 137 women with high-grade cervical intra-epithelial neoplasia (CIN 2-3) and 253 healthy age-matched women. The women answered a 94-item questionnaire on diet, smoking, oral contraceptive use and sexual history and donated specimens for diagnosis of present HPV infection (nested polymerase chain reaction on cervical brush samples) and for past or present HPV infections (HPV seropositivity). The previously described protective effects of dietary micronutrients were not detected. Pregnancy appeared to be a risk factor in the multivariate analysis (P < 0.0001). Prolonged oral contraceptive use and sexual history were associated with CIN 2-3 in univariate analysis, but these associations lost significance after taking HPV into account. Smoking was associated with CIN 2-3 (odds ratio (OR) 2.6, 95% confidence interval (CI) 1.7-4.0), the effect was dose-dependent (P = 0.002) and the smoking-associated risk was not affected by adjusting for HPV, neither when adjusting for HPV DNA (OR 2.5, CI 1.3-4.9) nor when adjusting for HPV seropositivity (OR 3.0, CI 1.9-4.7). In conclusion, after taking HPV into account, smoking appeared to be the most significant environmental risk factor for cervical neoplasia.

Dietary vitamin E and beta-carotene sources influence vitamin A and E storage in young rats fed marginal and adequate vitamin E

The effects of two vitamin E levels (30 and 75 IU/kg diet) and the interrelation of two vitamin E sources [dl-alpha-tocopheryl acetate (dl-alpha-TA) and d-alpha-tocopheryl acid succinate (d-alpha-TAS)] and three vitamin A sources [retinyl palmitate (RP), all-trans synthetic beta-carotene (SBC), and natural beta-carotene (NBC)] were studied. Dietary vitamin A sources provided 4,000 IU/kg. Twelve groups of Fischer 344 rats (10/group) were fed designated diets for eight weeks. For RP, SBC, and NBC, the increase in each vitamin E source from a marginal to an adequate dietary level caused a significant increase in liver and heart alpha-tocopherol. Among rats fed diets with an adequate level of vitamin E, d-alpha-TAS was not as effective as dl-alpha-TA in increasing liver alpha-tocopherol levels. Plasma retinol was lower in rats fed d-alpha-TAS than in those fed dl-alpha-TA. Among rats fed diets with an adequate level of dl-alpha-TA, those fed SBC had significantly higher liver and heart alpha-tocopherol concentrations than did all other groups (p < 0.05). Liver retinol equivalents for rats fed NBC were approximately 66% lower than those in rats fed SBC or RP (p < 0.05). The roles of the two vitamin E sources in alpha-tocopherol metabolism are not equivalent. These data indicate that vitamin A source influences the magnitude of the tissue vitamin A and E changes in response to the two vitamin E sources.

Low levels of serum vitamins A and E in blood and subsequent risk for cervical cancer: interaction with HPV seropositivity

Nutritional factors have been associated with risk of cervical cancer, but it is unclear whether the associations are of etiological significance or secondary to human papillomavirus (HPV) exposure. A delineation of this question requires a prospective study with invasive cancer as the end point. We conducted a nested case-control study in Finland and Sweden within a joint cohort of 405,000 women followed up for, on average, 4 years. Blood samples from 38 prospective cases of invasive cervical cancer diagnosed between 1985 and 1994 and 116 controls matched for age, country, and sample storage time were available for the study. Levels of retinol or unoxidized alpha-tocopherol in the blood were not risk factors for cervical cancer. However, joint-effect analysis of low levels of retinol disclosed statistically significant (p = 0.023) synergistic (more than multiplicative) interaction with HPV (HPV16, HPV18, or HPV33) seropositivity (observed relative risk = 2.6, 95% confidence interval = 0.7-8.8, expected relative risk = 0.3). Retinol might act as an effect modifier of the HPV-associated risk for cervical cancer; exposed women may require adequate levels for immunologic surveillance of HPV.