[Urogenital tumors following kidney transplantation-monocentric analysis of incidences and overview of urological preventive measures]. / Urogenitale Tumoren nach Nierentransplantation ­ monozentrische Aufarbeitung der Inzidenzen und Überblick urologischer Vorsorgemaßnahmen.

BACKGROUND: Urogenital tumors are among the most common solid malignancies after kidney transplantation (TX). OBJECTIVE: We analyzed the incidence and mortality of urogenital tumors after kidney TX in our own patient population as well as answered the question of recommended follow-up necessity and frequency in this cohort. MATERIALS AND METHODS: Retrospective monocentric data collection of tumor diseases and the most common urogenital tumors after kidney TX at the Transplant Center Dresden between 2010 and 2020 was done. From this, we derived recommendations for a useful follow-up concept. RESULTS: A total of 13% (93/710) of kidney TX patients developed a neoplasm. Older patients (60.1 ± 10.6 vs. 53.8 ± 12.5; p < 0.001), with higher Charlson scores (≥ 4: 68% vs. 46%; p < 0.001) and a previous tumor history (18% vs. 8%; p < 0.001) were more likely to develop a neoplasm after transplantation. In the multivariate analysis, previous tumor history was found to be an independent predictor of tumor development after renal transplantation (OR 2.2; 95%-KI [1.2-4.1]; p = 0.01). Urogenital tumors accounted for 30% (28/93) of all malignancies. Renal cell carcinoma of the native kidney was the most common (n = 12) neoplasm, followed by prostate cancer (n = 9). CONCLUSION: Most solid malignancies after kidney TX arise from the urinary tract. Due to their frequency, there is an urgent need for specialized urological therapy and long-term follow-up care. Even before listing for TX, risk factors can be recognized and individual concepts for follow-up care can be developed.

Occupational arsenic exposure and genitourinary cancer: systematic review and meta-analysis.

BACKGROUND: Existing evidence suggests that ingestion of high doses of arsenic through drinking water is associated with an increased risk of genitourinary cancers, while systematic evidence on workers exposed to arsenic is lacking. AIMS: The aim of this study is to systematically review the evidence on the association between occupational exposure to arsenic and genitourinary cancer risk and mortality. METHODS: A systematic literature search was carried out on Pubmed, Web of Science and Embase by including cohort and case-control studies. Study-specific relative risks (RRs) and the corresponding 95% confidence intervals (CIs) were pooled using Mandel-Paule random-effects model. Contour-enhanced funnel plot and Egger's test were used to assess the occurrence of publication bias. RESULTS: A total of 17 studies were included in the meta-analysis, 7 on cancer incidence (n = 161,244 individuals) and 10 on cancer mortality (n = 91,868). Most of them were cohort (71%) and industry-based studies (59%). The meta-analysis failed to detect an increased risk of genitourinary cancers among workers exposed to arsenic, except for a suggestive but not significant positive association for bladder cancer incidence (RR: 1.26, 95% CI: 0.89, 1.80), although this estimate was based on only three studies. No compelling evidence of publication bias was found (P = 0.885). CONCLUSIONS: Our findings did not show an association between occupational exposure to arsenic and genitourinary cancers, although further high-quality studies with detailed exposure assessment at the individual level are needed to clarify this relationship.

Bacterial dysbiosis and epithelial status of the California sea lion (Zalophus californianus) in the Gulf of California.

Despite the high incidence of urogenital carcinoma (UGC) in California sea lions stranded along California, no UGC has been reported in other areas of their distribution; however, cell morphologies typical of premalignant states have been found. Risk factors for UGC include high of organochlorines and infection with a gammaherpesvirus, OtHV-1, but the importance of the bacteriome for epithelial status remains unknown. We characterized the genital bacteriome of adult female California sea lions along their distribution in the Gulf of California and examined whether the diversity and abundance of the bacteriome varied spatially, whether there were detectable differences in the bacteriome between healthy and altered epithelia, and whether the bacteriome was different in California sea lions infected with OtHV-1 or papillomavirus. We detected 2270 ASVs in the genital samples, of which 35 met the criteria for inclusion in the core bacteriome. Fusobacteriia and Clostridia were present in all samples, at high abundances, and Actinobacteria, Alphaproteobacteria, and Campylobacteria were also well-represented. Alpha diversity and abundance of the California sea lion genital bacteriome varied geographically. The abundance of bacterial ASVs varied depending on the genital epithelial status and inflammation, with differences driven by classes Fusobacteriia, Clostridia, Campylobacteria and Alphaproteobacteria. Alpha diversity and abundance were lowest in samples in which OtHV-1 was detected, and highest those with papillomavirus. Our study is the first investigation of how the bacteriome is related to epithelial status in a wild marine species prone to developing cancer.

Application of Internet-based multidisciplinary management in patients with genitourinary cancers in China: A brief introduction to a new model of healthcare service for cancer survivors during COVID-19 pandemic.

The coronavirus disease 2019 (COVID-19) pandemic has triggered multiple global healthcare system crises. Apart from the pandemic itself, the travel restriction and social distance policy for the purpose of epidemic control has cast a shadow on the management of cancer survivors. Cancer survivors suffered a double blow from both the epidemic and cancer. To deal with the challenge, we explored a new Internet-based patient management model. This model has overcome the limitation of time and space and thus can help oncologists to provide remote multidisciplinary healthcare services for cancer survivors. These patients can get high-quality cancer management from multidisciplinary experts without too much transportation. This model has been applied in patients with genitourinary cancers and proved to be effective and efficient. Our study demonstrated that more patients benefited from this model during the pandemic of COVID-19, especially in those affected heavily by COVID-19. These results suggested that it can also give insight into the management of other cancer survivors in China. Given the long-term impact of the COVID-19 pandemic, we would like to introduce our new model of healthcare service and the application of Internet-based multidisciplinary management to our global peers and medical industries to help their cancer survivors who are delayed in treatment due to the COVID-19 pandemic.

Subsequent primary urogenital cancers among childhood and adolescent cancer survivors in the United States.

PURPOSE: To conduct an updated and comprehensive study on the risks of subsequent primary urogenital cancers for childhood and adolescent cancer survivors. METHODS: This longitudinal study was conducted using 9 cancer registries from the Surveillance, Epidemiology and End Results (SEER) Program with follow-up from 1975 to 2017. There were 43,991 patients diagnosed with first primary cancer from 1975 to 2016 before the age of 20 years who subsequently survived for at least 1 year. Standardized incidence ratios (SIRs) and absolute excess risks (AERs) for urogenital cancers were calculated. RESULTS: Compared with the general population, the risk of urinary system cancer was significantly higher in both female (SIR = 5.18, 95% CI: 3.65-7.14) and male (SIR = 2.80, 95% CI: 1.94-3.92) survivors of any first cancer, with shorter median interval length between first cancer and subsequent urinary system cancer for male survivors (19.9 years) than female survivors (29.3 years). Females also had significantly higher SIR than males for subsequent urinary system cancer (SIRfemale:male=1.86, 95% CI: 1.13-3.03) and kidney cancer (SIRfemale:male = 1.97, 95% CI: 1.11-3.53). Compared with the general population, females with any first cancer had significantly higher risks for cancers of the corpus uteri (SIR = 2.32, 95% CI: 1.49-3.45) and vulva (SIR = 4.27, 95% CI: 1.38-9.95). CONCLUSIONS: Childhood and adolescent cancer survivors may have greater female susceptibility for developing subsequent urinary system and kidney cancers, and these survivors may have higher risks for specific types of reproductive system cancers. Our findings may lead to better awareness and surveillance for urogenital cancer by these cancer survivors and their physicians.

Safety and preliminary efficacy of the Gam-COVID-Vac vaccine and outcomes of SARS-CoV-2 infection in Russian patients with genitourinary malignancies.

BACKGROUND: To our knowledge, there is no clinical data pertaining to COVID-19 outcomes and safety of COVID-19 vaccination in Russian patients with genitourinary (GU) malignancies. Aim of our analysis was to describe the characteristics of the COVID-19 infection course as well as preliminary safety and efficacy of Gam-COVID-Vac vaccine in patients with active GU malignancies. METHODS: Patients were retrospectively identified at nine cancer centers in different regions. Patients were included if COVID-19 was diagnosed by a polymerase chain reaction. Data from additional patients with GU cancers who had no positive SARS-CoV-2 RT-PCR test before vaccination and who received two doses of Gam-COVID-Vac (Sputnik V) between 11 February and 31 August 2021 were collected for safety assessment. Anonymized data were collected through an online registry covering demographics, treatments, and outcomes. RESULTS: The Gam-COVID-Vac vaccine was well tolerated; no grade 3-5 toxicities were reported in 112 vaccinated metastatic GU cancer patients. The most common grade 1 adverse events (81%) were injection site reactions (76%), flu-like illness (68%), and asthenia (49%). Five patients experienced grade 2 chills (4.5%) and 3 patients had grade 2 fever (2.7%). With median follow-up of 6.2 months, two COVID-19 cases were confirmed by RT-PCR test in the vaccine group (of 112 participants; 1.8%). Eighty-eight patients with COVID-19 disease were included in the analysis. The average age as of the study enrollment was 66 (range 39-81) and the majority of patients were male with renal cell carcinoma (RCC). Thirty-six patients (41%) had evidence of metastatic disease, of these 22 patients were receiving systemic therapy. More than half of patients required hospitalization. Fifty-four patients (61%) experienced complications. Sixteen patients who developed COVID-19 pneumonia required mechanical ventilator support. Sixteen patients (18%) died in a median of 23.5 days after the date of COVID-19 diagnosis was established. The 3-month survival rate was 82%. Clinical and/or radiographic progression of cancer during COVID-19 infection or the subsequent 3 months was observed in 10 patients (11.4%). CONCLUSION: Patients with GU malignancies are at increased risk of mortality from COVID-19 infection when compared to the general population. Vaccination could be safe in GU cancer patients. TRIAL REGISTRATION: retrospectively registered.

Acute urinary retention and risk of cancer: population based Danish cohort study.

OBJECTIVE: To examine the risk of urogenital, colorectal, and neurological cancers after a first diagnosis of acute urinary retention. DESIGN: Nationwide population based cohort study. SETTING: All hospitals in Denmark. PARTICIPANTS: 75 983 patients aged 50 years or older with a first hospital admission for acute urinary retention during 1995-2017. MAIN OUTCOME MEASURES: Absolute risk of urogenital, colorectal, and neurological cancer and excess risk of these cancers among patients with acute urinary retention compared with the general population. RESULTS: The absolute risk of prostate cancer after a first diagnosis of acute urinary retention was 5.1% (n=3198) at three months, 6.7% (n=4233) at one year, and 8.5% (n=5217) at five years. Within three months of follow-up, 218 excess cases of prostate cancer per 1000 person years were detected. An additional 21 excess cases per 1000 person years were detected during three to less than 12 months of follow-up, but beyond 12 months the excess risk was negligible. Within three months of follow-up the excess risk for urinary tract cancer was 56 per 1000 person years, for genital cancer in women was 24 per 1000 person years, for colorectal cancer was 12 per 1000 person years, and for neurological cancer was 2 per 1000 person years. For most of the studied cancers, the excess risk was confined to within three months of follow-up, but the risk of prostate and urinary tract cancer remained increased during three to less than 12 months of follow-up. In women, an excess risk of invasive bladder cancer persisted for several years. CONCLUSIONS: Acute urinary retention might be a clinical marker for occult urogenital, colorectal, and neurological cancers. Occult cancer should possibly be considered in patients aged 50 years or older presenting with acute urinary retention and no obvious underlying cause.

Characteristics of 1270 Chinese sibling pairs with cancer.

BACKGROUND: Previous research found that the cancer history of an individual's sibling may be a better indicator than that of the parents. We aim to provide recommendations for opportunistic screening for individuals whose sibling had been diagnosed with cancer. METHODS: During the physical examination in Cancer Hospital, Chinese Academy of Medical Sciences, 43,300 people were asked if they have at least two siblings who developed cancer. RESULTS: A total of 1270 sibling-pairs from 766 families developed cancer, including 367 pairs of brothers (Bro-pairs), 368 pairs of sisters (Sis-pairs), and 535 pairs of brother-and-sister (BroSis-pairs). The mean ages at diagnosis of cancer for the three groups were from 58 to 62 years. More than half of Bro-pairs (55.3%) or Sis-pairs (51.1%) had cancer from the same systemic origin, and more than a quarter of Bro-pairs (28.1%) and Sis-pairs (37.2%) developed the same type of cancer. However, only 36.0% of BroSis-pairs developed cancers from the same systemic origin, and 18.9% developed the same type of cancer. In Bro-pairs and BroSis-pairs, lung cancer and digestive system cancer were the most common cancers, while in Sis-pairs, breast cancer, lung cancer, cervical cancer, liver cancer and thyroid cancer were the most common ones. CONCLUSIONS: If an individual's sibling is diagnosed with cancer, the individual should consider participating in opportunistic screening annually, especially for lung cancer and digestive system cancers for both sexes. For sisters, breast cancer, cervical cancer and thyroid cancer should be screened early. Additionally, genetic services are essential for individuals who have siblings with cancer.

Exposición al radón y cáncer genitourinario en mineros / Radon exposure and genitourinary cancer in miners

OBJETIVO: Evaluar la asociación entre la exposición al radón y el cáncer genitourinario en población minera a través de una revisión sistemática de la literatura científica. MÉTODO: Se realizó una revisión sistemática de la literatura científica en MEDLINE (PubMed) combinando términos MeSH (Medical Subject Heading) y términos libres. Se realizó una escala específica de valoración de la calidad de los estudios incluidos. RESULTADOS: Se incluyeron 17 estudios. Todos fueron estudios de cohortes, excepto uno que fue un pool de datos. Todos los estudios incluían análisis de la relación entre la exposición al radón y el cáncer genitourinario. Los resultados son ambiguos: unos estudios apuntan hacia una asociación entre la exposición y el cáncer genitourinario, especialmente de riñón, y otros no encuentran asociación. CONCLUSIÓN: Los estudios incluidos presentan una gran heterogeneidad metodológica. No puede concluirse que exista una asociación entre la exposición al radón y el cáncer genitourinario. Es necesaria más investigación sobre el tema, con estudios que tengan más potencia estadística y mejor control de las variables confusoras, y preferentemente que sean prospectivos

OBJECTIVE: To assess the association between exposure to radon and genitourinary cancer in a mining population through a systematic review of the scientific literature. METHOD: A systematic review of the scientific literature was carried out in MEDLINE (PubMed), combining MeSH (Medical Subject Heading) terms and free terms. We applied a specific scale to assess the quality of the included studies. RESULTS: We included 17 studies; all were cohort studies with the exception of one which was a pooling of data. All studies included analysed the relationship between exposure to radon and genitourinary cancer. While some studies point towards an association between radon exposure and genitourinary cancer, especially kidney cancer, others do not find such association. CONCLUSIONS: The included studies showed great heterogeneity. It cannot be concluded that there is an association between exposure to radon and genitourinary cancer. More research is needed on this topic, designing studies with higher statistical power, better control of confounders, and preferably prospective

[Radon exposure and genitourinary cancer in miners]. / Exposición al radón y cáncer genitourinario en mineros.

OBJECTIVE: To assess the association between exposure to radon and genitourinary cancer in a mining population through a systematic review of the scientific literature. METHOD: A systematic review of the scientific literature was carried out in MEDLINE (PubMed), combining MeSH (Medical Subject Heading) terms and free terms. We applied a specific scale to assess the quality of the included studies. RESULTS: We included 17 studies; all were cohort studies with the exception of one which was a pooling of data. All studies included analysed the relationship between exposure to radon and genitourinary cancer. While some studies point towards an association between radon exposure and genitourinary cancer, especially kidney cancer, others do not find such association. CONCLUSIONS: The included studies showed great heterogeneity. It cannot be concluded that there is an association between exposure to radon and genitourinary cancer. More research is needed on this topic, designing studies with higher statistical power, better control of confounders, and preferably prospective.

Risk of Genitourinary Malignancy in the Renal Transplant Patient.

OBJECTIVE: To better understand the risk of genitourinary malignancies in the renal transplant patient. Currently, no consensus exists regarding screening and intervention, with much of the clinical decision-making based on historical practices established before recent progress in immunosuppression protocols and in genitourinary cancer diagnosis and management. METHODS: A database of all solid organ transplants performed at the University of Minnesota from 1984 to 2019 was queried for renal transplant recipients in whom development of subsequent urologic malignancies (prostate, bladder, renal, penile, and testicular cancer) was found. RESULTS: Among 6172 renal transplant recipients examined, cumulative incidence of all cancers of genitourinary etiology are presented over an average follow-up time of 10 years. Kidney cancer (combined graft and native), prostate cancer, and bladder cancer each demonstrated respective 30-year incidence of 4.6%, 8.7%, and 1.5% from the time of transplant. By comparison, age-matched data from the Surveillance, Epidemiology, and End Results database demonstrated 30-year cumulative incidence of 1.1%, 11.1%, and 1.7% for kidney cancer, prostate cancer, and bladder cancer respectively. The predominant genitourinary cancer was renal cell cancer, both of the native and of the transplanted kidney (native, n = 64; transplanted, n =11), followed by prostate cancer (n = 63), and bladder cancer (n = 37). CONCLUSION: In this closely followed cohort of renal transplant recipients, renal cancer occurs at a higher incidence rate than in the non-transplanted population, while a lower rate of prostate cancer was found, with bladder cancer demonstrating a comparable cumulative incidence between transplant patients and the national age-matched population.

Performing gynecologic cancer surgery during the COVID-19 pandemic in Turkey: A multicenter retrospective observational study.

OBJECTIVE: To report the perioperative outcomes of 200 patients with gynecologic cancer who underwent surgery during the Novel Coronavirus Disease (COVID-19) pandemic and the safety of surgical approach. METHODS: Data of patients operated between March 10 and May 20, 2020, were collected retrospectively. Data were statistically analyzed using IBM Statistical Package for the Social Sciences (SPSS) Statistics for Windows v. SP21.0. RESULTS: Data of 200 patients were included. Their mean age was 56 years. Of the patients, 54% (n=108), 27.5% (n=55), 12.5% (n=25), and 2% (n=4) were diagnosed as having endometrial, ovarian, cervical, and vulvar cancer, respectively. Of them, 98% underwent non-emergent surgery. A minimally invasive surgical approach was used in 18%. Stage 1 cancer was found in 68% of patients. Surgeons reported COVID-related changes in 10% of the cases. The rate of postoperative complications was 12%. Only two patients had cough and suspected pneumonic lesions on thoracic computed tomography postoperatively, but neither was positive for COVID-19 on polymerase chain reaction testing. CONCLUSION: Based on the present findings, it is thought that gynecologic cancer surgery should continue during the COVID-19 pandemic while adhering to the measures. Postponement or non-surgical management should only be considered in patients with documented infection. Gynecologic cancer surgery should continue during the COVID-19 pandemic while adhering to measures. Only 1% of patients developed COVID-19-related symptoms during the postoperative follow-up period.

Incidence, cost and gender differences of oropharyngeal and noncervical anogenital cancers in South Korea.

BACKGROUND: Human papillomavirus (HPV) is associated with a significant public health burden, yet few studies have been conducted in Asia, especially on noncervical cancers. We estimated the incidence and cost of oropharyngeal and noncervical anogenital (anal, vulvar, vaginal, penile) cancer in Korea. METHODS: We conducted a retrospective cohort study using Korea's National Health Insurance (NHI) claim database from 2013 to 2016. The main outcome measures were the number of respective cancer incidences during the study period and the annual costs per patient in the first year after diagnosis, which was adjusted by relevant variables based on the regression analysis. RESULTS: During the study period, 8022 patients with these cancers were identified, and oropharyngeal cancer comprised 46% of them. The crude incidence rate for male oropharyngeal cancer was significantly higher than that of females (3.1 vs. 0.7 per 100,000 as of 2016, respectively). Additionally, the crude incidence of male oropharyngeal cancer increased from 2.7 in 2013 to 3.1 in 2016, whereas that of female and other cancers was stable during the study period. The mean annual incidence-based cost per patient in 2016 was highest for oropharyngeal cancers (21,870 USD), and it was significantly higher in males than in females based on then regression analysis (p < .001). CONCLUSIONS: Oropharyngeal cancer comprises the highest number of HPV-associated noncervical cancer incidences in Korea, and the incidence and cost of oropharyngeal cancer was significantly higher among males than females. More aggressive public health policy toward males may decrease gender gap of oropharyngeal cancer.

Comprehensive analysis of the effect of rs2295080 and rs2536 polymorphisms within the mTOR gene on cancer risk.

There is still no conclusion on the potential effect of the rs2295080 and rs2536 polymorphisms of mTOR (mammalian target of rapamycin) gene on different cancers. Herein, we performed a comprehensive assessment using pooled analysis, FPRP (false-positive report probability), TSA (trial sequential analysis), and eQTL (expression quantitative trait loci) analysis. Eighteen high-quality articles from China were enrolled. The pooled analysis of rs2295080 with 9502 cases and 10,965 controls showed a decreased risk of urinary system tumors and specific prostate cancers [TG vs. TT, TG+GG vs. TT and G vs. T; P<0.05, OR (odds ratio) <1]. FPRP and TSA data further confirmed these results. There was an increased risk of leukemia [G vs. T, GG vs. TT, and GG vs. TT+TG genotypes; P<0.05, OR>1]. The eQTL data showed a potential correlation between the rs2295080 and mTOR expression in whole blood samples. Nevertheless, FPRP and TSA data suggested that more evidence is required to confirm the potential role of rs2295080 in leukemia risk. The pooled analysis of rs2536 (6653 cases and 7025 controls) showed a significant association in the subgroup of "population-based" control source via the allele, heterozygote, dominant, and carrier comparisons (P<0.05, OR>1). In conclusion, the TG genotype of mTOR rs2295080 may be linked to reduced susceptibility to urinary system tumors or specific prostate cancers in Chinese patients. The currently data do not strongly support a role of rs2295080 in leukemia susceptibility. Large sample sizes are needed to confirm the potential role of rs2536 in more types of cancer.

Correlation of Cancer Development and Human Papilloma Virus Infection in Patients After Organ Transplantation.

Immunosuppressed patients are at higher risk of developing human papilloma virus (HPV) cancerous and precancerous lesions in the anogenital region Carcinogenesis after organ transplantation due to immunosuppressive therapy is the major cause of long-term negative transplantation results. This is a rationale for the improvement of transplantation programs with carcinogenesis risk stratification in patients referred for transplantation. There is a need for a study on HPV-related carcinogenesis also in terms of its risk factors in the population after organ transplantation. This study aimed to assess the morbidity of anogenital carcinoma in patients with HPV infection, including those after organ transplantation and evaluate risk factors for carcinoma occurrence in patients after organ transplantation and with HPV infection. Our analysis directly indicates the group of patients with a high risk of HPV-related oncological complications of immunosuppression in anogenital region.

Risk of second primary breast cancer among cancer survivors: Implications for prevention and screening practice.

Second primary breast cancer (SPBC) is becoming one of the major obstacles to breast cancer (BC) control. This study was aimed to determine the trend of SPBC incidence over time and the risk of developing SPBC in site-specific primary cancer survivors in the United States. The Surveillance, Epidemiology, and End Results (SEER) 13 registry (1992-2015) was used to identify SPBC patients with previous malignancies. Standardized incidence ratio (SIR) was computed to compare the incidence rates of the observed cases of SPBC in cancer survivors over the expected cases in the general population. Elevated risk of SPBC was observed in women with previous BC (SIR = 1.74) or thyroid cancer (SIR = 1.17). Women with initial skin melanoma in older age (≥50 years) (SIR = 1.11), or White race (SIR = 1.11) presented an elevated incidence of SPBC than the general female population. Besides, Asian/Pacific Islander (API) women with cancer of corpus uteri, ovary, bladder, or kidney were prone to developing SPBC when compared with the general population, with SIRs of 1.61, 1.35, 1.48, and 1.70, respectively. Male BC patients showed profound risk of developing SPBC (SIR = 34.86). Male leukemia patients also presented elevated risk of developing SPBC (SIR = 2.06). Our study suggests significant increase of SPBC in both sexes in the United States. Elevated risk of SPBC exists in survivors with primary BC, female thyroid cancer, male leukemia, and API female cancer patients with primary genitourinary cancer. Our study is helpful in developing strategies for BC control and prevention on specific first primary cancer survivors with an elevated risk of SPBC.

Green tea (Camellia sinensis) for the prevention of cancer.

BACKGROUND: This review is an update of a previously published review in the Cochrane Database of Systematic Reviews (2009, Issue 3).Tea is one of the most commonly consumed beverages worldwide. Teas from the plant Camellia sinensis can be grouped into green, black and oolong tea, and drinking habits vary cross-culturally. C sinensis contains polyphenols, one subgroup being catechins. Catechins are powerful antioxidants, and laboratory studies have suggested that these compounds may inhibit cancer cell proliferation. Some experimental and nonexperimental epidemiological studies have suggested that green tea may have cancer-preventative effects. OBJECTIVES: To assess possible associations between green tea consumption and the risk of cancer incidence and mortality as primary outcomes, and safety data and quality of life as secondary outcomes. SEARCH METHODS: We searched eligible studies up to January 2019 in CENTRAL, MEDLINE, Embase, ClinicalTrials.gov, and reference lists of previous reviews and included studies. SELECTION CRITERIA: We included all epidemiological studies, experimental (i.e. randomised controlled trials (RCTs)) and nonexperimental (non-randomised studies, i.e. observational studies with both cohort and case-control design) that investigated the association of green tea consumption with cancer risk or quality of life, or both. DATA COLLECTION AND ANALYSIS: Two or more review authors independently applied the study criteria, extracted data and assessed methodological quality of studies. We summarised the results according to diagnosis of cancer type. MAIN RESULTS: In this review update, we included in total 142 completed studies (11 experimental and 131 nonexperimental) and two ongoing studies. This is an additional 10 experimental and 85 nonexperimental studies from those included in the previous version of the review. Eleven experimental studies allocated a total of 1795 participants to either green tea extract or placebo, all demonstrating an overall high methodological quality based on 'Risk of bias' assessment. For incident prostate cancer, the summary risk ratio (RR) in the green tea-supplemented participants was 0.50 (95% confidence interval (CI) 0.18 to 1.36), based on three studies and involving 201 participants (low-certainty evidence). The summary RR for gynaecological cancer was 1.50 (95% CI 0.41 to 5.48; 2 studies, 1157 participants; low-certainty evidence). No evidence of effect of non-melanoma skin cancer emerged (summary RR 1.00, 95% CI 0.06 to 15.92; 1 study, 1075 participants; low-certainty evidence). In addition, adverse effects of green tea extract intake were reported, including gastrointestinal disorders, elevation of liver enzymes, and, more rarely, insomnia, raised blood pressure and skin/subcutaneous reactions. Consumption of green tea extracts induced a slight improvement in quality of life, compared with placebo, based on three experimental studies. In nonexperimental studies, we included over 1,100,000 participants from 46 cohort studies and 85 case-control studies, which were on average of intermediate to high methodological quality based on Newcastle-Ottawa Scale 'Risk of bias' assessment. When comparing the highest intake of green tea with the lowest, we found a lower overall cancer incidence (summary RR 0.83, 95% CI 0.65 to 1.07), based on three studies, involving 52,479 participants (low-certainty evidence). Conversely, we found no association between green tea consumption and cancer-related mortality (summary RR 0.99, 95% CI 0.91 to 1.07), based on eight studies and 504,366 participants (low-certainty evidence). For most of the site-specific cancers we observed a decreased RR in the highest category of green tea consumption compared with the lowest one. After stratifying the analysis according to study design, we found strongly conflicting results for some cancer sites: oesophageal, prostate and urinary tract cancer, and leukaemia showed an increased RR in cohort studies and a decreased RR or no difference in case-control studies. AUTHORS' CONCLUSIONS: Overall, findings from experimental and nonexperimental epidemiological studies yielded inconsistent results, thus providing limited evidence for the beneficial effect of green tea consumption on the overall risk of cancer or on specific cancer sites. Some evidence of a beneficial effect of green tea at some cancer sites emerged from the RCTs and from case-control studies, but their methodological limitations, such as the low number and size of the studies, and the inconsistencies with the results of cohort studies, limit the interpretability of the RR estimates. The studies also indicated the occurrence of several side effects associated with high intakes of green tea. In addition, the majority of included studies were carried out in Asian populations characterised by a high intake of green tea, thus limiting the generalisability of the findings to other populations. Well conducted and adequately powered RCTs would be needed to draw conclusions on the possible beneficial effects of green tea consumption on cancer risk.