Stable glioma incidence and increased patient survival over the past two decades in Norway: a nationwide registry-based cohort study.

BACKGROUND: Surveillance of incidence and survival of central nervous system tumors is essential to monitor disease burden and epidemiological changes, and to allocate health care resources. Here, we describe glioma incidence and survival trends by histopathology group, age, and sex in the Norwegian population. MATERIAL AND METHODS: We included patients with a histologically verified glioma reported to the Cancer Registry of Norway from 2002 to 2021 (N = 7,048). Population size and expected mortality were obtained from Statistics Norway. Cases were followed from diagnosis until death, emigration, or 31 December 2022, whichever came first. We calculated age-standardized incidence rates (ASIR) per 100,000 person-years and age-standardized relative survival (RS).  Results: The ASIR for histologically verified gliomas was 7.4 (95% CI: 7.3-7.6) and was higher for males (8.8; 95% CI: 8.5-9.1) than females (6.1; 95% CI: 5.9-6.4). Overall incidence was stable over time. Glioblastoma was the most frequent tumor entity (ASIR = 4.2; 95% CI: 4.1-4.4). Overall, glioma patients had a 1-year RS of 63.6% (95% CI: 62.5-64.8%), and a 5-year RS of 32.8% (95% CI: 31.6-33.9%). Females had slightly better survival than males. For most entities, 1- and 5-year RS improved over time (5-year RS for all gliomas 29.0% (2006) and 33.1% (2021), p < 0.001). Across all tumor types, the RS declined with increasing age at diagnosis. INTERPRETATION: The incidence of gliomas has been stable while patient survival has increased over the past 20 years in Norway. As gliomas represent a heterogeneous group of primary CNS tumors, regular reporting from cancer registries at the histopathology group level is important to monitor disease burden and allocate health care resources in a population.

How Did Breast Cancer Patients Fare during Different Phases of the COVID-19 Pandemic in Norway Compared to Age-Matched Controls?

Little is known about how health-related quality of life (HRQoL) in breast cancer cases differed from that of controls during and after the COVID-19 pandemic. This study used data from an ongoing, nationwide HRQoL survey of 4279 newly diagnosed breast cancer cases and 2911 controls to investigate how breast cancer patients fared during different phases of the pandemic compared to controls. Responders during 2020-2022 were categorized into three COVID-19-related phases: the social restrictions phase, the high infection rate phase, and the post-pandemic phase. Across phases, breast cancer cases had significantly worse scores in most HRQoL domains compared to controls. Apart from slightly more insomnia in the high infection rate phase for both cases and controls, and better social functioning for young cases in the post-COVID-19 phase, the case-control differences in HRQoL remained consistent across phases. When the phases were assessed as one period, young women and those living with children <18 years of age fared the worst among breast cancer cases, while single women fared the worst among controls. In contrast, controls living with children <18 years of age exhibited better HRQoL than controls without children. In summary, women with breast cancer did not appear to fare differently than controls in terms of HRQoL across COVID-19 phases. However, breast cancer cases with young children fared worse in their HRQoL than other breast cancer cases.

Hospital surgical volume and colorectal cancer survival in Norway: A nationwide cohort study.

BACKGROUND: Studies of hospital surgical volume and colorectal cancer survival are inconclusive. We investigated whether surgical volume was associated with survival of patients operated for colorectal cancer in Norway. METHODS: Using Cancer Registry of Norway data, we compared excess mortality from colorectal cancer by hospital surgical volume among 26,989 colon and 9779 rectal cancer patients diagnosed 2009-2020 and followed-up to 31.12.2021. Hospitals were divided into terciles according to their three-year average annual surgical volume; colon: low (< 22), middle (22-73), high (> 73); rectal: low (< 17), middle (17-38), high (> 38). We estimated excess hazard ratios (EHR) with flexible parametric models adjusted for age, year, stage, surgical urgency and surgery location (within/outside patient's residential health trust). RESULTS: Low-volume hospitals had the highest proportion of late-stage or acutely operated colon cancer patients. Colon cancer patients operated at low- versus high-volume hospitals had significantly increased crude excess mortality (EHR = 1.30; 95 % CI = 1.14-1.48) but no difference after adjustment for age, year, and stage (EHR = 0.97; 0.85-1.11). High-volume hospitals had the highest proportion of late-stage rectal cancer patients and patients operated outside their residential area. Rectal cancer patients operated at low- versus high-volume hospitals did not have significantly different excess mortality before (EHR = 0.84; 0.64-1.10) or after (EHR = 1.03; 0.79-1.35) adjustment for age, year, stage, surgical urgency and surgery location. After accounting for case-mix, hospital surgical volume was not associated with excess mortality from colon (P = 0.40) or rectal cancer (P = 0.22). CONCLUSION: Low hospital surgical volume was not associated with poorer colorectal cancer survival.

Characterization of ovarian cancer survival by histotype and stage: A nationwide study in Norway.

Contemporary population-based data on ovarian cancer survival using current subtype classifications and by surgical status are sparse. We evaluated 1-, 3-, 5- and 7-year relative (and overall) survival, and excess hazards in patients with borderline tumors or invasive epithelial ovarian cancer diagnosed 2012 to 2021 in a nationwide registry-based cohort in Norway. Outcomes were evaluated by histotype, FIGO stage, cytoreduction surgery and residual disease. Overall survival was evaluated for non-epithelial ovarian cancer. Survival of women with borderline ovarian tumors was excellent (≥98.0% 7-year relative survival). Across all evaluated invasive epithelial ovarian cancer histotypes, 7-year relative survival for cases diagnosed with stages I or II disease was ≥78.3% (stage II high-grade serous). Survival for ovarian cancers diagnosed at stage ≥III differed substantially by histotype and time since diagnosis (eg, stage III, 5-year relative survival from 27.7% [carcinosarcomas] to 76.2% [endometrioid]). Overall survival for non-epithelial cases was good (91.8% 5-year overall survival). Women diagnosed with stage III or IV invasive epithelial ovarian cancer and with residual disease following cytoreduction surgery had substantially better survival than women not operated. These findings were robust to restriction to women with high reported functional status scores. Patterns for overall survival were similar to those for relative survival. We observed relatively good survival with early stage at diagnosis even for the high grade serous histotype. Survival for patients diagnosed at stage ≥III invasive epithelial ovarian cancer was poor for all but endometrioid disease. There remains an urgent need for strategies for risk reduction and earlier detection, together with effective targeted treatments.