Overall survival of patients with metastatic breast cancer in Sweden: a nationwide study

Abstract

Background Breast cancer is the most common cancer among women in Sweden. Whereas survival for the overall breast cancer population is well-documented, survival of patients with metastatic breast cancer (MBC) is harder to quantify due to the lack of reliable data on disease recurrence in national cancer registers. Methods This study used machine learning to classify the total MBC population in Sweden diagnosed between 2009 and 2016 using national registers, with the aim to estimate overall survival (OS). Results The total population consisted of 13,832 patients—2528 (18.3%) had de novo MBC whereas 11,304 (81.7%) were classed as having a recurrent MBC. Median OS for patients with MBC was found to be 29.8 months 95% confidence interval (CI) [28.9, 30.6]. Hormone-receptor (HR)-positive MBC had a median OS of 37.0 months 95% CI [35.9, 38.3] compared to 9.9 months 95% CI [9.1, 11.0] for patients with HR-negative MBC. Conclusion This study covered the entire MBC population in Sweden during the study time and may serve as a baseline for assessing the effect of new treatment strategies in MBC introduced after the study period.

HR+/HER2– de novo metastatic breast cancer: a true peculiar entity?

“…64 Different results were obtained from the subgroup analysis of the PALOMA-2 study, in which 37% of patients included had dnMBC and were randomized in a 2:1 ratio to receive palbociclib or placebo both in combination with letrozole. 58 Extended follow-up analysis (38 months) showed a mPFS of 27.9 (22)(23)(24)(25)(26)(27)(28)(29)(30)(31)(32)(33)(34) months versus 22 (13-27.4) months with a HR of 0.61 (95% CI 0.44-0.85), which was lower as compared to subgroups of patients with a DFI of >2 years (38.5 months) or with other favourable prognostic factors as bone-only disease (36 months). 64 On the other hand, a higher ORR was observed in the de novo cohort as compared to relapsed patients irrespective of the treatment arm.…”

“…A growing amount of data on clinical features and outcome of dnMBC have been obtained by several studies in different time spans of the National Cancer Institute's Surveillance, Epidemiology, and End Results (SEER) program, using the 18-registry database, which collects cancer incidence and survival data from 18 population-based cancer registries covering about 30% of the US population. 6,[18][19][20][21][22][23][24][25][26][27] Data were also extracted from other national or regional registries such as the California Cancer registry, 28 the Netherlands Cancer Registry, 29 the Cote d'Or Registry in France, 30 Sweden, 31 Modena Registry in Italy 32 and New Zealand Cancer Registry, 33 as well as from national databases such as the National Cancer database in the USA, 34 the Epidemiological Strategy and Medical Economics (ESME) in France 5,35,36 and the British Columbia Cancer Agency. 37 In addition, multicentric or large, single institution series have been reported from MD Anderson Cancer Center 38 and academic institutions from the USA, 3,39 Netherlands, 40 Japan 41 and China.…”

Real-world time trends in overall survival, treatments and patient characteristics in HR+/HER2− metastatic breast cancer: an observational study of the SONABRE Registry

“… 18 In Sweden in 2009–2016 the median overall survival of HR + ABC patients was 37.0 months. 26 Apart from differences in therapy use, differences in outcomes between observational studies may be caused by differences in patient populations and selection. As previously mentioned, the ESME cohort has a younger study population, which is probably explained by the patient selection from 18 comprehensive cancer centres, whereas SONABRE includes one academic comprehensive cancer centre, four teaching and three non-teaching.…”

The Metastatic Spread of Breast Cancer Accelerates during Sleep: How the Study Design can Affect the Results

“…Metastasis is a crucial step in breast cancer progression. Patients with metastasis are considered incurable (Valachis et al, 2022). About one-third of patients with early breast cancer will develop distant metastases (Lobbezoo et al, 2015).…”