Breast cancer incidence related with a population-based screening programme

Objective To investigate the impact of population mammography screening on breast cancer incidence trends in New Zealand. Methods Trends in age-specific rates of invasive breast cancer incidence (1994–2014) were assessed in relation to screening in women aged 50–64 from 1999 and 45–69 following the programme age extension in mid-2004. Results Breast cancer incidence increased significantly by 18% in women aged 50–64 compared with 1994–98 (p<0.0001), coinciding with the 1999 introduction of mammography screening, and remained elevated for four years, before declining to pre-screening levels. Increases over 1994–99 incidence occurred in the 45–49 (21%) and 65–69 (19%) age groups following the 2004 age extension (p<0.0001). Following establishment of screening (2006–10), elevated incidence in the screening target age groups was compensated for by lower incidence in the post-screening ⩾70 age groups than in 1994–98. Incidence in women aged ⩾45 was not significantly higher (+5%) after 2006 than in 1994–98. The cumulated risk of breast cancer in women aged 45–84 for 1994–98 was 10.7% compared with 10.8% in 2006–10. Conclusions Increases in breast cancer incidence following introduction of mammography screening in women aged 50–64 did not persist. Incidence inflation also occurred after introduction of screening for age groups 45–49 and 65–69. The cumulated incidence for women aged 45–84 over 2006–10 after screening was well established, compared with 1994–98 prior to screening, shows no increase in diagnosis. Over-diagnosis is not inevitable in population mammography screening programmes.

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Distinct temporal trends in breast cancer incidence from 1997 to 2016 by molecular subtypes: A population-based study of Scottish cancer registry data

10.1101/19011411 ◽

2019 ◽

Author(s):

Ines Mesa-Eguiagaray ◽

Sarah H Wild ◽

Philip S. Rosenberg ◽

Sheila M Bird ◽

David H Brewster ◽

...

Keyword(s):

Breast Cancer ◽

Cancer Registry ◽

Cancer Incidence ◽

Molecular Subtypes ◽

Breast Cancer Incidence ◽

Temporal Trends ◽

Population Based ◽

Registry Data ◽

Cancer Registry Data ◽

Er Status

AbstractBackgroundStrategies for breast cancer prevention are informed by assessing whether incidence differs by tumour biology. We describe temporal trends of breast cancer incidence by molecular subtypes in Scotland.MethodsPopulation-based cancer registry data on 72,217 women diagnosed with incident primary breast cancer from 1997 to 2016 were analysed. Age-standardised rates (ASR) and age-specific incidence were estimated by tumour subtype after imputing the 8% of missing oestrogen receptor (ER) status. Joinpoint regression and age- period- cohort models were used to assess whether significant differences were observed in incidence trends by ER status.ResultsER positive tumour incidence steadily increased particularly for women of screening age 50 to 69 years from 1997 till around 2011 (1.6%/year, 95%CI: 1.2 to 2.1). ER negative incidence decreased among all ages at a consistent rate of −0.7%/year (95%CI: −1.5, 0) from around 2000-2016. Compared to the 1941-1959 central birth cohort, women born 1912-1940 had lower incidence rate ratios (IRR) for ER+ tumours and women born 1960- 1986 had higher IRR for ER- tumours.ConclusionsWe show evidence of aetiologic heterogeneity of breast cancer. Future incidence and survival reporting should be monitored by molecular subtypes.

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Self-Selection for Mammography and Breast Cancer Incidence by Stage

Tumori Journal ◽

10.1177/030089169408000206 ◽

1994 ◽

Vol 80 (2) ◽

pp. 118-123 ◽

Cited By ~ 2

Author(s):

Lauro Bucchi ◽

Monica Serafini ◽

Oriana Nanni ◽

Gianfranco Buzzi ◽

Nori Morini ◽

...

Keyword(s):

Breast Cancer ◽

Cancer Incidence ◽

Breast Cancer Incidence ◽

Cancer Control ◽

Population Based ◽

Mortality Data ◽

Breast Cancer Patients ◽

Stage Distribution ◽

Self Selection ◽

Excess Incidence

Aims and Background In the field of breast cancer control, obtaining population-based data on spontaneous mammography (MG) screening should be a priority. This study focuses on the breast cancer incidence and stage distribution in relation to MG use in Ravenna (Italy), 1987-88. Methods We estimated the MG rates, expected (E) incidence based on mortality data, observed (O) incidence, predicted excess incidence based on MG rates, observed excess incidence, and stage distribution according to the MG history. Results The highest MG rate (37%) was found among residents aged 40-44 but none of these had a T1a-bN0 breast cancer diagnosed nor was the predicted excess incidence demonstrated. Between 45 and 64 years, 80% of self-selected screenees had repeat (“incidence”) MG and the O:E incidence ratio was 1.32 (95% Cl 1.09-1.58). The observed excess incidence was 3.8-fold (95% Cl 2.56-5.16) greater than that predicted. Advanced (T2+ and/or N1+) cases accounted for 42% of patients diagnosed within 3 years of their last MG, for 55% of those diagnosed more than 3 years after their last MG, and for 70% of those with no previous MG. Above age 70, a significant worsening of stage at diagnosis was associated with a clear-cut drop in the proportion of breast cancer patients with previous self-referral for MG. Conclusions The results indicate that self-selection and its implications are major features of spontaneous screening practice.

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