Is cervical screening preventing adenocarcinoma and adenosquamous carcinoma of the cervix?

While the incidence of squamous carcinoma of the cervix has declined in countries with organised screening, adenocarcinoma has become more common. Cervical screening by cytology often fails to prevent adenocarcinoma. Using prospectively recorded cervical screening data in England and Wales, we conducted a population-based case-control study to examine whether cervical screening leads to early diagnosis and down-staging of adenocarcinoma. Conditional logistic regression modelling was carried out to provide odds ratios (ORs) and 95% confidence intervals (CIs) on 12,418 women with cervical cancer diagnosed between ages 30 and 69 and 24,453 age-matched controls. Of women with adenocarcinoma of the cervix, 44.3% were up to date with screening and 14.6% were non-attenders. The overall OR comparing women up to date with screening with non-attenders was 0.46 (95% CI: 0.39-0.55) for adenocarcinoma. The odds were significantly decreased (OR: 0.22, 95% CI: 0.15-0.33) in up to date women with Stage 2 or worse adenocarcinoma, but not for women with Stage1A adenocarcinoma 0.71 (95% CI: 0.46-1.09). The odds of Stage 1A adenocarcinoma was double among lapsed attenders (OR: 2.35, 95% CI: 1.52-3.62) compared to non-attenders. Relative to women with no negative cytology within 7 years of diagnosis, women with Stage1A adenocarcinoma were very unlikely to be detected within 3 years of a negative cytology test (OR: 0.08, 95% CI: 0.05-0.13); however, the odds doubled 3-5 years after a negative test (OR: 2.30, 95% CI: 1.67-3.18). ORs associated with up to date screening were smaller for squamous and adenosquamous cervical carcinoma. Although cytology screening is inefficient at preventing adenocarcinomas, invasive adenocarcinomas are detected earlier than they would be in the absence of screening, substantially preventing Stage 2 and worse adenocarcinomas.

Cervical cancer: prevention and treatment.

Cervical cancer is the commonest cancer cause of death among women in developing countries and efforts to prevent the disease using newer approaches and HPV vaccination need to be explored. Detection of cervical cancer at an early stage is associated with excellent survival but most women in developing countries present with advanced and often untreatable disease, with very poor survival. The ratio between incidence and mortality from cervical cancer remains very high, largely due to lack of access to appropriate anti-cancer therapies in developing countries. In developed countries with functional screening programs, cervical cancer has been rendered a relatively rare disease. Ongoing efforts to refine the characteristics of screening tests continue, as does implementation of current HPV vaccines for the primary prevention of cervical cancer.

Human papillomavirus genotype attribution in invasive cervical cancer: a retrospective cross-sectional worldwide study.

BACKGROUND: Knowledge about the distribution of human papillomavirus (HPV) genotypes in invasive cervical cancer is crucial to guide the introduction of prophylactic vaccines. We aimed to provide novel and comprehensive data about the worldwide genotype distribution in patients with invasive cervical cancer. METHODS: Paraffin-embedded samples of histologically confirmed cases of invasive cervical cancer were collected from 38 countries in Europe, North America, central South America, Africa, Asia, and Oceania. Inclusion criteria were a pathological confirmation of a primary invasive cervical cancer of epithelial origin in the tissue sample selected for analysis of HPV DNA, and information about the year of diagnosis. HPV detection was done by use of PCR with SPF-10 broad-spectrum primers followed by DNA enzyme immunoassay and genotyping with a reverse hybridisation line probe assay. Sequence analysis was done to characterise HPV-positive samples with unknown HPV types. Data analyses included algorithms of multiple infections to estimate type-specific relative contributions. FINDINGS: 22,661 paraffin-embedded samples were obtained from 14,249 women. 10,575 cases of invasive cervical cancer were included in the study, and 8977 (85%) of these were positive for HPV DNA. The most common HPV types were 16, 18, 31, 33, 35, 45, 52, and 58 with a combined worldwide relative contribution of 8196 of 8977 (91%, 95% CI 90-92). HPV types 16 and 18 were detected in 6357 of 8977 of cases (71%, 70-72) of invasive cervical cancer. HPV types 16, 18, and 45 were detected in 443 of 470 cases (94%, 92-96) of cervical adenocarcinomas. Unknown HPV types that were identified with sequence analysis were 26, 30, 61, 67, 69, 82, and 91 in 103 (1%) of 8977 cases of invasive cervical cancer. Women with invasive cervical cancers related to HPV types 16, 18, or 45 presented at a younger mean age than did those with other HPV types (50·0 years [49·6-50·4], 48·2 years [47·3-49·2], 46·8 years [46·6-48·1], and 55·5 years [54·9-56·1], respectively). INTERPRETATION: To our knowledge, this study is the largest assessment of HPV genotypes to date. HPV types 16, 18, 31, 33, 35, 45, 52, and 58 should be given priority when the cross-protective effects of current vaccines are assessed, and for formulation of recommendations for the use of second-generation polyvalent HPV vaccines. Our results also suggest that type-specific high-risk HPV-DNA-based screening tests and protocols should focus on HPV types 16, 18, and 45.

Cervical cancer screening: patients understanding in major hospitals in Malaysia.

We studied women with cervical cancer to determine whether they had had a Pap smear within the 3 years preceding cancer development and their understanding of screening for this cancer. The study had 2 parts; Pathology Data and Survey Data. For pathology data, all cases of cervical cancer diagnosed in 2000-2006 were retrieved from eight hospitals and Pap smear history was obtained from clinical records. For the Survey data; patients who were still undergoing treatment in some of these hospitals and three others were administered structured questionnaires to determine their awareness about screening. The results showed 1431 cases of cervical cancer in women aged 25-85 were diagnosed in these hospitals. Most had not had a Pap smear within 3 years before cancer development. The percentages of patients who had had Pap smear ranged from 0-12%. Questionnaires were returned by 221 patients; 56.3% had none or only primary education and 61.1% had a household income of RM 1,000 or less. Level of education and the household income were strongly associated (p<0.05) with knowledge and having had a Pap test. The main reasons cited for not having had a Pap smear were "Never heard about it" (36.2%), "Shy" (10.4%), "Afraid to do it" (13.1%), "Think the test is not important" (8.1%) and "No encouragement from family" (4.5%). A large majority (95.9%) of the patients did not know the optimal interval. In conclusion, a large number of cervical cancer patients had not had a Pap smear within 3 years preceding cancer development and most had inadequate knowledge about this screening test.

Screening and adenocarcinoma of the cervix.

Screening has had a major impact on cervical cancer in many countries. Although there can be no doubt about its effectiveness in preventing squamous-cell carcinoma, there is little evidence of any benefit on adenocarcinoma and adenosquamous carcinoma of the cervix, and many authors have concluded that it is ineffective. A population-based case-control design was used in women aged 20-69 in the United Kingdom, with information on screening obtained from routine databases. Among 3,305 cases with known histology, 641 had adenocarcinoma and 133 adenosquamous carcinoma. The risk reduction associated with 3-yearly screening was greater for squamous carcinoma (75%, 95%CI 71-79%) and adenosquamous carcinoma (83%, 95%CI 68-91%) than for adenocarcinoma (43%, 95%CI 24-58%). Among stage 1B+ cases, 83% (335/406) of women with adenocarcinoma had been screened within 10 years of diagnosis. This is very similar to controls (82%, 3,292/3,965), but much higher than in women with squamous carcinoma (57%, 852/1,493). Incidence of adenocarcinoma was low within 2.5 years of a negative smear (OR 2.3, 95%CI 0.15-0.34), but was no different from the background rates 4.5-5.5 years after a negative smear. We conclude that screening has reduced the incidence of adenocarcinoma of the cervix, but the prognostic value of cytology is less (in both magnitude and duration) for adenocarcinoma than for squamous carcinoma. The impact of screening on adenosquamous carcinoma is similar to its impact on squamous carcinoma.

Human papillomavirus type-distribution in the cervix of Chinese women: a meta-analysis.

The aim of the study was to determine human papillomavirus (HPV) type-distribution in the cervix of Chinese women, and to estimate the potential future impact of HPV prophylactic vaccines for cervical cancer prevention in China. A total of 32 studies using polymerase chain reaction for HPV detection were included in the meta-analysis, including 2844 invasive cervical cancer (ICC), 820 high-grade squamous intraepithelial lesions (HSIL), 432 low-grade squamous intraepithelial lesions (LSIL) and 2902 women with normal cytology/histology. The overall and type-specific HPV prevalence of 18 HPV types (HPV 6, 16, 18, 31, 33, 35, 39, 45, 51, 52, 56, 58, 59, 66, 68, 70, 73 and 82 of different cervical stages) were estimated. Overall HPV prevalence was 83.7%, 66.2%, 61.3% and 11.2% in ICC, HSIL, LSIL and normal, respectively. HPV 16 was the predominant type in all cervical stages. Estimated HPV 16/18 positive fractions in ICC, HSIL, LSIL and normal were 69.7%, 45.5%, 32.23% and 4.6%, respectively. HPV-16/18 vaccine has the 69.7% potential prevention in ICC. HPV 58 and 52 were the priority HPV types in Chinese women.

Peroxisome proliferator-activated receptor delta and gamma agonists differentially alter tumor differentiation and progression during mammary carcinogenesis.

Peroxisome proliferator-activated receptor (PPAR) represents a ligand-dependent nuclear receptor family that regulates multiple metabolic processes associated with fatty acid beta-oxidation, glucose utilization, and cholesterol transport. These and other receptor-mediated actions pertain to their role in hypolipidemic and antidiabetic therapies and as potential targets for cancer chemopreventive agents. The present study evaluated the chemopreventive activity of two highly potent and selective PPARgamma and PPARdelta agonists in a progestin- and carcinogen-induced mouse mammary tumorigenesis model. Animals treated with the PPARgamma agonist GW7845 exhibited a moderate delay in tumor formation. In contrast, animals treated with the PPARdelta agonist GW501516 showed accelerated tumor formation. Significantly, tumors from GW7845-treated mice were predominantly ductal adenocarcinomas, whereas tumors from GW501516-treated animals were adenosquamous and squamous cell carcinomas. Gene expression analysis of tumors arising from GW7845- and GW501516-treated mice identified expression profiles that were distinct from each other and from untreated control tumors of the same histopathology. Only tumors from mice treated with the PPARgamma agonist expressed estrogen receptor-alpha in luminal transit cells, suggesting increased ductal progenitor cell expansion. Tumors from mice treated with the PPARdelta agonist exhibited increased PPARdelta levels and activated 3-phosphoinositide-dependent protein kinase-1 (PDK1), which co-associated, suggesting a link between the known oncogenic activity of PDK1 in mammary epithelium and PPARdelta activation. These results indicate that PPARdelta and PPARgamma agonists produce diverse, yet profound effects on mammary tumorigenesis that give rise to distinctive histopathologic patterns of tumor differentiation and tumor development.

Thioproline inhibits development of esophageal adenocarcinoma induced by gastroduodenal reflux in rats.

Several epidemiological cohort studies have suggested that duodeno-gastroesophageal reflux per se induces Barrett's esophagus leading to increased risk of the development of esophageal adenocarcinoma (EAC). However, the exact causative factors behind EAC remain unclear. Recently, we designed a new duodenal contents reflux model which retained normal stomach function. In this model, duodenal contents flowed back into the esophagus and stomach resulting in repeated re-entry into the esophagus through the site of esophagojejunostomy. To elucidate the factors underlying the development of EAC, thiazolidine-4-carboxylic acid (thioproline, TPRO) was applied to the new reflux models as a nitrite scavenger and as a probe to detect reactive nitrogen species (RNS). Post-operatively, 31 animals were divided into two groups according to diet. Animals belonging to the control group were given normal diet (n = 18), while the TPRO group was given food containing 0.5% TPRO (n = 13). All esophageal sections in both groups were examined using hematoxylin and eosin staining and immunohistochemical analysis of inducible nitric oxide synthase (iNOS). EACs developed in 7 of 18 rats (38.9%) of the control group, whereas no EACs were detected in the TPRO group (Fisher's exact test, P < 0.05). Conversely, esophageal squamous cell carcinoma (ESCC) was detected in 1 of 18 rats (5.6%) of the control group and in 1 of 13 rats (7.7%) of the TPRO group. The incidence of ESCC was not significantly different between the two groups (P = 0.671). iNOS protein was overexpressed in Barrett's esophagus of both groups. The present results suggest that RNS such as nitric oxide and peroxynitrite and nitroso compounds derived from reflux of duodenal contents play an important role in the development of EAC, and that the primary causes of ESCC and EAC may differ.

Significant pelvic recurrence in high-risk pathologic stage I--IV endometrial carcinoma patients after adjuvant chemotherapy alone: implications for adjuvant radiation therapy.

OBJECTIVE: To evaluate the risk of pelvic recurrence (PVR) in high-risk pathologic Stage I--IV endometrial carcinoma patients after adjuvant chemotherapy alone. METHODS: Between 1992 and 1998, 43 high-risk endometrial cancer patients received adjuvant chemotherapy. All patients underwent primary surgery consisting of total abdominal hysterectomy and bilateral salpingo-oophorectomy. No patients received preoperative radiation therapy (RT). Regional lymph nodes and peritoneal cytology were sampled in 62.8% and 83.7% of cases, respectively. Most patients had Stage III--IV disease (83.7%) or unfavorable histology tumors (74.4%). None had evidence of extra-abdominal disease. All patients received 4-6 cycles of chemotherapy as the sole adjuvant therapy, consisting primarily of cisplatin and doxorubicin. Recurrent disease sites were divided into pelvic (vaginal, nonvaginal) and extrapelvic (para-aortic, upper abdomen, liver, and extra-abdominal). Median follow-up was 27 months (range, 2--96 months). RESULTS: Twenty-nine women (67.4%) relapsed. Seventeen (39.5%) recurred in the pelvis and 23 (55.5%) in extrapelvic sites. The 3-year actuarial PVR rate was 46.5%. The most significant factors correlated with PVR were cervical involvement (CI) (p = 0.01) and adnexal (p = 0.05) involvement. Of the 17 women who developed a PVR, 8 relapsed in the vagina, 3 in the nonvaginal pelvis, and 6 in both. The 3-year vaginal and nonvaginal PVR rates were 37.8% and 26%, respectively. The most significant factor correlated with vaginal PVR was CI (p = 0.0007). Deep myometrial invasion (p = 0.02) and lymph nodal involvement (p = 0.03) were both correlated with nonvaginal PVR. Nine of the 29 relapsed patients (31%) developed PVR as their only (6) or first site (3) of recurrence. Factors associated with a higher rate of PVR (as the first or only site) were CI and Stage I--II disease. CONCLUSIONS: PVR is common in high-risk pathologic Stage I-IV endometrial cancer patients after adjuvant chemotherapy alone. These results support the continued use of locoregional RT in patients undergoing adjuvant chemotherapy. Further studies are needed to test the addition of chemotherapy to locoregional RT.

Changing rates of adenocarcinoma and adenosquamous carcinoma of the cervix in England.

BACKGROUND: A recent analysis showed little or no effect of screening on the incidence of adenocarcinoma of the cervix between 1971 and 1992. We have used additional data on cancers diagnosed in 1993-94 in England and up to 1997 in five English cancer registries to investigate more recent trends. METHODS: After inputing the number of adenocarcinomas in women with unknown histology, we fitted an age-cohort model to 8062 adenocarcinomas of the cervix diagnosed in England between 1971 and 1987. Predictions from this model were applied to the more recent data on 5854 cases. Residual effects were plotted against year of diagnosis in each of four age-groups. FINDINGS: We estimated the underlying risk of cervical adenocarcinoma to be 14 times (95% CI 11-19) greater in women born in the early 1960s than in cohorts born before 1935. An age-cohort model fitted the data for England well up to 1987, but substantially overestimated the numbers of adenocarcinomas in young women from 1990 onwards. In 1996-97 the incidence rate in women aged 25-54 years was less than 40% of that predicted from the age-cohort model. INTERPRETATION: The substantial increase in cervical adenocarcinoma in recent years is largely a birth-cohort effect presumably associated with greater exposure to human papillomavirus after the sexual revolution in the 1960s. The relative decline in younger women observed in more recent years suggests an effect of cervical screening.

Inhibitory effects of combined administration of antibiotics and anti-inflammatory drugs on lung tumor development initiated by N-nitrosobis(2-hydroxypropyl)amine in rats.

The effects of antibiotics and anti-inflammatory drugs on the promotion stage of lung carcinogenesis initiated with N-nitrosobis(2-hydroxypropyl)amine (BHP) in rats were investigated in two experiments with a similar protocol. In experiment 1, rats received tap water containing 2000 p.p.m. BHP for 12 weeks followed by basal diet or basal diet containing 0.02% erythromycin (EM), 0. 04% ampicillin (ABPC), 1.5% sho-saiko-to, 0.02% EM plus 1.5% sho-saiko-to or 0.04% ABPC plus 1.5% sho-saiko-to for 8 weeks after BHP administration. The development of adenocarcinomas (AC), squamous cell carcinomas (SqC) and adenosquamous carcinomas (ASqC) was completely inhibited in rats given ABPC plus sho-saiko-to and the numbers of lung lesions including alveolar hyperplasias, adenomas and carcinomas were decreased in rats given EM plus sho-saiko-to or ABPC plus sho-saiko-to. Neutrophil and macrophage infiltration into alveolar spaces of the lung were also markedly suppressed. In experiment 2, rats received BHP in the same manner as in experiment 1 and basal diet or basal diet containing 0.04% ABPC, 0.006% piroxicam, 0.04% ABPC plus 0.006% piroxicam and 0.04% ABPC plus 0.75% ougon for 8 weeks. The incidence and number of carcinomas, including ACs, SqCs and ASqCs were decreased in rats given ABPC plus piroxicam or ABPC plus ougon. Bacteria, mainly Escherichia coli, were detected in broncho-alveolar lavage of rats receiving BHP. The results suggest that chronic inflammation might be involved in the progression of lung carcinogenesis by BHP in rats and its suppression may therefore be useful as a chemopreventive strategy in lung cancer clinics.

The effect of dietary fermented milk products and lactic acid bacteria on the initiation and promotion stages of mammary carcinogenesis.

The effects of spray-dried yogurt powder product (YPP), bifidobacteria, and Lactobacillus acidophilus were studied during the initiation and promotion phases of carcinogenesis using the 7,12-dimethylbenz[a]anthracene (DMBA)-induced mouse mammary carcinogenesis model. In two separate studies, Sencar mice were fed a diet consisting of 86%, 43%, or 0% YPP or 0% YPP, but with added cultures of bifidobacteria or L. acidophilus. When the animals were 55-63 days old, DMBA was administered by intragastric gavage at 1 mg/mouse and continued once a week for six weeks. During the initiation study, the test diets were fed for four weeks before and during DMBA administration. One week after the final DMBA treatment, all animals were switched to a basal diet based on the AIN-76 formulation. For the promotion study, the diets were introduced one week after the final dose of DMBA and fed for the remainder of the study. Palpable tumor development was monitored weekly throughout the studies. For the initiation study, mice fed 86%, 43%, or 0% YPP or 0% YPP supplemented with bifidobacteria or L. acidophilus had a histologically verified mammary tumor incidence of 15%, 35%, 19%, 30%, and 20%, respectively. The histologically verified tumor incidence for the promotion study was 48%, 58%, 36%, 59%, and 43% in the mice fed diets consisting of 86%, 43%, or 0% YPP or 0% YPP supplemented with bifidobacteria or L. acidophilus, respectively. The data indicate that neither the initiation nor the promotion phase of carcinogenesis is significantly affected by diets composed of 86% YPP, 43% YPP, 0% YPP, or 0% YPP supplemented with bifidobacteria or L. acidophilus.

Experimental studies of the inhibitory effects of green tea catechin on mice large intestinal cancers induced by 1,2-dimethylhydrazine.

Three hundred Kunming mice were randomly divided into six groups (half males and half females in each group). Group 1 was the positive control group, Groups 2, 3, 4 and 5 were experimental groups and Group 6 was used as the solvent control group. Mice in Groups 1-4 were injected with 1,2-dimethylhydrazine (1,2-DMH) (20 mg/kg body wt.) solution subcutaneously once a week from the 2nd week to the 20th week. From the 1st week to the 23rd week, mice in Groups 2, 3 and 4 were given catechin (1 mg/mouse), catechin (2 mg/mouse) and EGCG (2 mg/mouse), respectively, five times a week. Mice in Group 5 received only catechin (3 mg/mouse) five times a week from the 1st to the 23rd week. Mice in Group 6 were injected with an equal volume of 1 mmol EDTA solution subcutaneously once a week from the 2nd to the 20th week. At the end of the 27th week, all the mice were killed by cervical dislocation (Zhu, Q.H. and Zhu, Q.F. (1991) Laboratory Animal Science, 1st edition. The Junior Educational Publisher, Guangdong). Pathological examinations indicated that the incidence of large intestinal cancers occurring in Group 1 was 80%, significantly higher than that in Groups 2, 3 and 4 (p < 0.001). No tumors were found in Groups 5 and 6. This might suggest that green tea has preventive effects on large intestinal cancer induction in spite of the different doses of catechin. Immunohistochemistry studies showed that green tea catechins could enhance the activity of superoxide dismutase (SOD) in tissues.