Background: Oesophageal cancer (OC) is one of the most common cancers and leading causes of cancer death in China. Survival from this disease is poor partly due to the high prevalence of advanced-stage at diagnosis. Screening for asymptomatic OC, as an early detection strategy, has long been promoted in China. In contrast, down-staging symptomatic OC, the other potential early diagnosis strategy, has not received sufficient attention. Aim: The overarching aim of this PhD work is to investigate correlates of stage at diagnosis in OC in China, with a view to inform cancer control strategies and, in particular, down-staging. Methods: This PhD research comprises three studies. (i) A systematic review of published data on OC stage-specific survival in China. Medline, EMBASE, Web of Science, and Wanfang were systematically searched for original studies published up to 31st May, 2019,that reported stage-specific survival from OC in China. Random-effects meta-analyses were performed to summarise survival differences for advanced-stage (stages III-IV) versus early-stage (stages 0-II) on both relative and absolute scales. Based on the pooled stage-specific survival differences, I estimated the number of OC deaths that could have potentially been prevented in China, in 2018, if stage at diagnosis had been shifted towards early disease under different scenarios. (ii) Two cohort studies to examine stage distribution at diagnosis,its changes over time, and its correlates among clinically-diagnosed OC patients admitted, between 2009-2018, to two cancer hospitals in China, one located in a high OC incidence area. Logistic regression was used to identify factors associated with advanced-stage at diagnosis from among demographic and socio-economic factors extracted from medical records data. (iii) A cross-sectional study (Pre-diagnostic journey of oesophageal cancer in Hua County, China [PROCH]) to investigate the length of the symptom-to-diagnosis (STD) interval, its correlates, as well as correlates of advanced-stage at diagnosis. Newly-diagnosed OC patients were recruited consecutively, between August 2018 and October 2020, from a county-level hospital in a high-incidence rural area. I designed a structured questionnaire and trained dialect-speaking local interviewers to collect detailed information regarding socio-economic, health literacy, health status, first symptoms, social support, and health-seeking journey of the patients in a face-to-face interview with the patients themselves or their proxies. Negative binomial regression was used to examine associations between patient-level and health system-level variables and the length of the STD interval. Logistic regression was used to identify correlates of advanced-stage OC at diagnosis. Results: (i) The literature search identified 150 eligible studies (n=127,042 patients), including 97 with non-overlapping populations (n=83,063 patients). Meta-analyses of the estimates reported by the non-overlapping studies showed that advanced-stage patients had a 92% higher hazard of death relative to early-stage patients (pooled hazard ratio 1.92, 95% CI 1.62-2.28, I2=49.4%), corresponding to an absolute 31.2 percentage points lower 5-year survival probability. Between 5.2% and 26.9% of OC deaths could have been prevented in China, in 2018, if the observed proportion of advanced-stage patients (~50%) had been reduced to ~40% (as reported by a real-life population-based screening programme) and to ~10% (as reported by a controlled screening trial). (ii) The two clinical cohorts together comprised 18,594 OC patients. In all, 54.9% of those with known stage were diagnosed at stage III/IV, but with this proportion being lower in the high-incidence setting (44.6% vs. 73.8%). Multivariable analyses showed that being female (adjusted odds ratio [aOR] in high-incidence settings: 0.72, 95% CI 0.66-0.79; aOR in non-high-incidence settings: 0.67, 95% CI 0.53-0.85) and having a family history of OC (aOR 0.87, 95% CI 0.79-0.96; aOR 0.73, 95% CI 0.60-0.89) were significantly associated with lower odds of being diagnosed with advanced-stage OC in both settings. (iii) The PROCH study recruited 411 newly-diagnosed OC patients, of whom 383 had stage information, including 200 (52.2%) at early stage and 183 (47.8%) at advanced stage.The median STD interval was 61 (interquartile range [IQR] 24-155) days. High awareness of OC risk factors was associated with a 35% shorter STD interval (incidence rate ratio [IRR] 0.65, 95% CI 0.46-0.93) whilst bypassing primary healthcare to visit first a secondary or tertiary hospital was associated, respectively, with a 69% (IRR 1.69, 95% CI 1.19-2.40) and a 122% (IRR 2.22, 95% CI 1.24-3.97) longer STD interval. The PROCH study confirmed the associations identified in the two clinical cohorts and, in addition, showed that high awareness of OC risk factor was associated with lower odds of being diagnosed with advanced disease (e.g., aOR for high vs. low: 0.57, 95% CI 0.32-1.02) whilst relying on government subsidies as the major income source (aOR 3.58, 95% CI 1.83-7.00) and visiting first a secondary healthcare facility instead of a primary healthcare provider (aOR 1.66, 95% CI 1.02-2.70) were associated with higher odds. After adjusting for age and sex, a longer STD interval was weakly associated with being diagnosed at an advanced stage (aOR per a 2-month STD increase: 1.03, 95% CI 0.99-1.08). Conclusions: Advanced-stage at OC diagnosis continues to be common among clinically-diagnosed OC patients in China. Promoting OC awareness and strengthening primary healthcare, to improve patient trust, may help to downstage this disease. Yet the likely impact of early detection of OC, either through screening or down-staging, may be limited in the absence of marked improvements in the treatment for all stages.