Elisabeth Åvall Lundqvist

The purpose of this study was to evaluate the role of sequence variants in the CYP2C8, ABCB1 and CYP3A4 genes and the CYP3A4 phenotype for the pharmacokinetics and toxicity of paclitaxel in ovarian cancer patients. Thirty-eight patients were treated with paclitaxel and carboplatin. The genotypes of CYP2C8*1B, *1C, *2, *3, *4, *5, *6, *7, *8 and P404A, ABCB1 G2677T/A and C3435T, as well as CYP3A4*1B, were determined by pyrosequencing. Phenotyping of CYP3A4 was performed in vivo with quinine as a probe. The patients were monitored for toxicity and 23 patients underwent a more extensive neurotoxicity evaluation. Patients heterozygous for G/A in position 2677 in ABCB1 had a significantly higher clearance of paclitaxel than most other ABCB1 variants. A lower clearance of paclitaxel was found for patients heterozygous for CYP2C8*3 when stratified according to the ABCB1 G2677T/A genotype. In addition, the CYP3A4 enzyme activity in vivo affected which metabolic pathway was dominant in each patient, but not the total clearance of paclitaxel. The exposure to paclitaxel correlated to the degree of neurotoxicity. Our findings suggest that interindividual variability in paclitaxel pharmacokinetics might be predicted by ABCB1 and CYP2C8 genotypes and provide useful information for individualized chemotherapy.

Human papillomavirus (HPV) exists as more than 100 genotypes. It is not well-established whether the different HPV types interfere with infection or pathogenesis by each other. Possible interactions in cervical carcinogenesis between infection with the most common HPV types (6, 11, 16, 18 and 33) were studied in a seroepidemiological case- control study of 218 women with primary untreated cervical cancer and 219 healthy age-matched control women. As previously shown, HPV-16 seropositivity was associated with cervical cancer risk [odds ratio (OR), 2.39], but HPV-16 was not associated with cervical cancer risk among HPV-6 seropositive women (OR, 1.0). The relative excess risk due to interaction between HPV-6 and -16 was -2. 35 (95% confidence interval, -0.04 to -4.65), indicating significant antagonism. The results suggest that infection with HPV-6 may interfere with HPV-16-associated cervical carcinogenesis.

AIM: The aim of this study is to evaluate the quality of data on endometrial (EC) and ovarian, fallopian tube, peritoneal, abdominal or pelvic cancers (OC) registered in the Swedish Quality Register of Gynecologic Cancer (SQRGC). METHOD: A random sample of 500 patients was identified in the SQRGC and their medical charts were reviewed for re-abstraction of 31 selected core variables by an independent validator. The data in the SQRGC and the re-abstracted data were compared. The data were collected from 25 hospitals evenly distributed throughout Sweden. The main outcomes were comparability, timeliness, completeness and validity. Coverage was compared with the National Cancer Register (NCR). Timeliness was defined as the speed of registration i.e. when patients were registered in the SQRGC relative to date of diagnosis. Internationally accepted coding systems for stage, grading and histologic type were used ensuring a high degree of comparability. Correlations were estimated using Pearson's correlation coefficient and Cohen´s kappa coefficient. RESULTS: The completeness was 95%. The timeliness was 88-91% within 12 months of diagnosis. The median degree of agreement between re-abstracted data and data in the SQRGC was 82.1%, with a median kappa value of 0.73 for ordinate variables and a median Pearson's correlation coefficient of 0.96. The agreements for the type of surgery were 76% (95% CI 70-81%; kappa 0.49) and type of primary treatment 90% (95% CI 87-94%; kappa 0.85) in OC and in EC 88% (95% CI 84-93%; kappa 0.84). The agreements for the FIGO stage were in OC and EC 74% (95% CI 68-80%; kappa 0.69) and 87% (95% CI 82-91%; kappa 0.79), respectively. CONCLUSIONS: The data in the Swedish Quality Register for Gynecologic Cancer are of adequate quality in order to be used as a basis for research and to evaluate possible differences in treatment, lead times and treatment results.