Downstaging is more important than screening for asymptomatic breast cancer
Authors: Cheng-Har Yip
Journal: The Lancet Global Health (2019)

Internationally, a wide disparity in 5-year survival for breast cancer exists, ranging from 90·2% in the USA, a high-income country, to as low as 66·1% in India, a low-middle-income country.1Allemani C Matsuda T Di Carlo V et al.Global surveillance of trends in cancer survival 2000–14 (CONCORD-3): analysis of individual records for 37 513 025 patients diagnosed with one of 18 cancers from 322 population-based registries in 71 countries.Lancet. 2018; 391: 1023-1075Summary Full Text Full Text PDF PubMed Scopus (2146) Google Scholar The main determinant of survival from breast cancer is early detection coupled with optimal access to treatment. Early detection is defined as early diagnosis, which aims to downstage symptomatic breast cancer, and screening mammography, which is looking for asymptomatic breast cancer.2WHOGuide to cancer early diagnosis. World Health Organization, Geneva2017http://www.who.int/iris/handle/10665/254500Date accessed: April 9, 2019Google Scholar Even in the absence of mammographic screening, improvements in detection can provide substantial benefit in settings where advanced-stage presentation is common.3Birnbaum JK Duggan C Anderson BO Etzioni R Early detection and treatment strategies for breast cancer in low-income and upper middle-income countries: a modelling study.Lancet Glob Health. 2018; 6: e885-e893Summary Full Text Full Text PDF PubMed Scopus (45) Google Scholar Early detection programmes in low-income and middle-income countries need to focus on public education on breast awareness (including self-examination of breasts) and clinical breast examination. However, a randomised controlled trial on self-examination of breasts as a method of early diagnosis in Shanghai, China, did not find decreased mortality from breast cancer.4Thomas DB Gao DL Ray RM et al.Randomized trial of breast self-examination in Shanghai: final results.J Natl Cancer Inst. 2002; 94: 1445-1457Crossref PubMed Scopus (552) Google Scholar A randomised controlled trial on clinical breast examination in Mumbai, although resulting in significant clinical downstaging, also did not lead to a decrease in mortality.5Mittra I Mishra GA Singh S et al.A cluster randomized, controlled trial of breast and cervix cancer screening in Mumbai, India: methodology and interim results after three rounds of screening.Int J Cancer. 2010; 126: 976-984PubMed Google Scholar In The Lancet Global Health, Isabel dos-Santos-Silva and colleagues6dos-Santos-Silva I De Stavola BL Renna Junior, NL et al.Ethnoracial and social trends in breast cancer staging at diagnosis in Brazil, 2001–14: a case only analysis.Lancet Glob Health. 2019; 7: e784-e797Summary Full Text Full Text PDF PubMed Scopus (33) Google Scholar report on their attempts to determine whether early detection policies in Brazil, namely raising public awareness, clinical breast examination, and mammographic screening (introduced in Brazil in 2004), have led to a decrease in late-stage disease at diagnosis. Using a database of 247 719 women diagnosed with breast cancer between 2001 and 2014, the authors found that the prevalence of late-stage disease at diagnosis remained high (approximately 40%) throughout the study period, showing that the early detection policies do not seem to have had any effect on stage of breast cancer at diagnosis. However, mammographic screening in Brazil appears to be opportunistic rather than population based, and hence is unlikely to reduce mortality due to breast cancer. Estimates of coverage range from 27% to 51%,6dos-Santos-Silva I De Stavola BL Renna Junior, NL et al.Ethnoracial and social trends in breast cancer staging at diagnosis in Brazil, 2001–14: a case only analysis.Lancet Glob Health. 2019; 7: e784-e797Summary Full Text Full Text PDF PubMed Scopus (33) Google Scholar and the International Agency for Research on Cancer has found that 70% of a population need to be covered to show a substantial effect.7International Agency for Research on CancerBreast cancer screening, 2nd edn. IARC handbooks on cancer prevention. International Agency for Research on Cancer, Lyon2016Google Scholar Thus, determining why mammographic screening is so poorly utilised in Brazil is important, as is whether women can readily access the available early detection program. dos-Santos-Silva and colleagues' study6dos-Santos-Silva I De Stavola BL Renna Junior, NL et al.Ethnoracial and social trends in breast cancer staging at diagnosis in Brazil, 2001–14: a case only analysis.Lancet Glob Health. 2019; 7: e784-e797Summary Full Text Full Text PDF PubMed Scopus (33) Google Scholar also found that late presentation was highest among women who identified as black or brown who had little or no formal education, and was lowest in women who identified as white who had a university education. Similarly, the Surveillance, Epidemiology, and End Results database in the USA also reported that black women were less likely to be diagnosed with stage I breast cancer than non-Hispanic white women.8Iqbal J Ginsburg O Rochon PA Sun P Narod SA Differences in breast cancer stage at diagnosis and cancer-specific survival by race and ethnicity in the United States.JAMA. 2015; 313: 165-173Crossref PubMed Scopus (402) Google Scholar Using evidence from mammographic screening trials and data on national breast cancer mortality in Brazil, dos-Santos-Silva and colleagues estimated 2500 breast cancer deaths could have been prevented by effective mammographic screening (ie, with follow-up treatment of those detected with cancer) of women aged 50–69 years in 2012.6dos-Santos-Silva I De Stavola BL Renna Junior, NL et al.Ethnoracial and social trends in breast cancer staging at diagnosis in Brazil, 2001–14: a case only analysis.Lancet Glob Health. 2019; 7: e784-e797Summary Full Text Full Text PDF PubMed Scopus (33) Google Scholar They also estimated that if as many as 80% and as low as 50% of all women diagnosed with disease at stage III or IV in the previous 5 years had been downstaged to stage II, 8000 deaths could have been prevented in 2012. If all women with breast cancer had equal access to treatment under the universal health-care system in Brazil, then clinical downstaging would save more lives than mammographic screening alone in Brazil. This hypothesis is in line with current concepts that mammographic screening is not the way forward in settings where women present with late-stage breast cancer.9Black E Richmond R Improving early detection of breast cancer in sub-Saharan Africa: why mammography may not be the way forward.Global Health. 2019; 15: 3Crossref PubMed Scopus (55) Google Scholar A limitation of this study is that trends in breast cancer mortality in Brazil were not reported. The goal of an early detection programme is to improve breast cancer survival. Since early detection policies did not have much of an effect on late-stage presentation, the authors have assumed that there would be little effect on mortality from the disease. Indeed, from Globocan 2018 data,10Bray F Ferlay J Soerjomataram I Siegel RL Torre LA Jemal A Global cancer statistics 2018: GLOBOCAN estimates of incidence and mortality worldwide for 36 cancers in 185 countries.CA Cancer J Clin. 2018; 68: 394-424Crossref PubMed Scopus (50356) Google Scholar the mortality-to-incidence ratio—a surrogate for mortality—due to breast cancer in Brazil was 0·20, which is higher than in high-income countries (eg, the USA [0·15] and the UK [0·15]), but lower than in other low-income and middle-income countries (eg, the upper-middle-income countries China [0·24] and Malaysia [0·39], the lower-middle-income countries Kenya [0·44] and India [0·49], and the low-income countries Tanzania [0·46] and Uganda [0·48]). The other major determinant of survival is access to treatment, which was not discussed in this Article, and from 2001 to 2014 treatment options would have improved and survival in Brazil would probably be better than in other low-income and middle-income countries because of the country's universal free access to health care since 1988.6dos-Santos-Silva I De Stavola BL Renna Junior, NL et al.Ethnoracial and social trends in breast cancer staging at diagnosis in Brazil, 2001–14: a case only analysis.Lancet Glob Health. 2019; 7: e784-e797Summary Full Text Full Text PDF PubMed Scopus (33) Google Scholar For instance, a study in Malaysia, an upper-middle-income country, found an improvement in breast cancer survival over two time periods (1993–97 and 1998–2002), although no significant change in the stage at presentation was seen, which is likely to be due to improved treatment strategies over time.11Taib NA Akmal M Mohamed I Yip CH Improvement in survival of breast cancer patients - trends over two time periods in a single institution in an Asia Pacific country, Malaysia.Asian Pac J Cancer Prev. 2011; 12: 345-349PubMed Google Scholar Nevertheless, this study is important because it highlights the need for further research into the barriers to early detection of breast cancer in Brazil, whether late presentation is due to psychosocial issues or a weak health-care system. Until at least 50% of late-stage diseases are downstaged to stage II, focus should be on timely diagnosis of symptomatic breast cancer rather than on screening for asymptomatic disease. For Globocan 2018 data see http://globocan.iarc.frThis online publication has been corrected. The corrected version first appeared at thelancet.com/lancetgh on May 22, 2019 For Globocan 2018 data see http://globocan.iarc.fr This online publication has been corrected. The corrected version first appeared at thelancet.com/lancetgh on May 22, 2019 I declare no competing interests. Ethnoracial and social trends in breast cancer staging at diagnosis in Brazil, 2001–14: a case only analysisThe persistently high prevalence of late-stage breast cancer at diagnosis across all ethnoracial and social strata in Brazil, although more substantially among the most disadvantaged populations, implies that early detection policies might have had little effect on breast cancer mortality so far, and highlights the need to focus primarily on timely diagnosis of symptomatic breast cancer rather than on screening for asymptomatic disease. Full-Text PDF Open AccessCorrection to Lancet Glob Health 2019; 7: e690–91Yip C-H. Downstaging is more important than screening for asymptomatic breast cancer. Lancet Glob Health 2019; 7: e690–91—In the fourth paragraph of this Comment, the third sentence should have read "If all women with breast cancer had equal access to treatment under the universal health-care system in Brazil, then clinical downstaging would save more lives than mammographic screening alone in Brazil." This correction has been made as of May 22, 2019. Full-Text PDF Open Access