Use of radiotherapy in patients with oesophageal, stomach, colon, rectal, liver, pancreatic, lung, and ovarian cancer: an International Cancer Benchmarking Partnership (ICBP) population-based study.

BACKGROUND: There is little evidence on variation in radiotherapy use in different countries, although it is a key treatment modality for some patients with cancer. Here we aimed to examine such variation. METHODS: This population-based study used data from Norway, the four UK nations (England, Northern Ireland, Scotland, and Wales), nine Canadian provinces (Alberta, British Columbia, Manitoba, New Brunswick, Newfoundland and Labrador, Nova Scotia, Ontario, Prince Edward Island, and Saskatchewan), and two Australian states (New South Wales and Victoria). Patients aged 15-99 years diagnosed with cancer in eight different sites (oesophageal, stomach, colon, rectal, liver, pancreatic, lung, or ovarian cancer), with no other primary cancer diagnosis occurring within the 5 years before to 1 year after the index cancer diagnosis or during the study period were included in the study. We examined variation in radiotherapy use from 31 days before to 365 days after diagnosis and time to its initiation, alongside related variation in patient group differences. Information was obtained from cancer registry records linked to clinical or patient management system data, or hospital administration data. Random-effects meta-analyses quantified interjurisdictional variation using 95% prediction intervals (95% PIs). FINDINGS: Between Jan 1, 2012, and Dec 31, 2017, of 902 312 patients with a new diagnosis of one of the studied cancers, 115 357 (12·8%) did not meet inclusion criteria, and 786,955 were included in the analysis. There was large interjurisdictional variation in radiotherapy use, with wide 95% PIs: 17·8 to 82·4 (pooled estimate 50·2%) for oesophageal cancer, 35·5 to 55·2 (45·2%) for rectal cancer, 28·6 to 54·0 (40·6%) for lung cancer, and 4·6 to 53·6 (19·0%) for stomach cancer. For patients with stage 2-3 rectal cancer, interjurisdictional variation was greater than that for all patients with rectal cancer (95% PI 37·0 to 84·6; pooled estimate 64·2%). Radiotherapy use was infrequent but variable in patients with pancreatic (95% PI 1·7 to 16·5%), liver (1·8 to 11·2%), colon (1·6 to 5·0%), and ovarian (0·8 to 7·6%) cancer. Patients aged 85-99 years had three-times lower odds of radiotherapy use than those aged 65-74 years, with substantial interjurisdictional variation in this age difference (odds ratio [OR] 0·38; 95% PI 0·20-0·73). Women had slightly lower odds of radiotherapy use than men (OR 0·88, 95% PI 0·77-1·01). There was large variation in median time to first radiotherapy (from diagnosis date) by cancer site, with substantial interjurisdictional variation (eg, oesophageal 95% PI 11·3 days to 112·8 days; pooled estimate 62·0 days; rectal 95% PI 34·7 days to 77·3 days; pooled estimate 56·0 days). Older patients had shorter median time to radiotherapy with appreciable interjurisdictional variation (-9·5 days in patients aged 85-99 years vs 65-74 years, 95% PI -26·4 to 7·4). INTERPRETATION: Large interjurisdictional variation in both use and time to radiotherapy initiation were observed, alongside large and variable age differences. To guide efforts to improve patient outcomes, underlying reasons for these differences need to be established. FUNDING: International Cancer Benchmarking Partnership (funded by the Canadian Partnership Against Cancer, Cancer Council Victoria, Cancer Institute New South Wales, Cancer Research UK, Danish Cancer Society, National Cancer Registry Ireland, The Cancer Society of New Zealand, National Health Service England, Norwegian Cancer Society, Public Health Agency Northern Ireland on behalf of the Northern Ireland Cancer Registry, DG Health and Social Care Scottish Government, Western Australia Department of Health, and Public Health Wales NHS Trust).

Diet and risk of gastro-oesophageal reflux disease in the Melbourne Collaborative Cohort Study.

OBJECTIVE: To examine associations between diet and risk of developing gastro-oesophageal reflux disease (GERD). DESIGN: Prospective cohort with a median follow-up of 15·8 years. Baseline diet was measured using a FFQ. GERD was defined as self-reported current or history of daily heartburn or acid regurgitation beginning at least 2 years after baseline. Sex-specific logistic regressions were performed to estimate OR for GERD associated with diet quality scores and intakes of nutrients, food groups and individual foods and beverages. The effect of substituting saturated fat for monounsaturated or polyunsaturated fat on GERD risk was examined. SETTING: Melbourne, Australia. PARTICIPANTS: A cohort of 20 926 participants (62 % women) aged 40-59 years at recruitment between 1990 and 1994. RESULTS: For men, total fat intake was associated with increased risk of GERD (OR 1·05 per 5 g/d; 95 % CI 1·01, 1·09; P = 0·016), whereas total carbohydrate (OR 0·89 per 30 g/d; 95 % CI 0·82, 0·98; P = 0·010) and starch intakes (OR 0·84 per 30 g/d; 95 % CI 0·75, 0·94; P = 0·005) were associated with reduced risk. Nutrients were not associated with risk for women. For both sexes, substituting saturated fat for polyunsaturated or monounsaturated fat did not change risk. For both sexes, fish, chicken, cruciferous vegetables and carbonated beverages were associated with increased risk, whereas total fruit and citrus were associated with reduced risk. No association was observed with diet quality scores. CONCLUSIONS: Diet is a possible risk factor for GERD, but food considered as triggers of GERD symptoms might not necessarily contribute to disease development. Potential differential associations for men and women warrant further investigation.