Conclusion

This report provides an update to two prior publications that described both trends in the incidence, mortality and survival of ovarian cancer, and geographic variation in treatment delivery for cases diagnosed between 2015 and 2019.

This disease profile reviews the latest data (up to 2019 diagnoses) on incidence, mortality, stage at diagnosis and survival of patients with ovarian cancer in England.

Main findings:

1. The crude incidence rate in England has remained reasonably stable, and the age standardised incidence rate has reduced, since 2001.
2. Crude incidence and mortality rates vary among sub-ICBs and Cancer Alliances, with variation beyond what might be expected by random chance, suggesting that there may be genuine differences between areas.
3. The proportions of patients diagnosed at early and late stages vary considerably around the country; some of this variability was likely due to data completeness but other factors should also be considered. These may relate to population and tumour characteristics geographical variation but may also reflect variation in access to diagnostic pathways relating to more frequent late diagnosis in some regions.
4. Completeness of stage data varied by geography; there is some room for improvement which would lead to better data quality for reporting.
5. Survival of patients has been gradually improving since 2001. Improving one-year survival may reflect progress in diagnosing the disease sooner, with increased awareness of the symptoms amongst women and primary care practitioners, and improved diagnostic pathways, enabling more women to be diagnosed while still well enough to undergo treatment. Increased five-year survival may additionally reflect improvements in surgical and chemotherapy treatments. Assessment of geographic variation in survival rates may help to identify areas of best practice and improve the outlook for all patients.

By using NDRS data to analyse cohorts of ovarian cancers (including or excluding borderline tumours as appropriate), we have been able to make clear comparisons between geographies and over time.

Building on this new understanding, the forthcoming national ovarian cancer audit will gain further insight into the factors behind the observed geographic variation and into best practices in diagnosis and treatment, aiming for improved outcomes for patients.

Reporting on data completeness back to clinical staff in the NHS via the CancerStats2 website (this opens in a new page) has been an ongoing part of the ovarian cancer audit feasibility pilot work. Improving the quality of data available to NDRS about patient performance status, stage, residual disease and surgeon grade will enable further valuable analysis to be undertaken.

Please note that this platform requires an N3/HSCN secure network connection.

Regarding patient demographics and tumour characteristics (Table 7 of the data downloads section.), findings from the refresh of the Geographic Variation report correspond with previous research and evidence from clinical practice, including that:

1. Women with stage 4 disease or no stage recorded, and tumours classed as miscellaneous and unspecified, were much less likely to receive any treatment.
2. Women with underlying medical conditions, identified by the Charlson comorbidity index, were less likely to receive surgery.
3. Older women were more likely to have chemotherapy alone or not receive any chemotherapy or surgery. Results shown in Table 12 indicate that the likelihood of receiving surgery was far lower for older age cohorts than for younger women, even after accounting for factors including stage and morphology. This variation may be explained by factors including comorbidities not captured by the Charlson comorbidity index, poor performance status, or patient choice (such as opting for chemotherapy over surgery; Appendix 11). Research is needed to clarify the reasons for diagnoses in older age groups having a lower probability of surgery.
4. There was very marked regional variation in surgical resection rates for cases of FIGO stage 2-4 and unrecorded stage ovarian cancer diagnosed in 2019.

These regional variations may be attributable to a variety of factors not accounted for in the maximally-adjusted models, including differences in access to primary care that enable early diagnosis, timely referral to secondary care and patient characteristics such as performance status which the models have not been able to control for. However, observed variation may also reflect real differences between gynaecological cancer centre multidisciplinary teams in the efficiency of diagnostic pathways or preparedness to perform radical surgery or administer chemotherapy to women with advanced disease.

Cross-tabulating age-adjusted results from this refresh of the Geographic Variation report (Table 18) against age-standardised net survival statistics from the refreshed Disease Profile report (Table 5) indicates that Cancer Alliances with lower probabilities of any treatment also exhibited lower five-year survival estimates (2015-2019 diagnoses). This correlation was weak, however (Pearson’s r=0.29).

Taken together, these refreshed results present an opportunity to target future studies designed to better understand the reasons for variation in the diagnosis and treatment of ovarian cancer patients between areas of England, as well as the impact of this variation on patient survival. Past results have already been used by consultants to push through positive changes in clinician practice, as summarised in Appendix 9.

The treatment pathway and survival of some patients analysed for this refreshed report will have been impacted to some degree by the COVID-19 pandemic, which had an immense impact on cancer diagnoses and access to treatment. ^{1 2} For example, for patients diagnosed in late 2019, their ovarian treatment pathways may have coincided with the initial COVID-19 lockdown starting in March 2020. It is expected that the fuller impact of the pandemic on cancer diagnosis and treatment will be captured in the forthcoming national ovarian cancer audit, which will analyse cases diagnosed and further analysis of treatments administered during 2020 onwards.

Notes:

1. Target Ovarian Cancer. 'Voices of women with ovarian cancer: the coronavirus pandemic and its impact'. 2020 July
2. Oxley S, Kalra A, Sideris M, Itzkowitz N, Evans O, Atakpa EC, Brentnall AR, Dworschak N, Gaba F, Gabe R, Sundar S, Wood N, Nicum S, Taylor A, Dobbs S, McCluggage WG, Nordin A, Legood R, Kehoe S, Ghaem-Maghami S, Manchanda R. Impact of Multiple COVID-19 Waves on Gynaecological Cancer Services in the UK. Cancers. 2023; 15(4):1273.