Younger age of cancer initiation is associated with shorter telomere length in Li-Fraumeni syndrome

Li-Fraumeni syndrome (LFS) is a cancer predisposition syndrome frequently associated with germ line TP53 mutations. Unpredictable and disparate age of cancer onset is a major challenge in the management of LFS. Genetic modifiers, including the MDM2-SNP309 polymorphism, and genetic anticipation have been suggested as plausible explanations for young age of tumor onset, but the molecular mechanisms for these observations are unknown. We speculated that telomere attrition will increase genomic instability and cause earlier tumor onset in successive generations. We analyzed mean telomere length and MDM2-SNP309 polymorphism status in individuals from multiple LFS families and controls. A total of 45 peripheral blood lymphocyte samples were analyzed from 9 LFS families and 15 controls. High rate of MDM2-SNP309 was found in TP53 carriers (P = 0.0003). In children, telomere length was shorter in carriers affected with cancer than in nonaffected carriers and wild-type controls (P < 0.0001). The same pattern was seen in adults (P = 0.002). Within each family, telomere length was shorter in children with cancer than in their nonaffected siblings and their noncarrier parents. Telomere attrition between children and adults was faster in carriers than in controls. Our results support the role of MDM2-SNP309 as a genetic modifier in LFS. The novel finding of accelerated telomere attrition in LFS suggests that telomere length could explain earlier age of onset in successive generations of the same family with identical TP53/MDM2-SNP309 genotypes. Furthermore, telomere shortening could predict genetic anticipation observed in LFS and may serve as the first rational biological marker for clinical monitoring of these patients.     

miR-34 is associated with poor prognosis of patients with gallbladder cancer through regulating telomere length in tumor stem cells

miR-34a has been identified as a tumor suppressor in several tumors, but its involvement in gallbladder cancer (GBC) has not been reported. In this study, the miR-34a level and telomere length were measured in 77 gallbladder adenocarcinomas and 36 peritumoral tissues by real-time PCR. Forced miR-34a expression was established by an adenovirus carrying a miR-34a expression cassette. The colony-forming ability of isolated CD44⁺CD133⁺ GBC tumor stem-like cells was measured by matrigel colony assay. The xenograft tumor models were established by inoculating nude mice with CD44⁺CD133⁺cells. Results showed that significantly lower miR-34a expression and longer telomere length were observed in gallbladder adenocarcinoma tissues, which correlated with poor prognosis of GBC patients. Forced overexpression of miR-34a inhibited the colony-forming ability of CD44⁺CD133⁺ GBC tumor stem-like cells in vitro and xenograft tumor growth in vivo. Injection of Ad-miR-34a downregulated PNUTS expression and reduced telomere length in xenograft GBC tumor cells. In conclusion, miR-34a is a tumor suppressor in gallbladder cancer. Both low miR-34a expression and long telomere length are markers for poor prognosis of patients with gallbladder adenocarcinoma. Our study also suggests that the miR-34a gene could be a target for targeting therapy of GBC.     

Molecular profiling of peripheral blood is associated with circulating tumor cells content and poor survival in metastatic castration-resistant prostate cancer

The enumeration of circulating tumor cells (CTCs) in peripheral blood correlates with clinical outcome in castration-resistant prostate cancer (CRPC). We analyzed the molecular profiling of peripheral blood from 43 metastatic CRPC patients with known CTC content in order to identify genes that may be related to prostate cancer progression. Global gene expression analysis identified the differential expression of 282 genes between samples with ≥5 CTCs vs <5 CTCs, 58.6% of which were previously described as over-expressed in prostate cancer (18.9% in primary tumors and 56.1% in metastasis). Those genes were involved in survival functions such as metabolism, signal transduction, gene expression, cell growth, death, and movement. The expression of selected genes was evaluated by quantitative RT-PCR. This analysis revealed a two-gene model (SELENBP1 and MMP9) with a high significant prognostic ability (HR 6; 95% CI 2.61 - 13.79; P<0.0001). The combination of the two-gene signature plus the CTCs count showed a higher prognostic ability than CTCs enumeration or gene expression alone (P<0.05). This study shows a gene expression profile in PBMNC associated with CTCs count and clinical outcome in metastatic CRPC, describing genes and pathways potentially associated with CRPC progression.     

Association of circulating leukocyte telomere length with survival in patients with colorectal cancer

IntroductionTelomere shortening, as seen with aging, can cause chromosomal instability and promote cancer progression. We investigated the association between circulating telomere length and overall and disease-free survival in a sub-cohort of patients with colorectal cancer.MethodsBaseline genomic DNA from blood leukocytes was extracted from N = 92 newly diagnosed stage I-IV patients with colorectal cancer enrolled at the ColoCare Study site in Heidelberg, Germany. Detailed information on clinicodemographic (including age) and lifestyle risk factors, and clinical outcomes (including recurrence and survival) was collected. Telomere length was measured in DNA using multiplex quantitative polymerase chain reaction. Kaplan Meier survival curves were generated comparing shorter to longer telomere lengths with log-rank testing.ResultsThe mean T/S ratio for study patients was 0.5 (range: 0.3–0.9). Shorter telomeres were associated with older age at baseline. Patients with shorter telomeres experienced a worse overall and disease-free survival, although this association did not reach statistical significance. Kaplan-Meier survival curves for those with circulating telomere length below vs. above the median showed poorer overall (log-rank p = 0.31) and disease-free survival (long-rank p = 0.23).ConclusionsOur results suggest that individuals with shorter telomeres, as seen with aging, may experience a worse overall and disease-free survival after colorectal cancer diagnosis. Larger sample sizes with longer follow-up are needed to further evaluate telomere length as a prognostic biomarker in colorectal cancer progression.     

Genetic polymorphisms in telomere pathway genes, telomere length, and breast cancer survival

The impact of genetic variants in telomere pathway genes on telomere length and breast cancer survival remains unclear. We hypothesized that telomere length and genetic variants of telomere pathway genes are associated with survival among breast cancer patients. A population-based cohort study of 1,026 women diagnosed with a first primary breast cancer was conducted to examine telomere length and 52 genetic variants of 9 telomere pathway genes. Adjusted Cox regression analysis was employed to examine associations between telomere length, genetic variants and all-cause and breast cancer-specific mortality. Longer telomere length was significantly correlated with all-cause mortality in the subgroup with HER-2/neu negative tumors (HR=1.90, 95% CI: 1.12-3.22). Carrying the PINX1-33 (rs2277130) G-allele was significantly associated with increased all-cause mortality (HR=1.45, 95% CI: 1.06-1.98). Three SNPs (TERF2-03 rs35439397, TERT-14 rs2853677, and TERT-67 rs2853669) were significantly associated with reduced all-cause mortality. A similar reduced trend for breast cancer-specific mortality was observed for carrying the TERT-14 (rs2853677) T-allele (HR=0.57, 95% CI: 0.39-0.84), while carrying the POT1-18 (rs1034794) T-allele significantly increased breast cancer-specific mortality (HR=1.48, 95% CI: 1.00-2.19). However, none of the associations remained significant after correction for multiple tests. A significant dose-response effect was observed with increased number of unfavorable alleles/genotypes (PINX1-33 G-allele, POT1-18 T-allele, TERF2-03 GG, TERT-14 CC, and TERT-67 TT genotypes) and decreased survival. These data suggest that unfavorable genetic variants in telomere pathway genes may help to predict breast cancer survival.     

Longer genotypically-estimated leukocyte telomere length is associated with increased adult glioma risk

Telomere maintenance has emerged as an important molecular feature with impacts on adult glioma susceptibility and prognosis. Whether longer or shorter leukocyte telomere length (LTL) is associated with glioma risk remains elusive and is often confounded by the effects of age and patient treatment. We sought to determine if genotypically-estimated LTL is associated with glioma risk and if inherited single nucleotide polymorphisms (SNPs) that are associated with LTL are glioma risk factors. Using a Mendelian randomization approach, we assessed differences in genotypically-estimated relative LTL in two independent glioma case-control datasets from the UCSF Adult Glioma Study (652 patients and 3735 controls) and The Cancer Genome Atlas (478 non-overlapping patients and 2559 controls). LTL estimates were based on a weighted linear combination of subject genotype at eight SNPs, previously associated with LTL in the ENGAGE Consortium Telomere Project. Mean estimated LTL was 31bp (5.7%) longer in glioma patients than controls in discovery analyses (P = 7.82×10-8) and 27bp (5.0%) longer in glioma patients than controls in replication analyses (1.48×10-3). Glioma risk increased monotonically with each increasing septile of LTL (O.R.=1.12; P = 3.83×10-12). Four LTL-associated SNPs were significantly associated with glioma risk in pooled analyses, including those in the telomerase component genes TERC (O.R.=1.14; 95% C.I.=1.03-1.28) and TERT (O.R.=1.39; 95% C.I.=1.27-1.52), and those in the CST complex genes OBFC1 (O.R.=1.18; 95% C.I.=1.05-1.33) and CTC1 (O.R.=1.14; 95% C.I.=1.02-1.28). Future work is needed to characterize the role of the CST complex in gliomagenesis and further elucidate the complex balance between ageing, telomere length, and molecular carcinogenesis.     

Subtelomeric DNA methylation and telomere length in human cancer cells

Subtelomeric epigenetic modifications are known to be associated with telomere length. We examined subtelomeric DNA methylation at seven sites for five chromosomes by methylation-specific PCR (MSP) and two sites for two chromosomes by bisulfite genomic sequencing (BGS) in 20 human cancer cell lines and subsequently analyzed their association with telomere length. Full-methylation (55/140) was more frequently found compared to un-methylation (35/140) (p = 0.01). Subtelomeric-methylation patterns varied from region to region; full-methylation and un-methylation were dominant at one of 9q sites (20/20) and 9p (18/20), respectively. MSP and BGS data exhibited no apparent correlation between methylation status and telomere length. In addition, Hep3B subclones that possessed different telomere lengths exhibited no changes in methylation status according to telomeres. In summary, subtelomeres might form distinct chromatin structures from region to region and effect of subtelomeric DNA methylation on telomere regulation might be little.     

外周血白细胞端粒相对长度与噪声性听力损失的相关性研究

目的：探讨外周血白细胞端粒相对长度与噪声性听力损失（NIHL）的相关性。方法：用SV104IS无线个体噪声剂量计对某电脑机箱外壳制造企业所有作业岗位进行噪声强度检测,选择噪声强度超标[L_{EX,8 h} ≥ 85 dB（A）]生产岗位的全体生产工人作为研究对象。采用问卷调查法获得研究对象的一般情况和职业史,实时荧光定量PCR检测研究对象外周血白细胞端粒相对长度,有序多分类Logistic回归法分析外周血白细胞端粒相对长度与噪声性听力损失（NIHL）的相关性。结果：该企业噪声超标作业岗位噪声强度（L_{EX,8 h}）均值为（91.30±3.22） dB（A）。本次研究共调查127名噪声作业者：双耳听力正常43人（33.86%）,双耳高频听阈提高75人（59.06%）,单耳或双耳语频听阈提高伴双耳高频提高9人（7.09%）。不同NIHL程度工人的端粒相对长度差异有统计学意义（P < 0.05）。有序多分类Logistic回归分析显示,噪声强度、年龄、端粒相对长度、性别是NIHL的影响因素（P < 0.05）。结论：外周血白细胞端粒长度可能是发生NIHL的易感性生物标志物。     

Predicting 5-fluorouracil toxicity in colorectal cancer patients from peripheral blood cell telomere length: a multivariate analysis

Background:

Identifying various pretreatment factors that predict chemotherapy-induced toxicity in colorectal cancer (CRC) patients undergoing treatment for their disease is crucial to optimising patient care.

Methods:

Seventy-three patients received adjuvant 5-fluorouracil (5FU)/leucovorin using either the Mayo Clinic (n=42) or a weekly schedule (n=31) and evaluated for clinical toxicity. Pretreatment blood analysis included measures of plasma uracil and dihydrouracil, peripheral blood mononuclear cell (PBMNC) telomere length (TL), standard biochemistry and cell differential analysis. On the first day of treatment 5FU-pharmacokinetic variables of area under the curve, half life and clearance were also measured. These variables together with age and gender were used in univariate and multivariate analysis as predictors of clinical toxicity.

Results:

For the Mayo schedule the primary toxicities were neutropenia (69%), mucositis (58%) and leukopenia (46%), with 70% of patients presenting with haematological toxicity ⩾grade 1 (neutropenia and/or leukopenia). Multivariate analysis showed that haematological toxicity was predicted by short TL, high platelet lymphocyte ratio (PLR) and low neutrophil count (R²=0.38, P<0.0006), whereas mucositis was predicted by age, TL and PLR (R²=0.34, P<0.001). For the weekly schedule diarrhoea predominated (16%), with female gender as the only predictive factor. Although measures of uracil metabolism correlated well with 5FU metabolism (r=0.45–0.49), they did not indicate abnormal pyrimidine metabolism in this cohort and not surprisingly failed to predict for 5FU toxicity.

Conclusion:

Short TL of PBMNC and an increased PLR were strong predictors of mucositis and haematological toxicity in CRC patients undergoing 5FU treatment in the adjuvant setting.     

Short telomere length in peripheral blood leukocyte predicts poor prognosis and indicates an immunosuppressive phenotype in gastric cancer patients

Compelling evidences indicate that relative telomere length (RTL) in peripheral blood leukocytes (PBLs) can predict the clinical outcome of several cancers. However, to date, the prognostic value of leukocyte RTL in gastric cancer (GC) patients has not been explored. In this study, relative telomere length (RTL) in peripheral blood leukocytes (PBLs) was measured using a real‐time PCR‐based method in a total of 693 GC patients receiving surgical resection. The prognostic value of leukocyte RTL was first explored in the training set (112 patients) using Kaplan–Meier and Cox proportional hazards regression analyses. Then an independent cohort of 581 patients was used as a validation set. To explore potential mechanism, we detected the immunophenotypes of peripheral blood mononuclear cells and plasma concentrations of several cytokines in GC patients. Patients with short RTL showed significantly worse overall survival (OS) and relapse‐free survival (RFS) than those with long RTL in all patient sets. Furthermore, leukocyte RTL and TNM stage exhibited a notable joint effect in prognosis prediction. Integration of TNM stage and leukocyte RTL significantly improved the prognosis prediction efficacy for GC. In addition, we found that patients with short RTL had a higher CD4+ T cell percentage in PBMCs, CD19+IL‐10+ Breg percentage in B cells and plasma IL‐10 concentration, indicating an enhanced immunosuppressive status with short leukocyte RTL. In conclusion, our study for the first time demonstrates that leukocyte RTL is an independent prognostic marker complementing TNM stage and associated with an immunosuppressive phenotype in the peripheral blood lymphocytes in GC patients.     

Analysis of telomere dynamics in peripheral blood cells from patients with Lynch syndrome

BACKGROUND:

In patients with Lynch syndrome, germline mutations in DNA mismatch repair (MMR) genes cause a high risk of developing a broad spectrum of cancers. To date, the management of patients with Lynch syndrome has represented a major challenge because of large variations in age at cancer onset. Several factors, including genetic anticipation, have been proposed to explain this phenotypic heterogeneity, but the molecular mechanisms remain unknown. Telomere shortening is a common event in tumorigenesis and also has been observed in different familial cancers. In this study, the authors investigated the possibility of a relation between telomere length and cancer onset in patients with Lynch syndrome.

METHODS:

The mean telomere length was measured using quantitative polymerase chain reaction in peripheral blood samples from a control group of 50 individuals, from 31 unaffected mutation carriers, and from 43 affected patients, and the results were correlated with both gene mutation and cancer occurrence. In affected patients, telomere attrition was correlated with age at cancer onset. In all patients, a t test was used to assess the linearity of the regression.

RESULTS:

A significant correlation between telomere length and age was observed in both affected and unaffected mutation carriers (P = .0016 and P = .004, respectively) and in mutS homolog 2 (MSH2) mutation carriers (P = .0002) but not in mutL homolog 1 (MLH1) mutation carriers. Telomere attrition was correlated significantly with age at onset in MSH2 carriers (P = .004), whereas an opposite trend toward longer telomeres in patients with delayed onset was observed in MLH1 carriers.

CONCLUSIONS:

The current data suggested that telomere dynamics differ between MLH1 and MSH2 mutation carriers. It is possible that subtle, gene‐specific mechanisms can be linked to cancer onset and anticipation in patients with Lynch syndrome. Cancer 2011;. © 2011 American Cancer Society.     

Risk of multiple myeloma is associated with polymorphisms within telomerase genes and telomere length

Compelling biological and epidemiological evidences point to a key role of genetic variants of the TERT and TERC genes in cancer development. We analyzed the genetic variability of these two gene regions using samples of 2,267 multiple myeloma (MM) cases and 2,796 healthy controls. We found that a TERT variant, rs2242652, is associated with reduced MM susceptibility (OR = 0.81; 95% CI: 0.72–0.92; p = 0.001). In addition we measured the leukocyte telomere length (LTL) in a subgroup of 140 cases who were chemotherapy‐free at the time of blood donation and 468 controls, and found that MM patients had longer telomeres compared to controls (OR = 1.19; 95% CI: 0.63–2.24; p_trend = 0.01 comparing the quartile with the longest LTL versus the shortest LTL). Our data suggest the hypothesis of decreased disease risk by genetic variants that reduce the efficiency of the telomerase complex. This reduced efficiency leads to shorter telomere ends, which in turn may also be a marker of decreased MM risk.     

Breast radiologic complete response is associated with favorable survival outcomes after neoadjuvant chemotherapy in breast cancer

BackgroundThe aim of this study was to examine the accuracy of radiologic complete response (rCR) in predicting pathologic complete response (pCR), and determine whether rCR is a predictor of favorable survival outcomes.Materials and methodsWe retrospectively reviewed breast cancer patients treated with neoadjuvant chemotherapy (NAC) followed by surgery from September 2007 to June 2016. Breast lesions and axillary nodes were measured by MRI and categorized into either disappeared (breast rCR) or residual disease (breast non-rCR) and either normalized (axillary rCR) or abnormal findings (axillary non-rCR) in the axillary nodes. Correlation between rCR and pCR were compared using Cohen’s Kappa statistics, and the recurrence-free survival (RFS) and overall survival (OS) rates were calculated by the Kaplan-Meier method.ResultsOut of the 1017 eligible patients, 287 (28.2%) achieved breast pCR, 165 (16.2%) achieved breast rCR, 529 (52.0%) had axillary pCR, and 274 (26.9%) achieved axillary rCR. The correlation between a breast rCR and pCR showed a Cohen’s Kappa value of 0.459, and between axillary rCR and pCR, the value was 0.384. During a median follow-up time of 48.0 months, the 5-year RFS rates were 90.6% for breast rCR, and 69.2% for breast non-rCR. The 5-year RFS rates were 82.3% for axillary rCR, and 68.8% for axillary non-rCR. Patients without breast rCR had a 2.4-fold significant increase in the risk of recurrence (p = 0.004) compared to patients with breast rCR.ConclusionAlthough rCR correlated with pCR by only moderate to fair degrees, breast rCR was a strong predictor for a favorable RFS outcome.     

Hypomethylation of DYRK4 in peripheral blood is associated with increased lung cancer risk

Lung cancer (LC) is the leading cause of cancer-related deaths worldwide. It is urgent to identify new biomarkers for the early detection of LC. DNA methylation in peripheral blood has been reported to be associated with cancers. We conducted two independent case–control studies and a nested case–control study (168 LC cases and 167 controls in study Ⅰ, 677 LC cases and 833 controls in study Ⅱ, 147 precancers and 21 controls in the nested case–control study). The methylation levels of DYRK4 CpG sites were measured using mass spectrometry and their correlations with LC were analyzed by logistic regression and nonparametric tests. Bonferroni correction was used for the multiple comparisons. LC-related decreased DYRK4 methylation was discovered in Study I and validated in Study II (the odds ratios [ORs] for the lowest vs. highest quartile of all three DYRK4 CpG sites ranged from 1.64 to 2.09, all p < 0.001). Combining the two studies, hypomethylation of DYRK4 was observed in stage I cases (ORs per −10% methylation ranged from 1.16 to 1.38, all p < 5.9E−04), and could be enhanced by male gender (ORs ranged from 1.77 to 4.17 via interquartile analyses, all p < 0.017). Hypomethylation of DYRK4_A_CpG_2 was significantly correlated with tumor size, length, and stage (p = 0.034, 0.002, and 0.002, respectively) in LC cases. Our study disclosed the association between DYRK4 hypomethylation in peripheral blood and LC, suggesting the feasibility of blood-based DNA methylation as new biomarker for LC detection.     

Breast cancer risk is positively associated with height

Inter- and intra-national epidemiological studies point to anassociation between socio-economic status and breast cancer risk.Although there is no direct evidence, the mostfavoured reason for this relationship is nutritional. Anenhanced dietary status, especially during childhood, would bereflected in adult body build. It is, therefore,surprising that there is uncertainty in the literatureconcerning the association between height and breast cancerrisk.In reviewing the publications on this topic itbecame apparent that case-control studies which found noassociation between height and risk tended to useself-reported height. In contrast reports claiming a significant,and positive, correlation tended to use heights whichwere measured by the investigators.In a prospective study we found in a cohort of 2731 ostensiblynormal women that, although there was a highlysignificant linear correlation between self-reported and measured height,the shortest women over-estimated their height whilst thetallest volunteers under-estimated theirs. The significance of cruderelative risk and height in this cohort wasmarkedly attenuated when self-reported height was used comparedto measured height. Such a systematic error couldhave a profound effect on the conclusions ofstudies in this field which relied on self-reportingand could explain the conflicting reports in theliterature.     

BRCA1 promoter methylation in peripheral blood cells is associated with increased risk of breast cancer with BRCA1 promoter methylation

BRCA1 promoter methylation reportedly plays an important part in the pathogenesis of human breast cancer. In the present study, we investigated whether or not BRCA1 promoter methylation in peripheral blood cells (PBCs) can serve as a risk factor for developing breast cancer. The association of BRCA1 promoter methylation in PBCs with breast cancer risk was examined in a case–control study (200 breast cancer patients and 200 controls). BRCA1 promoter methylation in PBCs and breast tumors was determined with a methylation-specific quantitative PCR assay. BRCA1 promoter methylation in PBCs was seen in 43 (21.5%) of the breast cancer patients and in 27 (13.5%) of the controls. The odds ratio for breast cancer adjusted for other epidemiological risk factors was 1.73 (1.01–2.96) and was statistically significant (P = 0.045). When breast tumors were classified into those with and without BRCA1 promoter methylation, the odds ratio was 0.84 (0.43–1.64) (P = 0.61) for BRCA1 promoter methylation-negative and 17.78 (6.71–47.13) (P < 0.001) for BRCA1 promoter methylation-positive breast tumors. BRCA1 promoter methylation in PBCs is significantly associated with risk of breast cancer with BRCA1 promoter methylation. This seems to indicate that BRCA1 promoter methylation in PBCs may constitute a novel risk factor for breast cancer with BRCA1 promoter methylation.     

Esophageal tumor length is independently associated with long‐term survival

BACKGROUND:

Esophageal cancer staging uses tumor depth as the sole criterion for assessment of the primary tumor (pT). To the authors' knowledge the impact of esophageal tumor length on long‐term outcome and the esophageal cancer staging system has not been fully evaluated in the current era.

METHODS:

All esophageal cancer patients (n = 209) undergoing surgery from 1995 to 2005 who did not receive preoperative chemotherapy or radiotherapy were reviewed. Maximum esophageal tumor length along a craniocaudal axis was determined pathologically after surgical resection. Univariate and multivariate analyses were used to assess the impact of esophageal tumor length (≤3 cm vs >3 cm) on long‐term survival.

RESULTS:

Esophageal tumor length was closely associated with long‐term survival (hazards ratio [HR] of 6.14 [95% confidence interval (95% CI), 4.1‐9.25]; 5‐year survival: ≤3 cm = 68%, >3 cm = 10% [P < .001]). Multivariate Cox regression analyses demonstrated tumor length (HR of 2.13 [95% CI, 1.26‐3.63]) was found to be a significant independent predictor of long‐term survival even when controlled for sex, age, tumor location, histology, margin positivity, surgical procedure, and current pTNM criteria. The incorporation of tumor length in pTNM staging significantly improves the ability to predict the long‐term survival of patients (5‐year survival for patients with tumors ≤3 cm and stages I, IIA, IIB, and III disease = 86%, 62%, 49%, and 22%, respectively; survival for patients with tumors measuring >3 cm and stages I, IIA, IIB, and III disease = 27%, 22%, 0%, and 8%, respectively [P < .1]).

CONCLUSIONS:

Esophageal tumor length is an independent predictor of long‐term survival in the current era and should be considered for incorporation into the current esophageal cancer staging system to better predict long‐term survival and identify high‐risk patients for postoperative therapy. Cancer 2009. © 2008 American Cancer Society.     

Metformin intake is associated with better survival in ovarian cancer

BACKGROUND:

The objective of this case‐control study was to identify any association of metformin intake with the survival of patients with ovarian cancer.

METHODS:

In this retrospective case‐control study, women with ovarian cancer who received metformin (cases) were compared with women with ovarian cancer who did not receive metformin (controls). A 2‐layered analysis was conducted. In preliminary analysis, all cases (the OC cohort) were compared with controls at a 1:2 ratio. Subsequently, in definitive analysis, only patients who had epithelial ovarian cancer (the EOC cohort) were compared with controls at a 1:3 ratio. In the EOC cohort, cases were matched with controls for age (±5 years), International Federation of Gynecology and Obstetrics stage, and residual disease. Prognostic variables and disease specific survival were compared using chi‐square tests, the Kaplan‐Meier (log‐rank) method, and Cox proportional hazards analysis.

RESULTS:

In a preliminary analysis of the OC cohort (72 cases and 143 controls), cases had better survival (5‐year disease‐specific survival for cases vs controls, 73% vs 44%; P = .0002). In the definitive analysis of the EOC cohort (61 cases and 178 controls), the distribution of age, disease stage, optimal cytoreduction, serous histology, and platinum chemotherapy remained similar between cases and controls (P > .05). Despite these similarities, cases had significantly better survival (5‐year disease‐specific survival for cases vs controls, 67% vs 47%; P = .007). On multivariate analysis, metformin remained an independent predictor of survival (hazard ratio, 2.2; 95% confidence interval, 1.2‐3.8; P = .007) after controlling for disease stage, grade, histology, chemotherapy, body mass index, and surgical cytoreduction.

CONCLUSIONS:

The results of this study indicated an association of metformin intake with survival in patients with ovarian cancer. The receipt of metformin was associated with better survival, and the authors concluded that metformin is worthy of clinical trials in ovarian cancer. Cancer 2013. © 2012 American Cancer Society.