Temporal trends and factors associated with the cancer diagnosed at stage IV in patients included in the integrated hospital-based cancer registry system in Brazil in two decades

BackgroundIn several countries, such as Brazil, the oncological diagnosis usually occurs at an advanced stage of the disease. Thus, the aim of this study was to investigate temporal trends and factors associated with the cancer diagnosed at stage IV in Brazil in two decades.MethodsSecondary-based study, with time series analysis for trend assessment and cross-sectional of factors associated with diagnosis of female breast, prostate, cervix uteri, colorectal, lung, stomach, lip and oral cavity, thyroid, esophagus or corpus uteri at stage IV.Results1,218,322 cases were evaluated. The types of cancer with the highest proportion of stage IV at diagnosis in men and women, respectively, were: lung (53.7% and 57.4%), stomach (48.4% and 45.0%) and lip/oral cavity (53.5% and 43.4%). Most showed an increasing trend of annual percent change of cancer diagnosed at stage IV, being more pronounced in corpus uteri cancer (2013–2019: +7.4%, p < 0.001). The odds of cancer diagnosed at stage IV were associated with different factors, according to primary tumor site, but marked by the inverse association with female sex [odds ratio (OR) ranging from 0.42 to 0.91, p < 0.001] and direct association in cases with < 7 years of study (OR ranging from 1.08 to 1.81, p < 0.001), living without a partner (OR ranging from 1.06, p < 0.050 to1.27, p < 0.001), living in the South and Southeast regions (OR ranging from 1.04 to 1.13, p < 0.001), with more than one tumor (OR ranging from 1.19, p < 0.050 to 1.54, p < 0.001) and treated in Centers of High Complexity in Oncology (OR ranging from 1.03, p < 0.050 to1.24, p < 0.001).ConclusionThere was a high frequency of cancer diagnosed at stage IV and an increasing trend in different cancer types, which were associated with distinct sociodemographic, lifestyle, and clinical factors.     

Intraoperative radiation therapy in uterine cervical cancer: A review

Locally advanced uterine cervical cancer continues to present a high number of pelvic relapses. Intraoperative radiation therapy (IORT) allows a precise therapeutic intensification in the surgical area in cases in which removal of the tumour recurrence is feasible. At the same time, IORT excludes the radiosensitive organs from the field of irradiation. While the first gynecological IORT took place in 1905, procedures have been limited over the years and the series are retrospective, including few patients. At the same, time recurrences are located at different pelvic areas. Both heterogeneity and the long recruiting time make it difficult to correctly interpret the published results. Despite this, we have reviewed the most relevant publications. Some institutions indicated IORT as a boost on the surgical bed of the excised tumor recurrence. In others, IORT permits an extra radiation dose after radical surgery of the primary tumor, usually in stage IIB. Most studies conclude that the addition of IORT increases the local control but probably with little impact on survival. On the other hand, there is a controversy in the indication of IORT in surgically resectable primary tumours. No clear advantage over the usual scheme of chemoradiation and brachytherapy has been detected. Randomized studies that allow a breakthrough in the conclusions are highly unlikely to be performed in this area.     

Completeness and validity in a national clinical thyroid cancer database: DATHYRCA

BackgroundAlthough a prospective national clinical thyroid cancer database (DATHYRCA) has been active in Denmark since January 1, 1996, no assessment of data quality has been performed. The purpose of the study was to evaluate completeness and data validity in the Danish national clinical thyroid cancer database: DATHYRCA.Study design and settingNational prospective cohort. Denmark; population 5.5 million. Completeness of case ascertainment was estimated by the independent case ascertainment method using three governmental registries as a reference. The reabstracted record method was used to appraise the validity. For validity assessment 100 cases were randomly selected from the DATHYRCA database; medical records were used as a reference.ResultThe database held 1934 cases of thyroid carcinoma and completeness of case ascertainment was estimated to 90.9%. Completeness of registration was around or above 90% in most instances. Perfect agreement on the diagnosis of thyroid carcinoma was found, both inter- and intra-observer, and κ values of selected variables showed overall good to excellent agreement.ConclusionIn a setup with public health insurance, personal identity numbers and extended governmental databases, it is possible to establish national clinical cancer databases with a satisfactory completeness and validity. The DATHYRCA database is considered reliable in terms of describing thyroid carcinoma at a national level.     

Isolated jejunal metastasis in a patient with cervical cancer: A case report

Background

In approximately 8% of cervical carcinoma patients, gastrointestinal tract is involved, most commonly the rectosigmoid portion, because of local extension. Isolated metastases to small bowel are exceedingly rare.

Case report

We present a case of a 63-year-old woman with cervical cancer who developed isolated jejunal metastasis 8 months after postoperative chemoradiotherapy. The patient was alive with no evidence of disease 6 months after resection of metastasis. Very few cases have been reported concerning squamous cell carcinoma of the cervix with documented metastases to the small bowel. There is only one published case report of cervical cancer with multiple metastases to the small intestine and jejunum. To our knowledge, this is the first case of cervical cancer with isolated jejunal metastasis, which was initially demonstrated with positron emission tomography and confirmed histopathologically.

Conclusion

Although the exact mechanism underlying the isolated metastasis is unknown, hematogenous spread or tumor seeding during surgery may play a role.     

Impact of major life events on breast-cancer-specific mortality: A case fatality study on 8000 breast cancer patients

BackgroundIt has been suggested that long-term activation of the body’s stress–response system and subsequent overexposure to stress hormones may be associated with increased morbidity. However, evidence on the impact of major life events on mortality from breast cancer (BC) remains inconclusive. The main aim of this study is to investigate whether major negatively or positively experienced life events before or after diagnosis have an effect on BC-specific mortality in women who have survived with BC for at least 2 years.MethodsWe conducted a case fatality study with data on life events from a self-administered survey and data on BC from the Finnish Cancer Registry. Cox models were fitted to estimate BC mortality hazard ratios (MRs) between those who have undergone major life events and those who haven’t.ResultsNone of the pre-diagnostic negative life events had any effect on BC-specific mortality. Regarding post-diagnostic events, the effect was greatest in women with moderate scores of events. As for event-specific scores, increased BC mortality was observed with spouse unemployment, relationship problems, and death of a close friend. By contrast, falling in love and positive developments in hobbies were shown to be associated with lower BC mortality (MRs 0.67, 95%CI: 0.49–0.92 and 0.74, 95%CI: 0.57–0.96, respectively). In an analysis restricted to recently diagnosed cases (2007), also death of a child and of a mother was associated with increased BC mortality.ConclusionsSome major life events regarding close personal relationships may play a role in BC-specific mortality, with certain negative life events increasing BC mortality and positive events decreasing it. The observed favorable associations between positive developments in romantic relationships and hobbies and BC mortality are likely to reflect the importance of social interaction and support.     

Effect of Pap-smear and sociodemographic factors on cervical cancer risk in Estonia: A population-based case-control study

BackgroundLike many Eastern-European countries, Estonia struggles with ineffective cervical cancer (CC) screening. Despite a long-term organised screening programme and high overall Pap-smear coverage, CC incidence and mortality remain very high. The aim of the study was to examine the reasons for high CC incidence in Estonia by analysing the effect of Pap-smears and sociodemographic factors on CC risk.MethodsIn this population-based case-control study, women aged ≥ 25 years with an in situ/invasive CC diagnosed in Estonia in 2011–2017 were defined as cases. Using a density sampling scheme, controls were randomly selected from general population. To estimate CC risk associated with having no Pap-smears during seven years before diagnosis (cases) or index date (controls), place of residence, interruption in health insurance, and several sociodemographic factors, multivariate logistic regression was used to calculate odds ratios (OR) with 95% confidence intervals (CI). Individual-level data from three population-based registries were used.ResultsAmong 1439 cases and 4317 controls, proportion of women with no Pap-smears was 53% and 35%, respectively. Women with no Pap-smears were at higher risk for CC (OR=2.35; 95% CI: 1.85–2.98). CC risk was increased among women who were younger, living in more remote regions, lower-educated, or divorced/widowed. Interruption in health insurance was associated with a 23% risk increase. Regional differences in CC risk were observed among screened women.ConclusionTo reduce the risk of CC in Estonia, efforts are necessary to increase screening coverage among high-risk women and ensure the quality of CC screening programme. Screening approaches and communication should be tailored to the needs of different population groups. Further studies are warranted to identify the reasons for regional differences in CC risk.     

宫颈癌癌前病变及宫颈癌患者阴道微生态失调相关因素

目的 探讨宫颈癌癌前病变及宫颈癌患者阴道微生态失调相关因素。 方法 选择2016年7月至2018年12月我院收治的200例宫颈癌和癌前病变患者为研究对象,其中宫颈癌患者100例(宫颈癌组),癌前病变患者100例(癌前组),另选50例健康女性为对照组。观察各组对象阴道微生态指标(菌群密集度、菌群多样性、pH和H2O2)水平、HPV感染情况及乳杆菌分布情况。分析患者阴道微生态变化与HPV感染的关系。 结果 癌前组和宫颈癌组阴道菌群密集度Ⅰ-Ⅳ级的患者分别占33.00%和42.00%,显著高于对照组的10.00%(χ2=15.762 9,P=0.000 1);菌群多样性Ⅰ-Ⅳ级的患者分别占35.00%和41.00%,同样高于对照组的6.00%(χ2=19.783 1,P4.5的患者分别占53.00%和56.00%,高于对照组的12.00%(χ2=29.267 3,P2O2阴性患者占比分别为63.00%和70.00%,显著高于对照组的18.00%(χ2=39.343 7,P2=63.624 2,P2=8.742 1,P结论 宫颈癌前病变和宫颈癌的发生与患者阴道微生态失调、HPV感染、乳杆菌减少密切相关;同时癌前病变的发展与阴道微生态失调具有相关性。     

The impact of health insurance affiliation and socioeconomic status on cervical cancer survival in Bucaramanga,Colombia

Cervical cancer is still an important cause of death in countries like Colombia. We aimed to determine whether socioeconomic status of residential address (SES) and type of health insurance affiliation (HIA) might be associated with cervical cancer survival among women in Bucaramanga, Colombia. All patients residing in the Bucaramanga Metropolitan Area diagnosed with invasive cervical cancer (ICD-0–3 codes C53.X) between 2008 and 2016 (n = 725) were identified through the population-based cancer registry, with 700 women having follow-up data for >5 years (date of study closure: Dec 31, 2021), yielding an overall 5-year survival estimate (95 % CI) of 56.4 % (52.7 – 60.0 %). KM estimates of 5-year overall survival were obtained to assess differences in cervical cancer survival by SES and HIA. Multivariable Cox-proportional hazards modeling was also conducted, including interaction effects between SES and HIA. Five-year overall survival was lower when comparing low vs. high SES (41.9 % vs 57.9 %, p < 0.0001) and subsidized vs. contributive HIA (45.1 % vs 63.0 %, p < 0.0001). Multivariable Cox modeling showed increased hazard ratios (HR) of death for low vs. high SES (HR = 1.78; 95 % CI = 1.18–2.70) and subsidized vs. contributive HIA (HR = 1.44; 95 % CI = 1.13–1.83). The greatest disparity in HR was among women of low SES affiliated to subsidized HIA (vs. contributive HIA and high SES) (HR=2.53; 95 % CI = 1.62–3.97). Despite Colombia’s universal healthcare system, important disparities in cervical cancer survival by health insurance affiliation and socioeconomic status remain.     

阴道菌群失调与宫颈癌发病的研究进展

宫颈癌是世界女性第四大常见恶性肿瘤,严重危害女性身体健康。为此,国内外学者和临床医生进行了大量的科学研究和临床实践,不断探索有效预防、筛查、干预和治疗宫颈癌及癌前病变的新举措。研究表明,阴道菌群影响HPV感染持续状态或病毒清除率,由此参与宫颈癌和癌前病变发生和发展过程,甚至可能在HPV感染→癌前病变→宫颈癌进程中起主导作用。特定的阴道菌群具有预测HPV持续感染的潜力,有望成为筛查宫颈癌和癌前病变以及指示疾病高风险的生物标志物,这为宫颈病变乃至宫颈癌的筛查和诊断提供了新契机。本文就阴道菌群在HPV相关宫颈癌中的作用进行综述。

     

Novel artificial intelligence machine learning approaches to precisely predict survival and site-specific recurrence in cervical cancer: A multi-institutional study

BackgroundMachine learning (ML) has been gradually integrated into oncologic research but seldom applied to predict cervical cancer (CC), and no model has been reported to predict survival and site-specific recurrence simultaneously. Thus, we aimed to develop ML models to predict survival and site-specific recurrence in CC and to guide individual surveillance.MethodsWe retrospectively collected data on CC patients from 2006 to 2017 in four hospitals. The survival or recurrence predictive value of the variables was analyzed using multivariate Cox, principal component, and K-means clustering analyses. The predictive performances of eight ML models were compared with logistic or Cox models. A novel web-based predictive calculator was developed based on the ML algorithms.ResultsThis study included 5112 women for analysis (268 deaths, 343 recurrences): (1) For site-specific recurrence, larger tumor size was associated with local recurrence, while positive lymph nodes were associated with distant recurrence. (2) The ML models exhibited better prognostic predictive performance than traditional models. (3) The ML models were superior to traditional models when multiple variables were used. (4) A novel predictive web-based calculator was developed and externally validated to predict survival and site-specific recurrence.ConclusionML models might be a better analytic approach in CC prognostic prediction than traditional models as they can predict survival and site-specific recurrence simultaneously, especially when using multiple variables. Moreover, our novel web-based calculator may provide clinicians with useful information and help them make individual postoperative follow-up plans and further treatment strategies.     

Imputation of missing prostate cancer stage in English cancer registry data based on clinical assumptions

BackgroundCancer stage can be missing in national cancer registry records. We explored whether missing prostate cancer stage can be imputed using specific clinical assumptions.MethodsProstate cancer patients diagnosed between 2010 and 2013 were identified in English cancer registry data and linked to administrative hospital and mortality data (n = 139,807). Missing staging items were imputed based on specific assumptions: men with recorded N-stage but missing M-stage have no distant metastases (M0); low/intermediate-risk men with missing N- and/or M-stage have no nodal disease (N0) or metastases; and high-risk men with missing M-stage have no metastases. We tested these clinical assumptions by comparing 4-year survival in men with the same recorded and imputed cancer stage. Multi-variable Cox regression was used to test the validity of the clinical assumptions and multiple imputation.ResultsSurvival was similar for men with recorded N-stage but missing M-stage and corresponding men with M0 (89.5% vs 89.6%); for low/intermediate-risk men with missing M-stage and corresponding men with M0 (92.0% vs 93.1%); and for low/intermediate-risk men with missing N-stage and corresponding men with N0 (90.9% vs 93.7%). However, survival was different for high-risk men with missing M-stage and corresponding men with M0. Imputation based on clinical imputation performs as well as statistical multiple imputation.ConclusionSpecific clinical assumptions can be used to impute missing information on nodal involvement and distant metastases in some patients with prostate cancer.     

A novel dynamic field-matching technique for treatment of patients with para-aortic node-positive cervical cancer: Clinical experience

Aim

To report outcomes for patients with para-aortic lymph node positive cervical cancer treated with a dynamic field-matching technique.

Background

PET staging of cervical cancer has increased identification of patients with para-aortic lymph node metastasis. IMRT enables dose escalation in this area, but matching IMRT fields with traditional whole pelvis fields presents a challenge.

Materials and methods

From 2003 to 2012, 20 patients with cervical cancer and para-aortic lymph node metastasis were treated utilizing the dynamic field-matching technique. As opposed to single-isocenter half-beam junction techniques, this technique employs wedge-shaped dose junctions for the abutment of fields. We reviewed the records of all patients who completed treatment with the technique and abstracted treatment, toxicity, and disease-related outcome data for analysis.

Results

Median prescribed dose to the whole pelvis field was 45 Gy and para-aortic IMRT field 50.4 Gy. All but 3 patients underwent HDR (13 pts) or LDR (4 pts) brachytherapy. All patients developed lower GI toxicity; 10 grade 1, 9 grade 2, and 1 grade 4 (enterovaginal fistula). Median DFS was 12.4 months with 1 and 2-year DFS 60.0% and 38.1%. One-year OS was 83.7% and 2-year OS, 64.4%. A total of 10 patients developed recurrence; none occurred at the matched junction.

Conclusions

The dynamic field-matching technique provides a means for joining conventional whole pelvis fields and para-aortic IMRT fields that substantially reduces dose deviations at the junction due to field mismatch. Treatment with the dynamic matching technique is simple, effective, and tolerated with no apparent increase in toxicity.     

A study of oxidative stress in cervical cancer- an institutional study

Cervical cancer is the second most common cause of cancer-related death among women worldwide, especially in developing countries. Oxidative stress has been associated with cervical cancer. Many studies demonstrated that the low level of antioxidants induces the production of free radicals that cause lipid peroxidation, DNA, and protein damage leading to mutations that favors malignant transformation. This is a case-control institutional study conducted to evaluate the level of oxidative stress in cervical cancer patients and the age-matched healthy controls. We measured level of TBARS expressed as MDA, activity of SOD and GSH level by the spectrophotometric method, and level of 8-OHdG was estimated using a competitive sandwich ELISA assay. Our results showed a significant increase in the level of lipid peroxidation in group IV when compared to the control, group II and group III (p < 0.001). The activity of SOD was also significantly higher in group IV when compared to the control group (p < 0.001), group II (p < 0.001), and group III (p < 0.001). The level of GSH was also significantly lower in group IV when compared to the control group (p < 0.01), group II (p < 0.01), and group III (p < 0.01). The level of 8-OHdG was significantly higher in group IV than in the other groups (p < 0.01). The results suggest that oxidative stress is involved in the pathogenesis of cervical cancer, which is demonstrated by an increased level of lipid peroxidation and higher levels of 8-OHdG and an altered antioxidant defense system.     

Male-origin microchimerism and endometrial cancer: A prospective case-cohort study

BackgroundMany women carry male cells of presumed fetal origin–so-called male-origin microchimerism (MOM)–in their circulation and tissues. Studies have found reduced risks of hormone dependent cancers, including breast and ovarian cancer, among MOM-positive women. The aim of this study was to investigate the association between MOM and endometrial cancer.MethodsWe designed a prospective case-cohort study including 76 cases and 505 controls from the Diet, Cancer and Health cohort aged 50–64 years and cancer-free at enrolment in 1993–1997. We analyzed blood samples for the presence of Y-chromosome (DYS14). We examined the association between MOM and endometrial cancer in weighted Cox regression models. As a negative control outcome, we studied the association between MOM and injuries to test for spurious associations.ResultsWe detected MOM in 65.9% controls and 54.0% cases. While we observed no overall association between MOM and endometrial cancer (HR=0.73, 95% CI: 0.47–1.15), we found a borderline significantly reduced rate of Type 1 endometrial cancer (HR=0.66, 95% CI: 0.39–1.00), but not other types of endometrial cancers (HR=1.00, 95% CI: 0.35–2.90). The reduced rate was not modified by hormonal exposure (P = 0.79). We found no association between MOM and risk of injuries (HR=0.96, 95% CI: 95% CI: 0.78–1.21).ConclusionsOur study suggests that MOM is inversely associated with Type 1 endometrial cancer, without evidence of an interaction with hormonal exposure. We encourage future research to confirm our findings.     

Population-based retrospective study to investigate preexisting and new depression diagnosis among head and neck cancer patients

This study aimed to estimate the pre-cancer prevalence and post-cancer incidence of depression in older adult head and neck cancer patients. Using SEER-Medicare files, cancer was identified from SEER data and depression diagnosis was identified using Medicare claims. Of 3533 head and neck cancer patients, 10.6% were diagnosed with depression during the two years prior to cancer diagnosis, and an additional 8.9% developed depression in the year following cancer diagnosis. This study supports the critical need of screening for depression throughout cancer diagnosis and treatment, as well as a preventative approach in depression development in the older head and neck cancer patient population.     

宫颈癌高危因素及筛查研究进展

宫颈癌发病率在女性恶性肿瘤占第二位。宫颈癌的高危因素很多,如病毒感染、性行为、宫颈病变等因素。大量的研究已经证实人乳头瘤病毒(Human Papillomavirus HPV)感染是宫颈癌发生的必要条件。近年来,宫颈癌的筛查方法也取得了较大的进展,新发展的薄层液基细胞学(Liquid-based cytology test,LCT)、检测高危型HPVDNA的技术及宫颈癌筛查系统(TruScreen),显著提高了宫颈癌和癌前病变的灵敏性和特异性,从而降低了宫颈癌的发生率。     

The burden of cervical cancer in Vietnam: Synthesis of the evidence

There is currently no national cervical screening or HPV immunization program in Vietnam. This study aims to synthesize available data on the burden of disease and to project the burden of cervical cancer to 2049 if no major interventions are implemented. We reviewed published data sources on risk factors for HPV prevalence, high-grade lesions, cervical cancer incidence and mortality in Vietnam from 1990 to 2017. We then used the available data to project the number of new cervical cancer cases for the period 2013–2049. Data on cervical cancer incidence and mortality in Vietnam are limited; two Vietnamese cancer registries have been reported on by the International Agency for Research on Cancer, which cover urban populations representing ∼20% of the national population. The reported age-standardized cervical cancer incidence in Hanoi was 6.7 (1993–1997), compared to 28.8 and 14.1 per 100,000 women in Ho Chi Minh City (1995–1998 and 2009–2012, respectively). Cancer mortality data are not uniformly available from cancer registries or mortality surveys in Vietnam because cause of death has not been routinely ascertained. Based on available urban population registry data, estimated rates in the rural population, and forward projection of existing trends, we estimate that without any further intervention, the number of new cases will increase from 6930 (range 5671–8493) in 2012 to 8562 (range 5775–12,762) in 2049, giving a total of 379,617 (range 276,879–542,941) new cases over the period 2013–2049. These findings help underpin the case for the delivery of HPV vaccination and cervical screening in Vietnam, and support similar initiatives in other low- and middle-income countries.     

Incidence of gynaecological cancer during the COVID-19 pandemic: A population-based study in the Netherlands

ObjectiveTo study the impact of the COVID-19 pandemic and consequent lockdown on the number of diagnoses of gynaecological malignancies in the Netherlands.MethodsWe performed a retrospective cohort study using data from the Netherlands Cancer Registry (NCR) on women of 18 years and older diagnosed with invasive endometrial, ovarian, cervical or vulvar cancer in the period 2017–2021. Analyses were stratified for age, socioeconomical status (SES) and region.ResultsThe incidence rate of gynaecological cancer was 67/100.000 (n = 4832) before (2017–2019) and 68/100.000 (n = 4833) during (2020) the COVID-19 pandemic. Comparing the number of diagnoses of the two periods for the four types of cancer separately showed no significant difference. During the first wave of COVID-19 (March-June 2020), a clear decrease in number of gynaecological cancer diagnoses was visible (20–34 %). Subsequently, large increases in number of diagnoses were visible (11–29 %). No significant differences in incidence were found between different age groups, SES and regions. In 2021 an increase of 5.9 % in number of diagnoses was seen.ConclusionIn the Netherlands, a clear drop in number of diagnoses was visible for all four types of gynaecological cancers during the first wave, with a subsequent increase in number of diagnoses in the second part of 2020 and in 2021. No differences between SES groups were found. This illustrates good organisation of and access to health care in the Netherlands.     

Time to diagnosis and stage of symptomatic colorectal cancer determined by three different sources of information: A population based retrospective study

BackgroundSurvival rates from colorectal cancer (CRC) are highly variable in Europe. This variability could potentially be explained by differences in healthcare system delays in diagnosis. However, even when such delays are reduced, the relationship of the diagnostic interval (time from presentation with symptoms to diagnosis) with outcome is uncertain.MethodsA total of 795 patients with CRC from 5 regions of Spain were retrospectively examined in this population-based multicenter study. Consecutive incident cases of CRC were identified from pathology services. The total diagnostic interval (TDI) was defined as the time from the first presentation with symptoms to diagnosis based on 3 different sources of information: (i) patient-recorded data (PR-TDI) by interview, (ii) hospital-recorded data (HR-TDI), and (iii) general practitioner-recorded data (GPR-TDI). Concordance correlation coefficients (CCCs) were used to estimate the agreement of 3 different TDIs. The TDIs of patients with different stages of CRC were also compared using the Kruskal-Wallis test.ResultsThe median TDI was 131 days based on patient interview data, 91 days based on HR data, and 111 days based on GPR data. Overall, the agreement of these TDIs was poor (CCC_PRvsHR = 0.399, CCC_PRvsGPR = 0.518, CCC_HRvsGPR = 0.383). Univariate analysis indicated that the TDI was greater in those with less advanced CRC for all 3 methods of calculation, but this association was only statistically significant for the HR-TDI (p = 0.021).ConclusionThere is no evidence that patients with more advanced CRC have longer TDIs. In fact, we found an inverse relationship between the TDI and CRC stage, an example of the “waiting time paradox”. This association may likely be due to the presence of unmeasured confounders as the stage when symptoms appear or the tumour aggressiveness.