Association of Reproductive Factors, Oral Contraceptive Use and Selected Lifestyle Factors with the Risk of Ovarian Borderline Tumors: A Danish Case-control Study

OBJECTIVE

The aim was to examine risk factors for ovarian borderline tumors overall, and according to histological subtype (serous vs. mucinous), in a large Danish population-based case-control study.

METHODS

Ovarian borderline cases and controls were recruited from 1995 to 1999, and personal interviews were conducted. In all, 202 cases and 1,564 randomly selected controls were included. The analysis was performed using multiple logistic regression models.

RESULTS

The risk of ovarian borderline disease decreased with increasing parity (OR=0.79 per birth, 95% CI: 0.63-0.98) and older age at first birth (OR=0.67 per 5 years, 95% CI: 0.53-0.84). Both a history of breastfeeding and use of oral contraceptives reduced the risk of borderline tumor, the effect being most pronounced for serous tumors. Increasing body mass index (BMI) was associated with elevated risk of serous borderline tumor (OR=1.05 per BMI unit; 95% CI: 1.00-1.10), whereas current smoking was a strong risk factor only for mucinous tumors (OR=2.10; 95% CI: 1.22-3.60). Finally, increasing consumption of milk (all types) was found to increase the risk of borderline disease (OR=1.04 per glass milk per week; 95% CI: 1.02-1.06), and increasing intake of total lactose also increased the risk significantly (OR=1.16 per 50 gram lactose per week; 95% CI: 1.06-1.26).

CONCLUSION

The risk profile of ovarian borderline tumors is similar to that of ovarian carcinomas, and we observed significant etiological differences between serous and mucinous borderline tumors.

Smoking and Overweight: Negative Prognostic Factors in Stage III Epithelial Ovarian Cancer

OBJECTIVE

Smoking and overweight are associated with poorer prognosis in several cancer types. The prognostic effect of smoking and body mass index (BMI) on ovarian cancer is unknown.

METHODS

Ovarian cancer cases were from the Danish MALOVA (MALignant OVArian cancer) study. Information on smoking status and BMI was obtained from a personal interview conducted closely after primary surgery. Cox regression models were used to estimate adjusted hazard ratios (HR) and 95% confidence intervals (95% CI) for ovarian cancer-specific death in relation to smoking variables and BMI.

RESULTS

A total of 295 women with stage III epithelial ovarian cancer were identified and followed to death or for a median of 7.3 years (range, 5.4-9.5 years). Median survival time for normal-weight never smokers was 2.8 years (95% CI, 2.3-3.2) compared with 1.2 years (95% CI, 0.8-2.3) for overweight current smokers. Current smokers had a significantly increased risk of ovarian cancer death compared with never smokers in multivariate Cox analysis (HR, 1.65; 95% CI, 1.22-2.24). The negative effect of smoking diminished with increasing time since a former smoker had stopped smoking (HR, 0.89; 95% CI, 0.80-0.98 per 5 years since stop of smoking). Overweight women also had an increased risk of ovarian cancer death (HR, 1.83; 95% CI, 1.38-2.42) compared with normal-weight women.

CONCLUSION

Smoking at the time of diagnosis and premorbid overweight were negative prognostic factors for ovarian cancer-specific survival. The negative effect of smoking decreased with increasing time since stop of smoking.

P53 mutations in tissue from Danish ovarian cancer patients

OBJECTIVES

The p53 gene, a tumor suppressor gene located on the short arm of chromosome 17 (17p13), has been found mutated in 30-80% of epithelial ovarian cancers (OC), with the most frequently detected mutations in the conserved regions of the gene. A small number of studies investigated the survival of patients with p53 mutations in OC, but their conclusions are not in agreement.

METHODS

We analyzed the frequency of p53 mutations in 124 Danish women with OC, using Single-Stranded Conformation Polymorphism analysis in addition with DNA sequencing and evaluated if mutations correlated with clinicopathological parameters and with patient survival.

RESULTS

Thirty-five (28%) ovarian tumors were found to contain one or more p53 variations, two of which were considered polymorphisms. Twenty-seven (82%) mutations were single nucleotide substitutions of which 23 (85%) were missense mutations and therefore led to amino acid substitutions. Significantly shorter survival was found for stage III/IV patients with a p53 missense mutation compared to stage III/IV OC patients with wild type p53 (P = 0.0018). Multivariate Cox regression analysis restricted to 107 OC patients with a p53 missense mutation or p53 wild type in the tumor tissue and with information on radicality of primary surgery showed that missense p53 mutation (HR = 2.5, 95% CI: 1.21-4.98), radicality after primary surgery (HR = 1.7, 95% CI: 1.04-2.88), tetranectin (mg/l: HR = 0.78, 95% CI: 0.67-0.91) and stage (I vs. III: HR = 0.30, 95% CI: 0.10-0.92, II vs. III: HR = 0.24, 95% CI: 0.05-1.05, IV vs. III: HR = 2.70, 95% CI: 1.22-5.98) were independent prognostic factors.

CONCLUSION

Missense mutations in the conserved regions of p53 may be of prognostic value in Danish OC patients.

Hormone therapy and the impact of estrogen intake on the risk of ovarian cancer

BACKGROUND

The association between menopausal hormone therapy (HT) and risk of ovarian cancer is as yet equivocal, and the effect of estrogen and estrogen-progestogen therapy, specifically the effect of the cumulative hormone intake, is unclear.

METHODS

We conducted a nationwide population-based case-control study in Denmark. Cases were women aged 35 to 79 years with incident ovarian cancer diagnosed between January 1, 1995, and May 30, 1999. Controls were frequency age-matched women from the Danish Central Population Register. The analyses included data on 376 cases who have not undergone hysterectomy and 1111 controls.

RESULTS

The risk of ovarian cancer in relation to oral HT increased with the cumulative intake of the estrogen component of HT but not with the duration or the cumulative intake of the progestogen component when the 3 variables were mutually adjusted. A simple trend was found such that each additional gram of estrogen was associated with the same relative increase. The odds ratio was constant throughout the range of cumulative intake. After adjustment for established risk factors, the estimated odds ratio per each additional gram of cumulative estrogen was 1.056 (95% confidence interval, 1.003-1.112), corresponding to an odds ratio of 1.31 (95% confidence interval, 1.01-1.70) per 5 g of estrogen.

CONCLUSIONS

Oral HT is associated with risk of ovarian cancer in women who have not undergone hysterectomy. Our results imply that the risk increases with cumulative oral estrogen intake but not with duration of HT, indicating that the increased ovarian cancer risk associated with oral HT may be diminished substantially by minimizing the daily dose of estrogen from oral HT.

The prognostic value of plasma soluble urokinase plasminogen activator receptor (suPAR) levels in stage III ovarian cancer patients

The level of the urokinase plasminogen activator receptor (uPAR) is elevated in tumor tissue from several forms of cancer. uPAR is shed from the cell surface and the soluble form, soluble urokinase plasminogen activator receptor (suPAR), has been detected in several body fluids. High plasma levels of suPAR in patients with colorectal cancer and high serum levels of suPAR in patients with recurrent metastatic breast cancer have been associated with poor prognosis. In patients with ovarian cancer (OC) it has been shown that the level of suPAR is very high in ascites and cystic fluid and that high serum levels of suPAR were associated with shorter survival of the patients. We evaluated suPAR preoperatively in plasma from primary OC stage III patients and tested for association with prognosis. The prognostic significance of suPAR was also compared to two biochemical markers; cancer antigen 125 (CA125) and tetranectin (TN). No significant differences were found between patients who died of OC compared to patients still alive regarding median plasma suPAR levels (p=0.62) and median serum CA125 levels (p=0.26). In contrast, a significant difference was found between dead and alive OC patients for the median serum TN level (p<0.0001). Dividing the patients into two groups, corresponding to preoperative plasma suPAR levels below or equal to 2.0 ng/ml and higher than 2.0 ng/ml, no significant difference in survival was found between the two groups (p=0.49). When different cut-off levels of plasma suPAR were considered (2.74 ng/ml, 3.25 ng/ml and 4.18 ng/ml), no significant differences in survival could be detected (p=0.58, p=0.68 and p=0.05). Multivariate Cox regression analysis showed that the only independent prognostic factors were radicality after primary surgery (RH=5.34; 95% CI, 2.34-12.20; p<0.0001) and preoperative serum TN (RH=0.69, 95% CI, 0.57-0.82; p<0.0001), whereas plasma suPAR (4.18 ng/ml), age, histological type of tumour and serum CA 125 had no independent prognostic value. In conclusion, preoperative plasma suPAR level was of no prognostic value in this cohort of Danish stage III OC patients.

Loss of heterozygosity on the X chromosome is an independent prognostic factor in ovarian carcinoma

BACKGROUND

Ovarian carcinoma (OC) is the fifth most frequent female cancer type and the fourth most frequent cause of death from cancer among women in Denmark. At the time they are diagnosed with OC, approximately 70% of patients have advanced disease. It is believed that loss of tumor suppressor gene activity plays an important role in the origin and progression of OC and other malignancies. Loss of heterozygosity (LOH) may be detected in individuals heterozygous for an allele and is associated with loss of function of tumor suppressor genes.

METHODS

The polymorphic marker regions (TP53, CACNLB1, D18S58, DXS538, and DXS454) were amplified by polymerase chain reaction followed by separation using gel electrophoresis before LOH was identified. In total, 160 women with primary epithelial OC were included in the study.

RESULTS

Univariate analyses showed significant differences in survival between patients who had advanced OC with LOH or with retention using the microsatellite markers DXS454 (P = 0.04) and DXS538 (P = 0.01). Multivariate Cox regression analysis that included all patients showed that DXS454 (relative hazard [RH] = 3.5; P = 0.002; 95% confidence interval [95% CI], 1.6-7.8), radicality of primary surgery (RH = 5.5; P < 0.0001; 95% CI, 2.7-11.1), and serum tetranectin level (RH = 0.8; P = 0.009; 95% CI, 0.7-0.9) were independent prognostic factors for survival. Multivariate Cox regression analysis restricted to patients with International Federation of Obstetrics and Gynecology Stage III-IV disease showed that DXS454 (RH = 3.4; P = 0.007; 95% CI, 1.4-8.1), radicality of primary surgery (RH = 5.4; P < 0.0001; 95% CI, 2.2-12.9), and serum tetranectin level (RH = 0.8; P = 0.042; 95% CI, 0.7-1.0) were independent prognostic factors.

CONCLUSIONS

LOH at DXS454 (Xq21-q23) appeared to be correlated with reduced survival in patients with OC.

High plasma YKL-40 level in patients with ovarian cancer stage III is related to shorter survival

YKL-40 (human cartilage glycoprotein-39) is a member of family 18 glycosyl hydrolases. YKL-40 is a growth factor and is secreted by cancer cells. High serum levels of YKL-40 in patients with colorectal cancer and recurrent metastatic breast cancer have been associated with a poor prognosis. We evaluated the prognostic value of plasma YKL-40 in patients with primary ovarian cancer (OC). YKL-40 was determined by ELISA in plasma obtained preoperatively from 47 women with stage III OC and in plasma from 79 healthy females. The results showed that plasma YKL-40 was elevated compared to healthy females in 57% of the OC patients and was highest in the patients who died during the follow-up compared to the patients still alive (186 vs. 78 micro g/l, p=0.002). Patients with high plasma YKL-40 (>130 micro g/l) had significantly (p=0.0003) shorter survival than patients with normal plasma YKL-40. Multivariate Cox regression analysis showed that plasma YKL-40 (RH=3.95; 95% CI, 1.52-10.27; p=0.005) and radicality after primary surgery (RH=4.03; 95% CI, 1.81-8.97; p=0.001) were independent prognostic factors of survival, whereas age, histological type of tumour and serum CA125 had no independent prognostic value. In conclusion, plasma levels of YKL-40 proved of prognostic value in stage III OC patients.

High plasma YKL-40 level in patients with ovarian cancer stage III is related to shorter survival

YKL-40 (human cartilage glycoprotein-39) is a member of family 18 glycosyl hydrolases. YKL-40 is a growth factor and is secreted by cancer cells. High serum levels of YKL-40 in patients with colorectal cancer and recurrent metastatic breast cancer have been associated with a poor prognosis. We evaluated the prognostic value of plasma YKL-40 in patients with primary ovarian cancer (OC). YKL-40 was determined by ELISA in plasma obtained preoperatively from 47 women with stage III OC and in plasma from 79 healthy females. The results showed that plasma YKL-40 was elevated compared to healthy females in 57% of the OC patients and was highest in the patients who died during the follow-up compared to the patients still alive (186 vs. 78 micro g/l, p=0.002). Patients with high plasma YKL-40 (>130 micro g/l) had significantly (p=0.0003) shorter survival than patients with normal plasma YKL-40. Multivariate Cox regression analysis showed that plasma YKL-40 (RH=3.95; 95% CI, 1.52-10.27; p=0.005) and radicality after primary surgery (RH=4.03; 95% CI, 1.81-8.97; p=0.001) were independent prognostic factors of survival, whereas age, histological type of tumour and serum CA125 had no independent prognostic value. In conclusion, plasma levels of YKL-40 proved of prognostic value in stage III OC patients.

Evaluation of a polymorphism in intron 2 of the p53 gene in ovarian cancer patients. From the Danish "Malova" Ovarian Cancer Study

BACKGROUND

The p53 gene is frequently mutated in various human tumours. In addition, single nucleotide polymorphisms are often observed in exons and introns of the p53 gene in normal tissues and tumours.

MATERIALS AND METHODS

A total of 210 blood and tissue samples from 182 ovarian cancers (OC) and 28 ovarian borderline tumours, in addition to blood samples from 72 healthy women, were analysed. The used analyses were PCR and SSCP. The distinguishable SSCP patterns were confirmed by DNA sequencing.

RESULTS

A polymorphism located at position 38 in intron 2 of the p53 gene was studied in blood and tumour tissues from Danish ovarian tumour patients and in blood from controls. Significant differences were found between the distributions of the genotypes in blood samples compared to the corresponding tissue samples (p = 0.0002). A tendency towards a significant difference in survival was observed between OC stage II patients with a shift from one genotype in the blood to another genotype in the tissue and patients with no shift (p = 0.05). In multivariate COX regression analysis restricted to stage III OC patients, the only independent factors found were shift, serum-tetranectin and age.

CONCLUSION

A shift from one p53 intron 2 genotype in the blood to another genotype in the tissue may be a prognostic factor in ovarian cancer patients.

Distribution of HER-2 overexpression in ovarian carcinoma tissue and its prognostic value in patients with ovarian carcinoma: from the Danish MALOVA Ovarian Cancer Study

BACKGROUND

The HER-2 (Human Epidermal Growth factor receptor-2, also known as c-erb-2/neu) protooncogene encodes a transmembrane receptor protein, M(r) 185,000. Studies have shown that the HER-2 oncogene is overexpressed in approximately 25-30% of ovarian carcinoma (OC) cases, but to the authors' knowledge, to date no consensus regarding overexpression and prognosis has been possible. The objective of the current study was first to analyze the presence of HER-2 overexpression in tissue from Danish OC patients and correlate the distribution of HER-2 overexpression with clinical and biochemical data and second to investigate the value of HER-2 overexpression as a prognostic marker in OC and to compare this value with the prognostic value of other biochemical markers.

METHODS

The study population was comprised of the first 181 patients diagnosed with epithelial OC who were included in the MALOVA study. The staining procedure for HER-2 overexpression was performed using the p185 antibody.

RESULTS

HER-2 overexpression was found in 95 of the 181 investigated cases (52.5%), in which 71 carcinomas (39.2%) were weakly positive (1+) and 24 carcinomas (13.3%) were moderately (2+) to intensely positive (3+). Increased HER-2 expression was found to be correlated with reduced survival. Significant differences in survival between patients with (1+, 2+, and 3+) and those without HER-2 overexpression were found for patients with International Federation of Gynecology and Obstetrics (FIGO) Stage I, Stage III, and Stage III/IV OC (Stage I: P = 0.021; Stage III: P = 0.0078; and Stage III/IV: P = 0.0054). Multivariate survival analyses including all 181 OC patients demonstrated that HER-2 overexpression is a prognostic marker (P = 0.003) together with disease stage, serum tetranectin level, and patient age. For patients with Stage III OC, the only independent prognostic factors detected were HER-2 overexpression (P = 0.009) and serum tetranectin level (P <or= 0.0001).

CONCLUSIONS

The results of the current study show that HER-2 overexpression has prognostic value both in univariate and multivariate survival analyses. Therefore, the clinical relevance of this observation should be established conclusively by therapy that targets HER-2 in a prospective Phase II clinical trial.

K-ras alterations in Danish ovarian tumour patients. From the Danish "Malova" Ovarian Cancer study

OBJECTIVE

Activation of ras oncogenes has been demonstrated in ovarian tumours. All the reported studies are based on a relatively small number of patients and the results therefore remain a subject of debate.

METHODS

In this study, we analyzed the presence of mutations at codons 12 and 13 of the K-ras gene in 165 Danish women with ovarian tumours, including 138 invasive ovarian cancers and 27 borderline ovarian tumours, using a restriction fragment length polymorphism-polymerase chain reaction technique and evaluated whether such alterations were associated with the clinicopathological parameters of the patients and survival.

RESULTS

K-ras codon 12 gene mutations were found in 8.7% of ovarian cancer patients and in 14.8% of the borderline ovarian tumour patients. A K-ras codon 13 gene mutation was found in 1.5% of ovarian cancer patients. K-ras mutations were found with a significantly higher frequency in mucinous tumours compared to serous tumours (P = 0.011).

CONCLUSIONS

Mutation frequency was correlated with the histological type of tumour, but not with stage, radicality of operation, and age. Furthermore, no significant difference in survival was demonstrated between patients with or without K-ras mutation, neither in the univariate nor in the multivariate survival analyses.

P53 autoantibodies in sera from Danish ovarian cancer patients and their correlation with clinical data and prognosis

The p53 gene, a tumour suppressor gene located on the short arm of chromosome 17 (17p13), is frequently mutated in various human tumours. Accumulation of p53 protein in neoplastic cells and its release following tumour necrosis can lead to development of circulating autoantibodies (AAb) against p53. Earlier studies of ovarian cancer (OC) patients reported different frequencies of p53 AAb and conclusions regarding the clinical and prognostic value of these AAb have not been in agreement. We therefore analysed for the presence of p53 AAb in a total of 227 preoperative serum samples from 193 OC patients and 34 patients with ovarian borderline tumours, and, in addition, serum samples from 86 healthy controls. An enzyme-linked immunosorbent assay (ELISA) was used to measure serum IgG antibodies against p53. The p53 protein used in the assay was produced as a hexahistidine-tagged fusion protein by baculovirus-infected Spodoptera frugiperda cells. Cut-off values for p53 AAb were evaluated, and correlations of p53 AAb with clinical-, biochemical data and survival were examined. We found a low sensitivity for p53 AAb alone, and no major additional effect of the detection rate of CA125 was found. No significant associations were found between p53 AAb and clinical stage, age, histological subtype and radicality after primary surgery. In contrast, we found significantly elevated CA125 levels in p53 AAb-positive patients compared to lower CA125 levels in p53 AAb-negative patients (p=0.003). No significant differences were found between p53 AAb-positive and p53 AAb-negative patients in the univariate and multivariate survival analyses. In conclusion, in a screening study for OC serum p53 AAb levels are of no diagnostic value, even if combined with the tumour marker CA125. The presence of increased serum p53 AAb in patients with diagnosed OC could not be correlated with any clinical data and preoperative serum p53 AAb status had no evident value.

Distribution of p53 codon 72 polymorphisms in ovarian tumour patients and their prognostic significance in ovarian cancer patients

BACKGROUND

The p53 gene is frequently mutated in various human tumours. In addition, single nucleotide polymorphisms are often observed in exons and introns of the p53 gene in normal tissues and tumours.

MATERIALS AND METHODS

The prevalence of a polymorphism involving codon 72 of exon 4 in the p53 gene was studied in peripheral white blood cells and tumour tissues from Danish ovarian tumour patients and in peripheral white blood cells from controls. The analyses were performed by Polymerase Chain Reaction (PCR), Restriction Fragment Length Polymorphism (RFLP) and DNA sequencing. The amino acid residue at this position is either arginine (p53-Arg) or proline (p53-Pro).

RESULTS

There was no correlation between the frequency of the three genotypes (Pro/Pro, Arg/Arg and Arg/Pro) and age, stage or histological type of the tumour. A significant difference in survival was observed between ovarian cancer stage III patients with a shift from one genotype in the blood to another genotype in the tissue and patients with no shift (p=0.0216).

CONCLUSION

Kaplan-Meier survival analyses and multivariate Cox regression analysis stratified to stage III ovarian cancer patients showed that a shift from one genotype in the blood to another genotype in the tissue is a prognostic factor in Danish ovarian cancer patients.

[P-pills and risk of breast cancer. A review of studies published 1970-1990]

A review of five cohort and 33 case-control studies provides evidence of an increased risk of breast cancer in women aged less than 45 years who were exposed to oral contraceptives for 5-10 years. It is probable that the increased risk is related to oral contraceptive use before the first pregnancy. No association was found between oral contraceptive use and breast cancer risk in women aged 45 years or more.